Wave gear device

Abstract

The present invention provides a wave gear device. The wave generator rotates at the same speed as the input component around the central axis. The flexible external tooth gear has a body, external teeth, a diaphragm, and a fixed portion. The body is arranged radially outward from the wave generator and is bent into a non-circular shape by the wave generator. The external teeth are provided on the outer peripheral surface of one axial side of the body. The diaphragm extends radially outward from the end of the other axial side of the body. The fixed portion extends radially outward from the end of the radially outward side of the diaphragm. The internal tooth gear is arranged radially outward from the body and has internal teeth on the inner peripheral surface that mesh with the external tooth portion. The housing is fixed to the fixed portion from the other axial side. One of the internal tooth gear and the flexible external tooth gear is fixed, and the other rotates around the central axis. The sealing component is arranged between the diaphragm and the housing, or between the end of the other axial side of the body and the housing.

Description

Technical Field

[0001] The present invention relates to a wave gear device. Background Art

[0002] Conventionally, there are known wave gear devices that are mainly used in speed reducers. For example, Japanese Patent Application Laid-Open No. 2005-69402 discloses a conventional wave gear device.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2005-69402

[0004] The wave gear device (1) disclosed in Japanese Patent Application Laid-Open No. 2005-69402 includes a rigid internally toothed gear (10) and a top-hat-shaped flexible externally toothed gear (20). 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 surfaces located on the same plane, and a strain gauge (41) is attached to the boundary portion of these end faces. It is believed that such a wave gear device (1) can detect the torque applied to the flexible externally toothed gear (20).

[0005] 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) may reach the 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, the grease may adhere to the strain gauge (41), thereby potentially causing adverse chemical or electrical effects on the strain gauge (41). Summary of the Invention

[0006] An object of the present invention is to reduce the possibility of grease adhering to an electric wire or a conductor layer when an electrical component including an electric wire or a conductor layer is arranged in a space formed between a housing and a diaphragm in the axial direction.

[0007] In accordance with the present invention, a wave gear device is provided that includes an input member, a wave generator, a flexible externally toothed gear, an internally toothed gear, and a housing, and further includes a sealing member. The input member rotates about a central axis. The wave generator rotates about the central axis at the same rotational speed as the input member. The flexible externally toothed gear includes a body, external teeth, a diaphragm, and a fixed portion. The body is positioned radially outward from the wave generator and is bent into a non-circular shape by the wave generator. The external teeth are provided on the outer circumferential surface of one axial side of the body. The diaphragm extends radially outward from the end of the body on the other axial side. The fixed portion extends radially outward from the end of the diaphragm on the radially outward side. The internally toothed gear is positioned radially outward from the body and has internal teeth on its inner circumferential surface that mesh with the external teeth. The housing is fixed to the fixed portion from the other axial side. One of the internally toothed gear and the flexible externally toothed gear is fixed, while the other rotates about the central axis. The rotation of the wave generator causes the radial length of the body to shift, thereby changing the meshing position of the flexible externally toothed gear and the internally toothed gear circumferentially about the central axis. The flexible externally toothed gear and the internally toothed gear rotate relative to each other based on the difference in the number of teeth between the external and internal teeth. The sealing member is positioned between the diaphragm and the housing, or between the other axial end of the body and the housing.

[0008] According to the present invention, a wave gear device is provided that can reduce the possibility of grease adhering to an electric wire or a conductor layer when an electric component including an electric wire or a conductor layer is arranged in a space formed axially between a housing and a diaphragm. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a longitudinal sectional view of the wave gear device according to the first embodiment.

[0010] Figure 2 yes Figure 1 FIG. 1 is a cross-sectional view of the wave gear device 1 taken along line AA.

[0011] Figure 3 This is a top view of the torque detection sensor.

[0012] Figure 4 It is the circuit diagram of a single-arm bridge circuit.

[0013] Figure 5 This is a longitudinal sectional view showing the structure of a seal member in the wave gear device according to the first embodiment.

[0014] Figure 6It is a longitudinal sectional view showing the structure of a seal member in a wave gear device according to a second embodiment.

[0015] Figure 7 It is a longitudinal sectional view showing the structure of a seal member in a wave gear device according to a third embodiment.

[0016] Figure 8 It is a longitudinal sectional view showing the structure of a seal member in a wave gear device according to a fourth embodiment.

[0017] Figure 9 It is a longitudinal sectional view showing the structure of a seal member in a wave gear device according to a fifth embodiment.

[0018] Figure 10 It is a longitudinal sectional view showing the structure of a seal member in a wave gear device according to a sixth embodiment.

[0019] Figure 11 It is a longitudinal sectional view showing the structure of a seal member in a wave gear device according to a seventh embodiment.

[0020] Figure 12 It is a longitudinal sectional view showing the structure of a seal member in a wave gear device according to an eighth embodiment.

[0021] Figure 13 It is a longitudinal sectional view showing the structure of a seal member in a wave gear device according to a ninth embodiment.

[0022] Figure 14 It is a longitudinal sectional view showing the structure of a seal member in a wave gear device according to a tenth embodiment.

[0023] Description of labels

[0024] 1: Wave gear device; 9: Center axis; 10: Input component; 20: Wave generator; 30: Flexible external gear; 31: Body; 32: External teeth; 33: Diaphragm; 34: Fixed portion; 40: Internal gear; 41: Internal teeth; 50: Housing; 51: Cylindrical portion; 52: Step portion; 60: Sealing component; 61: Main body; 62: Lip; 70: Torque detection sensor; 71: Substrate; 72: Single-arm bridge circuit. DETAILED DESCRIPTION

[0025] The following describes exemplary embodiments of the present application with reference to the accompanying drawings. In this application, directions parallel to the central axis of the wave gear device are referred to as "axial directions," directions perpendicular to the central axis of the wave gear device are referred to as "radial directions," and directions along an arc centered on the central axis of the wave gear device are referred to as "circumferential directions." However, the term "parallel directions" also includes substantially parallel directions. Furthermore, the term "perpendicular directions" also includes substantially perpendicular directions.

[0026] <1. First embodiment>

[0027] <1-1. Overall Structure of a Wave Gear Unit>

[0028] Figure 1 It is a longitudinal sectional view of the wave gear device 1 according to the first embodiment. Figure 2 yes Figure 1 A cross-sectional view of a wave gear device 1 taken at position AA. This wave gear device 1 transmits rotational motion at a first rotational speed, obtained from a motor, to a second rotational speed, lower than the first, while shifting (reducing) the speed to a later stage. For example, the wave gear device 1 is incorporated into the joints of a small robot along with a motor for use. However, the wave gear device of the present invention can also be used in other equipment, such as assistive clothing, rotary tables, indexing tables for machine tools, wheelchairs, and automated guided vehicles.

