Working body of the machine

Rice. one

Reasons for using gears:

the need to change the magnitude of the speed and direction of movement.

The need to increase several times the torque on the drive wheels (when starting off, on climbs).

Gear assignment:

selection of the optimal speed of movement;

regulation of the speed of movement (increase, decrease);

change of rotating moments and forces of motion;

transmission of power over a distance.

Broadcast - This is a mechanism that serves to transfer mechanical energy over a distance with the conversion of speeds and moments.

To transmit rotational motion, they use: friction, sieve, gear, worm, chain drives.

According to the principle of transmission, they are divided into 2 groups:

Gears based on the use of friction forces between the gear elements (friction, sieve).

Engagement gears operating as a result of pressure between teeth or cams on interacting parts (gear, worm, chain).

Gear classification:

By the nature of the change in the transmission speed, there are down and up.

According to the design of the transmission, there are open (without a closing housing) and closed (common housing with sealing and lubrication).

According to the number of steps - single-stage and multi-stage.

Section 3. Gear Mechanisms and Movement Transformation. Varieties, device, purpose.

Topic: "Transmissions that transform movement."

There are two types of motion transformation:

converting rotational motion into translational,

transformation of translational motion into rotational.

To convert rotational motion into translational, a rack and pinion gear and a screw-nut transmission are used.

To convert translational motion into rotational, only a rack and pinion gear is used.

rack and pinion

Transfer and conversion of rotational motion into translational and vice versa is carried out by a cylindrical wheel 1 and rail 2 (Fig. 1).

Rice. 1. Rack and pinion

Advantages rack and pinion: reliability, compactness, durability, low loads on shafts and bearings, constant gear ratio due to the absence of slippage.

Flaws: high requirements for manufacturing accuracy, noise at high speeds, rigidity. They are used in a wide range of areas and working conditions - from watches and instruments to the heaviest machines.

Gear screw - nut

This is a screw mechanism that serves to convert rotational motion into translational.

These gears provide a large gain in strength, the possibility of obtaining slow movement, a large bearing capacity with small dimensions, the possibility of achieving high accuracy of movement, simplicity of design and manufacture - these are their dignity.

These gears are widely used in various mechanisms: jacks, screw presses, table movement mechanisms, testing machines, measuring instruments.

The leading link that performs rotational motion can be like a screw 1 , so is the nut 2 .

To shortcomings These mechanisms include: high friction losses and low efficiency, increased intensity and thread wear due to high friction.

Screw-nut gears are divided into sliding and rolling gears.

Sliding gears require lubrication between the screw and nut, or the nut can be made of bronze.

In rolling gears, helical grooves are made on the screw and nut, which serve as raceways for balls (Fig. 3).

Rice. 2 Transmission screw - nut Fig. 3 Ball screw

The invention relates to mechanisms for converting rotational motion into translational motion. The mechanism contains an annular shaft, a sun shaft located inside the annular shaft and a plurality of planetary shafts. The annular shaft has an internal threaded portion and first and second annular gears, which are internal gears. The sun shaft includes an external threaded portion and first and second sun gears, the sun gears being external gears. The planetary shafts are arranged around the sun shaft, each of the shafts including an external threaded portion and first and second planetary gears, which are external gears. The outer threaded portion of each planetary shaft engages with the inner threaded portion of the annular shaft and with the outer threaded portion of the sun shaft. The first and second planetary gears each mesh with the first and second ring gears and sun gears, respectively. In this case, the planetary shafts are configured to provide relative rotation between the first planetary gear and the second planetary gear. The solution is aimed at reducing the wear of the mechanism and increasing the efficiency of converting rotational motion into translational motion. 14 w.p. f-ly, 9 ill.

Drawings to the RF patent 2386067

Technical field

The present invention relates to a rotation/translation conversion mechanism for converting rotational motion into translational motion.

State of the art

As a rotation-translation conversion mechanism, for example, a conversion mechanism disclosed in WO 2004/094870 (hereinafter Document 1) has been proposed. The conversion mechanism includes an annular shaft which has a space extending therein in the axial direction, a sun shaft which is located inside the annular shaft, and planetary shafts which are arranged around the sun shaft. In addition, the outer threaded portions formed on the outer circumference of the planetary shafts engage with the inner threaded portions formed on the inner circumference of the annular shaft and the outer threaded portions formed on the outer circumference of the sun shaft. Thus, force is transferred between these components. The planetary motion of the planetary shafts, which is obtained when the annular shaft rotates, causes the sun shaft to translate along the axial direction of the annular shaft. That is, the conversion mechanism converts the rotational motion supplied to the annular shaft into the translational motion of the sun shaft.

In the aforementioned conversion mechanism, two gear trains are provided so that the force is transmitted by the gear engagement in addition to the engagement of the threaded portions between the annular shaft and the planetary shafts. That is, said conversion mechanism includes a gear train which is formed by a first ring gear provided at one end of the annular shaft and a first planetary gear provided at one end of the planetary shaft so as to mesh with the first ring gear, and a gear train which formed by a second ring gear provided at the other end of the annular shaft and a second planetary gear provided at the other end of the planetary shaft so as to mesh with the second ring gear.

In the conversion mechanism of Document 1, when the rotational phase of the first annular gear differs from the rotational phase of the second annular gear shaft, the planetary shafts are located between the annular shaft and the sun shaft in an oblique state with respect to the home position (the position in which the center lines of the planetary shafts are parallel to the center line solar shaft). Thus, the engagement of the threaded portions between the annular shaft, the planetary shafts and the sun shaft becomes uneven. This increases local wear, thus reducing the efficiency of converting rotational motion into translational motion. Such a problem occurs not only in the above conversion mechanism, but in any conversion mechanism including gear trains formed by the gears of the planetary shafts and the gear of at least one of the annular shaft and the sun shaft.

Brief description of the invention

Accordingly, an object of the present invention is to provide a rotation/translation conversion mechanism that suppresses tilt of the planetary shafts caused by the engagement of the planetary shafts and a gear of at least one of the annular shaft and the sun shaft.

To achieve this object, the first aspect of the present invention provides a rotation/translation conversion mechanism that includes an annular shaft, a sun shaft, a planetary shaft, and a first gear and a second gear. The annular shaft is provided with a space extending therein in the axial direction. The solar shaft is located inside the annular shaft. The planetary shaft is located around the sun shaft. The first gear train and the second gear train transmit the force between the annular shaft and the planetary shaft. The conversion mechanism converts the rotational motion of one of the annular shaft and the sun shaft into translational motion and along the axial direction of the other one of the annular shaft and the sun shaft due to the planetary motion of the planetary shaft. The planetary shaft includes a first planetary gear that configures a first gear train part and a second gear that configures a second gear train part. The planetary shaft is formed to allow relative rotation between the first planetary gear and the second planetary gear.

The second aspect of the present invention provides a rotation/translation conversion mechanism that includes an annular shaft, a sun shaft, a planetary shaft, and a first gear and a second gear. The annular shaft is provided with a space extending therein in the axial direction. The solar shaft is located inside the annular shaft. The planetary shaft is located around the sun shaft. The first gear train and the second gear train transmit power between the planetary shaft and the sun shaft. The conversion mechanism converts the rotational motion of one of the planetary shaft and the sun shaft into translational motion and, along the axial direction, the other one of the planetary shaft and the sun shaft due to the planetary motion of the planetary shaft. The planetary shaft includes a first planetary gear that forms part of the first gear and a second gear that forms part of the second gear. The planetary shaft is formed to allow relative rotation between the first planetary gear and the second planetary gear.

Brief description of the drawings

Fig. 1 is a perspective view illustrating a conversion mechanism in a mechanism for converting rotational motion into translational motion according to the first embodiment of the present invention;

Fig. 2 is a perspective view illustrating the internal structure of the conversion engine of Fig. 1;

Fig. 3(A) is a sectional view illustrating the crown shaft of the conversion mechanism of Fig. 1;

Fig. 3(B) is a sectional view illustrating a state in which the crown shaft part of Fig. 1 is disassembled;

Fig. 4(A) is a front view illustrating the sun shaft of the conversion mechanism of Fig. 1;

Fig. 4(B) is a front view illustrating a state in which the sun shaft part of Fig. 4(A) is disassembled;

Fig. 5(A) is a front view illustrating the planetary shaft of the conversion mechanism of Fig. 1;

Fig. 5(B) is a front view illustrating a state in which the part of Fig. 5(A) has been disassembled;

Fig. 5(C) is a sectional view taken along the center line of the rear planetary gear of Fig. 5(A);

Fig. 6 is a sectional view taken along the center line of the conversion mechanism of Fig. 1;

Fig. 7 is a sectional view taken along line 7-7 of Fig. 6 illustrating the conversion mechanism of Fig. 1;

Fig. 8 is a sectional view taken along line 8-8 of Fig. 6 illustrating the conversion mechanism of Fig. 1; and

Fig. 9 is a sectional view taken along line 9-9 of Fig. 6 illustrating the conversion mechanism of Fig. 1.

