JP2021092270A - Wave gear device - Google Patents

Abstract

To provide a wave gear device which is hardly broken and capable of suppressing increase in size of the device.SOLUTION: A wave gear device 100 includes: an internal gear portion 30 having an inner gear 31; a wave generation portion 10 having a cam portion 12; a flex gear portion 20 having an outer gear 21; an output shaft portion 40 rotated together with the flex gear portion 20; and a transmission portion T for transmitting power of the flex gear portion 20 to the output shaft portion 40. The flex gear portion 20 has an adjacent portion 22 adjacent to the outer gear 21. The output shaft portion 40 has an opposite portion 41 opposed to the adjacent portion 22. The adjacent portion 22 is provided with an inserted portion H into which the transmission portion T is inserted, and which permits relative displacement of the flex gear portion 20 and the output shaft portion 40 in a circumferential direction about an axis Ax. A plurality of pairs of the transmission portion T and the inserted portion H are arranged in the circumferential direction.SELECTED DRAWING: Figure 2

Description

The present invention relates to a strain wave gearing.

For example, in a robot in which an arm operates via a joint, the rotation of a motor built in an arbitrary arm is decelerated by a speed reducer, and the decelerated output is used to rotationally drive the arm connected to the arm. ing. As a speed reducer of this type, a speed reducer using a wave gearing device is known.

In Patent Document 1, an annular circular spline (rigid internal gear), a thin-walled cup-shaped flexspline (flexible external gear) located on the inner peripheral side thereof, and an annular circular spline (flexible external gear) are fitted on the inner peripheral side. A wave gear device including a wave generator having an elliptical cam is disclosed. The flexspline is flexed into an elliptical shape by the cam of the wave generator and partially meshes with the circular spline. Then, when the cam of the wave generator rotates according to the rotation input of the motor or the like, the meshing position of both gears moves in the circumferential direction, and the relative rotational movement according to the difference in the number of teeth of both gears is between the two gears. appear. The strain wave gearing according to Patent Document 1 has a configuration in which a deceleration rotation output is obtained from a flexspline, and specifically, has a structure in which an output shaft is attached to a diaphragm forming the bottom of the flexspline.

Japanese Unexamined Patent Publication No. 2012-72912

First, the strain wave gearing according to Patent Document 1 has a problem that the flexspline is easily damaged due to its structure. This is due to the following reasons. Here, as a force transmission point from the rotating flexspline to the output shaft, consider a plurality of virtual points arranged in the circumferential direction centered on the rotation axis of the output shaft (hereinafter referred to as an axis). The vector of the force applied to each virtual point from the rotating flexspline is not uniformly oriented in the circumferential direction due to the flexibility of the flexspline and the elliptical shape of the cam, and the phase depends on the point. There is a gap. Since the output shaft is fixed to the diaphragm that closes one end of the cylindrical portion, the flexspline according to Patent Document 1 has a structure that transmits a rotational force to the output shaft all around the cylindrical portion, as described above. In this way, the force vector that caused the phase shift is probably included. Then, an unnecessary stress that does not contribute to the torque for rotating the output shaft around the rotation axis is generated in the cylindrical portion of the flexspline, and an unnecessary twisting force is applied. In addition to the unnecessary twisting force being applied, the flexspline has a problem that it is easily damaged because its cylindrical portion is formed with a very thin wall (for example, a wall thickness of about 0.1 mm). is there.

Further, the flexspline according to Patent Document 1 has a structure in which the output shaft is fixed to a diaphragm that closes one end of the cylindrical portion, so that the position of the output shaft is input by the height of the cylindrical portion (length along the axis). It moves away from the rotating body on the side (for example, the cam of the wave generator). Therefore, there is also a problem that the wave gear device tends to increase in the direction along the axis.

An object of the present invention is to provide a strain wave gearing device that is not easily damaged and can suppress an increase in size of the device.

In order to achieve the above object, the strain wave gearing according to the first aspect of the present invention is
An internal gear portion having an inner gear formed along the inner peripheral surface,
A wave generating part having a cam part that rotates around an axis line in response to a rotation input,
A flex having a ring-shaped outer gear formed along the outer peripheral surface with a smaller number of teeth than the inner gear and having an inner peripheral side fitted into the wave generating portion, and an adjacent portion adjacent to the outer gear in the direction along the axis. Gear part and
An output shaft portion having a facing portion facing the adjacent portion in the radial direction about the axis and rotating with respect to the internal gear portion together with the flex gear portion.
It is provided with a transmission unit that is fixed to the facing portion, extends toward the adjacent portion, and transmits the power of the flex gear portion to the output shaft portion.
The cam portion has N (N is an integer of 2 or more) poles located at equal intervals in the circumferential direction about the axis, and the outer gear is engaged with the inner gear at N points.
In the adjacent portion, the transmission portion is inserted, and an inserted portion that allows a relative displacement between the flex gear portion and the output shaft portion in the circumferential direction is provided.
There are a plurality of pairs of the transmission portion and the insertion portion, and they are arranged in the circumferential direction.

In order to achieve the above object, the strain wave gearing according to the second aspect of the present invention is
An internal gear portion having an inner gear formed along the inner peripheral surface,
A wave generating part having a cam part that rotates around an axis line in response to a rotation input,
A flex having a ring-shaped outer gear formed along the outer peripheral surface with a smaller number of teeth than the inner gear and having an inner peripheral side fitted into the wave generating portion, and an adjacent portion adjacent to the outer gear in the direction along the axis. Gear part and
An output shaft portion having a facing portion facing the adjacent portion in the radial direction about the axis and rotating with respect to the internal gear portion together with the flex gear portion.
A transmission portion fixed to the adjacent portion, extending toward the facing portion, and transmitting the power of the flex gear portion to the output shaft portion is provided.
The cam portion has N (N is an integer of 2 or more) poles located at equal intervals in the circumferential direction about the axis, and the outer gear is engaged with the inner gear at N points.
The transmitting portion is inserted into the facing portion, and an inserted portion that allows a relative displacement between the flex gear portion and the output shaft portion in the circumferential direction is provided.
There are a plurality of pairs of the transmission portion and the insertion portion, and they are arranged in the circumferential direction.

According to the present invention, it is hard to be damaged and the size of the device can be suppressed.

It is external drawing of the robot which incorporates the wave gear device which concerns on one Embodiment of this invention. It is a block diagram which includes the schematic cross section of the main structure of the wave gear device which concerns on the said embodiment. (A) is a view of the main configuration of the wave gear device according to the same embodiment as seen from the axial direction, and is a diagram showing a case where the number of poles of the cam portion is 2, and FIG. 3 (b) is a view showing the case where the number of poles is 2. It is a figure which shows a part of the outer peripheral surface of the flex gear part of (a). It is a figure for demonstrating the arrangement and function of the transmission part provided in the wave gear device which concerns on the said embodiment. (A) to (d) are principle diagrams for explaining the deceleration operation of the strain wave gearing according to the same embodiment. The cam portion and the flex gear portion are viewed from the axial direction, (a) shows the case where the number of poles of the cam portion is 3, and (b) shows the case where the number of poles of the cam portion is 4. It is a figure which shows. The cam portion and the flex gear portion are viewed from the axial direction, (a) shows a case where the number of poles of the cam portion is 5, and (b) shows a case where the number of poles of the cam portion is 6. It is a figure which shows. The cam portion and the flex gear portion are viewed from the axial direction, (a) shows a case where the number of poles of the cam portion is 7, and (b) shows a case where the number of poles of the cam portion is 8. It is a figure which shows. (A) is a schematic cross-sectional view of the main configuration of the wave gear device according to the same embodiment, and (b) is a schematic cross-sectional view of the main configuration of the wave gear device according to the conventional example. It is a figure which shows the modification 1 which modified the partial structure in the wave gear device which concerns on the said embodiment. (A) is a diagram showing a modification 2 in which a partial configuration of the strain wave gearing according to the same embodiment is modified, and (b) is a modification showing a modification of a partial configuration of the strain wave gearing according to the same embodiment. It is a figure which shows Example 3.

An embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the strain wave gearing device 100 according to the present embodiment is incorporated in an industrial robot 200. The robot 200 is composed of, for example, a vertical articulated robot, and includes a robot main body 210 installed on a base 201 and a controller 220 for driving and controlling the robot main body 210. The robot main body 210 includes a first arm 211, a second arm 212 connected to the first arm 211 via a strain wave gearing device 100, and a motor 213 shown in FIG. The motor 213 is composed of a servomotor or the like, and operates under the control of the controller 220. The controller 220 rotationally drives the second arm portion 212 via the motor 213 and the wave gear device 100 built in the first arm 211, thereby performing positioning control, angle control, and angle control of the second arm 212 with respect to the first arm 211. Rotation speed control is performed.

As shown in FIG. 2, the wave gear device 100 includes a wave generation unit 10, a flex gear unit 20, an internal gear unit 30, an output shaft unit 40, a support unit 50, and a transmission unit T.

In FIG. 2, hatching showing a cross section of a partial configuration is omitted in consideration of legibility, and the first arm 211 and the second arm 212 are shown by virtual lines. Further, in the following, when the configuration of the strain wave gearing 100 is described, the right side in FIG. 2 may be referred to as an input side (Fig. Si), and the left side may be referred to as an output side (Fig. So). The same applies to FIG. 9 described later.

The wave generation unit 10 includes a cylindrical shaft portion 11, a cam portion 12 integrally formed with the cylindrical shaft portion 11, and a wave bearing 13.

The end of the cylindrical shaft portion 11 is rotatably supported by the bearing B1 and the end of the output side is rotatably supported by the bearing B2. The bearing B1 is provided on the immovable portion 211a which is immovable with respect to the first arm 211. The bearing B2 is provided on the inner peripheral surface of the output shaft portion 40. The bearings B1 and B2 are composed of, for example, ball bearings. As a result, the cylindrical shaft portion 11 is rotatably supported around the axis AX with respect to the first arm 211. The rotational power of the motor 213 is transmitted to the cylindrical shaft portion 11 via a known transmission mechanism. The transmission mechanism may be a gear mechanism, a belt mechanism using a timing belt and a pulley, or the like.

The cam portion 12 is provided so as to project in the outer diameter direction from the outer peripheral surface of the cylindrical shaft portion 11. The cam portion 12 is provided at a position adjacent to the bearing B1 in a direction along the axis AX (hereinafter, also referred to as “axis direction”). The cam portion 12 has N (N is an integer of 2 or more) poles located at equal intervals in the circumferential direction about the axis AX. Hereinafter, the number of poles included in the cam portion 12 is referred to as the number of poles. For example, when the number of poles is N = 2, the cam portion 12 has an elliptical shape when viewed from the axial direction, as shown in FIG. 3A.

As shown in FIGS. 2 and 3A, the wave bearing 13 can roll between the inner ring 13i fixed to the outer peripheral surface of the cam portion 12, the flexible outer ring 13o, and the inner ring 13i and the outer ring 13o. It has a plurality of balls 13b inserted in a state. The inner ring 13i may be composed of a portion including an outer peripheral surface of the cam portion 12.

The flex gear portion 20 is made of a metal material such as special steel and has flexibility. For example, the flex gear portion 20 is formed in a cylindrical shape along the axial direction. The flex gear portion 20 has an outer gear 21 and an adjacent portion 22 integrally formed with the outer gear 21.

The outer gear 21 has teeth 21a having a predetermined number of teeth t formed along the outer peripheral surface and is formed in a ring shape, and the inner peripheral side is fitted into the outer ring 13o of the wave generating portion 10. The plurality of teeth 21a in the outer gear 21 are arranged along the circumferential direction at a constant pitch. The number of teeth t of the outer gear 21 is set to be smaller than the number of teeth Ti of the inner gear 31, which will be described later. For example, when the number of poles of the cam portion 12 is N, the relationship between the number of teeth t and the number of teeth Ti is set so that "Ti = t + N" holds. For example, in the case of N = 2, the relationship of "Ti = t + 2" is established.

The adjacent portion 22 is a portion that is adjacent to the outer gear 21 in the axial direction and protrudes toward the output side of the outer gear 21. As shown in FIGS. 3A and 3B, the adjacent portion 22 is provided with an inserted portion H into which the transmission portion T is inserted. The power of the flex gear portion 20 is transmitted to the output shaft portion 40 via the transmission portion T inserted into the inserted portion H. The same number of inserted portions H as those of the transmitting portions T are provided, and a plurality of inserted portions H are provided along the circumferential direction centered on the axis AX. The transmission portion T and the inserted portion H will be described in detail later.

In addition, in FIGS. 3A and 3B, the adjacent portion 22 of the flex gear portion 20 is partially shown. Further, FIG. 3B is a view of a part of the outer peripheral surface of the flex gear portion 20 as viewed from the direction of 0 ° shown in FIG. 3A.

Further, the shape of the adjacent portion 22 is arbitrary, and the entire circumference may protrude from the outer gear 21 in a ring shape, or each portion where the inserted portion H is provided protrudes toward the output side from the outer gear 21. You may. Further, although not shown, a portion recessed toward the outer peripheral side is provided at a position corresponding between adjacent teeth 21a formed on the outer gear 21 on the inner peripheral surface of the flex gear portion 20. The flex gear portion 20 may be satisfactorily bent easily.

The internal gear portion 30 is a portion that is formed with rigidity by a metal material and is fixed to the inside of the first arm 211, and is partially connected to the outer gear 21 of the flex gear portion 20 that is bent by the cam portion 12. It has an inner gear 31 that meshes.

The inner gear 31 has teeth 31a having a predetermined number of teeth Ti (Ti> t) formed along the inner peripheral surface and is formed in a ring shape. The plurality of teeth 31a in the inner gear 31 are arranged along the circumferential direction at a constant pitch.

The output shaft portion 40 rotates with respect to the internal gear portion 30 together with the flex gear portion 20. The output shaft portion 40 is rotatably supported by the support portion 50 around the axis AX with respect to the internal gear portion 30. The output shaft portion 40 has rigidity and is formed in a ring shape, for example, by a metal material. The output shaft portion 40 is opposed to the adjacent portion 22 of the flex gear portion 20 in the radial direction (hereinafter, also simply referred to as “diameter direction”) about the axis AX, and the output side of the facing portion 41. It has a supported portion 42, which is a portion supported by the supporting portion 50, and is located at. The facing portion 41 is formed with a fixing hole 41a for fixing the transmission portion T to the output shaft portion 40. As shown in FIG. 2, the facing portion 41 of the output shaft portion 40 is located on the inner peripheral side of the adjacent portion 22 of the flex gear portion 20.