[0029] like Figure 1 and Figure 2 As shown, the wave gear device 1 of this embodiment includes an input member 10, a wave generator 20, a flexible external gear 30, an internal gear 40, a first frame 45, a second frame 92, a housing 50, and a sealing member 60. Figure 1 The wave gear device 1 of this embodiment has Figure 3 A torque detection sensor 70 is shown as an electrical installation. Figure 3 It is a top view of the torque detection sensor 70 .

[0030] The input member 10 rotates at a first rotational speed before deceleration. In this embodiment, the input member 10 has a generally cylindrical shape extending along the central axis 9. The input member 10 may be a motor shaft, or may be a component connected to a motor (not shown) directly or via a power transmission mechanism such as gears. When the motor is driven, the input member 10 rotates at a first rotational speed about the central axis 9.

[0031] The wave generator 20 is a mechanism that causes the body 31 of the flexible externally toothed gear 30 described later to undergo periodic flexural deformation. When the motor is driven, the wave generator 20 rotates at a first rotational speed along with the input member 10 about the central axis 9. The wave generator 20 of this embodiment includes a flexible bearing 22 and an elliptical cam 21. The input member 10 and the cam 21 can be configured as follows. Figure 1 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 that they can rotate relative to each other. The flexible bearing 22 can be displaced in the radial direction in response to the rotation of the cam 21.

[0032] The flexible externally toothed gear 30 is a thin, roughly annular gear that is capable of flexing and deforming. The flexible externally toothed gear 30 is supported so as to be rotatable about the central axis 9. The flexible externally toothed gear 30 of this embodiment includes a body 31, a plurality of external teeth 32, a diaphragm 33, and a fixing portion 34. The body 31 extends axially in a cylindrical shape 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 the internally toothed gear 40, described later. The diaphragm 33 is an annular portion that extends radially outward from the other axial end of the body 31. The fixing portion 34 is an annular portion that extends further radially outward from the radially outward end of the diaphragm 33. The axial thickness of the fixing portion 34 is greater than the axial thickness of the diaphragm 33.

[0033] The body 31 is flexible and therefore radially deformable. In particular, the front end of the body 31, located radially inward of the internal gear 40, is free, allowing for greater radial displacement than the rest of the body. Meanwhile, the other axial end of the body 31 is fixed to the fixing portion 34 and is therefore less susceptible to radial deformation than the axial end. Furthermore, as the body 31 deforms, the diaphragm 33 slightly flexes in the axial direction, but the fixing portion 34 exhibits little deformation.

[0034] like Figure 2As shown, 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 near the end portion on the axial side of the body 31. Furthermore, the plurality of external teeth 32 are arranged at regular intervals along 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 axis of the elliptical cam 21. As a result, the end portion on the axial side of the body 31 is deformed into an elliptical shape. As a result, the external teeth 32 of the body 31 mesh with the internal teeth 41 of the internally toothed gear 40 described later at two circumferential locations corresponding to the major axis of the ellipse. Hereinafter, the circumferential positions where the external teeth 32 and the internal teeth 41 mesh are referred to as "meshing positions."

[0035] The internal gear 40 is in the shape of a ring centered on the central axis 9. The internal gear 40 is fixed to an output component 91 for extracting power rotating at a second speed after deceleration, for example, by fastening with screws. The rigidity of the internal gear 40 is much higher than the rigidity of the body 31 of the flexible external gear 30. Therefore, the internal gear 40 can be regarded as a rigid body in essence. The internal gear 40 has a plurality of internal teeth 41. The plurality of internal teeth 41 protrude radially inward from the inner circumferential surface of the internal gear 40. In addition, the plurality of internal teeth 41 are arranged at a certain interval along the circumferential direction. The number of external teeth 32 of the flexible external gear 30 is slightly different from the number of internal teeth 41 of the internal gear 40.

[0036] The first frame 45 is an annular portion extending in a direction along the central axis 9. The first frame 45 is located radially outward of the body 31, axially on one side of the diaphragm 33, and on the other axial side of the internally toothed gear 40. The first frame 45 is fixed to the internally toothed gear 40 together with the output member 91.

[0037] The second frame 92 is located radially outward from the first frame 45. The second frame 92 is rotatable relative to the first frame 45. Threaded holes, through which fastening members such as screws can be inserted, are provided on the outer periphery of the second frame 92. The threaded holes extend in the axial direction.

[0038] The housing 50 is a roughly annular member. It is fixed to the fixing portion 34 of the flexible externally toothed gear 30 from the other axial side. The fixing portion 34 is provided with a through-hole that overlaps with the threaded hole of the second frame 92. This through-hole extends axially. Furthermore, the outer periphery of the housing 50 is provided with a through-hole that overlaps with the through-hole of the fixing portion 34 and the threaded hole of the second frame 92. This through-hole extends axially. With the through-holes of the housing 50, the through-holes of the fixing portion 34, and the threaded holes of the second frame 92 overlapping, the housing 50 is fixed to the fixing portion 34 by inserting and tightening fasteners such as screws. The housing 50 is fixed to the frame of the device in which the wave gear device 1 is mounted, for example, by screw fastening.

[0039] The housing 50 has a cylindrical portion 51 extending radially inwardly along the central axis 9. The input member 10 is disposed radially inwardly of the cylindrical portion 51. A rolling ball bearing 59 is disposed between the input member 10 and the cylindrical portion 51. This allows the input member 10 to rotate relative to the housing 50. Specifically, the input member 10 rotates relative to the housing 50, the flexible externally toothed gear 30, and the second frame 92.

[0040] When the cam 21 rotates at the first speed, the major axis of the ellipse of the flexible external gear 30 also rotates at the first speed. As a result, the meshing position of the external teeth 32 and the internal teeth 41 also changes in the circumferential direction at the first speed. In addition, as described above, the number of external teeth 32 of the flexible external gear 30 is slightly different from the number of internal teeth 41 of the internal gear 40. Due to this difference in the number of teeth, the meshing position of the external teeth 32 and the internal teeth 41 changes slightly in the circumferential direction each time the cam 21 rotates. As a result, the internal gear 40 rotates at a second speed, which is lower than the first speed, with respect to the flexible external gear 30 and centered on the central axis 9. Therefore, the rotational motion of the second speed after deceleration can be extracted from the output component 91 that rotates at the same speed as the internal gear 40.

