阅读说明：本技术 波动齿轮装置 (Wave gear device ) 是由 高木大辅 坪根太平 于 2020-09-10 设计创作，主要内容包括：本发明提供波动齿轮装置。波动发生器以中心轴线为中心,以与输入部件相同的转速进行旋转。挠性外齿齿轮具有体部、外齿、隔膜部以及固定部。体部配置在波动发生器的半径方向外方,通过波动发生器而呈非正圆状挠曲。外齿设置于体部的轴向一侧的外周面。隔膜部从体部的轴向另一侧的端部向半径方向外方扩展。固定部从隔膜部的半径方向外方侧的端部向半径方向外方扩展。内齿齿轮配置于体部的半径方向外方,在内周面具有与外齿部分啮合的内齿。壳体从轴向另一侧固定于固定部。内齿齿轮和挠性外齿齿轮中的一方被固定,另一方以中心轴线为中心进行旋转。密封部件配置于隔膜部与壳体之间,或者配置于体部的轴向另一侧的端部与壳体之间。(The invention provides a wave gear device. The wave generator rotates around the central axis at the same rotational speed as the input member. The flexible externally toothed gear includes a body portion, external teeth, a diaphragm portion, and a fixing portion. The body portion is disposed radially outward of the wave generator, and is deflected in a non-perfect circle by the wave generator. The external teeth are provided on the outer peripheral surface of the body portion on one axial side. The diaphragm portion is radially outwardly expanded from the other axial end of the body portion. The fixed portion extends radially outward from the radially outward end of the diaphragm portion. The internal gear is disposed radially outward of the body and has internal teeth on an inner peripheral surface thereof that mesh with the external teeth. The housing is fixed to the fixing portion from the other axial side. One of the internal gear and the flexible external gear is fixed, and the other rotates about the central axis. The seal member is disposed between the diaphragm portion and the case, or between the other axial end of the body portion and the case.)

1. A wave gear device having:

an input member that rotates about a central axis;

a wave generator that rotates at the same rotational speed as the input member around the central axis;

a flexible externally toothed gear having a body portion disposed radially outward of the wave generator and deflected in a non-perfect circle by the wave generator, external teeth provided on an outer peripheral surface of one axial side of the body portion, a diaphragm portion extending radially outward from an end of the other axial side of the body portion, and a fixing portion extending radially outward from an end of the diaphragm portion on the radially outward side;

an internal gear disposed radially outward of the body and having internal teeth on an inner peripheral surface thereof, the internal teeth meshing with the external teeth; and

a housing fixed to the fixing portion from the other axial side,

one of the internal gear and the flexible external gear is fixed, and the other rotates about the central axis,

the length of the body in the radial direction is displaced by the rotation of the wave generator, and the meshing position of the flexible externally toothed gear and the internally toothed gear changes in the circumferential direction around the central axis,

the flexible externally toothed gear and the internally toothed gear relatively rotate in accordance with the difference in the number of teeth of the external teeth and the internal teeth,

the wave gear device further includes a seal member disposed between the diaphragm portion and the housing or disposed between an end portion of the body portion on the other axial side and the housing.

2. The wave gear device according to claim 1,

a substrate having a conductor layer is mounted on the other surface of the diaphragm portion in the axial direction.

3. The wave gear device according to claim 1 or 2,

the seal member is located between a surface on the other axial side of the diaphragm portion and a surface on one axial side of the housing.

4. The wave gear device according to claim 1 or 2,

the housing has a cylindrical portion extending from an end portion on an inner side in a radial direction toward one side in an axial direction,

the sealing member is located between an inner peripheral surface of the body portion and an outer peripheral surface of the cylindrical portion.

5. The wave gear device according to claim 2,

the seal member is located between a surface on the other axial side of the base plate and a surface on one axial side of the housing.

6. The wave gear device according to claim 3,

the seal member has:

an annular main body portion; and

an annular lip portion extending from the main body portion toward the other axial side and toward the radially inner side or the radially outer side,

the front end of the lip is in contact with an axial surface of the housing.

7. The wave gear device according to claim 5,

the seal member has:

an annular main body portion; and

an annular lip portion extending from the main body portion toward one axial side and toward a radially inner side or a radially outer side,

the tip of the lip portion is in contact with the other surface of the substrate in the axial direction or the other surface of the diaphragm portion in the axial direction.

8. The wave gear device according to any one of claims 1, 2, 5 to 7,

the housing has a stepped portion that holds the seal member.

9. The wave gear device according to claim 2,

the base plate extends to a position radially inward of the body portion when viewed in the axial direction.

10. The wave gear device according to claim 9,

the housing has a cylindrical portion extending from an end portion on an inner side in a radial direction toward one side in an axial direction,

an end portion of the substrate on an inner side in a radial direction is in contact with an outer peripheral surface of the cylindrical portion,

the substrate functions as the sealing member.

11. The wave gear device according to any one of claims 2, 5, 7, 9 to 10,

the conductor layer has a first resistive line pattern and a second resistive line pattern,

the first resistance line pattern is an arc-shaped or annular pattern in which a plurality of resistance lines inclined to one side in the circumferential direction with respect to the radial direction of the diaphragm are arranged in the circumferential direction,

the second resistance line pattern is an arc-shaped or annular pattern in which a plurality of resistance lines inclined to the other side in the circumferential direction with respect to the radial direction of the diaphragm are arranged in the circumferential direction.

Technical Field

The present invention relates to a wave gear device.

Background

Conventionally, a wave gear device mainly used for a speed reducer is known. For example, japanese patent application laid-open No. 2005-69402 discloses a conventional wave gear device.

Patent document 1: japanese patent laid-open No. 2005-69402

A wave gear device (1) disclosed in Japanese patent application laid-open No. 2005-69402 includes a rigid internally toothed gear (10) and a flexible externally toothed gear (20) in a silk hat shape. The end face of the hub (23) of the flexible externally toothed gear (20) and the end face of the diaphragm (22) are continuous flat faces that are located on the same plane, and a strain gauge (41) is attached to the boundary portion of these end faces. It is considered that according to such a wave gear device (1), the torque applied to the flexible externally toothed gear (20) can be detected.

However, in the wave gear device (1) disclosed in japanese patent application laid-open No. 2005-69402, grease filled in the meshing portion between the flexible externally toothed gear (20) and the rigid internally toothed gear (10) or the like may reach a space formed in the axial direction between the large-diameter end plate (4) fixed to the hub (23) and the hub (23). In this case, grease adheres to the strain gauge (41), and the strain gauge (41) may be adversely affected chemically or electrically.

Disclosure of Invention

The purpose of the present invention is to reduce the possibility of grease adhering to an electric wire or a conductor layer when an electric component having the electric wire or the conductor layer is disposed in a space formed between a housing and a diaphragm portion in an axial direction.