The support portion 50 is made of, for example, a cross roller bearing, the outer ring 51 is fixed to the internal gear portion 30, and the inner ring 52 is fixed to the supported portion 42 of the output shaft portion 40. As a result, the support portion 50 rotatably supports the output shaft portion 40 with respect to the internal gear portion 30 around the axis AX.

In this embodiment, the output shaft portion 40 is connected to the second arm 212, which is the load of the strain wave gearing device 100, via the inner ring 52 of the support portion 50. As a result, the second arm 212 rotates around the axis AX as the output shaft portion 40 rotates. The mode in which the output shaft portion 40 is supported by the support portion 50 is arbitrary, and may be, for example, a mode in which the inner peripheral surface of the inner ring 52 of the support portion 50 is fixed to the output shaft portion 40. Further, the connection method between the output shaft portion 40 and the load (second arm 212 in this example) is also arbitrary, for example, the load is connected to the disk-shaped plate portion fixed to the output shaft portion 40. You may.

As shown in FIG. 2, between the support portion 50 and the cam portion 12 in the axial direction, the adjacent portion 22 of the flex gear portion 20 and the facing portion 41 of the output shaft portion 40 are located. When the transmission unit T fixed to the output shaft unit 40 is pushed by the flex gear unit 20 in the circumferential direction around the axis AX (hereinafter, also simply referred to as “circumferential direction”), the output shaft unit 40 is pressed. , Rotates with the flex gear portion 20.

The transmission unit T transmits the power of the flex gear unit 20 to the output shaft unit 40, and is fixed to the facing portion 41 of the output shaft unit 40. The transmission portion T is composed of, for example, a columnar pin, is inserted into the fixing hole 41a of the facing portion 41, and is fixed by a known fixing method such as screwing, fitting, fixing, and welding. The transmission portion T extends along the radial direction centered on the axis AX and extends toward the adjacent portion 22 of the flex gear portion 20, and is inserted into the inserted portion H provided in the adjacent portion 22.

As shown in FIGS. 3A and 3B, the insertion portion H has the transmission portion T inserted, and the diameter in the circumferential direction (FIG. C) is the outer diameter of the pin constituting the transmission portion T. It consists of elongated holes longer than (diameter). As a result, the inserted portion H is displaced relative to the flex gear portion 20 and the transmission portion T in the circumferential direction (that is, the relative displacement between the flex gear portion 20 and the output shaft portion 40 in the circumferential direction). Tolerate. Further, the elongated hole as the inserted portion H is a through hole that penetrates the adjacent portion 22 in the radial direction about the axis AX. Therefore, the inserted portion H also allows a relative displacement between the flex gear portion 20 and the transmission portion T in the radial direction (that is, a relative displacement between the flex gear portion 20 and the output shaft portion 40 in the radial direction). .. The length of the inserted portion H in the circumferential direction may be set so that the first pair and the second pair, which will be described later, can appear as the pair of the transmitting portion T and the inserted portion H. Further, the width of the inserted portion H in the axial direction is slightly larger than the outer diameter of the pins constituting the transmitting portion T, and does not hinder the movement of the transmitting portion T in the inserted portion H in the circumferential direction and the radial direction. It may be the size. As shown in FIG. 4, a plurality of pairs of the transmitting portion T and the inserted portion H are provided along the circumferential direction and are arranged at equal intervals in the circumferential direction.

(About deceleration operation)
Next, the deceleration operation of the strain wave gearing device 100 having the above configuration will be described mainly with reference to FIGS. 5 (a) to 5 (d) with reference to FIGS. 1 to 3. The number of poles N of the cam portion 12 is arbitrary as long as it is an integer of 2 or more, depending on the purpose. First, a case where the cam portion 12 has an elliptical shape with N = 2 will be described.

When the motor 213 is operated under the control of the controller 220 of the robot 200, the rotational power of the motor 213 is transmitted to the cam portion 12 of the wave generating portion 10 via a transmission mechanism (not shown), and the cam portion 12 is relatively around the axis AX. It rotates at high speed.

Here, in order to facilitate understanding of the explanation, as shown in FIG. 5A, the cam portion 12 before the start of rotation has an initial elliptical long axis that coincides with an axis passing through 0 ° and 180 °. It shall be at position Cs. The angle shown is an angle centered on the axis AX, and it is assumed that the angle increases in the clockwise direction with the 12 o'clock direction as 0 °. Further, the cam portion 12 is assumed to rotate clockwise.

As shown in FIG. 5A, the cam portion 12 at the initial position Cs has the flex gear portion 20 (specifically, the flex gear portion 20 (specifically,) at two meshing positions E of 0 ° and 180 ° corresponding to the two poles. , The outer gear 21) in which the reference numeral is omitted in FIG. 5 is meshed with the internal gear portion 30 (specifically, the inner gear 31 in which the reference numeral is omitted in FIG. 5). In this state, it is assumed that the fixed point Xo of the internal gear portion 30 is set to the position of 0 ° and the reference point Xf of the flex gear portion 20 is also set to the position of 0 °.

FIG. 5B shows a state in which the cam portion 12 is rotated by 90 ° from the initial position Cs and its major axis direction is at the position C1 corresponding to the axes passing through 90 ° and 270 °.
When the cam portion 12 is displaced from the initial position Cs to the position C1, the meshing positions E of the flex gear portion 20 and the internal gear portion 30 move to the positions of 90 ° and 270 °. At this time, the number of teeth of the outer gear 21 is t, the number of teeth of the inner gear 31 is Ti = t + 2, and the difference in the number of teeth is Ti−t = 2. Therefore, the reference point Xf of the flex gear portion 20 is a fixed point. It rotates counterclockwise by 1/2 tooth, which is 1/4 (= 90 ° / 360 °) of the difference in the number of teeth "2" with respect to Xo. Assuming that the rotation angle in the counterclockwise direction is θ1, it is represented by θ1 = {(360 ° / Ti) × 2} / 4.

FIG. 5C shows a state in which the cam portion 12 is rotated by 180 ° from the initial position Cs and its major axis direction is at the position C2 corresponding to the axes passing through 180 ° and 0 °.
When the cam portion 12 is displaced from the initial position Cs to the position C2, the meshing positions E of the flex gear portion 20 and the internal gear portion 30 move to the positions of 180 ° and 0 °. At this time, the reference point Xf of the flex gear portion 20 rotates counterclockwise by one tooth, which is 1/2 (= 180 ° / 360 °) of the difference in the number of teeth "2" with respect to the fixed point Xo. To do. Assuming that the rotation angle in the counterclockwise direction is θ2, it is represented by θ2 = {(360 ° / Ti) × 2} / 2.