Best Mode for Carrying Out the Invention

Next, the first embodiment of the present invention will be described with reference to FIGS. 1-9. Hereinafter, the configuration of the rotation/translation conversion mechanism 1 according to the first embodiment, the operation method of the conversion mechanism 1, and the operation principle of the conversion mechanism 1 will be described in this order.

The conversion mechanism 1 is formed by a combination of a crown shaft 2 which has a space extending therein in the axial direction, a sun shaft which is located inside the crown shaft 2, and planetary shafts 4 which are arranged around the sun shaft 3. The crown shaft 2 and the sun shaft 3 are arranged in a state in which the center lines are aligned or substantially aligned with each other. The sun shaft 3 and the planetary shafts 4 are arranged in a state in which the center lines are parallel or substantially parallel to each other. In addition, the planetary shafts 4 are arranged around the sun shaft 3 at equal intervals.

In the first embodiment, the position where the center lines of the components of the conversion mechanism 1 are aligned or substantially aligned with the center line of the sun shaft 2 will be referred to as the centered position. Also, a position where the center lines of the components are parallel or substantially parallel to the center line of the sun shaft 3 will be referred to as the parallel position. That is, crown shaft 2 is held in a centered position. In addition, the planetary shafts 4 are held in a parallel position.

In the conversion mechanism 1, the threaded sections and the gear provided on the crown shaft 2 engage with the threaded section and the gear provided on each of the planetary shafts 4, so that force is transferred from one component to another between the crown shaft 2 and the planetary shafts 4. In addition, , the threaded portion and the gear provided on the sun shaft 3 engage with the threaded portion and the gear provided on each of the planetary shafts 4 so that force is transferred from one component to another between the sun shaft 3 and the planetary shafts 4.

The conversion engine 1 operates as described below based on the combination of such components. When one of the components including the crown shaft 2 and the sun shaft 3 is rotated using the center line of the crown shaft 2 (the sun shaft 3) as the axis of rotation, the planetary shafts 4 perform planetary motion around the sun shaft 3 due to the force transmitted from one from components. Accordingly, due to the force transmitted from the planetary shafts to the crown shaft 2 and the sun shaft 3, the crown shaft 2 and the sun shaft 3 move relative to the planetary shafts 4 parallel to the center line of the crown shaft 2 (the sun shaft 3).

Thus, the conversion mechanism 1 converts the rotary motion of one of the crown shaft and the sun shaft 3 into translational motion of the other one of the crown shaft 2 and the sun shaft 3. In the first embodiment, the direction in which the sun shaft 3 is pushed out of the crown shaft 2 along the axial direction the sun shaft 3 is indicated as the forward direction FR, and the direction in which the sun shaft 3 extends into the crown shaft 2 is indicated as the rear direction RR. In addition, when the predetermined position of the conversion mechanism 1 is taken as the origin, the area in the forward direction FR from the origin is indicated as the front side, and the area in the rear direction RR from the origin is indicated as the rear side.

The front race 51 and the rear race 52, which support the sun shaft 3, are attached to the crown shaft 2. The crown shaft 2, the front race 51 and the rear race 52 move as a whole. At the crown shaft 2, the open area of ​​the front side is closed by the front race 51. In addition, the open area of ​​the rear side is closed by the back race 52.

The sun shaft 3 is supported by the bearing 51A of the front race 51 and the bearing 52A of the rear race 52. The planetary shafts 4 are not supported by either the front race 51 or the rear race 52. That is, in the conversion mechanism 1, while the radial position of the sun shaft 3 is limited by the engagement of threaded sections and gears, front cage 51 and rear cage 52, the radial position of the planetary shafts 4 is limited only by the engagement of the threaded sections and gears.

The conversion mechanism 1 applies the following configuration to lubricate the inside of the crown shaft 2 (locations where the threaded portions and gears of the crown shaft 2, the sun shaft 3 and the planetary shafts 4 mesh with each other) properly. Lubrication holes 51H for supplying lubrication to the crown shaft 2 are formed in the front case 51. In addition, an O-ring 53 for sealing the inside of the crown shaft 2 is installed on each of the front case 51 and the rear case 52. The front case 51 and the rear case 52 correspond to the bearing members. .

The configuration of the crown shaft 2 will be described with reference to FIG. The crown shaft 2 is formed by a combination of the crown shaft main body 21 (annular shaft main body), the front ring gear 22 (first ring gear), and the rear ring gear 23 (second ring gear). At the crown shaft 2, the center line (axis) of the crown shaft main body 21 corresponds to the center line (axis) of the crown shaft 2. Therefore, when the center line of the crown shaft main body 21 is aligned or substantially aligned with the center line of the sun shaft 3, the crown shaft 2 is in a centered position. The front ring gear 22 and the rear ring gear each correspond to an annular gear with internal teeth.

The crown shaft main body 21 includes a main body threaded portion 21A that is provided with an inner threaded portion 24 formed on the inner circumferential surface, a main body gear portion 21B on which the front ring gear is mounted, and a main body gear portion 21C on which the front ring gear is mounted. rear ring gear 23.

The front ring gear 22 is formed as an internal helical gear separately from the crown shaft main body 21 . In addition, the front ring gear 22 is formed such that its center line is aligned with the center line of the crown shaft main body 21 when mounted on the crown shaft main body 21. As for the method of fitting the front ring gear 22 to the crown shaft main body 21, the front ring gear 22 is press-fitted to the crown shaft main body 21 in the first embodiment. The front ring gear 22 may be attached to the crown shaft main body 21 in a manner other than a press fit.

The rear ring gear 23 is formed as an internal helical gear separately from the crown shaft main body 21 . In addition, the rear ring gear 23 is formed such that its center line is aligned with the center line of the crown shaft main body 21 when mounted on the crown shaft main body 21. As for the method of fitting the rear ring gear 23 to the crown shaft main body 21, the rear ring gear 23 is press-fitted to the crown shaft main body 21 in the first embodiment. The rear ring gear 23 may be attached to the crown shaft main body 21 in a manner other than a press fit.

In the ring shaft 2, the front ring gear 22 and the rear ring gear 23 are formed as gears having the same shape. That is, the specifications (such as the reference pitch diameter and the number of teeth) of the front ring gear 22 and the rear ring gear 23 are set to the same values.

The sun shaft 3 is formed by the combination of the sun shaft main body 31 (sun shaft main body) and the rear sun gear 33. At the sun shaft 3, the center line (axis) of the sun shaft main body 31 corresponds to the center line (axis) of the sun shaft 3.

The sun shaft main body 31 is formed by a main body threaded portion 31A which has an outer threaded portion 34 formed on its outer circumferential surface, a main body gear portion 31B on which a front sun gear 32 (first sun gear) serving as a gear is formed. an externally engaged oblique tooth, and a main body gear portion 31C on which the rear sun gear (second sun gear) is mounted. The front sun gear 32 and the rear sun gear each correspond to an externally geared sun gear.

The rear sun gear 33 is formed as an external helical gear separately from the sun shaft main body 31 . In addition, the rear sun gear 33 is formed such that its center line is aligned with the center line of the sun shaft main body 31 when mounted on the sun shaft main body 31 . As for the method of mounting the rear sun gear 33 to the sun shaft main body 31, the rear sun gear 33 is press-fitted to the sun shaft main body 31 in the first embodiment. The rear sun gear 33 may be attached to the sun shaft main body 31 in a manner other than a press fit.

On the sun shaft 3, the front sun gear 32 and the rear sun gear 33 are formed as gears having the same shape. That is, the specifications (such as the reference pitch diameter and the number of teeth) of the front sun gear 32 and the rear sun gear 33 are set to the same values.

The configuration of the planetary shafts 4 will be described with reference to FIG. Each planetary shaft 4 is formed by a combination of the planetary shaft main body 41 (planetary shaft main body) and the rear planetary gear 43. At the planetary shaft 4, the center line (axis) of the planetary shaft main body 41 corresponds to the center line (axis) of the planetary shaft 4. Therefore, when the center line of the main body 41 of the planetary shaft is parallel or substantially parallel to the center line of the sun shaft 3, the planetary shaft 4 is in a parallel position.