[0041] <1-2. Torque Detection Sensor>

[0042] The torque detection sensor 70 is a sensor that detects the circumferential torque applied to the flexible externally toothed gear 30. Figure 1 Not shown, but in this embodiment, Figure 3 The rear surface of a main body portion 711 (to be described later) of the illustrated torque detection sensor 70 is fixed to the surface on the other axial side of the diaphragm portion 33 .

[0043] Figure 3 This is a top view of the torque detection sensor 70 as viewed from the other side of the axial direction. Figure 3As shown, the torque detection sensor 70 includes a substrate 71. The substrate 71 of this embodiment is a flexible substrate that can be flexibly deformed. The substrate 71 includes a main body 711 in an annular shape centered on the central axis 9 and a baffle 712 that protrudes radially outward from the main body 711. The substrate 71 includes a conductor layer L1. The conductor layer L1 of this embodiment is located on the end face (surface) on the other axial side of the substrate 71.

[0044] like Figure 3 As shown, the conductive layer L1 includes a first resistor line pattern R1 and a second resistor line pattern R2. As described later, the first resistor line pattern R1 and the second resistor line pattern R2 are assembled into a single-arm bridge circuit 72. In other words, the single-arm bridge circuit 72 is mounted on the surface of the main body 711. Furthermore, the signal processing circuit 73 is mounted on the baffle portion 712.

[0045] The first resistance wire pattern R1 is a conductor that is bent and extends circumferentially in an overall arc-shaped or ring-shaped pattern. In this embodiment, the first resistance wire pattern R1 is provided within a range of approximately 360° around the central axis 9. The material of the first resistance wire pattern R1 is, for example, copper or an alloy containing copper. The first resistance wire pattern R1 includes a plurality of straight first resistance wires r1 and a plurality of return portions r11. The plurality of first resistance wires r1 are arranged at equal intervals along the circumferential direction in a posture that is approximately parallel to each other. In the first resistance wire pattern R1, the first resistance wires r1 adjacent to each other in the circumferential direction are alternately connected to each other on one side and the other side of the radial direction through the return portions r11, and are connected in series as a whole. When viewed from the other axial side of the substrate 71, each first resistance wire r1 is inclined toward one side of the circumferential direction relative to the radial direction of the flexible external tooth gear 30. The inclination angle of the first resistance wire r1 relative to the radial direction is, for example, 45°.

[0046] The second resistance wire pattern R2 is a conductor that bends and extends circumferentially, forming an overall arc or ring-shaped pattern. In this embodiment, the second resistance wire pattern R2 is arranged within a range of approximately 360° around the central axis 9. The material of the second resistance wire pattern R2 is, for example, copper or an alloy containing copper. The second resistance wire pattern R2 is located radially inward of the first resistance wire pattern R1. That is, the first resistance wire pattern R1 and the second resistance wire pattern R2 are arranged at positions that do not overlap. The second resistance wire pattern R2 includes a plurality of linear second resistance wires r2 and a plurality of return portions r12. The plurality of second resistance wires r2 are arranged at equal intervals along the circumferential direction in a substantially parallel manner. In the second resistance wire pattern R2, circumferentially adjacent second resistance wires r2 are alternately connected to each other on one side and the other side of the radial direction via the return portions r12, and are connected in series as a whole. When viewed from the other axial side of the substrate 71, each second resistance wire r2 is inclined toward the other circumferential side relative to the radial direction of the flexible externally toothed gear 30. The inclination angle of the second resistance wire r2 with respect to the radial direction is, for example, -45°.

[0047] Figure 4 is a circuit diagram of a single-arm bridge circuit 72 including a first resistance line pattern R1 and a second resistance line pattern R2. Figure 4 As shown, the single-arm bridge circuit 72 of this embodiment includes a first resistance line pattern R1, a second resistance line pattern R2, a first fixed resistor Ra, and a second fixed resistor Rb. The first resistance line pattern R1 and the second resistance line pattern R2 are connected in series. The first fixed resistor Ra and the second fixed resistor Rb are connected in series. Moreover, between the + pole and the - pole of the power supply voltage, the columns of the two resistance line patterns R1 and R2 are connected in parallel with the columns of the two fixed resistors Ra and Rb. In addition, 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 resistor Ra and the second fixed resistor Rb are connected to a voltmeter V.

[0048] The resistance values ​​of the first and second resistance wire patterns R1 and R2 change depending on the torque applied to the flexible externally toothed gear 30. For example, when a torque is applied to the flexible externally toothed gear 30 in a direction circumferentially toward one side about the central axis 9 when viewed from one axial side, the resistance value of the first resistance wire pattern R1 decreases, while the resistance value of the second resistance wire pattern R2 increases. On the other hand, when a torque is applied to the flexible externally toothed gear 30 in a direction circumferentially toward the other side about the central axis 9 when viewed from one axial side, the resistance value of the first resistance wire pattern R1 increases, while the resistance value of the second resistance wire pattern R2 decreases. Thus, the first and second resistance wire patterns R1 and R2 exhibit resistance value changes in opposite directions relative to the torque.

[0049] Furthermore, when the resistance values ​​of the first and second resistance line patterns R1 and R2 change, the potential difference between the midpoint M1 of the first and second resistance line patterns R1 and R2 and the midpoint M2 of the first and second fixed resistors Ra and Rb changes, thereby changing the value measured by the voltmeter V. Therefore, the direction and magnitude of the torque applied to the flexible externally toothed gear 30 can be detected based on the value measured by the voltmeter V.

[0050] The signal processing circuit 73 is a circuit for detecting the torque applied to the flexible externally toothed gear 30 based on the potential difference signal between the midpoints M1 and M2 measured by a voltmeter V. Specifically, the signal processing circuit 73 detects the torque applied to the flexible externally toothed gear 30 based on the output signal of the single-arm bridge circuit 72. The single-arm bridge circuit 72, which includes a first resistance line pattern R1 and a second resistance line pattern R2, is electrically connected to the signal processing circuit 73. The signal processing circuit 73 includes, for example, an amplifier for amplifying the potential difference between the midpoints M1 and M2, and a circuit for calculating the direction and magnitude of the torque based on the amplified electrical signal. The detected torque is output to an external device connected to the signal processing circuit 73 via a wired or wireless connection.