FIG. 5D shows a state in which the cam portion 12 is rotated 360 ° from the initial position Cs and its major axis direction is at the position C3 corresponding to the axes passing through 0 ° and 180 °.
When the cam portion 12 is displaced from the initial position Cs to the position C3 (that is, when it is rotated by 360 °), the meshing positions E of the flex gear portion 20 and the internal gear portion 30 return to the positions of 0 ° and 180 °. At this time, the reference point Xf of the flex gear portion 20 rotates counterclockwise by the difference "2" in the number of teeth with respect to the fixed point Xo. Assuming that the rotation angle in the counterclockwise direction is θ3, it is represented by θ3 = (360 ° / Ti) × 2.

As described above, when the cam portion 12 is rotated, the flex gear portion 20 is elastically deformed, and the meshing position E with the internal gear portion 30 is sequentially moved. Then, when the cam portion 12 makes one rotation in the clockwise direction, the flex gear portion 20 moves counterclockwise by the number of teeth 2 (= Tit). As a result, the output shaft unit 40, which rotates and moves together with the flex gear unit 20 via the plurality of transmission units T, is decelerated at a reduction ratio i = (Ti−t) / t with respect to the rotation speed of the cam unit 12. To. That is, according to the strain wave gearing device 100, the load connected to the output shaft portion 40 (in this example, the second arm 212) can be rotationally controlled with high accuracy by the output decelerated by the reduction ratio i described above. it can. The reduction ratio i is arbitrary, but is set to, for example, about 1/30 to 1/320.

In the above, the case where the number of poles N is N = 2 has been described, but since the idea is the same for the case where N ≧ 3, they will be collectively described here. When the number of poles is N ≧ 3, the shape of the cam portion 12 when viewed from the axial direction is a regular N-angle shape, and for example, between each pole portion and the adjacent pole portions gently swells in the outer peripheral direction. It has a curved surface. 6 to 8 show a case where the number of poles N is 3 to 8. Although not shown, the same can be achieved in the case of N ≧ 9.

The outer gear 21 of the flex gear portion 20 is bent by the cam portion 12 having N poles via the wave bearing 13, and meshes with the inner gear 31 of the internal gear portion 30 at N points. When the number of poles of the cam portion 12 is N, the number of teeth t of the outer gear 21 (hereinafter, also referred to as the number of teeth t of the flex gear portion 20) and the number of teeth Ti of the inner gear 31 (hereinafter, the number of teeth Ti of the internal gear portion 30). The relationship of) is set so that "Ti = t + N" holds.
Then, for example, when the cam portion 12 rotates 360 ° clockwise, the flex gear portion 20 moves counterclockwise by N teeth. That is, when the number of poles of the cam portion 12 is N, when the cam portion 12 rotates at an angle of (360 ° / N), the flex gear portion 20 moves with respect to the internal gear portion 30 by one tooth. When the number of poles of the cam portion 12 is N, the output shaft portion 40 fixed to the flex gear portion 20 has a reduction ratio i = (Ti−t) / t = N / t with respect to the rotation speed of the cam portion 12. Is decelerated.

As described above, the wave gear device 100 receives the rotation input from the motor 213 regardless of whether the number of poles N of the cam unit 12 is set to N = 2 or N ≧ 3. When the cam portion 12 of the wave generating portion 10 rotates accordingly, the meshing position E of both gears of the flex gear portion 20 and the internal gear portion 30 moves in the circumferential direction, and according to the difference in the number of teeth of both gears. , The flex gear portion 20 rotates with respect to the internal gear portion 30 in the direction opposite to that of the cam portion 12.

(About the transmission part T and the inserted part H)
From here, the transmission unit T and the insertion unit H will be described. FIG. 4 shows an example of arrangement of the transmission portion T and the inserted portion H, which is suitable when the number of poles N of the cam portion 12 is N = 4 (that is, the shape shown in FIG. 6B).

In FIG. 4, in the figure shown on the outer peripheral side of the figure of the flex gear portion 20 and the output shaft portion 40 viewed from the axial direction, the cam portion 12 having N = 4 poles has an axis line according to the operation of the motor 213. The figure which shows the relative displacement of the transmission part T and the inserted part H when the flex gear part 20 is seen from the outer peripheral side in the range of 0 ° to 90 ° in the figure when rotating around AX (hereinafter, It is called a relative displacement diagram). Looking at the relative displacement diagram of FIG. 4, it can be seen that the position of the transmission portion T with respect to the inserted portion H is not uniform at each position where the transmission portion T is provided. This is due to the phase shift as described in the above-mentioned problem. In the strain wave gearing device 100 according to the present embodiment, the action of the transmission portion T and the inserted portion H described below causes unnecessary stress that does not contribute to the rotation of the output shaft portion 40 due to the above-mentioned phase shift. The output shaft portion 40 is rotated with reduced transmission efficiency and good transmission efficiency.

In the example shown in FIG. 4, 16 transmission portions T arranged at equal intervals in the circumferential direction are fixed to the facing portions 41 of the output shaft portion 40. Further, the adjacent portion 22 of the flex gear portion 20 is provided with 16 inserted portions H into which each of the 16 transmission portions T is inserted. That is, the pair of the transmitting portion T and the inserted portion H are arranged in the circumferential direction at every 360 ° / 16 (= 22.5 °).

As shown in the relative displacement diagram of FIG. 4, when a certain transmission portion T is located in the 0 ° direction and is located in the center of the inserted portion H corresponding to the transmission portion T in the circumferential direction, 45 The transmission unit located in the ° direction and the transmission unit T located in the 90 ° direction are located at the center of the corresponding inserted portion H in the circumferential direction. The transmission portion T located in each of the 0 °, 45 °, and 90 ° directions does not contribute to the rotation of the output shaft portion 40 because it is not in contact with the inserted portion H into which the transmission portion T is inserted in the circumferential direction. ..

On the other hand, when a certain transmission portion T is located in the 0 ° direction and is located in the center of the inserted portion H corresponding to the transmission portion T in the circumferential direction, the transmission is located in the 22.5 ° direction. The portion T is located at one end (clockwise end in the drawing) of the inserted portion H to be inserted. Further, in this state, the transmission portion T located in the 67.5 ° direction is located at the other end (counterclockwise end in the drawing) of the inserted portion H to be inserted in the circumferential direction. The transmission portion T located in the 22.5 ° direction abuts in the circumferential direction with the inserted portion H of the flex gear portion 20 that moves counterclockwise when the cam portion 12 rotates clockwise. , Contributes to the rotation of the output shaft portion 40. The transmission portion T located in the 67.5 ° direction comes into contact with the inserted portion H of the flex gear portion 20 that moves clockwise when the cam portion 12 rotates counterclockwise in the circumferential direction. , Contributes to the rotation of the output shaft portion 40.

The behavior of the transmitting portion T and the inserted portion H in each range of 90 ° to 180 °, 180 ° to 270 °, 270 ° to 360 ° is the same as that of the transmitting portion T and the inserted portion H in the range of 45 ° to 90 °. This is the same as the insertion portion H. That is, at each position where the central angle with respect to the axis AX is 22.5 °, the transmission unit T that contributes to the rotation of the output shaft unit 40 (that is, the transmission unit T that receives the force from the flex gear unit 20 in the circumferential direction). And the transmission unit T that does not contribute to rotation appear alternately. Further, although the relative displacement diagram of FIG. 4 is shown statically, in the process in which the output shaft portion 40 rotates by 22.5 °, the transmission portion T that did not contribute to the rotation of the output shaft portion 40 is flexed. It is displaced with respect to the inserted portion H to the transmission portion T that abuts on the gear portion 20 in the circumferential direction and contributes to the rotation of the output shaft portion 40. On the contrary, the transmission portion T that has come into contact with the flex gear portion 20 in the circumferential direction and contributes to the rotation of the output shaft portion 40 becomes the transmission portion T that does not contribute to the rotation of the output shaft portion 40, and is inserted into the insertion portion H. Displace with respect to.