The planetary shaft main body 41 is formed by a main body threaded portion 41A, which is provided with an outer threaded portion 44 formed on its outer circumferential surface, by a main body gear portion 41B on which a front planetary gear 42 (first planetary gear) serving as a gear is formed. externally geared with an oblique tooth, a rear shaft 41R on which the rear planetary gear 43 (second planetary gear) is mounted, and a front shaft 41F which is inserted into the mandrel during the assembly sequence of the conversion mechanism 1. In addition, the front planetary gear 42 and the rear planetary gear 43 each correspond to an externally geared planetary gear.

The rear planetary gear 43 is formed as an external helical gear separately from the planetary shaft main body 41 . In addition, by inserting the rear shaft 41R of the planetary shaft main body 41 into the bearing hole 43H, the rear planetary gear 43 is mounted on the planetary shaft main body 41. In addition, the rear planetary gear 43 is formed such that its center line is aligned with the center line of the planetary shaft main body 41 when mounted on the planetary shaft main body 41 .

As for the method of mounting the rear planetary gear 43 to the planetary shaft main body 41, loose fit is applied in the first embodiment so that the rear planetary gear is rotatable relative to the planetary shaft main body 41. As for the installation method for allowing the planetary shaft main body 41 and the rear planetary gear 43 to rotate relative to each other, an installation method other than loose fit may be adopted.

On the planetary shaft 4, the front planetary gear 42 and the rear planetary gear 43 are formed as gears having the same shape. That is, the specifications (such as the reference pitch diameter and the number of teeth) of the front planetary gear 42 and the rear planetary gear 43 are set to the same values.

With reference to FIGS. 6 to 9, the relationship between the components of the conversion engine 1 will be described. In this specification, a conversion mechanism 1 equipped with nine planetary shafts 4 is given as an example, although the number of planetary shafts 4 can be changed upon request.

In the transformation mechanism 1, the action of the components is allowed or limited as mentioned in (a)-(c) below.

(a) As for the crown shaft 2, the crown shaft main body 21, the front ring gear 22 and the rear ring gear 23 are prevented from rotating relative to each other. In addition, the crown shaft main body 21, the front yoke 51, and the rear yoke 52 are prevented from rotating relative to each other.

(b) As for the sun shaft 3, the sun shaft main body 31 and the rear sun gear 33 are prevented from rotating relative to each other.

(c) As for the planetary shaft 4, the planetary shaft main body 41 and the rear planetary gear 43 are allowed to rotate relative to each other.

In the conversion mechanism 1, the sun shaft 3 and the planetary shafts 4, the force is transferred between the components, as described below, due to the engagement of the threaded portions and gears of the crown shaft 2.

As for the crown shaft 2 and the planetary shafts 4, the inner threaded portion 24 of the crown shaft main body 21 and the outer threaded portion 44 of each planetary shaft main body 41 engage with each other. In addition, the front ring gear 22 of the main body 21 of the crown shaft and the front planetary gear 42 of each main body 41 of the planetary shaft are engaged with each other. In addition, the rear ring gear 23 of the main body 21 of the crown shaft and the rear planetary gear 43 of each main body 41 of the planetary shaft are engaged with each other.

Thus, when rotational motion is applied to the crown shaft 2 or the planetary shafts 4, the force is transmitted to the other one of the crown shaft 2 and the planetary shafts 4 through the engagement of the inner threaded portion 24 and the outer threaded portions 44, the engagement of the front ring gear 22 and the front planetary gears. 42, meshing the rear ring gear 23 and the rear planetary gears 43.

At the sun shaft 3 and the planetary shafts 4, the outer threaded portion 34 of the sun shaft main body 31 and the outer threaded portion 44 of each planetary shaft main body 41 engage with each other. In addition, the front sun gear 32 of the sun shaft main body 31 and the front planetary gear 42 of each planetary shaft main body 41 are engaged with each other. In addition, the rear sun gear 33 of the sun shaft main body 31 and the rear planetary gear 43 of each planetary shaft main body 41 are engaged with each other.

Thus, when rotational motion is applied to the sun shaft 3 or the planetary shafts 4, the force is transmitted to the other one of the sun shaft 3 and the planetary shafts 4 through the engagement of the external threaded section 34 and the external threaded sections 44, the engagement of the front sun gear 32 and the front planetary gears 42, meshing the rear sun gear 33 and the rear planetary gears 43.

As described above, the conversion mechanism 1 includes a deceleration mechanism formed by the inner threaded portion 24 of the crown shaft 2, the outer threaded portion 24 of the crown shaft 2, the outer threaded portion 34 of the sun shaft 3, and the outer threaded portions 44 of the planetary shafts 4, the deceleration mechanism (the first gear) formed by the front ring gear 22, the front sun gear 32 and the front planetary gears 42, and the deceleration mechanism (second gear) formed by the rear ring gear 23, the rear sun gear 33 and the rear planetary gears 43.

In the conversion mechanism 1, according to the threads of each threaded portion, the operation mode (motion conversion mode) for converting the rotational movement into the translational movement is determined based on the number and method of setting the number of teeth of each gear. That is, as the motion conversion mode, either the sun shaft motion mode in which the sun shaft 3 is translated due to the rotational motion of the crown shaft, or the annular shaft motion mode in which the crown shaft 2 is translational due to the rotational motion of the sun shaft 3 is selected. the operation method of the conversion mechanism 1 in each motion conversion mode is described.

(A) When the sun shaft movement mode is applied as the motion conversion mode, the rotational motion is converted to translational motion as described below. When rotational motion is applied to the annular shaft 2, the force is transmitted from the annular shaft 2 to the planetary shafts 4 through the engagement of the front ring gear 22 and the front planetary gears 42, the engagement of the rear ring gear 23 and the rear planetary gears 43, the engagement of the internal threaded section 24 and the external threaded sections 44. Thus, the planetary shafts 4 rotate, with their central axes serving as centers of rotation, around the sun shaft 3 and wrap around the sun shaft 3, with the central axis of the sun shaft 3 serving as the center of rotation. Accompanying the planetary motion of the planetary shafts 4, the force is transmitted from the planetary shafts 4 to the sun shaft 3 through the engagement of the front planetary gears 42 and the front sun gear 32, the engagement of the rear planetary gears 43 and the rear sun gear 33, the engagement of the external threaded sections 44 and the external threaded section 34 Accordingly, the sun shaft 3 is displaced in the axial direction.

(B) When the annular shaft movement mode is applied as the motion conversion mode, the rotational motion is converted into translational motion as described below. When rotational motion is applied to the sun shaft 3, the force is transmitted from the sun shaft 3 to the planetary shafts 4 through the engagement of the front sun gear 32 and the front planetary gears 42, the engagement of the rear sun gear 33 and the rear planetary gears 43, the engagement of the external threaded portion 34 and the external threaded sections 44. Thus, the planetary shafts 4 rotate, with their central axes serving as centers of rotation, around the sun shaft 3 and wrap around the sun shaft 3, with the central axis of the sun shaft 3 serving as the center of rotation. Accompanying the planetary motion of the planetary shafts 4, the force is transmitted from the planetary shafts 4 to the ring shaft 2 through the engagement of the front planetary gears 42 and the front ring gear 22, the engagement of the rear planetary gears 43 and the rear ring gear 23, the engagement of the external threaded sections 44 and the internal threaded section 24 Correspondingly, the crown shaft 2 is displaced in the axial direction.

The operating principle of the conversion mechanism 1 will now be described. Hereinafter, the reference pitch diameter and the number of gear teeth of the crown shaft 2, the sun shaft 3, and the planetary shafts 4 are expressed as shown in the following (A) to (F). In addition, the reference pitch diameter and the number of threads of the threaded portions of the crown shaft 2, the sun shaft 3, and the planetary shafts 4 are expressed as shown in (a) through (f) below.

"Reference Pitch Diameter and Number of Gear Teeth"

(A) Effective ring gear diameter, DGr: reference pitch diameter of ring gears 22, 23.

(B) Effective sun gear diameter, DGs: reference pitch diameter of sun gears 32, 33.

(C) Effective planetary gear diameter, DGp: reference pitch diameter of planetary gears 42, 43.

(D) Number of ring gear teeth, ZGr: Number of ring gear teeth 22, 23.

(E) Number of sun gear teeth, ZGs: number of sun gear teeth 32, 33.

(F) Number of planetary gear teeth, ZGp: number of planetary gear teeth 42, 43.

"Reference Pitch Diameter and Number of Threads of Threaded Sections"

(a) Effective diameter of the annular threaded portion, DSr: reference pitch diameter of the inner threaded portion 24 of crown shaft 2.

(b) Effective diameter of the sun threaded portion, DSs: reference pitch diameter of the outer threaded portion 34 of the sun shaft 3.

(c) Effective planetary thread diameter DSp: reference pitch diameter of the outer threaded portions of 44 planetary shafts 4.

(d) Number of threads of the annular thread section, ZSr: number of threads of the inner thread section 24 of crown shaft 2.