[0051] The wave gear device 1 of the present embodiment can detect the torque applied to the flexible externally toothed gear 30 throughout the entire circumference by including the torque detection sensor 70 having the above-described configuration.

[0052] Conventional wave gear devices, particularly those without electrical components between the housing and the diaphragm, typically have annular sealing members disposed around the entire circumference of the central axis between the fixed portion and the housing, and between the fixed portion and the second frame. This is to prevent grease, which fills the meshing area between the flexible externally toothed gear and the internally toothed gear, from leaking out of the wave gear device.

[0053] However, when an electrical component (substrate 71) having wires or a conductive layer is mounted between the housing 50 and the diaphragm 33 as in this embodiment, in order to prevent grease from adhering to the wires or conductive layer, it is necessary to block grease from entering the component radially inward, as compared to conventional methods. Furthermore, when an electrical component is mounted between the housing 50 and the diaphragm 33 as in this embodiment, the wiring extending from the electrical component must be routed radially outward (toward the outside of the wave gear device 1). Therefore, it is necessary to remove at least a portion of the circumferential portion of the conventional annular seal member.

[0054] In this regard, the wave gear device 1 of this embodiment can block the intrusion of grease from the radially inner side compared to the conventional device due to the unique structure of the present application. In addition, at least a portion of the circumferential direction of the conventional annular seal member can be eliminated.

[0055] Hereinafter, the configuration unique to the present application will be described for each embodiment.

[0056] <1-3. Regarding Sealing Parts>

[0057] The wave gear device 1 of the first embodiment includes a seal member 60 as a structure unique to the present application. Figure 5 1 is a longitudinal sectional view showing the structure of the seal member 60 in the wave gear device 1 according to the first embodiment. The seal member 60 is made of an elastically deformable material such as rubber and has a main body 61 and a lip 62 .

[0058] The main body 61 is annular in shape with the central axis 9 as the center, and is a portion having thickness in the axial direction. In addition, the lip 62 of the present embodiment extends from the outer edge portion of the other axial side of the main body 61 toward the other axial side and toward the radially inner side. The shape of the lip 62 is roughly annular and inclined relative to the radial direction. The surface of the main body 61 on one axial side contacts the surface of the substrate 71 on the other axial side. The end portion (front end portion) of the lip 62 on the other axial side contacts the surface of the housing 50 on one axial side.

[0059] The sealing member 60 is positioned between the housing 50 and the base plate 71 in an axially compressed state. More specifically, the sealing member 60 is positioned between the axially opposite surface of the base plate 71 and the axially opposite surface of the housing 50 in a state where the sealing member 60 is pressurized in a direction such that the tip of the lip portion 62 approaches the axially opposite surface of the main body 61.

[0060] The wave gear device 1 of this embodiment prevents the spread of grease by the seal member 60 as described above. Therefore, the grease filling the meshing portion between the external teeth 32 and the internal teeth 41 can be prevented from reaching the surface of the base plate 71 .

[0061] In particular, in the wave gear device 1 of this embodiment, the lip portion 62 is pressed against the axially one side surface of the housing 50, which is less prone to axial deflection. Therefore, the seal member 60 easily deforms in response to the axial deflection of the diaphragm portion 33. Consequently, in this embodiment, the sealing performance of the seal member 60 is more fully exerted.

[0062] As described above, the wave gear device 1 of this embodiment includes an input member 10, a wave generator 20, a flexible externally toothed gear 30, an internally toothed gear 40, a housing 50, and a sealing member 60. The sealing member 60 is disposed between the diaphragm 33 and the housing 50, and is positioned radially inward of the flexible externally toothed gear 30. This prevents grease from entering the meshing area between the external teeth 32 and the internal teeth 41 and the like, from reaching the space formed axially between the housing 50 and the diaphragm 33. Consequently, when electrical components having wires or a conductive layer, such as the torque detection sensor 70, are disposed in the space formed axially between the housing 50 and the diaphragm 33, the likelihood of grease adhering to the wires or conductive layer can be reduced.

[0063] In the wave gear device 1 of the present embodiment, the substrate 71 having the conductor layer L1 is attached to the other axial surface of the diaphragm portion 33. This reduces the possibility of grease adhering to the surface of the substrate 71.

[0064] In the wave gear device 1 of this embodiment, the seal member 60 is located between the other axial surface of the substrate 71 and the one axial surface of the housing 50. This allows the seal member 60 to elastically deform in response to axial bending deformation of the substrate 71.

[0065] Furthermore, the sealing member 60 of this embodiment includes a main body 61 and a lip portion 62. The tip of the lip portion 62 contacts one axial surface of the housing 50. This allows the tip of the lip portion 62 to contact the one axial surface of the housing 50, since the lip portion 62 deforms less in the axial direction than the other axial surface of the substrate 71. Therefore, when the diaphragm 33 and substrate 71 flex and deform, the sealing member 60 easily follows their deformation, thereby improving sealing performance.

[0066] Furthermore, in the wave gear device 1 of this embodiment, the torque applied to the diaphragm portion 33 of the flexible externally toothed gear 30 can be detected using the output signal from the one-arm bridge circuit 72 including the first and second resistance wire patterns R1 and R2. Furthermore, grease that fills the meshing portion between the external teeth 32 and the internal teeth 41 is less likely to reach the first and second resistance wire patterns R1 and R2.

[0067] In particular, in the wave gear device 1 of this embodiment, there is no relative circumferential movement between the housing 50 and the base plate 71 (diaphragm portion 33). Consequently, there is no circumferential slippage between the housing 50 and the seal member 60, nor between the base plate 71 and the seal member 60. Consequently, deterioration of the seal member 60 due to wear and other factors can be suppressed.

[0068] In particular, in the wave gear device 1 of this embodiment, the sealing member 60 is disposed radially inwardly of the diaphragm portion 33. Consequently, at least a portion of the circumferential portion of a sealing member, such as an O-ring, located radially outwardly of the diaphragm portion 33 can be omitted. Consequently, wiring extending from the substrate 71, which serves as an electrical component, can be routed outside the wave gear device 1.

[0069] <2. Second embodiment>

[0070] The following describes the unique configuration of the present invention in a second embodiment of a wave gear device 200. In the following description, components having the same configuration and function as those described in the previous embodiment are denoted by the same reference numerals, and duplicate descriptions are omitted. This also applies to subsequent embodiments.