As described above, the case where the number of poles of the cam portion 12 is N = 4 and the number of pairs of the transmission portion T and the inserted portion H is 16 (4 × N) is summarized.
When the number of poles of the cam portion 12 is N = 4, when the cam portion 12 rotates by an angle of (360 ° / 4), the flex gear portion 20 moves with respect to the internal gear portion 30 by one tooth. In this way, within the range of 90 °, which is the rotation angle of the cam portion 12 for moving the flex gear portion 20 by one tooth with respect to the internal gear portion 30, every 90 ° / 4 = 22.5 °. , The transmission unit T that contributes to the rotation of the output shaft unit 40 and the transmission unit T that does not contribute to the rotation appear alternately. The pair of the transmitting portion T and the inserted portion H within the range of 90 ° is a pair in which the transmitting portion T is located at one end of the inserted portion H in the circumferential direction (hereinafter, referred to as “first pair”). And a pair in which the transmission portion T is located at the other end of the insertion portion H in the circumferential direction (hereinafter, referred to as a “second pair”). The first pair corresponds to the pair of the transmitting portion T and the inserted portion H located in the 22.5 ° direction in the relative displacement diagram of FIG. The second pair corresponds to the pair of the transmitting portion T and the inserted portion H located in the 67.5 ° direction in the relative displacement diagram of FIG. Considering this within the range of 360 °, the 16 pairs of the transmitting portion T and the inserted portion H are the four first pairs arranged at equal intervals in the circumferential direction and the pair in the circumferential direction. Includes four second pairs arranged at equal intervals.

The above idea is not limited to the case of N = 4, and can be generalized. Therefore, a case where the number of poles of the cam portion 12 is N (an integer of 2 or more) and there are (4 × N) pairs of the transmission portion T and the inserted portion H will be described. The pairs of the transmitting portion T and the inserted portion H are arranged at equal intervals in the circumferential direction.
When the cam portion 12 having N poles rotates by an angle of (360 ° / N), the flex gear portion 20 moves with respect to the internal gear portion 30 by one tooth. As described above, within the range of the rotation angle (360 ° / N) of the cam portion 12 for moving the flex gear portion 20 by one tooth with respect to the internal gear portion 30, {360 ° / (4 ×). For each N)}, the transmission unit T that contributes to the rotation of the output shaft unit 40 and the transmission unit T that does not contribute to the rotation appear alternately. The pair of the transmitting portion T and the inserted portion H within the range of (360 ° / N) includes the first pair in which the transmitting portion T is located at one end of the inserted portion H in the circumferential direction and the transmitting portion T. Includes a second pair located at the other end of the inserted portion H in the circumferential direction. Considering this within the range of 360 °, the (4 × N) pairs of the transmitting portion T and the inserted portion H are the N first pairs arranged at equal intervals in the circumferential direction. Includes N second pairs evenly spaced in the circumferential direction.

As described above, if the wave gearing device 100 is provided with (4 × N) pairs of the transmitting portion T and the inserted portion H, the output shaft portion 40 rotates every {360 ° / (4 × N)}. The transmission unit T that contributes to the rotation and the transmission unit T that does not contribute to the rotation appear alternately. As a result, the relative displacement of the transmission portion T and the inserted portion H in the circumferential direction can be absorbed by the cam method. Therefore, according to the strain wave gearing device 100, unnecessary stress that does not contribute to the torque for rotating the output shaft portion 40 around the axis AX is reduced from being generated in each of the flex gear portion 20 and the output shaft portion 40, and is unnecessary. It is possible to reduce the application of a twisting force to the flex gear portion 20.

Further, when the flex gear portion 20 flexed by the cam portion 12 rotationally moves with respect to the internal gear portion 30, both gears of the flex gear portion 20 and the internal gear portion 30 move while meshing with each other. With pulsation in the direction. However, since the inserted portion H according to the present embodiment allows the relative displacement between the flex gear portion 20 and the transmitting portion T in the radial direction, the relative displacement of the transmitting portion T and the inserted portion H in the radial direction is also allowed. Can be absorbed. This also makes it possible to reduce the above-mentioned unnecessary stress.

In addition to reducing unnecessary stress, the pair of the transmitting portion T and the inserted portion H is the first pair in which the transmitting portion T is located at one end of the inserted portion H in the circumferential direction and the transmitting portion T. Includes a second pair located at the other end of the inserted portion H in the circumferential direction. As a result, the force in the circumferential direction can be efficiently transmitted from the flex gear portion 20 to the output shaft portion 40.

As a result, according to the strain wave gearing device 100 of the present embodiment, the mechanical loss due to the connection between the flex gear portion 20 and the output shaft portion 40 can be significantly reduced, and good transmission efficiency can be realized. Further, it is possible to prevent the flex gear portion 20 from being damaged.

Further, since the output points for transmitting the force from the flex gear portion 20 to the output shaft portion 40 (that is, the position where the transmission portion T is provided) can be evenly distributed in the circumferential direction, the flex gear portion 20 and the internal gear portion 30 can be uniformly dispersed. The load per meshing portion E is reduced, and as a result, the output shaft portion 40 can be rotated with high torque.

The number of pairs of the transmitting portion T and the inserted portion H is not limited to (4 × N). Depending on the number of N, the number of pairs of the transmitting portion T and the inserted portion H can be arbitrarily changed.
For example, when the number of poles N of the cam portion 12 is N = 8 (that is, the shape shown in FIG. 8B), assuming that the pair of the transmission portion T and the inserted portion H is (4 × N) = 32. Within the range of (360 ° / N) = 45 °, which is the rotation angle of the cam portion 12 for moving the flex gear portion 20 by one tooth with respect to the internal gear portion 30, {360 ° / (4 × N). )} = Every 11.25 °, the transmission unit T that contributes to the rotation of the output shaft unit 40 and the transmission unit T that does not contribute to the rotation appear alternately. Considering this within the range of 360 °, the 32 pairs of the transmitting portion T and the inserted portion H are the eight first pairs arranged at equal intervals in the circumferential direction and the pair in the circumferential direction. Includes eight second pairs arranged at equal intervals.
However, since it is considered that four pairs of the first pair and four pairs of the second pair are sufficient to stably rotate the output shaft portion 40, the pair of the transmission portion T and the insertion portion H is considered to be sufficient. May be (2 × N) = 16. Further, not only in the case of N = 8, the pair of the transmitting portion T and the inserted portion H is set to (2 × N), and N pairs of the first pair and N pairs are provided respectively. It is considered that a configuration in which all the transmission units T contribute to the rotation of the output shaft unit 40 is also possible. Further, the number of pairs of the transmitting portion T and the inserted portion H may be set regardless of the number of N. For example, if 16 pairs of the transmission portion T and the insertion portion H are arranged at equal intervals in the circumferential direction and at least 4 or more pairs of the second pair of the first pair are provided, the number of N can be increased. Therefore, the output shaft portion 40 can be rotated stably. In this way, the output shaft portion 40 to which the transmission portion T is fixed can be shared regardless of the number of poles N of the cam portion 12, so that manufacturing efficiency can be improved.