(e) Number of threads of the sun threaded section, ZSs: number of threads of the external threaded section 34 of the sun shaft 3.

(f) Number of threads of the planetary thread section, ZSp: number of threads of the external threads of the 44 planetary shafts 4.

In the conversion mechanism 1, when the sun shaft 3 is displaced relative to the planetary shafts 4 in the axial direction, the ratio of the number of threads of the solar threaded section ZSs to the number of threads of the planetary threaded section ZSp (the ratio ZSA of the number of threads of the solar to planetary threads) is different from the ratio of the number of threads of the solar gears ZGs to the number of teeth of the planetary gear ZGp (ratio ZGA of the number of sun teeth to planetary gears). The ratio of the number of threads of the annular threaded section ZSr to the number of threads of the planetary threaded section ZSp (ratio ZSB of the number of annular to planetary threads) is equal to the ratio of the number of teeth of the ring gear ZGr to the number of teeth of the planetary gear ZGp (the ratio ZGB of the number of annular to planetary teeth). That is, the following [expression 11] and [expression 12] are satisfied.

In the transformation mechanism 1, when the crown shaft 2 is displaced relative to the planetary shafts 4 in the axial direction, the ratio of the number of threads of the annular thread section ZSr to the number of threads of the planetary thread section ZSp (the ratio ZSB of the number of threads of the solar to planetary threads) is different from the ratio of the number of teeth of the annular gear ZGr to the number of teeth of the planetary gear ZGp (ratio ZGB of the number of teeth of the annular to the planetary). The ratio of the number of threads of the sun threaded section ZSs to the number of threads of the planetary threaded section ZSp (the ratio ZSA of the number of threads of the solar to planetary threads) is equal to the ratio of the number of sun gear teeth ZGs to the number of planetary gear teeth ZGp (the ratio ZGA of the number of sun to planetary teeth). That is, the following [expression 21] and [expression 22] are satisfied.

Here, the deceleration mechanism formed by the inner threaded portion 24, the outer threaded portion 34, and the outer threaded portions 44 will be referred to as the first planetary deceleration mechanism, and the deceleration mechanism formed by the ring gears 22, 23, the sun gears 32, 33, and the planetary gears 42, 43 will be listed as the second planetary deceleration mechanism.

When the sun shaft 3 is displaced relative to the planetary shafts 4 in the axial direction, the ratio ZSA of the number of solar to planetary threads of the first planetary deceleration mechanism is different from the ratio ZGA of the number of solar to planetary teeth of the second planetary deceleration mechanism, as shown by [expression 11] and [expression 12] . When the crown shaft 2 is displaced relative to the planetary shafts 4 in the direction along the axial direction of the crown shaft 2, the ratio ZSB of the annular to planetary threads of the first planetary retard mechanism is different from the ratio ZGB of the number of annular to planetary teeth of the second planetary retardation mechanism, as shown by [expression 21] and [expression 22].

As a result, in any of the above cases, a force acts between the first planetary retardation mechanism and the second planetary retardation mechanism to form a difference in the rotation angle by an amount corresponding to a difference between the thread number ratio and the tooth number ratio. However, since the threaded portions of the first planetary deceleration mechanism and the gears of the second planetary deceleration mechanism are formed as a whole, a difference in rotation angle cannot be generated between the first planetary deceleration mechanism and the second planetary deceleration mechanism. Thus, the sun shaft 3 or crown shaft 2 moves relative to the planetary shafts 4 in the axial direction in order to absorb the difference in rotation angle. At this time, the component that is displaced in the axial direction (sun shaft 3 or crown shaft 2) is determined as described below.

(a) When the ratio of the number of threads of the sun thread section ZSs to the number of threads of the planetary thread section ZSp differs from the ratio of the number of sun gear teeth ZGs to the number of planetary gear teeth ZGp, the sun shaft 3 is displaced relative to the planetary shafts 4 in the axial direction.

(b) When the ratio of the number of threads of the annular thread section ZSr to the number of threads of the planetary thread section ZSp differs from the ratio of the number of teeth of the ring gear ZGr to the number of teeth of the planetary gear ZGp, the crown shaft 2 is displaced relative to the planetary shafts 4 in the axial direction.

Thus, the conversion mechanism 1 uses the difference in the rotation angle generated according to the difference in the ratio of the number of threads and the ratio of the number of teeth of the sun shaft or crown shaft relative to the planetary shafts 4 between the two kinds of planetary deceleration mechanisms, and obtains an axial displacement corresponding to the difference in the angle of rotation, along the threaded sections, thereby converting the rotational movement into translational movement.

In the conversion mechanism 1, by setting at least one of the "number of active teeth" and "number of active threads" described below to a value other than "0" for the crown shaft 2 or the sun shaft 3, a translational movement of the sun shaft 3 based on the ratio between the ratio ZSA of the number of solar to planetary threads and the ratio ZGA of the number of solar to planetary teeth, or the translational movement of the crown shaft 2 based on the ratio between the ratio ZSB of the number of annular to planetary threads and the ratio ZGB of the number of teeth circular to planetary.

"Setting the number of active teeth"

In a typical planetary retardation mechanism (planetary gear-type retardation mechanism) formed by a ring gear, a sun gear, and planetary gears, that is, a planetary gear-type retardation mechanism that retards rotation by meshing gears, the relationship represented by the following is satisfied with [ expression 31] to [expression 33]. [Expression 31] represents the ratio established between the reference pitch diameters of the ring gear, sun gear, and planetary gears. [Expression 32] represents the ratio established between the numbers of teeth of the ring gear, sun gear, and planetary gears. [Expression 33] represents the relationship established between the reference pitch diameters and the numbers of teeth of the ring gear, sun gear, and planetary gear.

DAr: ring gear reference pitch diameter

DAs: sun gear reference pitch diameter

DAp: reference pitch diameter of planetary gear

ZAr: number of teeth of the ring gear

ZAs: number of sun gear teeth

ZAp: number of teeth of the planetary gear

In the conversion mechanism 1 of the first embodiment, provided that the second planetary deceleration mechanism, that is, the deceleration mechanism formed by the ring gears 22, 23, the sun gears 32, 33, and the planetary gears 42, 43, has the same configuration as the above mechanism deceleration of the planetary gear type, the ratio set between the reference pitch diameters of the gears, the relationship set between the number of gear teeth, and the relationship set between the reference pitch diameter and the number of gear teeth are represented by [Expression 41] to [Expression 43].

In the case where the number of teeth of the ring gears is 22, 23, the sun gears are 32, 33, and the planetary gears are 42, 43, when the ratios presented in [Expression 41] to [Expression 43] are satisfied, is indicated as the reference number of teeth, "the number of active teeth " is expressed as the difference between the number of teeth and the reference number of teeth of each gear. In the conversion mechanism 1, by setting the number of active teeth of one of the crown shaft 2 and the sun shaft 3 to a value other than "0", the crown shaft 2 or the sun shaft 3 can be translated. That is, when the reference number of teeth of the ring gears 22, 23 is represented by the reference number of ring teeth, ZGR, and the reference number of teeth of the sun gears 32, 33 is represented by the reference number of sun teeth, ZGS, by setting the number of teeth of the ring gears 22, 23 or sun gears 32 , 33, from the condition that one of the following [expressions 44] and [expressions 45] is satisfied, the crown shaft 2 or the sun shaft 3 can move forward.

When [expression 44] is satisfied, the ring shaft 2 is translated. When [expression 45] is satisfied, the sun shaft 3 is translated.

"Setting the number of active threads"

In the planetary deceleration mechanism (planetary thread type deceleration mechanism) which is identical to the above planetary gear type deceleration mechanism and is formed by an annular thread portion corresponding to the ring gear, a sun thread portion corresponding to the sun gear, and planetary thread portions corresponding to the planetary gears , that is, in the planetary thread type deceleration mechanism which decelerates rotation like the above planetary gear type deceleration mechanism, only by the engagement of the thread portions, the ratios represented by the following [Expression 51] to [Expression 53] are satisfied. [Expression 51] represents the relationship established between the reference pitch diameters of the annular threaded portion, the solar threaded portion, and the planetary threaded portions. [Expression 52] represents the relationship established between the number of teeth of the annular threaded portion, the sun threaded portion, and the planetary threaded portions. [Expression 53] represents the relationship established between the reference pitch diameter and the number of teeth of the annular thread portion, the sun thread portion, and the planetary thread portions.