[0071] 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 portion 262 is provided instead of the seal member 60 . Figure 6 This is a longitudinal sectional view showing the structure of the lip portion 262 in the wave gear device 200 according to the second embodiment.

[0072] The lip portion 262 is made of an elastically deformable material such as rubber, and is fixed to the base plate 71 by, for example, bonding.

[0073] The lip portion 262 extends from the radially inward edge (inner edge) of the base plate 71 toward one side in the axial direction and radially inward. The lip portion 262 has a generally circular ring shape that is inclined relative to the radial direction. In other words, the lip portion 262 has a tapered shape, with the radius of the outer circumference narrowing toward the axial direction. The axial end (front end) of the lip portion 62 contacts the outer circumference of the cylindrical portion 51 of the housing 50.

[0074] The lip portion 262 is located between the back surface of the base plate 71 and the outer peripheral surface of the cylindrical portion 51 while being compressed in the radial and axial directions. The wave gear device 200 of the second embodiment includes the lip portion 262 as described above, which prevents grease that fills the meshing portion between the external teeth 32 and the internal teeth 41 from reaching the surface of the base plate 71.

[0075] <3. Third embodiment>

[0076] Hereinafter, a configuration unique to the present application in the wave gear device 300 according to the third embodiment will be described.

[0077] The wave gear device 300 of the third embodiment differs from the wave gear device 1 of the first embodiment in that a sealing member 360 is provided instead of the sealing member 60 and the housing 50 has a step portion 52 . Figure 7 It is a longitudinal sectional view showing the structure of the seal member 360 and the step portion 52 in the wave gear device 300 according to the third embodiment.

[0078] The step portion 52 is provided on one axial surface of the housing 50. The radially inward surface of the step portion 52 protrudes axially from the radially outward surface of the housing 50, forming a stepped shape. The stepped surface of the step portion 52 is continuously formed throughout the entire circumference. In other words, the stepped surface of the step portion 52 has a cylindrical shape centered on the central axis 9.

[0079] The sealing member 360 includes a main body 361 and a lip 362. The main body 361 is annular centered on the central axis 9 and has an axial thickness. The axial thickness of the main body 361 is substantially equal to the height of the stepped surface of the stepped portion 52. Furthermore, the inner diameter of the main body 361 is substantially equal to the outer diameter of the stepped surface of the stepped portion 52.

[0080] In addition, the lip portion 362 of the present embodiment extends from the outer edge portion of the axial side of the main body 361 toward the axial side and toward the radial inner side. The shape of the lip portion 362 is a roughly circular ring that is inclined relative to the radial direction. The main body 361 is mounted on the step portion 52. That is, the inner edge portion of the other axial side of the main body 361 contacts the step portion 52 and is positioned. The surface of the main body 361 on the other axial side contacts the surface of the housing 50 on the one axial side. The end portion (front end portion) of the lip portion 362 on the one axial side contacts the surface of the substrate 71 on the other axial side.

[0081] The sealing member 360 is positioned between the housing 50 and the base plate 71 while being compressed in the axial direction. More specifically, the sealing member 360 is positioned between the other axial surface of the base plate 71 and the one axial surface of the housing 50, and radially inward of the flexible externally toothed gear 30, while being pressurized in a direction such that the tip of the lip portion 362 approaches the one axial surface of the main body 361.

[0082] As shown above, the sealing member 360 of this embodiment includes a main body 361 and a lip portion 362. The tip of the lip portion 362 contacts the other axial surface of the substrate 71. As a result, when the diaphragm 33 and substrate 71 flex and deform in the axial direction, the sealing member 360 easily follows their deformation, thereby improving sealing performance.

[0083] Furthermore, in the wave gear device 300 of this embodiment, the housing 50 has the step portion 52 that holds the sealing member 360. This allows the sealing member 360 to be positioned in the axial and radial directions. As a result, the sealing performance is improved.

[0084] <4. Fourth embodiment>

[0085] Hereinafter, a configuration unique to the present application in the wave gear device 400 according to the fourth embodiment will be described.

[0086] The wave gear device 400 of the fourth embodiment differs from the wave gear device 1 of the first embodiment in that a seal member 460 is provided instead of the seal member 60 and the radially inner edge (inner edge) of the base plate 71 does not reach the position where the seal member 460 is arranged. Figure 8 This is a longitudinal sectional view showing the structure of a seal member 460 in a wave gear device 400 according to the fourth embodiment.

[0087] The sealing member 460 is made of an elastically deformable material such as rubber and includes a main body 461 and a lip 462 .

[0088] The main body 461 is annular in shape with the central axis 9 as the center, and is a portion having thickness in the axial direction. In addition, the lip 462 of this embodiment extends from the outer edge portion of the other axial side of the main body 461 toward the other axial side and radially inward. The shape of the lip 462 is generally annular and inclined relative to the radial direction. The surface of the main body 461 on one axial side contacts the surface of the diaphragm 33 on the other axial side. The end portion (front end portion) of the other axial side of the lip 462 contacts the surface of the housing 50 on one axial side.

[0089] The sealing member 460 is positioned between the housing 50 and the diaphragm 33 while being compressed in the axial direction. More specifically, the sealing member 460 is positioned between the axially one surface of the housing 50 and the axially other surface of the diaphragm 33, and radially inward of the flexible externally toothed gear 30, while being pressurized in a direction such that the tip of the lip portion 462 approaches the axially other surface of the main body 461.

[0090] The wave gear device 400 of the present embodiment includes the seal member 460 as described above, and can thereby prevent the 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 .

[0091] In particular, in the wave gear device 400 of this embodiment, the axial end surface of the main body 461 of the seal member 460 contacts the diaphragm 33 rather than the substrate 71. Therefore, in this embodiment, the radially inner edge of the substrate 71 does not protrude radially inward beyond the diaphragm 33. As a result, the likelihood of grease adhering to the back surface of the substrate 71 is reduced. Consequently, the likelihood of grease adhering to the back surface of the substrate 71 and adhering to the conductor layer L1 via the outer surface of the substrate 71 is also reduced.

[0092] As described above, in the wave gear device 400 of this embodiment, the seal member 460 is located between the other axial surface of the diaphragm portion 33 and the one axial surface of the housing 50. This allows the seal member 460 to be arranged between the diaphragm portion 33, which has a smaller deformation amount than the body portion 31, and the housing 50, thereby suppressing expansion and contraction of the seal member 460. Consequently, deterioration of the seal member 460 can be suppressed.