As described above, the strain wave gearing device in which the number of pairs of the transmitting portion T and the inserted portion H is set to (2 × N) or a fixed value (for example, 16) regardless of the number of N. Even with 100, unnecessary stress can be reduced and good transmission efficiency can be realized by the same action as described above.

In the "first pair", "the transmission portion T is located at one end of the inserted portion H in the circumferential direction" means that the transmission portion T is in contact with one end of the inserted portion H in the circumferential direction. The mode may be close to each other, and when the flex gear portion 20 moves toward the transmission portion T, the transmission portion T can be immediately pushed in the circumferential direction by one end of the inserted portion H. Just do it. Similarly, in the "second pair", "the transmission portion T is located at the other end of the inserted portion H in the circumferential direction" means that the transmission portion T is the other end of the inserted portion H in the circumferential direction. The mode may be in contact with or close to each other, and when the flex gear portion 20 moves toward the transmission portion T, the transmission portion T can be immediately pushed in the circumferential direction by the other end of the inserted portion H. Any aspect can be used.

Further, "a pair of a plurality of transmission units T and an inserted portion H are arranged at equal intervals in the circumferential direction" means that a plurality of transmission units T arranged at equal intervals in the circumferential direction correspond to each of them. It suffices as long as it is inserted into a plurality of inserted portions H.

Further, as long as the first pair and the second pair can be created, the pair of the transmission portion T and the insertion portion H may not be arranged at equal intervals in the circumferential direction. In this case, from the viewpoint of stably rotating the output shaft portion 40, the center of gravity of the entire output shaft portion 40 and the plurality of transmission portions T fixed to the output shaft portion 40 is aligned with the axis AX, and the minimum moment of inertia around the axis AX is minimized. It is preferable to try to make it.

From here on, further advantages of the strain wave gearing device 100 according to the present embodiment will be described by comparing FIGS. 9 (a) and 9 (b). FIG. 9A is a diagram obtained by extracting the strain wave gearing device 100 according to the present embodiment from FIG. 2, and FIG. 9B is a strain wave gearing apparatus according to a conventional example as disclosed in the above-mentioned patent document. It is a figure which shows 100p.

In the strain wave gearing device 100p according to the conventional example, the configuration corresponding to each configuration of the strain wave gearing device 100 according to the present embodiment is shown by adding "p" to the end of the reference numeral. Explaining the main correspondence between the conventional example and the present embodiment, the wave generator 10p corresponds to the wave generating section 10, the flexspline 20p corresponds to the flex gear section 20, and the circular spline 30p corresponds to the internal gear section 30. ..

As shown in FIG. 9B, the flexspline 20p according to the conventional example has a cylindrical portion because the output shaft 40p is fixed by a fixing member Tp to a diaphragm that closes the output side end of the cylindrical portion. The position of the output shaft 40p moves away from the rotating body on the input side (for example, the cam of the wave generator 10p) by the length Lp corresponding to the height.

On the other hand, as shown in FIG. 9A, the strain wave gearing device 100 according to the present embodiment has a structure in which a force is transmitted from the adjacent portion 22 of the flex gear portion 20 to the output shaft portion 40 via the transmission portion T. At the same time, the adjacent portion 22 of the flex gear portion 20 and the opposing portion 41 of the output shaft portion 40 are located between the support portion 50 and the cam portion 12. As a result, the length L can be set from the cam portion 12 to the output point of the flex gear portion 20 (that is, the position of the transmission portion T that transmits the force from the flex gear portion 20 to the output shaft portion 40). In addition, each configuration can be made compact in the axial direction, and the wave gear device 100 can be made compact.

Further, in the wave gear device 100 according to the present embodiment, the flex gear portion 20 has a bottomless tubular shape (ring shape when viewed from the axial direction), and the end portion on the output side is formed like the flexspline 20p according to the conventional example. Since the flex gear portion 20 is not blocked by the diaphragm, the flexibility of the flex gear portion 20 can be maintained while ensuring a certain thickness of the flex gear portion 20. Therefore, the resistance of the flex gear portion 20 to buckling can be improved, and the flex gear portion 20 is not easily damaged. The wall thickness of the flex gear portion 20 is not limited, but can be set to, for example, about 0.5 mm to 1 mm. Further, the flex gear portion 20 has a bottomless tubular shape, and is easier to process than a bottomed tubular one such as the flexspline 20p according to the conventional example.

Further, in the conventional example, the cylindrical portion of the flexspline 20p needs to have a certain length in the axial direction due to the structure, and the support portion 50p supporting the output shaft 40p is from the meshing position of the flexspline 20p and the circular spline 30p. Go away. In such a conventional structure, stress in an oblique direction with respect to the axis AX is likely to be applied to both the flexspline 20p and the circular spline 30p, and the gears of each other are likely to be worn.
On the other hand, in the strain wave gearing device 100 according to the present embodiment, since the adjacent portion 22 of the flex gear portion 20 and the opposing portion 41 of the output shaft portion 40 are located between the support portion 50 and the cam portion 12, they are located on each other. It is difficult for stress in the diagonal direction with respect to the axis AX to be applied to the meshing flex gear portion 20 and the internal gear portion 30. As a result, one tooth ridge and the other tooth bottom in the flex gear portion 20 and the internal gear portion 30 can be brought into contact with each other along the axial direction, and wear of the gears of each other can be suppressed.

Further, in the strain wave gearing device 100 according to the present embodiment, not only the cam portion 12, but also the flex gear portion 20 and the output shaft portion 40 are hollow in a ring shape when viewed from the axial direction, so that wiring or the like is passed therethrough. Space can be secured inside. According to the strain wave gearing device 100 according to the present embodiment, it goes without saying that the backlash can be eliminated in principle and the lost motion can be minimized.

Further, according to the strain wave gearing device 100 according to the present embodiment, not only the number of poles of the cam portion 12 is N = 2 but also a variation of N ≧ 3 can be provided, which has the following advantages. First, consider a case where the cam of the wave generator 10p is set in an elliptical shape as in the wave gear device 100p according to the conventional example (the reference numerals of the conventional example conform to FIG. 9B). If the number of teeth of the circular spline 30p is Ti, the pitch circle diameter is D, the number of teeth of the flexspline 20p is t, and the pitch circle diameter is d, the reduction ratio i is "i = (Ti-t) / t =". It can be considered as "2 / t" or "i = (D-d) / d". Then, in order to reduce the value of the reduction ratio i (to obtain a more decelerated rotational output), it is necessary to increase the number of teeth t or increase the ratio of the diameter d of the flexspline 20p to the diameter D of the circular spline 30p. .. On the other hand, in order to increase the value of the reduction ratio i (suppress the degree of deceleration of the rotational output), it is necessary to reduce the number of teeth t or reduce the ratio of the diameter d of the flexspline 20p to the diameter D of the circular spline 30p. .. As described above, relying only on the elliptical cam as in the conventional example causes various restrictions on the size and conditions of the device, and it is difficult to realize all reduction ratios.