DBr: reference pitch diameter of the annular threaded section

DBs: reference pitch diameter of the solar threaded section

DBp: reference pitch diameter of the planetary thread

ZBr: number of threads of the annular threaded section

ZBs: number of threads of the sun threaded section

ZBp: number of threads of the planetary threaded section

In the conversion mechanism 1 according to the first embodiment, provided that the first planetary retardation mechanism has the same configuration as the above-mentioned planetary threaded type retardation mechanism, the ratio set between the reference pitch diameters of the threaded portions, the ratio set between the number of threads of the threaded sections, and the ratio established between the reference pitch diameters and the number of threads of the threaded sections, are expressed as follows from [expression 61] to [expression 63].

In the case where the number of threads of the inner threaded portion 24 of the crown shaft 2, the outer threaded portion 34 of the sun shaft 3, and the outer threaded portions 44 of the planetary shafts 4 when the ratios of [Expression 61] to [Expression 63] above are satisfied, is indicated as the reference number number of threads, the "number of active threads" is represented as the difference between the number of threads of each thread section and the reference number of threads. In the conversion mechanism 1, by setting the number of active threads of one of the crown shaft 2 and the sun shaft 3 to a value other than "0", the crown shaft 2 or the sun shaft 3 is translated. That is, when the reference number of threads of the inner threaded portion 24 of the crown shaft 2 is represented by the reference number of annular threads ZSR and the reference number of threads of the outer threaded portion 34 of the sun shaft 3 is represented by the reference number of the sun threads ZSS, the crown shaft 2 or the sun shaft 3 is moved forward by setting the number of threads such that one of the following [Expression 64] and [Expression 65] is satisfied.

When [expression 64] is satisfied, the crown shaft 2 is translated. When [expression 65] is satisfied, the sun shaft 3 is translated.

In a typical planetary gear type deceleration mechanism, the number of planetary gears is a divisor of the sum of the number of sun gear teeth and the number of ring gear teeth. Thus, the number of planetary shafts 4 (planetary number Np) in the conversion mechanism 1 is a common divisor of "the divisors of the sum of the number of threads of the sun threaded section ZSs and the number of threads of the annular threaded section ZSr" and "the divisors of the sum of the number of sun gear teeth ZGs and the number ring gear teeth ZGr.

In the conversion mechanism 1, the threaded portions and gears are simultaneously engaged by setting the number of teeth of the ring gear ZGr, the number of teeth of the sun gear ZGs, and the number of teeth of the planetary gear ZGp (the total ratio of the number of teeth ZGT) to the ratio of the effective diameter of the ring gear DGr to the effective diameter of the sun gear DGs and the planetary gear effective diameter DGp (Total Effective Diameter Ratio, ZST). That is, by setting the number of teeth of the gears and the number of threads of the threaded portions such that the relationship of the following [Expression 71] is satisfied, the threaded portions and the gears are engaged at the same time.

However, in this case, since the rotational phases of the planetary shafts 4 are the same, the beginning and end of the engagement of the planetary gears 42, 43, ring gears 22, 23, and sun gears 32, 33 accompanying rotation coincide. This causes torque ripple due to gear meshing, which can increase operating noise and reduce gear life.

Thus, in the conversion mechanism 1, the total tooth number ratio ZGT and the total effective diameter ratio ZST are set to different values ​​within a range in which the following conditions (A) to (C) are satisfied. The total tooth number ratio ZGT and the total effective diameter ratio ZST can be set to different values ​​within a range in which at least one of conditions (A)-(C) is satisfied.

(A) In the case where the number of sun gear teeth, ZGs, if the relationship of [Equation 71] is satisfied is indicated as the reference number of sun teeth ZGSD, the actual number of sun gear teeth ZGs is different from the reference number of sun teeth ZGSD.

(B) In the case where the number of teeth of the ring gear, ZGr, if the ratio of [Expression 71] is satisfied as the reference number of ring teeth ZGRD, the actual number of teeth of the ring gear ZGr is different from the reference number of ring teeth ZGRD.

(C) The planetary number Np is different from the divisor of the number of planetary gear teeth ZGp, that is, the planetary number Np and the number of planetary gear teeth ZGp do not have a divisor other than "1".

Since this achieves an operation method in which the threaded portions and gears are engaged simultaneously, and an operation method in which the rotational phases of the planetary shafts 4 are different from each other, torque ripples caused by the gear engagement are suppressed.

The main items representing the specifications of the conversion mechanism 1 are given in the following items (A) to (I), including the number of active threads and the number of active teeth.

(B) Solar/planetary thread ratio

(E) Gear tooth ratio

(F) Ratio of effective diameters of threaded sections

(G) Ratio of effective gear diameters

(H) Number of active threads

(I) Number of active teeth

The details of the above items will be described below.

The "motion conversion mode" of (A) represents the operation mode for converting rotational motion into translational motion. That is, when the sun shaft 3 is translated by the rotational movement of the crown shaft 2, the motion conversion mode is in the "sun shaft moving mode". When the crown shaft 2 is translated by the rotational motion of the sun shaft 3, the motion conversion mode is in the "annular shaft moving mode".

The “thread ratio of the threaded portions” of (D) represents the ratio of the number of threads of the sun thread portion ZSs, the number of threads of the planetary thread portion ZSp, and the number of threads of the annular thread portion ZSr. That is, "the ratio of the number of threads of threaded portions" is "ZSs:ZSp:ZSr".

The "gear tooth ratio" of (E) represents the ratio of the number of sun gear teeth ZGs, the number of planetary gear teeth ZGp, and the number of ring gear teeth ZGr. That is, the ratio of the number of gear teeth is ZGs:ZGp:ZGr.

The "effective thread diameter ratio" of (F) represents the ratio of the effective diameter of the solar thread portion DSs, the effective diameter of the planetary thread portion DSp, and the effective diameter of the annular thread portion DSr. That is, the ratio of the effective diameters of the threaded sections is DSs:DSp:DSr.

The “gear effective diameter ratio” of (G) represents the ratio of the effective sun gear diameter DGs, the effective planetary gear diameter DGp, and the effective ring gear diameter DGr. That is, the ratio of effective gear diameters is DGs:DGp:DGr.

The "number of active threads" by (H) represents the difference between the actual number of threads of the threaded section (the number of threads by (D)) and the reference number of threads. That is, when the motion conversion mode is in the sun shaft movement mode, the number of active threads is a value obtained by subtracting the reference number of sun threads ZSS from the number of threads of the sun thread portion ZSs in (D). When the motion conversion mode is in the annular shaft movement mode, the number of active threads is a value obtained by subtracting the reference number of annular threads ZSR from the number of threads of the annular threaded section ZSr in (D).

The "number of active teeth" in (I) represents the difference between the actual number of gear teeth (the number of teeth in (E)) and the reference number of teeth. That is, when the motion conversion mode is in the sun shaft moving mode, the number of effective teeth is a value obtained by subtracting the reference number of sun teeth ZGS from the number of sun gear teeth ZGs in (E). In addition, when the motion conversion mode is in the annular shaft moving mode, the number of active teeth is a value obtained by subtracting the reference number of annular teeth ZGR from the number of teeth of the annular gear ZGr in (E).

Now, a separate setting method for the above items will be illustrated.

Installation example 1

(C) Number of planetary shafts: "4"

(D) The ratio of the number of threads of the threaded sections: "3:1:5"

(E) Gear tooth ratio: "31:9:45"

(G) Effective gear diameter ratio: "3.44:1:5"

(H) Number of active threads: "0"

(I) Number of active teeth: "4"

Installation example 2

(A) Motion conversion mode: "sun shaft moving mode"

(B) Solar/planetary thread ratio: "reverse direction"

(D) The ratio of the number of threads of the threaded sections: "4:1:5"

(F) Effective thread diameter ratio: "3:1:5"

(G) Effective gear diameter ratio: "3.1:1:5"

Installation example 3

(A) Motion conversion mode: "sun shaft moving mode"

(B) Solar/planetary thread ratio: "forward direction"

(C) Number of planetary shafts: "9"

(D) The ratio of the number of threads of the threaded sections: "-5:1:5"

(E) Gear tooth ratio: "31:10:50"

(F) Effective thread diameter ratio: "3:1:5"

(G) Effective gear diameter ratio: "3.1:1:5"

(H) Number of active threads: "-8"

(I) Number of active teeth: "1"

Installation example 4

(A) Motion conversion mode: "sun shaft moving mode"

(B) Solar/planetary thread ratio: "reverse direction"

(C) Number of planetary shafts: "11"

(D) The ratio of the number of threads of the threaded sections: "5:1:6"

(E) Gear tooth ratio: "39:10:60"

(F) Effective thread diameter ratio: "4:1:6"

(G) Effective gear diameter ratio: "3.9:1:6"

(H) Number of active threads: "1"

(I) Number of active teeth: "-1"

Installation example 5

(A) Motion conversion mode: "sun shaft moving mode"