In an aspect of the present application, there is provided a wave gear device having an input member, a wave generator, a flexible externally toothed gear, an internally toothed gear, and a housing, and further having a seal member. The input member rotates about a central axis. The wave generator rotates at the same rotational speed as the input member, centering on the central axis. The flexible externally toothed gear includes a body portion, external teeth, a diaphragm portion, and a fixing portion. The body portion is disposed radially outward of the wave generator, and is deflected in a non-perfect circle by the wave generator. The external teeth are provided on an outer peripheral surface of one axial side of the body. The diaphragm portion extends radially outward from the other axial end of the body portion. The fixing portion extends radially outward from an end portion of the diaphragm portion on the radially outward side. The internal gear is disposed radially outward of the body and has internal teeth on an inner peripheral surface thereof, which mesh with the external teeth. The housing is fixed to the fixing portion from the other axial side. One of the internal gear and the flexible external gear is fixed, and the other rotates about the central axis. The length of the body in the radial direction is displaced by the rotation of the wave generator, and the meshing position of the flexible externally toothed gear and the internally toothed gear changes in the circumferential direction around the central axis. The flexible externally toothed gear and the internally toothed gear relatively rotate according to the difference in the number of teeth of the external teeth and the internal teeth. The seal member is disposed between the diaphragm portion and the case, or between an end portion of the other side in the axial direction of the body portion and the case.

According to an aspect of the present invention, there is provided a wave gear device capable of reducing the possibility of grease adhering to an electric wire or a conductor layer when an electric component having the electric wire or the conductor layer is disposed in a space formed between a housing and a diaphragm portion in an axial direction.

Drawings

Fig. 1 is a longitudinal sectional view of a wave gear device of a first embodiment.

Fig. 2 is a cross-sectional view of the wave gear device 1 at the position a-a of fig. 1.

Fig. 3 is a plan view of the torque detection sensor.

Fig. 4 is a circuit diagram of a single-arm bridge circuit.

Fig. 5 is a longitudinal sectional view showing the configuration of a seal member in the wave gear device of the first embodiment.

Fig. 6 is a longitudinal sectional view showing the structure of a seal member in the wave gear device of the second embodiment.

Fig. 7 is a longitudinal sectional view showing the structure of a seal member in a wave gear device of a third embodiment.

Fig. 8 is a longitudinal sectional view showing the structure of a seal member in a wave gear device of the fourth embodiment.

Fig. 9 is a longitudinal sectional view showing the structure of a seal member in a wave gear device of a fifth embodiment.

Fig. 10 is a longitudinal sectional view showing the structure of a seal member in a wave gear device of a sixth embodiment.

Fig. 11 is a longitudinal sectional view showing the structure of a seal member in a wave gear device of a seventh embodiment.

Fig. 12 is a longitudinal sectional view showing the structure of a seal member in a wave gear device of an eighth embodiment.

Fig. 13 is a longitudinal sectional view showing the structure of a seal member in a wave gear device of a ninth embodiment.

Fig. 14 is a longitudinal sectional view showing the structure of a seal member in a wave gear device of the tenth embodiment.

Description of the reference symbols

1: a wave gear device; 9: a central axis; 10: an input section; 20: a wave generator; 30: a flexible externally toothed gear; 31: a body portion; 32: an outer tooth; 33: a diaphragm portion; 34: a fixed part; 40: an internal gear; 41: internal teeth; 50: a housing; 51: a cylindrical portion; 52: a step portion; 60: a sealing member; 61: a main body portion; 62: a lip portion; 70: a torque detection sensor; 71: a substrate; 72: a single-arm bridge circuit.

Detailed Description

Hereinafter, exemplary embodiments of the present application will be described with reference to the drawings. In the present application, a direction parallel to the central axis of the wave gear device is referred to as an "axial direction", a direction perpendicular to the central axis of the wave gear device is referred to as a "radial direction", and a direction along an arc centered on the central axis of the wave gear device is referred to as a "circumferential direction". However, the "parallel direction" also includes a substantially parallel direction. The "vertical direction" also includes a substantially vertical direction.

< 1. first embodiment >

< 1-1. integral Structure of wave gear device

Fig. 1 is a longitudinal sectional view of a wave gear device 1 of a first embodiment. Fig. 2 is a cross-sectional view of the wave gear device 1 at the position a-a of fig. 1. The wave gear device 1 is a device that transmits a rotational motion at a first rotational speed obtained from a motor to a subsequent stage while shifting (decelerating) the rotational motion to a second rotational speed lower than the first rotational speed. The wave gear device 1 is used by being assembled to a joint of a small robot together with a motor, for example. However, the wave gear device of the present invention may be used for other devices such as an auxiliary garment, a rotary table, an index table of a machine tool, a wheelchair, and an automated guided vehicle.

As shown in fig. 1 and 2, the wave gear device 1 of the present embodiment includes an input member 10, a wave generator 20, a flexible externally toothed gear 30, an internally toothed gear 40, a first frame 45, a second frame 92, a housing 50, and a seal member 60. In addition, although not shown in fig. 1, the wave gear device 1 of the present embodiment has the torque detection sensor 70 shown in fig. 3 as an electrical component. Fig. 3 is a plan view of the torque detection sensor 70.

The input member 10 is rotated at a first rotational speed before being decelerated. The input member 10 of the present embodiment is substantially cylindrical and extends along the central axis 9. The input member 10 may be a motor shaft, or may be a member connected to a motor outside the figure directly or via a power transmission mechanism such as a gear. When the motor is driven, the input member 10 rotates around the central axis 9 at a first rotational speed.

The wave generator 20 is a mechanism that generates periodic flexural deformation in the body portion 31 of the flexible externally toothed gear 30, which will be described later. When the motor is driven, the wave generator 20 is also rotated together with the input member 10 at the first rotational speed around the center axis 9. The wave generator 20 of the present embodiment includes a flexible bearing 22 and an elliptical cam 21. The input member 10 and the cam 21 may be formed of one member as shown in fig. 1, or may be separate members. The flexible bearing 22 is disposed between the cam 21 and the flexible externally toothed gear 30. The flexible bearing 22 supports the flexible externally toothed gear 30 and the cam 21 so as to be rotatable relative to each other. The flexible bearing 22 can be displaced in the radial direction in accordance with the rotation of the cam 21.