On the other hand, according to the variation in which the number of poles of the cam portion 12 is N ≧ 3, even if at least one of the number of teeth Ti of the internal gear portion 30 and the number of teeth t of the flex gear portion 20 is kept constant. As can be seen from the reduction ratio i = N / t, the reduction ratio value can be increased (suppressing the deceleration degree of the rotational output) simply by increasing the number of poles, and the reduction ratio value can be increased simply by reducing the number of poles. It can be made smaller (more decelerated rotational output can be obtained). In addition to the variation of the number of poles, by setting the number of teeth Ti and the number of teeth t and changing the diameter of the flex gear part 20 and the internal gear part 30, it is possible to realize a reduction ratio of almost innumerable variations. it can.

The present invention is not limited to the above embodiments and drawings. Changes (including deletion of components) can be made as appropriate without changing the gist of the present invention. A modified example in which a partial configuration of the strain wave gearing 100 is modified will be described below.

(Modification example 1)
As in the modified example 1 shown in FIG. 10, the output shaft portion 40 may be positioned on the outer peripheral side of the flex gear portion 20. In this case, the facing portion 41 of the output shaft portion 40 is located on the outer peripheral side of the adjacent portion 22 of the flex gear portion 20. Then, the transmission portion T fixed to the facing portion 41 extends toward the axis AX and is inserted into the inserted portion H provided in the adjacent portion 22. In FIG. 10, in the figure shown on the outer peripheral side of the figure of the flex gear portion 20 and the output shaft portion 40 viewed from the axial direction, the cam portion 12 having N = 4 poles has an axis line according to the operation of the motor 213. It is a figure which shows the relative displacement of the transmission part T and the inserted part H when the flex gear part 20 is seen from the inner circumference side in the range of 0 ° to 90 ° in the figure when rotating about AX. .. Also in the first modification, the number and functions of the pair of the transmitting portion T and the inserted portion H can be set in the same manner as in the above-described embodiment.

(Modifications 2 and 3)
As shown in FIGS. 11A and 11B, the transmission portion T may be fixed to the flex gear portion 20 and the insertion portion H may be provided on the output shaft portion 40. In such a case, the output shaft portion 40 may be positioned on the inner peripheral side of the flex gear portion 20 as in the modified example 2 shown in FIG. 11 (a), or as in the modified example 3 shown in FIG. 11 (b). In addition, the output shaft portion 40 may be located on the outer peripheral side of the flex gear portion 20.
The transmission portion T according to the modified examples 2 and 3 is fixed to the adjacent portion 22 of the flex gear portion 20. The transmission portion T extends along the radial direction centered on the axis AX and extends toward the facing portion 41 of the output shaft portion 40, and is inserted into the inserted portion H provided in the facing portion 41.
The inserted portion H according to the modified examples 2 and 3 is formed of an elongated hole in which the transmission portion T is inserted and the diameter in the circumferential direction is longer than the outer diameter (diameter) of the pin constituting the transmission portion T. As a result, the inserted portion H is displaced relative to the output shaft portion 40 and the transmission portion T in the circumferential direction (that is, the relative displacement between the output shaft portion 40 and the flex gear portion 20 in the circumferential direction). Tolerate. Further, the inserted portion H allows a relative displacement between the output shaft portion 40 and the transmission portion T in the radial direction (that is, a relative displacement between the output shaft portion 40 and the flex gear portion 20 in the radial direction). If possible, it may be a bottomed hole shown in FIGS. 11A and 11B, or a through hole (not shown). Also in the modifications 2 and 3, the number and functions of the pair of the transmission portion T and the insertion portion H can be set in the same manner as in the above-described embodiment.

(Other variants)
In the above, the example in which the strain wave gearing 100 is incorporated in the robot 200 made of a vertical articulated robot has been shown, but the present invention is not limited to this. The wave gear device 100 can be incorporated into various robots such as a horizontal articulated robot and a delta type robot. Further, the device in which the strain wave gearing device 100 is incorporated is not limited to the robot, and may be arbitrary as long as it is used for the purpose of obtaining a rotation output decelerated at a desired reduction ratio with respect to the rotation input. The strain wave gearing device 100 may be incorporated in, for example, precision machines other than robots, hobby supplies, home appliances, in-vehicle parts, and the like.

Further, the number of teeth t of the flex gear portion 20 and the number of teeth Ti of the internal gear portion 30 are arbitrary as long as Ti> t. However, when the number of poles of the cam portion 12 is N, it is preferable to set the relationship between the number of teeth t and the number of teeth Ti as "Ti = t + N".

In the above, an example in which one transmission unit T is composed of one pin has been shown, but one transmission unit T may be composed of a plurality of pins arranged in the axial direction. In such a case, the inserted portion H corresponding to the transmitting portion T may be provided in a size such that a plurality of pins constituting the transmitting portion T can be inserted. The inserted portion H may allow relative displacement between the flex gear portion 20 and the output shaft portion 40 in the circumferential direction and the radial direction.

Further, the material of the member constituting the wave gear device 100 is arbitrary and is not limited to metal, and can be appropriately selected depending on the purpose such as engineering plastic, resin, ceramic and the like.

(1) The strain wave gearing device 100 described above includes a transmission unit T that transmits the power of the flex gear unit 22 to the output shaft unit 40. In the above embodiment and the first modification, the transmission portion T is fixed to the facing portion 41 of the output shaft portion 40 and extends toward the adjacent portion 22 of the flex gear portion 20. A transmission portion T is inserted into the adjacent portion 22, and an inserted portion H that allows a relative displacement between the flex gear portion 20 and the output shaft portion 40 in the circumferential direction is provided.
(2) Further, in the strain wave gearing device 100 according to the modified examples 2 and 3 shown in FIGS. 11A and 11B, the transmission portion T is fixed to the adjacent portion 22 of the flex gear portion 20 and is fixed to the output shaft portion. It extends toward the facing portion 41 of the 40. A transmission portion T is inserted into the facing portion 41, and an inserted portion H that allows a relative displacement between the flex gear portion 20 and the output shaft portion 40 in the circumferential direction is provided.
In any of the configurations described in (1) and (2) above, there are a plurality of pairs of the transmitting portion T and the inserted portion H, which are arranged in the circumferential direction. Further, the cam portion 12 has N (N is an integer of 2 or more) poles located at equal intervals in the circumferential direction, and the outer gear 21 meshes with the inner gear 31 at N points. The number of teeth t of the outer gear 21 is preferably N less than the number of teeth Ti of the inner gear 31 (t = Ti−N).

According to the configurations (1) and (2) above, as described above, unnecessary stress applied mainly to the flex gear portion 20 can be suppressed, so that the strain wave gearing device 100 is less likely to be damaged. Further, since the portion for transmitting the force from the flex gear portion 20 to the output shaft portion 40 is an adjacent portion 22 adjacent to the outer gear 21, it is possible to suppress the increase in size of the wave gear device 100 mainly in the axial direction. .. Further, if the number of poles N is arbitrarily set, various reduction ratios can be realized with a simple configuration.