(B) Solar/planetary thread ratio: "reverse direction"

(C) Number of planetary shafts: "7"

(D) The ratio of the number of threads of the threaded sections: "2:1:5"

(E) Gear tooth ratio: "25:9:45"

(F) Effective thread diameter ratio: "3:1:5"

(G) Effective gear diameter ratio: "2.78:1:5"

(H) Number of active threads: "-1"

(I) Number of active teeth: "-2"

Installation example 6

(A) Motion conversion mode: "sun shaft moving mode"

(B) Solar/planetary thread ratio: "reverse direction"

(C) Number of planetary shafts: "5"

(D) The ratio of the number of threads of the threaded sections: "11:2:14"

(E) Gear tooth ratio: "58:11:77"

(F) The ratio of the effective diameters of the threaded sections: "6:1:8"

(G) Effective gear diameter ratio: "5.8:1.1:7.7"

(H) Number of active threads: "1"

(I) Number of active teeth: "3"

Installation example 7

(B) Solar/planetary thread ratio: "reverse direction"

(C) Number of planetary shafts: "9"

(E) Gear tooth ratio: "30:10:51"

(F) Effective thread diameter ratio: "3:1:5"

(G) Effective gear diameter ratio: "3:1:5.1"

(H) Number of active threads: "1"

(I) Number of active teeth: "1"

As described above, the first embodiment has the following advantages.

(1) The operations and advantages of the conversion mechanism 1 according to the first embodiment will now be described based on comparison with the rotation/translation conversion mechanism (basic motion conversion mechanism) equipped with planetary shafts in which the front planetary gear and the rear planetary gear are formed as an integral part. with the main shaft.

In the above basic motion conversion mechanism, if there is a rotation phase shift between the front ring gear and the rear ring gear, the planetary shafts are arranged between the crown shaft and the sun shaft in an oblique state with respect to the central axis of the sun shaft (crown shaft) in accordance with the phase shift. Thus, the engagement of the threaded portions between the crown shaft, the sun shaft and the planetary shafts 4 becomes uneven, which locally increases the pressure between the threaded portions and the gears. As a result, localized wear is caused, correspondingly reducing the service life of the conversion mechanism and reducing the conversion efficiency from rotational motion to translational motion due to increased wear.

In contrast, in the conversion mechanism 1 according to the first embodiment, the planetary shafts 4 are formed to allow the front planetary gear 42 and the rear planetary gear 43 to rotate relative to each other. Thus, the rotational phase shift between the front ring gear 22 and the rear ring gear 23 is absorbed. the associated shaft main body 41 (relative rotation of the front planetary gear 42 and the rear planetary gear 43). This suppresses the inclination of the planetary shafts 4 caused by the misalignment between the rotation phase of the front ring gear 22 and the rotation phase of the rear ring gear 23. Thus, uniform engagement of the threaded portions and uniform engagement of the gears between the crown shaft 2, the sun shaft 3 and the planetary shafts 4 is achieved. as a result, the service life of the conversion mechanism 1 and the motion conversion efficiency are improved.

(2) To suppress the inclination of the planetary shafts 4, for example, the conversion mechanism 1 is manufactured as described below. That is, in the manufacturing process of the conversion mechanism 1, the offset between the rotational phase of the front ring gear 22 and the rotational phase of the rear ring gear 23 is reduced by combining the components along with adjusting the rotational phases of the front ring gear and the rear ring gear 23. However, in this case, since the rotational phases of the gears must strictly regulated, performance is degraded. Moreover, the phase displacement could not be sufficiently reduced despite the fact that the rotational phases of the gears are controlled. Therefore, this countermeasure is not preferred.

In contrast, the conversion mechanism 1 of the first embodiment uses a configuration in which rotational phase shift is absorbed due to the relative motion of the front planetary gear 42 and the rear planetary gear 43 as described above. Therefore, the performance is improved and the inclination of the planetary shafts 4 is more appropriately suppressed.

(3) In each of the planetary shafts 4 of the conversion mechanism of the first embodiment, the front planetary gear 42 and the external threaded portion 44 are integrally formed with the shaft main body 41. As a result, during production of the planetary shafts 4, the front planetary gear 42 and the outer threaded portion 44 can be rolled simultaneously, which improves productivity.

(4) In the conversion mechanism 1 of the first embodiment, the radial position of the sun shaft 3 is limited by the engagement of the threaded portions and the engagement of the gears, the front race 51 and the rear race 52. The radial position of the planetary shafts 4 is limited by the engagement of the threaded portions and the engagement of the gears. As a result, since the conversion mechanism 1 is constituted by a minimum number of components for limiting the planetary shafts 4, the planetary shafts 4 are restrained from tilting about the axial direction of the sun shaft 3 properly.

(5) In the conversion mechanism 1 of the first embodiment, the front case 51 is provided with oil holes 51H. Thus, since lubricant can be supplied to the engagement portion of the threaded portions and gears through the lubrication holes 51H, the service life of the threaded portions and gears is improved. In addition, since foreign objects in the conversion mechanism 1 are ejected to the outside as lubricant is supplied through the lubrication holes 51H, reduction in conversion efficiency and malfunction due to foreign objects are suppressed.

(6) In the conversion mechanism 1 of the first embodiment, the total tooth number ratio ZGT and the total effective diameter ratio ZST are set to different values ​​within a range in which conditions (A) to (C) are satisfied. This achieves a method of operation in which the engagement of the threaded portions and the engagement of the gears is obtained simultaneously, and a method of operation in which the phases of rotation of the planetary shafts 4 differ from each other. Thus, torque ripples caused by gear meshing are suppressed. In addition, operating noises are reduced, and the durability life is improved accordingly.

The first embodiment can be modified as follows.

As a configuration for allowing the front planetary gear 42 and the rear planetary gear 43 to rotate relative to each other, the first embodiment adopts a configuration in which the shaft main body 41 and the rear planetary gear 43 are separately formed. However, this may be modified as described below. The shaft main body 41, the front planetary gear 42, and the rear planetary gear 43 are separately formed and connected so that these components rotate relative to each other. This allows the front planetary gear 42 and the rear planetary gear 43 to rotate relative to each other.

The conversion engine 1 of the first embodiment is a conversion engine that operates based on the following operating principles. That is, the rotational motion is converted into translational motion due to the difference between the rotation angles formed in accordance with the difference between the ratio of the number of teeth and the ratio of the number of threads of the sun shaft 3 or crown shaft 2 to the planetary shafts 4 in the two types of planetary deceleration mechanisms. In contrast, the conversion engine of the embodiment described below is a conversion engine that operates based on the following operating principles. The conversion engine of the second embodiment differs from the conversion engine 1 of the first embodiment in that the configuration described below is applied, but the other configuration is the same as that of the conversion engine 1 of the first embodiment.

When the planetary gear type deceleration mechanism is formed by the sun gears, due to the ratio of the rotation direction of the gears, the sun gear tooth inclination line and the planetary gear tooth inclination line are set in opposite directions from each other, and the twist angles of the gears are set to the same value. Further, as the ring gear, a gear having a twist angle that is in the same direction as the planet gear is used.

Therefore, in order to configure the deceleration mechanism (planetary gear type deceleration mechanism) which is the same as the planetary gear engagement type deceleration mechanism, the starting angle of the helix line of the sun threaded portion corresponding to the sun gear of the planetary threaded portion corresponding to the planetary gear and the annular threaded portion corresponding to the ring gear are set to the same value, and the sun threaded portion has a threaded portion in the opposite direction. In such a planetary threaded gear deceleration mechanism, neither component is axially displaced relative to the other component. However, provided that such a state where relative movement in the axial direction does not occur is referred to as the reference state, the sun threaded portion or the annular threaded portion can be displaced in the axial direction by changing the advance angle of the sun threaded portion or the annular threaded portion from the reference state along with with the engagement of threaded sections.

In general, the pitches of the threads need to be set to the same size in order to fully engage two threaded portions. In addition, in the planetary threaded type deceleration mechanism, in order to align all the advance angles of the sun threaded portion, the planetary threaded portions, and the annular threaded portion, the ratio of the reference pitch diameter of the sunthreaded portion, the planetary threaded portions, and the annular threaded portion must be adjusted to the ratio the number of threads of the solar threaded section, the planetary threaded sections and the annular threaded section.

Therefore, in the deceleration mechanism of the planetary threaded gear type, the conditions in which none of the components move in the axial direction are the following conditions (1) to (3):

(1) A relationship in which only the sun thread portion is a reverse thread among the sun thread portion, the planetary thread portions, and the annular thread portion.

(2) The thread pitches of the sun thread, the planetary threads and the annular thread are the same size.