The flexible externally toothed gear 30 is a thin, substantially annular gear that can be flexibly deformed. The flexible externally toothed gear 30 is supported to be rotatable about the center axis 9. The flexible externally toothed gear 30 of the present embodiment includes a body portion 31, a plurality of external teeth 32, a diaphragm portion 33, and a fixing portion 34. The body 31 extends cylindrically in the axial direction around the central axis 9. The axial end of the body 31 is located radially outward of the wave generator 20 and radially inward of an internal gear 40 described later. The diaphragm portion 33 is an annular portion that radially extends outward from the other axial end of the body portion 31. The fixing portion 34 is an annular portion that extends radially outward from the radially outward end of the diaphragm portion 33. The thickness of the fixing portion 34 in the axial direction is larger than the thickness of the diaphragm portion 33 in the axial direction.

The body 31 is flexible and thus can be deformed in the radial direction. In particular, the distal end portion of the body portion 31 located radially inward of the internal gear 40 is a free end, and therefore can be displaced radially more than other portions. On the other hand, the other axial end of the body 31 is a fixed end connected to the fixing portion 34, and therefore is less likely to be deformed in the radial direction than the one axial end. Further, the diaphragm portion 33 slightly deforms in a flexing manner in the axial direction as the body portion 31 deforms, but the fixing portion 34 hardly deforms.

As shown in fig. 2, the flexible externally toothed gear 30 has a plurality of external teeth 32. The plurality of external teeth 32 protrude radially outward from the outer peripheral surface of the body 31 in the vicinity of the one axial end. In addition, the plurality of external teeth 32 are arranged at a constant pitch in the circumferential direction. The body 31 is pressed radially outward by the outer ring of the flexible bearing 22 of the wave generator 20 at two circumferential locations corresponding to the positions of the major axes of the elliptical cams 21. Thereby, the axial end of the body 31 is deformed in an elliptical manner. As a result, the external teeth 32 of the body 31 mesh with internal teeth 41 of an internal gear 40 described later at two locations corresponding to the major axes of the ellipses in the circumferential direction. Hereinafter, the circumferential position at which the external teeth 32 mesh with the internal teeth 41 is referred to as a "meshing position".

The internal gear 40 has an annular shape centered on the central axis 9. The internal gear 40 is fixed to an output member 91 for extracting power rotated at the reduced second rotation speed, for example, by screw fastening. The rigidity of the internal gear 40 is much higher than that of the body portion 31 of the flexible external gear 30. Therefore, the internal gear 40 can be regarded as a substantially rigid body. The internal gear 40 has a plurality of internal teeth 41. The plurality of internal teeth 41 protrude radially inward from the inner peripheral surface of the internal gear 40. The plurality of internal teeth 41 are arranged at a predetermined pitch in the circumferential direction. The flexible externally toothed gear 30 has a slightly different number of external teeth 32 than the number of internal teeth 41 of the internal gear 40.

The first frame 45 is an annular portion extending in the direction along the center axis 9. The first frame 45 is located radially outward of the body 31, on one axial side of the diaphragm 33, and on the other axial side of the internal gear 40. The first frame 45 is fixed together with the output member 91 with respect to the internal gear 40.

The second frame 92 is located radially outward of the first frame 45. The second frame 92 is rotatable with respect to the first frame 45. A screw hole into which a fastening member such as a screw can be inserted is provided in the outer peripheral portion of the second frame 92. The threaded bore extends in an axial direction.

The housing 50 is a substantially annular member. The housing 50 is fixed to the fixing portion 34 of the flexible externally toothed gear 30 from the other axial side. Here, the fixing portion 34 is provided with a through hole overlapping the screw hole of the second frame 92. The through hole extends in the axial direction. Further, a through hole that overlaps the through hole of the fixing portion 34 and the screw hole of the second frame 92 is provided in the outer peripheral portion of the housing 50. The through hole extends in the axial direction. The housing 50 is fixed to the fixing portion 34 by inserting and fastening a fastening member such as a screw in a state where the through hole of the housing 50, the through hole of the fixing portion 34, and the screw hole of the second frame 92 overlap each other. The housing 50 is fixed to a housing of the device in which the wave gear device 1 is mounted, for example, by fastening with screws.

The housing 50 has a cylindrical portion 51 extending along the center axis 9 on the radially inner side. The input member 10 is disposed radially inward of the cylindrical portion 51. A rolling ball bearing 59 is disposed between the input member 10 and the cylindrical portion 51. Thereby, the input member 10 can rotate with respect to the housing 50. That is, the input member 10 rotates relative to the housing 50, the flexible externally toothed gear 30, and the second frame 92.

When the cam 21 rotates at the first rotational speed, the major axis of the ellipse of the flexible externally toothed gear 30 also rotates at the first rotational speed. Then, the meshing position of the external teeth 32 and the internal teeth 41 also changes at the first rotational speed in the circumferential direction. As described above, the number of the external teeth 32 of the flexible externally toothed gear 30 is slightly different from the number of the internal teeth 41 of the internal gear 40. The meshing position of the external teeth 32 and the internal teeth 41 slightly changes in the circumferential direction every time the cam 21 rotates according to the difference in the number of teeth. As a result, the internal gear 40 rotates with respect to the flexible externally toothed gear 30 at the second rotation speed lower than the first rotation speed around the central axis 9. Therefore, the rotational motion at the second reduced rotational speed can be taken out from the output member 91 that rotates at the same rotational speed as the internal gear 40.

< 1-2 > about torque detecting sensor

The torque detection sensor 70 is a sensor that detects a torque applied to the flexible externally toothed gear 30 in the circumferential direction. Although not shown in fig. 1, in the present embodiment, a rear surface of a main body 711 described later of the torque detection sensor 70 shown in fig. 3 is fixed to the other surface in the axial direction of the diaphragm portion 33.

Fig. 3 is a plan view of the torque detection sensor 70 as viewed from the other axial side. As shown in fig. 3, the torque detection sensor 70 has a substrate 71. The substrate 71 of the present embodiment is a flexible substrate that can be flexibly deformed. The base plate 71 includes an annular body 711 centered on the central axis 9, and a baffle 712 protruding radially outward from the body 711. The substrate 71 has a conductor layer L1. The conductor layer L1 of the present embodiment is located on the other axial end surface (front surface) of the substrate 71.

As shown in fig. 3, the conductor layer L1 includes a first resistance line pattern R1 and a second resistance line pattern R2. As described later, the first resistance line pattern R1 and the second resistance line pattern R2 are assembled into the single-arm bridge circuit 72. In other words, the single bridge circuit 72 is mounted on the surface of the main body 711. Further, the signal processing circuit 73 is mounted on the baffle portion 712.