[0093] <5. Fifth embodiment>

[0094] Hereinafter, a configuration unique to the present application in the wave gear device 500 according to the fifth embodiment will be described.

[0095] The wave gear device 500 of the fifth embodiment differs from the wave gear device 1 of the first embodiment in that a sealing member 560 is provided instead of the sealing member 60 , the housing 50 has a step portion 52 , and the radially inner edge (inner edge) of the base plate 71 does not reach the position where the sealing member 560 is arranged. Figure 9 It is a longitudinal sectional view showing the structure of a seal member 560 and a step portion 52 in a wave gear device 500 according to the fifth embodiment.

[0096] The sealing member 560 includes a main body 561 and a lip 562. The main body 561 is annular centered on the central axis 9 and has an axial thickness. The axial thickness of the main body 561 is substantially equal to the height of the stepped surface of the stepped portion 52. Furthermore, the inner diameter of the main body 561 is substantially equal to the outer diameter of the stepped surface of the stepped portion 52.

[0097] In addition, the lip portion 562 of this embodiment extends from the outer edge portion of the main body portion 561 on one axial side toward the axial side and radially inward. The lip portion 562 is shaped like a substantially circular ring that is inclined relative to the radial direction. The main body portion 561 is attached to the step portion 52. That is, the inner edge portion of the main body portion 561 on the other axial side contacts the step portion 52 and is positioned. The surface of the main body portion 561 on the other axial side contacts the surface of the housing 50 on one axial side. The end portion (front end portion) of the lip portion 562 on one axial side contacts the surface of the diaphragm portion 33 on the other axial side.

[0098] The sealing member 560 is positioned between the housing 50 and the diaphragm 33 while being compressed in the axial direction. More specifically, the sealing member 560 is positioned radially inward of the flexible externally toothed gear 30, between one axial surface of the housing 50 and the other axial surface of the diaphragm 33, while being pressurized in a direction such that the tip of the lip portion 562 approaches one axial surface of the main body 561.

[0099] The wave gear device 500 of the present embodiment includes the seal member 560 as described above, and can thereby prevent the 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 .

[0100] In particular, in the wave gear device 500 of this embodiment, the tip of the lip portion 562 of the sealing member 560 contacts the diaphragm portion 33 rather than the substrate 71. This reduces the likelihood of grease adhering to the back surface of the substrate 71. Consequently, the likelihood of grease adhering to the back surface of the substrate 71 and adhering to the conductor layer L1 via the outer surface of the substrate 71 is also reduced.

[0101] <6. Sixth embodiment>

[0102] Hereinafter, a configuration unique to the present application in the wave gear device 600 according to the sixth embodiment will be described.

[0103] The wave gear device 600 of the sixth embodiment differs from the wave gear device 1 of the first embodiment in that a sealing member 660 is provided, and a step portion 53 is provided instead of the sealing member 60 and the housing 50 . Figure 10 It is a longitudinal sectional view showing the structure of a seal member 660 and a step portion 53 in a wave gear device 600 according to the sixth embodiment.

[0104] The step portion 53 is provided on the outer circumferential surface of the cylindrical portion 51 of the housing 50. The step portion 53 is arranged so that the outer circumferential surface on one axial side of the cylindrical portion 51 is closer to the central axis 9 than the outer circumferential surface on the other axial side, forming a stepped shape. The stepped surface of the step portion 53 is continuously formed along the entire circumference of the cylindrical portion 51. In other words, the stepped surface of the step portion 53 forms an annular shape centered on the central axis 9.

[0105] The sealing member 660 includes a main body 661 and a lip 662. The main body 661 is a cylindrical portion extending axially about the central axis 9. The radial thickness of the main body 661 is substantially equal to the height of the stepped surface of the stepped portion 53. Furthermore, the inner diameter of the main body 661 is substantially equal to the outer diameter of the lower region of the stepped portion 53 of the cylindrical portion 51.

[0106] In addition, the lip portion 662 of the present embodiment extends from the outer edge portion on the other axial side of the main body portion 661 toward one axial side and toward the radially outward side. The shape of the lip portion 662 is a roughly circular ring that is inclined relative to the radial direction. The main body portion 661 is mounted on the step portion 53. That is, the inner edge portion on the other axial side of the main body portion 661 contacts the step portion 53 and is positioned. The inner peripheral surface of the main body portion 661 contacts the outer peripheral surface of the lower part of the step portion 53. The end portion (front end portion) on the radially outward side of the lip portion 662 contacts the outer peripheral surface of the body portion 31 of the flexible external tooth gear 30.

[0107] The sealing member 660 is positioned between the cylindrical portion 51 of the housing 50 and the body 31 of the flexible externally toothed gear 30 while being radially compressed. More specifically, the sealing member 660 is positioned between the cylindrical portion 51 and the other axial end of the body 31 while being pressurized in a direction such that the tip of the lip portion 662 approaches the outer circumferential surface of the body 661.

[0108] As described above, in the wave gear device 600 of this embodiment, the housing 50 includes the cylindrical portion 51. The sealing member 660 is disposed between the inner circumferential surface of the body 31 and the outer circumferential surface of the cylindrical portion 51, and is positioned on the other axial side of the flexible externally toothed gear 30. This allows the radial dimension of the sealing member 660 to be reduced.

[0109] In particular, the seal member 660 of this embodiment is arranged axially away from the axially free end of the flexible externally toothed gear 30. Therefore, the elastic deformation of the seal member 660 is less likely to fail to follow the flexural deformation of the body 31, thereby reducing the sealing performance.

[0110] <7. Seventh embodiment>

[0111] Hereinafter, a configuration unique to the present application in the wave gear device 700 according to the seventh embodiment will be described.

[0112] The wave gear device 700 of the seventh embodiment differs from the wave gear device 1 of the first embodiment in that a sealing member 760 is provided instead of the sealing member 60 . Figure 11 This is a longitudinal sectional view showing the structure of a sealing member 760 in a wave gear device 700 according to the seventh embodiment.

[0113] The sealing member 760 includes a main body 761 and a lip 762. The main body 761 is a cylindrical portion extending axially about the central axis 9. The outer diameter of the main body 761 is substantially identical to the inner diameter of the other axial end of the body 31 of the flexible externally toothed gear 30.