(3) The ratio of the reference pitch diameter of the sun thread portion, the planetary thread portions, and the annular thread portion is the same as the ratio of the number of threads of the sun thread portion, the planetary thread portions, and the annular thread portion.

In contrast, when the number of threads of the sun threaded portion or the annular threaded portion is increased from the number of threads of the above (2) by an integer number of threads, the sun threaded portion or the annular threaded portion is moved in the axial direction relative to the other threaded portions. Thus, the second embodiment reflects the above idea in the configuration of the conversion engine 1. This allows the conversion mechanism 1 to convert rotational motion into translational motion.

When the sun shaft moving mode is applied, the conversion mechanism 1 is configured to satisfy the following conditions (A) to (D). When the annular shaft moving mode is applied, the conversion mechanism 1 is configured to satisfy the following conditions (A)-(C) and (E):

(A) The twisting direction of the outer threaded portion 34 of the sun shaft 3 is opposite to the twisting direction of the outer threaded portions 44 of the planetary shafts 4.

(B) The twisting direction of the inner threaded portion 24 of the crown shaft 2 is the same as the twisting direction of the outer threaded portions 44 of the planetary shafts 4.

(C) The thread pitches of crown shaft 2, sun shaft 3 and planetary shafts 4 are identical.

(D) With regard to the relationship between the reference pitch diameter and the number of threads of the threaded portions of the crown shaft 2, the sun shaft 3 and the planetary shafts 4, provided that the ratio when none of the crown shaft 2, the sun shaft 3 and the planetary shafts 4 undergoes a relative displacement in the axial direction, is indicated as a reference ratio, the number of threads of the external threaded portion 34 of the sun shaft 3 is larger or smaller than the number of threads in the reference ratio by an integer.

(E) Regarding the relationship between the reference pitch diameter and the number of threads of the threaded portions of the crown shaft 2, the sun shaft 3 and the planetary shafts 4, provided that the ratio when none of the crown shaft 2, the sun shaft 3 and the planetary shafts 4 undergoes a relative displacement in the axial direction, is indicated as a reference ratio, the number of threads of the inner threaded portion 24 of the crown shaft 2 is larger or smaller than the number of threads in the reference ratio by an integer.

In the conversion mechanism 1, assuming that there is no relative displacement in the axial direction between the annular shaft 2, the sun shaft 3, and the planetary shafts 4, the relationship represented by [Expression 81] is established between the reference pitch diameter and the number of threads of the threaded portions.

In the case where the number of threads of the inner threaded portion 24 of the crown shaft 2, the outer threaded portion 34 of the sun shaft 3, and the outer threaded portions 44 of the planetary shafts 4, when the ratio of [Expression 81] is satisfied, is assumed to be the "reference number of threads", and the difference between the number of threads of the threaded portions and the reference number of threads is assumed to be the "number of active threads", the ring shaft 2 or the sun shaft 3 can be translated in the conversion mechanism 1 by setting the "number of effective threads" of one of the ring shaft 2 and the sun shaft 3 to a value other than "0". That is, when the reference number of threads of the inner threaded portion 24 of the crown shaft 2 is indicated as the reference number of annular threads ZSR, and the reference number of threads of the outer threaded portion 34 of the sun shaft 3 is indicated as the reference number of sun threads ZSS, the crown shaft 2 or the sun shaft 3 is translated by setting the number of threads such that one of the following [expression 82] and [expression 83] is satisfied.

A separate setting method will be given in "Special Examples of the Method for Setting the Number of Threads".

The main items representing the specifications of the conversion mechanism 1 of the second embodiment include the following items (A) to (E) including the reference pitch diameter ratio and the ratio of the number of teeth.

(A) Motion conversion mode

(B) Solar/planetary thread ratio

(C) Number of planetary shafts

(D) The ratio of the number of threads of the threaded sections

(E) Number of active threads

Details of the above items will be described next.

The "motion conversion mode" of (A) represents the operation mode for converting rotational motion into translational motion. That is, when the sun shaft 3 is translated by the rotational movement of the crown shaft 2, the motion conversion mode is in the "sun shaft movement mode". In addition, when the crown shaft 2 is translated by the rotational movement of the sun shaft 3, the motion conversion mode is in the "annular shaft movement mode".

The “sun/planetary threaded portion ratio” of (B) represents the twisting direction ratio between the outer threaded portion 34 of the sun shaft 3 and the outer threaded portions 44 of the planetary shafts 4. That is, when the twisting direction of the outer threaded portion 34 of the sun shaft 3 and the twisting direction of the outer threaded sections 44 of the planetary shafts 4 are opposite to each other, the ratio of the solar/planetary threaded sections is "reverse direction". In addition, when the twisting direction of the outer threaded portion 34 of the sun shaft 3 and the twisting direction of the outer threaded portions 44 of the planetary shafts 4 are the same as each other, the ratio of the sun/planetary threaded portions is "forward direction".

The "number of planetary shafts" in (C) represents the number of planetary shafts 4 arranged around the sun shaft 3.

The “thread ratio of the threaded portions” of (D) represents the ratio of the number of threads of the sun thread portion ZSs, the number of threads of the planetary thread portion ZSp, and the number of threads of the annular thread portion ZSr. That is, the ratio of the number of threads of the threaded portions is ZSs:ZSp:ZSr.

The "number of effective threads" in (E) represents the difference between the actual number of threads of the threaded section (number of threads in (D)) and the reference number of threads. That is, when the motion conversion mode is in the sun shaft movement mode, the number of active threads is a value obtained by subtracting the reference number of sun threads ZSS from the number of threads of the sun thread portion ZSs in (D). In addition, when the motion conversion mode is in the annular shaft moving mode, the number of effective threads is a value obtained by subtracting the reference number of annular threads, ZSR, from the number of threads of the annular threaded section, ZSr, in (D).

Installation example 1

(A) Motion conversion mode: "sun shaft moving mode"

(B) Solar/planetary thread ratio: "reverse direction"

(C) Number of planetary shafts: "9"

(D) The ratio of the number of threads of the threaded sections: "4:1:5"

(F) Number of active threads: "1"

Installation example 2

(A) Motion conversion mode: "ring shaft moving mode"

(B) Solar/planetary thread ratio: "reverse direction"

(C) Number of planetary shafts: "9"

(D) The ratio of the number of threads of the threaded sections: "3:1:6"

(E) Number of active threads: "1"

The conversion mechanism 1 of the second embodiment further uses the following setting method for the number of teeth and the reference pitch diameter of the gears and the number of threads and the reference pitch diameter of the threaded portions.

[A] The effective diameter of the planetary thread DSp and the effective diameter of the planetary gear DGp are set to the same size. In addition, the ratio of the number of teeth of the planetary gear ZGp and the number of teeth of the ring gear ZGr are set to the same size as the ratio of the effective diameter of the planetary thread portion DSp and the effective diameter of the annular thread portion DSr. Thus, the ratio of the number of teeth of the planetary gear ZGp and the number of teeth of the ring gear ZGr is equal to the ratio of the number of threads of the planetary thread section ZSp and the number of threads of the annular thread section ZSr. Thus, the ratio of the amount of rotation of the crown shaft 2 and the planetary shafts 4 is precisely limited by the ratio of the number of teeth of the ring gears 22, 23 and the planetary gears 42, 43. In addition, the ratio of the effective diameter of the planetary threaded portion DSp and the effective diameter of the annular threaded portion DSr is maintained in relation to effective diameter, which should be set initially.

[B] The effective diameter of the planetary thread DSp and the effective diameter of the planetary gear DGp are set to the same size. In addition, the ratio of the number of teeth of the planetary gear ZGp and the number of teeth of the sun gear ZGs are set to the same size as the ratio of the effective diameter of the planetary thread portion DSp and the effective diameter of the sun thread portion DSs. Thus, the ratio of the number of planetary gear teeth ZGp and the number of sun gear teeth ZGs is equal to the ratio of the number of threads of the planetary threaded portion ZSp to the number of threads of the sun threaded portion ZSs. Thus, the ratio of the number of rotations of the sun shaft 3 and the planetary shafts 4 is precisely limited by the ratio of the number of teeth of the sun gears 32, 33 and the planetary gears 42, 43. In addition, the ratio of the effective diameter of the planetary thread portion DSp and the effective diameter of the sun thread portion DSs is maintained at the ratio effective diameter, which should be set initially.

As described above, the conversion mechanism 1 according to the second embodiment has advantages that are the same as those of (1) to (4) and (5) of the first embodiment.

The second embodiment may be modified as will be described later.

In the second embodiment, the front ring gear 22 and/or the rear ring gear 23 may be omitted. That is, the configuration may be modified so that the front planetary gear 42 and/or the rear planetary gear 43 does not mesh with the ring shaft 2.