The first resistance line pattern R1 is a pattern in which one conductor is bent and extends in the circumferential direction, and is entirely in the shape of an arc or a ring. In the present embodiment, the first resistance line pattern R1 is provided in a range of approximately 360 ° around the center axis 9. The material of the first resistance line pattern R1 uses, for example, copper or an alloy containing copper. The first resistance line pattern R1 includes a plurality of linear first resistance lines R1 and a plurality of turn portions R11. The plurality of first resistance lines r1 are arranged at equal intervals in the circumferential direction in a substantially parallel posture to each other. In the first resistance line pattern R1, the circumferentially adjacent first resistance lines R1 are alternately connected to each other at one side and the other side in the radial direction by the turn-back portion R11, and are connected in series as a whole. When viewed from the other axial side of the substrate 71, each first resistance line r1 is inclined to one circumferential side with respect to the radial direction of the flexible externally toothed gear 30. The first resistance line r1 is inclined at an angle of, for example, 45 ° with respect to the radial direction.

The second resistance line pattern R2 is a pattern in which one conductor is bent and extends in the circumferential direction, and is entirely in the shape of an arc or a ring. In the present embodiment, the second resistance line pattern R2 is provided in a range of approximately 360 ° around the center axis 9. The material of the second resistance line pattern R2 uses, for example, copper or an alloy containing copper. The second resistance line pattern R2 is located radially inward of the first resistance line pattern R1. That is, the first resistance line pattern R1 and the second resistance line pattern R2 are disposed at positions that do not overlap with each other. The second resistance line pattern R2 includes a plurality of linear second resistance lines R2 and a plurality of turn portions R12. The plurality of second resistance lines r2 are arranged at equal intervals in the circumferential direction in a substantially parallel posture to each other. In the second resistance line pattern R2, the circumferentially adjacent second resistance lines R2 are alternately connected to each other at one side and the other side in the radial direction by the turn-back portion R12, and are connected in series as a whole. When viewed from the other axial side of the substrate 71, each second resistance line r2 is inclined to the other circumferential side with respect to the radial direction of the flexible externally toothed gear 30. The second resistance line r2 is inclined at an angle of, for example, -45 ° with respect to the radial direction.

Fig. 4 is a circuit diagram of the one-arm bridge circuit 72 including the first resistance line pattern R1 and the second resistance line pattern R2. As shown in fig. 4, the one-arm bridge circuit 72 of the present embodiment includes a first resistance line pattern R1, a second resistance line pattern R2, a first fixed resistance Ra, and a second fixed resistance Rb. The first resistance line pattern R1 is connected in series with the second resistance line pattern R2. The first fixed resistor Ra and the second fixed resistor Rb are connected in series. Further, between the + pole and the-pole of the power supply voltage, the columns of the two resistance line patterns R1, R2 are connected in parallel with the columns of the two fixed resistances Ra, Rb. In addition, a midpoint M1 of the first and second resistance line patterns R1 and R2 and a midpoint M2 of the first and second fixed resistances Ra and Rb are connected to the voltmeter V.

Each resistance value of the first resistance line pattern R1 and the second resistance line pattern R2 varies according to the torque applied to the flexible externally toothed gear 30. For example, when a torque is applied to the flexible externally toothed gear 30 toward the circumferential direction side centering on the central axis 9 as viewed from the axial direction side, the resistance value of the first resistance line pattern R1 decreases, and the resistance value of the second resistance line pattern R2 increases. On the other hand, when a torque is applied to the flexible externally toothed gear 30 toward the other side in the circumferential direction centered on the central axis 9 as viewed from the one side in the axial direction, the resistance value of the first resistance line pattern R1 increases, and the resistance value of the second resistance line pattern R2 decreases. Thus, the first resistance line pattern R1 and the second resistance line pattern R2 represent resistance value changes in opposite directions to each other with respect to the torque.

When the respective resistance values of the first resistance line pattern R1 and the second resistance line pattern R2 change, the potential difference between the midpoint M1 of the first resistance line pattern R1 and the second resistance line pattern R2 and the midpoint M2 of the first fixed resistance Ra and the second fixed resistance Rb changes, and therefore the measured value of the voltmeter V changes. Therefore, the direction and magnitude of the torque applied to the flexible externally toothed gear 30 can be detected from the measured value of the voltmeter V.

The signal processing circuit 73 is a circuit for detecting the torque applied to the flexible externally toothed gear 30 from a potential difference signal between the midpoint M1 and the midpoint M2 measured by the voltmeter V. That is, the signal processing circuit 73 detects the torque applied to the flexible externally toothed gear 30 based on the output signal of the one-arm bridge circuit 72. The one-arm bridge circuit 72 including the first resistance line pattern R1 and the second resistance line pattern R2 is electrically connected to the signal processing circuit 73. The signal processing circuit 73 includes, for example, an amplifier that amplifies the potential difference between the midpoints M1, M2, and a circuit for calculating the direction and magnitude of the torque from the amplified electric signal. The detected torque is output to an external device connected to the signal processing circuit 73 by wire or wirelessly.

The wave gear device 1 of the present embodiment can detect the torque applied to the entire circumference of the flexible externally toothed gear 30 by the torque detection sensor 70 having the above-described configuration.

In a conventionally known wave gear device, particularly a wave gear device having no electrical components between a housing and a diaphragm portion, annular seal members are generally provided between a fixed portion and the housing and between the fixed portion and a second frame, the annular seal members being arranged around a central axis on the entire circumference in the circumferential direction. This is to prevent the grease filled in the meshing portion between the flexible externally toothed gear and the internally toothed gear from leaking to the outside of the wave gear device.

However, in the case where the electrical component (substrate 71) having the electric wire or the conductor layer is mounted between the housing 50 and the diaphragm portion 33 as in the present embodiment, it is necessary to block the penetration of the grease on the radially inner side than the conventional case in order to prevent the grease from adhering to the electric wire or the conductor layer. Further, when the electrical components are mounted between the case 50 and the diaphragm portion 33 as in the present embodiment, it is necessary to draw out the wiring extending from the electrical components to the radially outer side (outside the wave gear device 1). Therefore, at least a part of the annular seal member provided in the related art in the circumferential direction needs to be omitted.

In this regard, the wave gear device 1 of the present embodiment has a structure unique to the present application, and can block the penetration of grease more radially inward than in the related art. Further, at least a part of the annular seal member provided in the related art in the circumferential direction can be eliminated.

Hereinafter, a structure unique to the present application will be described for each embodiment.

< 1-3 > about sealing member

The wave gear device 1 of the first embodiment has a seal member 60 as a structure unique to the present application. Fig. 5 is a longitudinal sectional view showing the configuration of a seal member 60 in the wave gear device 1 of the first embodiment. The seal member 60 is made of an elastically deformable material such as rubber. The seal member 60 has a main body portion 61 and a lip portion 62.