[0114] Furthermore, the lip portion 762 of this embodiment extends from the inner edge of the main body 761 on the other axial side toward one side and radially inward. The lip portion 762 has a generally annular shape that is radially inclined. The outer circumferential surface of the main body 761 contacts the inner circumferential surface of the body 31 of the flexible externally toothed gear 30. The radially inward end (front end) of the lip portion 762 contacts the outer circumferential surface of the cylindrical portion 51 of the housing 50.

[0115] The sealing member 760 is positioned between the cylindrical portion 51 of the housing 50 and the body 31 of the flexible externally toothed gear 30 while being radially compressed. More specifically, the sealing member 760 is positioned between the cylindrical portion 51 and the other axial end of the body 31, and on the other axial side of the flexible externally toothed gear 30, while being pressurized in a direction such that the tip of the lip portion 762 approaches the inner circumferential surface of the body 761.

[0116] The wave gear device 700 of the present embodiment includes the seal member 760 as described above, and can thereby prevent the 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 .

[0117] In particular, in the wave gear device 700 of this embodiment, the tip of the lip portion 762 of the seal member 760 contacts the cylindrical portion 51 of the housing 50, not the body 31 of the flexible externally toothed gear 30. Here, while the body 31 flexes and deforms in the radial direction, the housing 50 hardly deforms. By making the tip of the lip portion 762 contact the cylindrical portion 51 of the housing 50, which is a substantially rigid body, the seal member 760 easily follows the radial flexion and deformation of the body 31.

[0118] <8. Eighth embodiment>

[0119] Hereinafter, a configuration unique to the present application in the wave gear device 800 according to the eighth embodiment will be described.

[0120] The wave gear device 800 of the eighth embodiment differs from the wave gear device 1 of the first embodiment in that the wave gear device 800 does not include the sealing member 60 , the housing 50 includes a step portion 54 , and includes a base plate 871 instead of the base plate 71 . Figure 12 It is a longitudinal sectional view showing the structures of the step portion 54 and the base plate 871 in the wave gear device 800 according to the eighth embodiment.

[0121] The step portion 54 is provided on the outer circumferential surface of the cylindrical portion 51 of the housing 50. The step portion 54 is arranged so that the outer circumferential surface on one axial side of the cylindrical portion 51 is closer to the central axis 9 than the outer circumferential surface on the other axial side, forming a stepped shape. The stepped surface of the step portion 54 is formed continuously over the entire circumference of the cylindrical portion 51.

[0122] Compared with substrate 71, the radially inner side edge (inner edge) of substrate 871 extends further inward in the radial direction. In detail, substrate 871 extends to the end portion on the radially inner side of the step surface of step portion 54. Substrate 871 contacts the step surface of step portion 54. Substrate 871 is positioned by the step surface of step portion 54. The space formed in the radial direction between the body 31 and the cylindrical portion 51 and the space formed in the axial direction between the shell 50 and the diaphragm portion 33 are separated by substrate 871. Thus, the radially inner side end portion of substrate 871 functions as a sealing component that prevents grease filled in the meshing portion of the external teeth 32 and the internal teeth 41, etc. from reaching the surface of substrate 871 (the surface on the other side of the axial direction).

[0123] As described above, in the wave gear device 800 of this embodiment, the base plate 871 extends radially inward of the body portion 31 when viewed in the axial direction. As a result, grease that fills the meshing portion between the external teeth 32 and the internal teeth 41 is blocked by the radially inward end of the base plate 871 and is less likely to reach the space formed between the housing 50 and the diaphragm portion 33.

[0124] <9. Ninth embodiment>

[0125] Hereinafter, a configuration unique to the present application in the wave gear device 900 according to the ninth embodiment will be described.

[0126] The wave gear device 900 of the ninth 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 a step portion 55 , and a base plate 971 is provided instead of the base plate 71 . Figure 13 It is a longitudinal sectional view showing the structure of the step portion 55 and the base plate 971 in the wave gear device 900 according to the ninth embodiment.

[0127] The step portion 55 is provided on the outer circumferential surface of the cylindrical portion 51 of the housing 50. The step portion 55 is arranged so that the outer circumferential surface on one axial side of the cylindrical portion 51 is farther from the central axis 9 than the outer circumferential surface on the other axial side, forming a stepped shape. The stepped surface of the step portion 55 is formed continuously over the entire circumference of the cylindrical portion 51 in the circumferential direction.

[0128] Compared with substrate 71, the radially inner side edge (inner edge) of substrate 971 extends further inward in the radial direction. In detail, substrate 971 extends to the end portion on the radially inner side of the step surface of step portion 55. Substrate 971 contacts the step surface of step portion 55. Substrate 971 is positioned by the step surface of step portion 55. The space formed in the radial direction between the body 31 and the cylindrical portion 51 and the space formed in the axial direction between the shell 50 and the diaphragm portion 33 are separated by substrate 971. Thus, the radially inner side end portion of substrate 971 functions as a sealing component that prevents grease filled in the meshing portion of the external teeth 32 and the internal teeth 41, etc. from reaching the surface of substrate 971 (the surface on the other side of the axial direction).

[0129] As described above, in the wave gear device 900 of this embodiment, the base plate 971 extends radially inward of the body 31 when viewed in the axial direction. As a result, grease that fills the meshing portion between the external teeth 32 and the internal teeth 41 is blocked by the radially inward end of the base plate 971 and is less likely to reach the space formed between the housing 50 and the diaphragm 33.

[0130] <10. Tenth embodiment>

[0131] Hereinafter, a configuration unique to the present application in the wave gear device 100 according to the tenth embodiment will be described.

[0132] The wave gear device 100 of the tenth embodiment differs from the wave gear device 1 of the first embodiment in that the wave gear device 100 does not include the sealing member 60 and includes a base plate 171 instead of the base plate 71 . Figure 14 It is a longitudinal sectional view showing the structure of a base plate 171 in a wave gear device 100 according to the tenth embodiment.

[0133] Compared with substrate 71, the edge portion (inner edge portion) on the radially inner side of substrate 171 extends further inward in the radial direction. In detail, substrate 171 extends to the outer peripheral surface of the cylindrical portion 51. That is, the inner edge portion of substrate 171 contacts the outer peripheral surface of the cylindrical portion 51. The space formed between the body 31 and the cylindrical portion 51 in the radial direction and the space formed between the shell 50 and the diaphragm portion 33 in the axial direction are separated by substrate 171. Thus, the end portion on the radially inner side of substrate 171 functions as a sealing component that prevents grease filled in the meshing portion of the external teeth 32 and the internal teeth 41, etc. from reaching the surface of substrate 171 (the surface on the other side of the axial direction).