(3) Further, the pair of the plurality of transmission portions T and the insertion portion H may be arranged at equal intervals in the circumferential direction. According to this configuration, the output points for transmitting the force from the flex gear portion 20 to the output shaft portion 40 can be evenly distributed in the circumferential direction, so that the output shaft portion 40 can be rotated with high torque.

(4) Further, in the pair of the plurality of transmission portions T and the inserted portion H, when the cam portion 12 is rotating about the axis AX, the transmission portion T is placed at one end of the insertion portion H in the circumferential direction. It may include a first pair located and a second pair in which the transmitting portion T is located at the other end of the inserted portion H in the circumferential direction. According to this configuration, as described above, the force in the circumferential direction can be efficiently transmitted from the flex gear portion 20 to the output shaft portion 40.

(5) Preferably, the number of pairs of the transmitting portion T and the inserted portion H may be 2 × N or more. The pair of the transmitting portion T and the inserted portion H may be 4 × N or more, or may be a fixed number (for example, 16) regardless of the number of poles N.

(6) Further, the inserted portion H also allows a relative displacement between the flex gear portion 20 and the output shaft portion 40 in the radial direction. According to this configuration, the relative displacement between the flex gear portion 20 and the output shaft portion 40 in the radial direction can also be absorbed, so that the above-mentioned unnecessary stress can be reduced more satisfactorily.

(7) The strain wave gearing device 100 further includes a support portion 50 that rotatably supports the output shaft portion 40 with respect to the internal gear portion 30, and the adjacent portion 22 and the opposing portion 41 include the support portion 50 and the cam portion 12. Located between. According to this configuration, as described above, the length in the axial direction from the cam portion 12 to the output point of the flex gear portion 20 (that is, the position of the transmission portion T that transmits the force from the flex gear portion 20 to the output shaft portion 40). It is possible to make the wave gear device 100 compact by making each configuration compact in the axial direction. If the length to the output point can be suppressed in this way, one tooth ridge and the other tooth bottom in the flex gear portion 20 and the internal gear portion 30 can be brought into contact with each other along the axial direction, and the gears of each other can be brought into contact with each other. Wear can also be suppressed. The support portion 50 is not limited to the cross roller bearing, and may be a ball bearing or a bearing that rotatably supports the output shaft portion 40 by sliding it.

(8) Preferably, the transmission portion T is composed of a columnar pin, and the inserted portion H is composed of an elongated hole whose diameter in the circumferential direction is longer than the outer diameter of the pin.

(9) As shown in FIGS. 4 and 11A, if the facing portion 41 of the output shaft portion 40 is located on the inner peripheral side of the adjacent portion 22 of the flex gear portion 20, the strain wave gearing device 100 It is possible to suppress the increase in size in the radial direction.

(10) As shown in FIGS. 10 and 11B, if the facing portion 41 of the output shaft portion 40 is located on the outer peripheral side of the adjacent portion 22 of the flex gear portion 20, the axis of the wave gear device 100 A space for wiring and the like can be secured inside around the AX.

In the above description, in order to facilitate the understanding of the present invention, the description of known technical matters has been omitted as appropriate.

100 ... Wave gear device 10 ... Wave generating part 11 ... Cylindrical shaft part, 12 ... Cam part, 13 ... Wave bearing 20 ... Flex gear part 21 ... Outer gear, 22 ... Adjacent part, H ... Inserted part 30 ... Internal gear part 31 ... Inner gear 40 ... Output shaft part 41 ... Opposing part, 42 ... Supported part 50 ... Supporting part T ... Transmission part 200 ... Robot, 201 ... Base 210 ... Robot body part 211 ... First arm, 212 ... Second arm, 213 ... Motor 220 ... Controller

Claims (10)

An internal gear portion having an inner gear formed along the inner peripheral surface,
A wave generating part having a cam part that rotates around an axis line in response to a rotation input,
A flex having a ring-shaped outer gear formed along the outer peripheral surface with a smaller number of teeth than the inner gear and having an inner peripheral side fitted into the wave generating portion, and an adjacent portion adjacent to the outer gear in the direction along the axis. Gear part and
An output shaft portion having a facing portion facing the adjacent portion in the radial direction about the axis and rotating with respect to the internal gear portion together with the flex gear portion.
It is provided with a transmission unit that is fixed to the facing portion, extends toward the adjacent portion, and transmits the power of the flex gear portion to the output shaft portion.
The cam portion has N (N is an integer of 2 or more) poles located at equal intervals in the circumferential direction about the axis, and the outer gear is engaged with the inner gear at N points.
In the adjacent portion, the transmission portion is inserted, and an inserted portion that allows a relative displacement between the flex gear portion and the output shaft portion in the circumferential direction is provided.
There are a plurality of pairs of the transmission portion and the insertion portion, which are arranged in the circumferential direction.
Strain wave gearing. An internal gear portion having an inner gear formed along the inner peripheral surface,
A wave generating part having a cam part that rotates around an axis line in response to a rotation input,
A flex having a ring-shaped outer gear formed along the outer peripheral surface with a smaller number of teeth than the inner gear and having an inner peripheral side fitted into the wave generating portion, and an adjacent portion adjacent to the outer gear in the direction along the axis. Gear part and
An output shaft portion having a facing portion facing the adjacent portion in the radial direction about the axis and rotating with respect to the internal gear portion together with the flex gear portion.
A transmission portion fixed to the adjacent portion, extending toward the facing portion, and transmitting the power of the flex gear portion to the output shaft portion is provided.
The cam portion has N (N is an integer of 2 or more) poles located at equal intervals in the circumferential direction about the axis, and the outer gear is engaged with the inner gear at N points.
The transmitting portion is inserted into the facing portion, and an inserted portion that allows a relative displacement between the flex gear portion and the output shaft portion in the circumferential direction is provided.
There are a plurality of pairs of the transmission portion and the insertion portion, which are arranged in the circumferential direction.
Strain wave gearing. A plurality of pairs of the transmission portion and the insertion portion are arranged at equal intervals in the circumferential direction.
The strain wave gearing according to claim 1 or 2. A plurality of pairs of the transmitting portion and the inserted portion are
When the cam portion is rotating about the axis, the transmission portion is located at one end of the insertion portion in the circumferential direction, and the transmission portion is the insertion portion of the first pair. Includes a second pair located at the other end in the circumferential direction.
The strain wave gearing according to any one of claims 1 to 3. There are 2 × N or more pairs of the transmission part and the insertion part.
The strain wave gearing according to any one of claims 1 to 4. The inserted portion also allows a relative displacement of the flex gear portion and the output shaft portion in the radial direction.
The strain wave gearing according to any one of claims 1 to 5. A support portion that rotatably supports the output shaft portion with respect to the internal gear portion is further provided.
The adjacent portion and the opposing portion are located between the support portion and the cam portion.
The strain wave gearing according to any one of claims 1 to 6. The transmission part is composed of columnar pins.
The inserted portion is composed of an elongated hole whose diameter in the circumferential direction is longer than the outer diameter of the pin.
The strain wave gearing according to any one of claims 1 to 7. The facing portion is located on the inner peripheral side of the adjacent portion.
The strain wave gearing according to any one of claims 1 to 8. The facing portion is located on the outer peripheral side of the adjacent portion.
The strain wave gearing according to any one of claims 1 to 8.

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