The body portion 61 is annular around the central axis 9, and has a thickness in the axial direction. The lip 62 of the present embodiment extends from the outer edge of the body 61 on the other axial side toward the other axial side and toward the radially inner side. The lip 62 has a substantially annular shape inclined with respect to the radial direction. One surface of the body 61 in the axial direction is in contact with the other surface of the substrate 71 in the axial direction. The other axial end (tip end) of the lip 62 contacts the one axial face of the housing 50.

The seal member 60 is positioned between the housing 50 and the base plate 71 in a state compressed in the axial direction. More specifically, the seal member 60 is disposed between the other surface in the axial direction of the base plate 71 and the one surface in the axial direction of the housing 50 in a state of being pressed in a direction in which the distal end portion of the lip portion 62 is brought closer to the other surface in the axial direction of the body portion 61.

The wave gear device 1 of the present embodiment prevents the grease from spreading by the seal member 60 as described above. Therefore, grease filled in the meshing portion between the external teeth 32 and the internal teeth 41 and the like can be prevented from reaching the surface of the substrate 71.

In particular, in the wave gear device 1 of the present embodiment, the lip portion 62 is pressed against the surface on one axial side of the housing 50 that is less deflected in the axial direction, and therefore the seal member 60 is easily deformed following the deflection deformation of the diaphragm portion 33 in the axial direction. Therefore, in the present embodiment, the sealing performance of the sealing member 60 is more sufficiently exhibited.

As described above, the wave gear device 1 of the present embodiment includes the input member 10, the wave generator 20, the flexible externally toothed gear 30, the internally toothed gear 40, the housing 50, and the seal member 60. The seal member 60 is disposed between the diaphragm portion 33 and the housing 50, and is disposed at a position radially inward of the flexible externally toothed gear 30. Thus, grease filled in the meshing portion between the external teeth 32 and the internal teeth 41 and the like does not easily reach the space formed between the housing 50 and the diaphragm portion 33 in the axial direction. Therefore, when the electric component having the electric wire or the conductor layer, such as the torque detection sensor 70, is disposed in the space formed between the housing 50 and the diaphragm portion 33 in the axial direction, the possibility of the grease adhering to the electric wire or the conductor layer can be reduced.

In the wave gear device 1 of the present embodiment, the substrate 71 having the conductor layer L1 is attached to the other surface of the diaphragm portion 33 in the axial direction. This can reduce the possibility of grease adhering to the surface of the substrate 71.

In the wave gear device 1 of the present embodiment, the seal member 60 is positioned between the other surface in the axial direction of the base plate 71 and the one surface in the axial direction of the housing 50. This allows the seal member 60 to elastically deform following the axial deflection deformation of the substrate 71.

The seal member 60 of the present embodiment includes a main body portion 61 and a lip portion 62. The front end of the lip 62 contacts an axial surface of the housing 50. Accordingly, the amount of deformation in the axial direction is smaller than that of the other surface in the axial direction of the base plate 71, and the tip end portion of the lip portion 62 can be brought into contact with the one surface in the axial direction of the housing 50. Therefore, when the diaphragm portion 33 and the substrate 71 are deformed by flexing, the sealing member 60 is easily deformed to follow them, and the sealing performance is improved.

In the wave gear device 1 of the present embodiment, the torque applied to the diaphragm portion 33 of the flexible externally toothed gear 30 can be detected by the output signal from the single arm bridge circuit 72 including the first resistance line pattern R1 and the second resistance line pattern R2. Further, grease filled in the meshing portions of the external teeth 32 and the internal teeth 41, and the like, does not easily reach the first resistance line pattern R1 and the second resistance line pattern R2.

In particular, in the wave gear device 1 of the present embodiment, relative circumferential movement does not occur between the housing 50 and the base plate 71 (diaphragm portion 33). Therefore, no slip in the circumferential direction occurs between the housing 50 and the seal member 60 and between the base plate 71 and the seal member 60. Therefore, deterioration of the seal member 60 due to abrasion or the like can be suppressed.

In particular, in the wave gear device 1 of the present embodiment, the seal member 60 is disposed on the radially inner side of the diaphragm portion 33. Therefore, at least a part of the sealing member, such as an O-ring, on the radially outer side of the diaphragm portion 33 in the circumferential direction can be omitted. As a result, the wiring extending from the base plate 71 as the electrical component can be led out to the outside of the wave gear device 1.

< 2. second embodiment >

Hereinafter, a configuration unique to the present application in the wave gear device 200 of the second embodiment will be described. In the following description, the same components having the same structures and functions as those described in the above embodiments are denoted by the same reference numerals, and redundant description thereof is omitted. The same applies to the following embodiments.

The wave gear device 200 of the second embodiment differs from the wave gear device 1 of the first embodiment in that a seal member 260 having only a lip 262 is provided instead of the seal member 60. Fig. 6 is a longitudinal sectional view showing the configuration of the lip 262 in the wave gear device 200 of the second embodiment.

The lip 262 is made of a material that can elastically deform, such as rubber. The lip 262 is fixed to the base plate 71 by, for example, bonding or the like.

The lip 262 extends from an edge (inner edge) on the radially inner side of the base 71 toward the axial direction side and the radially inner side. The lip 262 is shaped in a substantially annular shape inclined with respect to the radial direction. In other words, the lip 262 is tapered such that the radius of the outer peripheral surface becomes narrower toward one axial side. An end portion (tip end portion) of the lip portion 62 on one axial side is in contact with the outer peripheral surface of the cylindrical portion 51 of the housing 50.

The lip 262 is positioned between the back surface of the base plate 71 and the outer peripheral surface of the cylindrical portion 51 in a radially and axially compressed state. The wave gear device 200 according to the second embodiment has the lip 262 as described above, and thus can prevent grease filled in the meshing portion between the external teeth 32 and the internal teeth 41 from reaching the surface of the base plate 71.

< 3. third embodiment >

Hereinafter, a configuration unique to the present application in the wave gear device 300 of the third embodiment will be described.

The wave gear device 300 of the third embodiment differs from the wave gear device 1 of the first embodiment in that a seal member 360 is provided instead of the seal member 60 and the housing 50 has a stepped portion 52. Fig. 7 is a longitudinal sectional view showing the configuration of the seal member 360 and the step portion 52 in the wave gear device 300 of the third embodiment.

The step 52 is provided on one axial surface of the housing 50. The stepped portion 52 is formed in a stepped shape in which the radially inner surface of the axially one surface of the case 50 protrudes axially further than the radially outer surface. The step surface of the step portion 52 is continuously formed over the entire circumferential range in the circumferential direction. That is, the stepped portion 52 has a cylindrical shape centered on the central axis 9.

The sealing member 360 has a main body portion 361 and a lip portion 362. The main body 361 is annular about the central axis 9 and has a thickness in the axial direction. The thickness of the main body 361 in the axial direction is substantially equal to the height of the step surface of the step portion 52. The inner diameter of the main body 361 substantially matches the outer diameter of the step surface of the step portion 52.