In the second embodiment, the front sun gear 32 and/or the rear sun gear 33 may be omitted. That is, the configuration may be modified such that the front planetary gear 42 and/or the rear planetary gear 43 does not mesh with the sun shaft 3.

CLAIM

1. The mechanism for converting rotational/translational motion, containing:

an annular shaft having a space extending therein in an axial direction, the annular shaft including an internal threaded section and first and second annular gears, the annular gears being internal gears,

a sun shaft located inside the annular shaft and including an external threaded portion and first and second sun gears, the sun gears being external gears, and

a plurality of planetary shafts arranged around the sun shaft, each of which includes an external threaded portion and first and second planetary gears, the planetary gears being external gears,

while the outer threaded section of each planetary shaft engages with the inner threaded section of the annular shaft and with the outer threaded section of the sun shaft, each first planetary gear engages with the first ring gear and with the first sun gear, each second planetary gear engages with the second ring gear and with the second a sun gear, wherein the conversion mechanism converts the rotational motion of one of the annular shaft and the sun shaft into translational motion of the other one of the annular shaft and the sun shaft along the axial direction due to the planetary motion of the planetary shafts,

wherein the planetary shafts are configured to provide relative rotation between the first planetary gear and the second planetary gear.

2. The conversion mechanism according to claim 1, in which each planetary shaft is formed by a combination of the main body of the planetary shaft, made in one piece with the external threaded section and the first planetary gear, and the second planetary gear, formed separately from the main body of the planetary shaft, while the second the planetary gear is rotatable relative to the main body of the planetary shaft.

3. The conversion mechanism of claim 1, wherein each planetary shaft is formed by a combination of a planetary shaft main body integral with the external threaded portion, and a first planetary gear and a second planetary gear that are formed separately from the planetary shaft main body, wherein the first planetary gear and the second planetary gear are rotatable relative to the main body of the planetary shaft.

4. The conversion mechanism of claim 1, wherein each annular shaft is formed by a combination of an annular shaft main body integral with the internal threaded portion, and a first annular gear and a second annular gear that are formed separately from the annular shaft main body, wherein the first ring gear and the second ring gear are rotatable relative to the main body of the planetary shaft.

5. The conversion mechanism according to claim 1, wherein the internal threaded portion, the first ring gear and the second ring gear of the annular shaft are movable together.

6. The conversion mechanism according to claim 1, in which the sun shaft is formed by a combination of the main body of the sun shaft, made in one piece with the external threaded section and the first sun gear, and the second sun gear formed separately from the main body of the sun shaft, while the second sun the gear is movable relative to the main body of the sun shaft.

7. The conversion mechanism according to claim 1, wherein the outer threaded portion, the first sun gear and the second sun gear of the sun shaft are movable together.

8. The conversion mechanism according to claim 1, wherein when the ratio of the number of teeth of each ring gear, the number of teeth of each sun gear, and the number of teeth of each planetary gear is indicated as the ratio of the number of teeth, and the ratio of the reference pitch diameter of each ring gear, the reference pitch diameter of each of the sun gear and the reference pitch diameter of each planetary gear is indicated as the ratio of the effective diameters, the ratio of the number of teeth and the ratio of the effective diameters are set to different values.

9. The conversion mechanism according to claim 1, in which the radial position of the sun shaft is limited by the bearing element attached to the annular shaft, the engagement of the threaded sections and the engagement of the gears, while the radial position of the planetary shaft is limited by the engagement of the threaded sections and the engagement of the gears.

10. The conversion mechanism according to claim 9, wherein the bearing element is a pair of bearings attached to the annular shaft to cover open areas at the ends of the annular shaft, and the bearing element is provided with holes for supplying lubricant to the engagement area of ​​the threaded sections and the engagement area of ​​the gears between the annular shaft , sun shaft and planetary shaft.

11. The conversion mechanism according to claim 1, wherein the first ring gear and the second ring gear have the same shape, the first sun gear and the second sun gear have the same shape, and the first planetary gear and the second planetary gear have the same shape.

12. The conversion mechanism according to claim 11, wherein when the number of threads of the outer threaded portion of the planetary shaft is indicated as the number of threads of the planetary threaded portion, the number of threads of the outer threaded portion of the sun shaft is indicated as the number of threads of the solar threaded portion, the number of teeth of the planetary gear is indicated as the number of planetary gear teeth, and the number of sun gear teeth is indicated as the number of sun gear teeth, the ratio of the number of threads of the sun threaded part to the number of threads of the planetary threaded part is different from the ratio of the number of sun gear teeth to the number of planetary gear teeth,

13. The conversion mechanism according to claim 11, wherein when the number of threads of the outer threaded portion of the planetary shaft is indicated as the number of threads of the planetary threaded portion, the number of threads of the outer threaded portion of the annular shaft is indicated as the number of threads of the annular threaded portion, the number of teeth of the planetary gear is indicated as the number of teeth of the planetary gear, and the number of teeth of the ring gear is indicated as the number of teeth of the ring gear, the ratio of the number of threads of the annular threaded part to the number of threads of the planetary threaded part is different from the ratio of the number of teeth of the ring gear to the number of teeth of the planetary gear,

while the sun shaft moves forward due to the planetary movement of the planetary shafts, accompanying the rotational movement of the annular shaft.

14. The conversion mechanism according to any one of claims 1 to 10, wherein the twisting direction of the inner threaded portion of the annular shaft and the twisting direction of the outer threaded portions of the planetary shafts are in the same direction as each other, the twisting direction of the outer threaded portion of the sun shaft and the twisting direction external threaded sections of the planetary shafts are in opposite directions to each other, and the internal threaded section of the annular shaft, the external threaded section of the sun shaft and the external threaded sections of the planetary shafts have the same thread pitches as any other,

in this case, in the case when the ratio of the reference pitch diameter and the number of threads of the threaded sections of the annular shaft, the sun shaft and the planetary shafts, if the relative movement in the axial direction does not occur between the annular shaft, the sun shaft and the planetary shafts, is indicated as a reference ratio, and the number number of threads of the outer threaded section of the sun shaft is different from the number of threads in the reference ratio, and

while the sun shaft moves forward due to the planetary movement of the planetary shafts, accompanied by the rotational movement of the annular shaft.

15. The conversion mechanism according to any one of claims 1 to 10, wherein the twisting direction of the inner threaded portion of the annular shaft and the twisting direction of the outer threaded portions of the planetary shafts are in the same direction as each other, the twisting direction of the outer threaded portion of the sun shaft and the twisting direction external threaded sections of the planetary shafts are in opposite directions to each other, while the internal threaded section of the annular shaft, the external threaded section of the sun shaft and the external threaded sections of the planetary shafts have the same thread pitches as any other,

in this case, in the case when the ratio of the reference pitch diameter and the number of threads of the threaded sections of the annular shaft, the sun shaft and the planetary shafts, if the relative movement in the axial direction does not occur between the annular shaft, the sun shaft and the planetary shaft, is indicated as a reference ratio, and the number number of threads of the inner threaded section of the annular shaft differs from the number of threads in the reference ratio,

while the annular shaft moves forward due to the planetary movement of the planetary shafts, accompanied by the rotational movement of the sun shaft.

Mechanisms for converting rotational motion into rectilinear or reciprocating.

To convert rotational motion into rectilinear or reciprocating motion, crank, rocker, cam, hydraulic and pneumatic mechanisms are used in machine tools.

Crank mechanisms consist of a crank disk with a trunnion and a connecting rod pivotally connected to it. The course of the slider driven by the connecting rod is changed by rearranging the crank pin on the disk in the radial direction.

Rice. 125.

rocker mechanism consists of a crank disk 1, a backstage 2 (Fig. 125), swinging around axis 3. The other end of the backstage is connected to a slider 4. When the crank disk rotates, pin 5, which enters the rocker stone 6, causes the backstage to swing around axis 3.

At the same time, the rocker slides into the slots in the rocker. When changing the radius R of the crank by rearranging its pin in the radial slot of the disk, the stroke of the slider 4 changes.

Cam mechanisms divided into cylindrical and disk. The former consist of a cylinder with a copier groove or protrusion, along which, when the cylinder rotates, a finger with a roller connected to a slider slides. The second ones are profiled cams with fingers with rollers resting against their peripheral surface. These fingers are connected to sliders which are reciprocated as the cams rotate.

AT hydraulic drives the movement of the piston transmitted to the slider is carried out when oil is pumped by a gear or vane pump alternately into the cylinder cavities located on both sides of the piston.

Changing the stroke length of the slider is made by rearranging the stops acting on the lever. The latter changes the position of the spool, which closes and opens in turn the windows of the channels for inlet and outlet of oil from the cylinder.