[0134] As described above, in the wave gear device 100 of this embodiment, the radially inward end portion of the base plate 171 contacts the outer circumferential surface of the cylindrical portion 51, allowing the base plate 171 to function as a sealing member. Thus, even without providing a separate sealing member, the base plate 171 can be extended radially inward, allowing the radially inward end portion of the base plate 171 to function as a sealing member. This reduces the number of components.

[0135] <11. Modifications>

[0136] As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment.

[0137] The direction in which the lip extends from the main body may also differ from that shown in the above-described embodiment. For example, in the first embodiment, instead of the lip 62 extending from the outer edge of the main body 61 on the other axial side toward the other axial side and radially inward, the lip may extend from the inner edge of the main body on the other axial side toward the other axial side and radially outward. Alternatively, in the fourth embodiment, instead of the lip 462 extending from the outer edge of the main body 461 on the other axial side toward the other axial side and radially inward, the lip may extend from the inner edge of the main body on the other axial side toward the other axial side and radially outward.

[0138] In the first embodiment and the third embodiment, 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.

[0139] In the space formed in the axial direction between the housing 50 and the diaphragm portion 33, other electrical components such as a temperature sensor may be mounted in addition to the torque detection sensor 70, or other electrical components such as a temperature sensor may be mounted instead of the torque detection sensor 70. Of course, the electrical components may also be omitted.

[0140] Instead of positioning the substrate by means of a stepped portion as in the eighth and ninth embodiments, a labyrinth structure may be provided between the inner edge of the substrate and the cylindrical portion of the housing. In other words, the labyrinth structure may be used to clamp the inner edge of the substrate in the axial direction, thereby preventing the movement of grease.

[0141] The substantially annular sealing members between the fixing portion 34 and the housing 50 and between the fixing portion 34 and the second frame 92 shown in the respective figures may be omitted.

[0142] In the eighth to tenth embodiments described above, a reinforcing plate having, for example, an annular shape may be attached to the radially inner end portion of the substrate from one axial side or the other axial side.

[0143] A sealing structure using a sealing member and a sealing structure using an end portion on the radially inner side of the substrate may be combined.

[0144] In the above embodiment, the flexible externally toothed gear 30 is fixed to the frame of the device in which the wave gear device 1 is mounted via the housing 50, and the internally toothed gear 40 rotates about the central axis 9. However, instead, the internally toothed gear may be fixed to the frame of the device in which the wave gear device is mounted, and the flexible externally toothed gear may rotate about the central axis.

[0145] Furthermore, the detailed structure of the wave gear device may be modified as appropriate without departing from the spirit of the present invention. Furthermore, the elements of the above-described embodiments and modifications may be combined as appropriate without causing inconsistencies.

[0146] Industrial applicability

[0147] The present application can be used in a wave gear device.

Claims

1. A wave gear device comprising: an input member that rotates about a central axis; a wave generator that rotates about the central axis at the same rotational speed as the input member; A flexible externally toothed gear comprising a body, external teeth, a diaphragm, and a fixed portion, wherein the body is arranged radially outward from the wave generator and is bent into a non-circular shape by the wave generator, the external teeth are provided on the outer peripheral surface of one axial side of the body, the diaphragm extends radially outward from the end portion on the other axial side of the body, and the fixed portion extends radially outward from the end portion on the radially outward side of the diaphragm, the deformation of the diaphragm is less than the deformation of the body, the end portion on the other axial side of the body is a fixed end connected to the fixed portion, and the deformation of the end portion on the other axial side of the body is less than that of the end portion on the one axial side of the body; an internally toothed gear disposed radially outward of the body and having internal teeth on its inner circumferential surface for meshing with the externally toothed portion; and a housing fixed to the fixing portion from the other axial side, One of the internally toothed gear and the flexible externally toothed gear is fixed, and the other rotates about the central axis. By rotating the wave generator, the radial length of the body is displaced, so that the meshing position of the flexible external gear and the internal gear changes along the circumferential direction with the central axis as the center. The flexible externally toothed gear and the internally toothed gear rotate relative to each other according to the difference in the number of teeth between the external teeth and the internal teeth. The wave gear device further includes a sealing member disposed between the diaphragm portion and the housing, or between the other axial end portion of the body portion and the housing.

2. The wave gear device according to claim 1, wherein: A substrate having a conductor layer is attached to the other axial side surface of the diaphragm portion.

3. The wave gear device according to claim 1 or 2, wherein: The sealing member is located between the surface of the diaphragm portion on the other axial side and the surface of the housing on the one axial side.

4. The wave gear device according to claim 1 or 2, wherein: The housing has a cylindrical portion extending from an inner end portion in the radial direction toward one side in the axial direction. The sealing member is located between the inner peripheral surface of the body portion and the outer peripheral surface of the cylindrical portion.

5. The wave gear device according to claim 2, wherein: The sealing member is located between the surface of the substrate on the other axial side and the surface of the housing on the one axial side.

6. The wave gear device according to claim 3, wherein: The sealing component has: a ring-shaped main body; and The annular lip portion extends from the main body toward the other axial side and toward the radial inner side or the radial outer side. The front end portion of the lip portion contacts one axial side surface of the housing.

7. The wave gear device according to claim 5, wherein: The sealing component has: a ring-shaped main body; and The annular lip portion extends from the main body portion toward one side in the axial direction and toward the radial inner side or the radial outer side, The front end portion of the lip portion is in contact with the surface of the substrate on the other axial side or the surface of the diaphragm portion on the other axial side.

8. The wave gear device according to any one of claims 1, 2, 5 to 7, wherein: The housing has a stepped portion for holding the sealing member.

9. The wave gear device according to claim 2, wherein: When viewed in the axial direction, the substrate extends to a position radially inward of the body.

10. The wave gear device according to claim 9, wherein: The housing has a cylindrical portion extending from an inner end portion in the radial direction toward one side in the axial direction. The radially inner end of the substrate contacts the 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, wherein: The conductor layer has a first resistance line pattern and a second resistance line pattern, The first resistance wire pattern is an arc-shaped or annular pattern formed by arranging a plurality of resistance wires in a circumferential direction and tilted toward one side relative to the radial direction of the diaphragm. The second resistance wire pattern is an arc-shaped or annular pattern in which a plurality of resistance wires are arranged in the circumferential direction and tilted toward the other circumferential side with respect to the radial direction of the diaphragm.

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