The lip portion 362 of the present embodiment extends from the outer edge portion of the body portion 361 on one axial side toward one axial side and toward the inner side in the radial direction. The lip 362 has a substantially annular shape inclined with respect to the radial direction. The body 361 is attached to the step portion 52. That is, the inner edge portion on the other axial side of the main body 361 is positioned in contact with the stepped portion 52. The other axial surface of the body 361 contacts one axial surface of the housing 50. An end portion (tip end portion) on one axial side of the lip portion 362 contacts a surface on the other axial side of the base plate 71.

The seal member 360 is positioned between the housing 50 and the base plate 71 in a state compressed in the axial direction. More specifically, the seal member 360 is disposed between the other surface in the axial direction of the base plate 71 and the one surface in the axial direction of the case 50 and at a position radially inward of the flexible externally toothed gear 30 in a state in which the seal member is pressed in a direction in which the distal end portion of the lip portion 362 is brought closer to the one surface in the axial direction of the body portion 361.

As described above, the seal member 360 of the present embodiment includes the body 361 and the lip 362. The tip end of the lip 362 contacts the other axial surface of the base plate 71. Accordingly, when the diaphragm portion 33 and the substrate 71 are deformed in the axial direction, the sealing member 360 is easily deformed to follow them, and the sealing performance is improved.

In addition, in the wave gear device 300 of the present embodiment, the housing 50 has the stepped portion 52 that holds the seal member 360. This enables the seal member 360 to be positioned in the axial and radial directions. As a result, the sealing performance is improved.

< 4. fourth embodiment >

Hereinafter, a configuration unique to the present application in the wave gear device 400 of the fourth embodiment will be described.

The wave gear device 400 of the fourth embodiment is different from the wave gear device 1 of the first embodiment in that a sealing member 460 is provided instead of the sealing member 60 and the edge portion (inner edge portion) on the radially inner side of the base plate 71 does not reach the position where the sealing member 460 is disposed. Fig. 8 is a longitudinal sectional view showing the configuration of a seal member 460 in a wave gear device 400 of the fourth embodiment.

The sealing member 460 is made of a raw material that can elastically deform, such as rubber. The seal member 460 has a main body portion 461 and a lip portion 462.

The body 461 is annular about the central axis 9 and has a thickness in the axial direction. The lip 462 of the present embodiment extends from the outer edge of the other axial side of the body 461 toward the other axial side and toward the radially inner side. The lip 462 has a substantially annular shape inclined with respect to the radial direction. One surface of the body 461 in the axial direction contacts the other surface of the diaphragm 33 in the axial direction. An end portion (front end portion) on the other axial side of the lip portion 462 is in contact with a surface on one axial side of the housing 50.

The seal member 460 is positioned between the housing 50 and the diaphragm portion 33 in a state compressed in the axial direction. More specifically, the seal member 460 is disposed between the one axial surface of the housing 50 and the other axial surface of the diaphragm portion 33 and at a radially inward side of the flexible externally toothed gear 30 in a state of being pressed in a direction in which the distal end portion of the lip portion 462 is brought closer to the other axial surface of the body portion 461.

The wave gear device 400 of the present embodiment includes the above-described seal member 460, and thus can prevent grease filled in the meshing portion between the external teeth 32 and the internal teeth 41 from reaching the surface of the base plate 71.

In particular, in the wave gear device 400 of the present embodiment, the axial end surface of the main body portion 461 of the seal member 460 is not in contact with the base plate 71 but is in contact with the diaphragm portion 33. Therefore, in the present embodiment, the radially inner edge of the base plate 71 does not protrude radially inward beyond the diaphragm portion 33. As a result, the possibility of grease adhering to the back surface of the substrate 71 is reduced. Therefore, the grease adhering to the rear surface of the substrate 71 is less likely to adhere to the conductor layer L1 via the outer surface of the substrate 71.

As described above, in the wave gear device 400 of the present embodiment, the seal member 460 is positioned between the other surface in the axial direction of the diaphragm portion 33 and the one surface in the axial direction of the housing 50. Accordingly, the seal member 460 can be disposed between the diaphragm portion 33 and the housing 50, which are less deformed than the body portion 31, and therefore, expansion and contraction of the seal member 460 can be suppressed. Therefore, the deterioration of the sealing member 460 can be suppressed.

< 5. fifth embodiment >

A specific configuration of the wave gear device 500 according to the fifth embodiment will be described below.

The wave gear device 500 of the fifth embodiment differs from the wave gear device 1 of the first embodiment in that a seal member 560 is provided instead of the seal member 60, the housing 50 has a stepped portion 52, and the edge portion (inner edge portion) on the radially inner side of the base plate 71 does not reach the position where the seal member 560 is disposed. Fig. 9 is a longitudinal sectional view showing the configuration of the seal member 560 and the stepped portion 52 in the wave gear device 500 of the fifth embodiment.

The sealing member 560 has a body portion 561 and a lip portion 562. The body 561 is annular around the central axis 9 and has a thickness in the axial direction. The thickness of the body 561 in the axial direction is substantially equal to the height of the step surface of the step portion 52. The inner diameter of the body 561 is substantially equal to the outer diameter of the step surface of the step portion 52.

The lip portion 562 of the present embodiment extends from the outer edge portion of the body portion 561 in the axial direction toward the axial direction and radially inward. The lip portion 562 has a substantially annular shape inclined with respect to the radial direction. The body 561 is attached to the step 52. That is, the inner edge portion of the body portion 561 on the other axial side is positioned in contact with the step portion 52. The other surface of the body 561 in the axial direction is in contact with one surface of the housing 50 in the axial direction. An end portion (tip end portion) on one axial side of the lip portion 562 is in contact with a surface on the other axial side of the diaphragm portion 33.

The seal member 560 is positioned between the housing 50 and the diaphragm portion 33 in a state compressed in the axial direction. More specifically, the seal member 560 is disposed between the one surface in the axial direction of the housing 50 and the other surface in the axial direction of the diaphragm portion 33 and at a position radially inward of the flexible externally toothed gear 30 in a state in which the tip end portion of the lip portion 562 is pressed in a direction in which the tip end portion is brought closer to the one surface in the axial direction of the body portion 561.

The wave gear device 500 of the present embodiment has the above-described seal member 560, and thus can prevent grease filled in the meshing portion between the external teeth 32 and the internal teeth 41 from reaching the surface of the substrate 71.

In particular, in the wave gear device 500 of the present embodiment, the tip end portion of the lip portion 562 of the seal member 560 is not in contact with the base plate 71 but in contact with the diaphragm portion 33. This reduces the possibility of grease adhering to the back surface of the substrate 71. Therefore, the grease adhering to the rear surface of the substrate 71 is less likely to adhere to the conductor layer L1 via the outer surface of the substrate 71.

< 6. sixth embodiment >

Hereinafter, a configuration unique to the present application in the wave gear device 600 of the sixth embodiment will be described.

The wave gear device 600 of the sixth embodiment differs from the wave gear device 1 of the first embodiment in that a seal member 660 is provided instead of the seal member 60 and the housing 50 has a stepped portion 53. Fig. 10 is a longitudinal sectional view showing the configuration of the seal member 660 and the step portion 53 in the wave gear device 600 of the sixth embodiment.

The step portion 53 is provided on the outer peripheral surface of the cylindrical portion 51 of the housing 50. The step portion 53 is disposed such that one of the outer peripheral surfaces of the cylindrical portion 51 in the axial direction is closer to the central axis 9 than the other outer peripheral surface in the axial direction, and has a step shape. The stepped surface of the stepped portion 53 is continuously formed over the entire circumferential range of the cylindrical portion 51 in the circumferential direction. That is, the step surface of the step portion 53 has an annular shape centered on the central axis 9.

The sealing member 660 has a main body portion 661 and a lip portion 662. The body 661 is a cylindrical portion extending in the axial direction about the central axis 9. The thickness of the body portion 661 in the radial direction substantially matches the height of the step surface of the step portion 53. The inner diameter of the body portion 661 substantially matches the outer diameter of a lower region of the stepped portion 53 of the cylindrical portion 51.

The lip portion 662 of the present embodiment extends from the outer edge portion of the other axial side of the body portion 661 toward the one axial side and the radially outward side. The lip portion 662 is substantially annular and inclined with respect to the radial direction. The body 661 is attached to the step portion 53. That is, the inner edge portion on the other axial side of the body portion 661 is positioned in contact with the stepped portion 53. The inner peripheral surface of the body portion 661 contacts the outer peripheral surface of the lower portion of the step portion 53. An end portion (tip end portion) on the radially outer side of the lip portion 662 contacts the outer peripheral surface of the body portion 31 of the flexible externally toothed gear 30.

The seal member 660 is positioned between the cylindrical portion 51 of the housing 50 and the body portion 31 of the flexible externally toothed gear 30 in a radially compressed state. More specifically, the seal member 660 is disposed between the cylindrical portion 51 and the other axial end of the body portion 31 in a state of being pressurized in a direction in which the distal end of the lip portion 662 comes closer to the outer peripheral surface of the body portion 661.

As described above, in the wave gear device 600 of the present embodiment, the housing 50 has the cylindrical portion 51. The seal member 660 is disposed between the inner peripheral surface of the body portion 31 and the outer peripheral surface of the cylindrical portion 51 and at the other axial side of the flexible externally toothed gear 30. This can reduce the radial dimension of the sealing member 660.

In particular, the seal member 660 of the present embodiment is disposed at a position axially distant from an end portion on one axial side, which is a free end, of the flexible externally toothed gear 30. Therefore, it is not easy to cause a case where the elastic deformation of the sealing member 660 does not follow the flexural deformation of the body portion 31, and the sealing property is impaired.

< 7. seventh embodiment >

Hereinafter, a configuration unique to the present application in the wave gear device 700 of the seventh embodiment will be described.

The wave gear device 700 of the seventh embodiment differs from the wave gear device 1 of the first embodiment in that a seal member 760 is provided instead of the seal member 60. Fig. 11 is a longitudinal sectional view showing the structure of a seal member 760 in a wave gear device 700 of a seventh embodiment.

The sealing member 760 has a body portion 761 and a lip portion 762. The main body portion 761 is a cylindrical portion extending in the axial direction with the center axis line 9 as a center. The outer diameter of the body portion 761 substantially matches the inner diameter of the other axial end of the body portion 31 of the flexible externally toothed gear 30.

The lip 762 of the present embodiment extends from an inner edge of the other axial side of the body 761 toward the one axial side and radially inward. The lip 762 has a substantially annular shape inclined with respect to the radial direction. The outer peripheral surface of the body portion 761 contacts the inner peripheral surface of the body portion 31 of the flexible externally toothed gear 30. An end portion (distal end portion) on the radially inner side of the lip 762 contacts the outer peripheral surface of the cylindrical portion 51 of the housing 50.

The seal member 760 is positioned between the cylindrical portion 51 of the housing 50 and the body portion 31 of the flexible externally toothed gear 30 in a radially compressed state. More specifically, the seal member 760 is disposed between the cylindrical portion 51 and the other axial end of the body portion 31 and at the other axial end of the flexible externally toothed gear 30 in a state of being pressurized in a direction in which the distal end of the lip 762 is brought closer to the inner circumferential surface of the body portion 761.

The wave gear device 700 of the present embodiment has the above-described seal member 760, and thus can prevent grease filled in the meshing portion between the external teeth 32 and the internal teeth 41 from reaching the surface of the base plate 71.

In particular, in the wave gear device 700 of the present embodiment, the tip end portion of the lip 762 of the seal member 760 is in contact with the cylindrical portion 51 of the housing 50 without being in contact with the body portion 31 of the flexible externally toothed gear 30. Here, the body 31 is deformed in a radial direction, but the housing 50 is hardly deformed. Since the tip of the lip 762 is brought into contact with the cylindrical portion 51 of the substantially rigid housing 50 in this way, the seal member 760 is easily deformed to follow the bending deformation of the body portion 31 in the radial direction.

< 8 > eighth embodiment

Hereinafter, a configuration unique to the present application in the wave gear device 800 of the eighth embodiment will be described.

The wave gear device 800 of the eighth embodiment differs from the wave gear device 1 of the first embodiment in that the sealing member 60 is not provided, the housing 50 has the step portion 54, and the base plate 871 is provided instead of the base plate 71. Fig. 12 is a longitudinal sectional view showing the configuration of the step portion 54 and the base plate 871 in the wave gear device 800 of the eighth embodiment.

The step portion 54 is provided on the outer peripheral surface of the cylindrical portion 51 of the housing 50. The step portion 54 is disposed such that one of the outer peripheral surfaces of the cylindrical portion 51 in the axial direction is closer to the central axis 9 than the other outer peripheral surface in the axial direction, and has a step shape. The stepped surface of the stepped portion 54 is continuously formed over the entire circumferential range of the cylindrical portion 51 in the circumferential direction.

The edge portion (inner edge portion) of the substrate 871 on the radially inner side extends further radially inward than the substrate 71. Specifically, the substrate 871 extends to the radially inward end of the stepped surface of the stepped portion 54. The base 871 comes into surface contact with the step of the step portion 54. The substrate 871 is positioned by the stepped surface of the step portion 54. A space formed between the body portion 31 and the cylindrical portion 51 in the radial direction and a space formed between the housing 50 and the diaphragm portion 33 in the axial direction are separated by the base plate 871. Thus, the radially inner end of the base 871 functions as a seal member that prevents grease filled in the meshing portion between the external teeth 32 and the internal teeth 41 and the like from reaching the surface (the other surface in the axial direction) of the base 871.

As described above, in the wave gear device 800 of the present embodiment, the base 871 extends to the radially inner side than the body portion 31 when viewed in the axial direction. Thus, the grease filled in the meshing portion between the external teeth 32 and the internal teeth 41 is blocked by the radially inner end of the base 871, and does not easily reach the space formed between the housing 50 and the diaphragm portion 33.

< 9. ninth embodiment >

Hereinafter, a configuration unique to the present application in the wave gear device 900 of the ninth embodiment will be described.

The wave gear device 900 of the ninth embodiment differs from the wave gear device 1 of the first embodiment in that the seal member 60 is not provided, the housing 50 has the step portion 55, and the base plate 971 is provided instead of the base plate 71. Fig. 13 is a longitudinal sectional view showing the configuration of the stepped portion 55 and the base plate 971 in the wave gear device 900 of the ninth embodiment.

The step portion 55 is provided on the outer peripheral surface of the cylindrical portion 51 of the housing 50. The step portion 55 is disposed such that one of the outer peripheral surfaces of the cylindrical portion 51 in the axial direction is farther from the central axis 9 than the other outer peripheral surface in the axial direction, and is stepped. The stepped surface of the stepped portion 55 is continuously formed over the entire circumferential range of the cylindrical portion 51 in the circumferential direction.

The edge portion (inner edge portion) of the base plate 971 on the radially inner side extends further radially inward than the base plate 71. Specifically, the base plate 971 extends to the end portion on the radially inner side of the step surface of the step portion 55. The base plate 971 is in surface contact with the step of the step portion 55. The substrate 971 is positioned by the step surface of the step portion 55. A space formed between the body portion 31 and the cylindrical portion 51 in the radial direction and a space formed between the housing 50 and the diaphragm portion 33 in the axial direction are partitioned by the base plate 971. Thus, the radially inner end of the base plate 971 functions as a seal member that prevents grease filled in the meshing portion between the external teeth 32 and the internal teeth 41 from reaching the surface (the axially other surface) of the base plate 971.

As described above, in the wave gear device 900 of the present embodiment, the base plate 971 extends to the radially inner side of the body portion 31 as viewed in the axial direction. Thus, the grease filled in the meshing portion between the external teeth 32 and the internal teeth 41 is blocked by the radially inner end of the base 971, and does not easily reach the space formed between the housing 50 and the diaphragm portion 33.

< 10. tenth embodiment >

Hereinafter, a configuration unique to the present application in the wave gear device 100 of the tenth embodiment will be described.

The wave gear device 100 of the tenth embodiment differs from the wave gear device 1 of the first embodiment in that the sealing member 60 is not provided and the substrate 171 is provided instead of the substrate 71. Fig. 14 is a longitudinal sectional view showing the structure of a base plate 171 in a wave gear device 100 of the tenth embodiment.

The edge (inner edge) of the substrate 171 on the radially inner side extends further radially inward than the substrate 71. In detail, the substrate 171 extends to the outer peripheral surface of the cylindrical portion 51. That is, the inner edge of the substrate 171 contacts the outer peripheral surface of the cylindrical portion 51. A space formed between the body portion 31 and the cylindrical portion 51 in the radial direction and a space formed between the housing 50 and the diaphragm portion 33 in the axial direction are partitioned by the base plate 171. Thus, the radially inner end of the base plate 171 functions as a seal member that prevents grease filled in the meshing portion between the external teeth 32 and the internal teeth 41 and the like from reaching the surface (the other surface in the axial direction) of the base plate 171.

As described above, in the wave gear device 100 of the present embodiment, the end portion of the substrate 171 on the radially inner side is in contact with the outer peripheral surface of the cylindrical portion 51, and the substrate 171 functions as a seal member. Accordingly, the substrate 171 can be extended inward in the radial direction without providing a separate sealing member, and the end portion of the substrate 171 on the inward side in the radial direction can function as a sealing member. Therefore, the number of parts can be reduced.

< 11. modification example >

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments.

The direction in which the lip portion extends from the main body portion may also be different from that shown in the above embodiments. For example, in the first embodiment, instead of the lip portion 62 extending from the outer edge portion on the other axial side of the body portion 61 to the other axial side and radially inward, the lip portion may extend from the inner edge portion on the other axial side of the body portion to the other axial side and radially outward. Alternatively, in the fourth embodiment, instead of the lip portion 462 extending from the outer edge portion on the other axial side of the main body 461 toward the other axial side and toward the radially inner side, the lip portion may extend from the inner edge portion on the other axial side of the main body toward the other axial side and toward the radially outer side.

In the first and third embodiments, the sealing member may be held on the substrate by contact pressure or may be fixed to the substrate by an adhesive or the like.

In addition to the torque detection sensor 70, another electrical component such as a temperature sensor or another electrical component such as a temperature sensor may be mounted in the space formed between the housing 50 and the diaphragm portion 33 in the axial direction, instead of the torque detection sensor 70. Of course, the electrical components may be omitted.

Instead of positioning the substrate by the step portion as in the eighth and ninth embodiments, a labyrinth structure may be provided between the inner edge portion of the substrate and the cylindrical portion of the housing. That is, the movement of the grease may be prevented by sandwiching the inner edge portion of the substrate in the axial direction by the labyrinth structure.

The substantially annular seal members shown in the drawings between the fixing portion 34 and the housing 50 and between the fixing portion 34 and the second frame 92 may be omitted.

In the eighth to tenth embodiments, for example, an annular reinforcing plate may be attached to the radially inner end of the base plate from one axial side or the other axial side.

The sealing structure by the sealing member and the sealing structure by the end portion on the radially inner side of the substrate may be combined.

In the above embodiment, the flexible externally toothed gear 30 is fixed to a housing of an apparatus in which the wave gear device 1 is mounted via the case 50, and the internal gear 40 rotates about the central axis 9. Alternatively, the internal gear may be fixed to a housing of an apparatus in which the wave gear device is mounted, and the flexible external gear may rotate about the central axis.

Further, the detailed configuration of the wave gear device may be appropriately modified within a range not departing from the gist of the present invention. Further, the elements appearing in the above embodiments and modifications may be appropriately combined within a range not to contradict each other.

Industrial applicability

The present application can be used for a wave gear device.