Flexing meshing gear device

Abstract

Provided is a flexspline type gear device capable of good torque detection. Therefore, the flexspline type gear device (1) includes a vibration generating body (30A), an external gear (33) that is flexibly deformed by the vibration generating body, and an internal gear (41) that engages with the external gear, the internal gear having an internal tooth ring portion (412) having internal teeth (411) formed on an inner periphery, an external linking portion (413) linked to an external member, a flexible portion (414) having a structure that is more easily deformed than the internal tooth ring portion, and a strain measurement mechanism (416) provided on the flexible portion.

Description

Technical Field

[0001] This invention relates to a flexural meshing gear device. Background Technology

[0002] In gear devices such as flexural meshing gear devices with external gears capable of flexural deformation, a strain gauge is mounted on the outer periphery of the fixed frame of the internal gear, and torque is detected based on the detected strain (see, for example, Patent Document 1).

[0003] Previous technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Utility Model Application Publication No. 07-20537 Summary of the Invention

[0006] The technical problem to be solved by the invention

[0007] However, in the aforementioned conventional gear devices, the strain gauge is mounted on the outer periphery of the fixing frame of the internal gear. Therefore, it is located in a position where the internal gear is not prone to strain caused by torque, and thus, sufficient detection accuracy may not be obtained.

[0008] The purpose of this invention is to provide a flexural meshing gear device capable of good torque detection.

[0009] means for solving technical problems

[0010] This invention relates to a flexural meshing gear device, which comprises:

[0011] Vibrating body;

[0012] The external gear is flexed and deformed by the vibrating body; and

[0013] The internal gear meshes with the external gear, wherein,

[0014] The internal gear is configured to have an internal tooth ring-shaped portion with internal teeth formed on its inner circumference, an external connecting portion connected to an external component, a deformable portion disposed between the internal tooth ring-shaped portion and the external connecting portion and which is more deformable than the internal tooth ring-shaped portion, and a strain measuring mechanism disposed on the deformable portion.

[0015] Invention Effects

[0016] According to the present invention, a flexural meshing gear device capable of good torque detection is provided. Attached Figure Description

[0017] Figure 1 This is an axial sectional view showing the flexural meshing gear device according to the first embodiment of the present invention.

[0018] Figure 2 This is a three-dimensional view of the first internal tooth component.

[0019] Figure 3 This is a front view of another example of the first internal gear component of the flexural meshing gear device according to the second embodiment of the present invention, viewed from the axial direction.

[0020] Figure 4 This is a front view of another example of the first internal gear component of the flexural meshing gear device according to the third embodiment of the present invention, viewed from the axial direction.

[0021] Figure 5 This is a magnified partial front view showing the periphery of the support member of the first internal tooth member in the third embodiment.

[0022] Figure 6 This is a front view of another example of the first internal gear component of the flexural meshing gear device according to the fourth embodiment of the present invention, viewed from the axial direction.

[0023] Figure 7 This is a front view of another example of the first internal gear component of the flexural meshing gear device according to the fifth embodiment of the present invention, viewed from the axial direction.

[0024] Figure 8 This is a perspective view showing another example of the first internal gear component of the flexural meshing gear device according to the sixth embodiment of the present invention.

[0025] Figure 9 This is an axial sectional view of the first internal tooth component according to the sixth embodiment of the present invention.

[0026] Figure 10 This is an axial sectional view of the first internal tooth component according to the seventh embodiment of the present invention.

[0027] Figure 11 This is a front view of the first internal tooth component according to the eighth embodiment of the present invention.

[0028] Figure 12 This is a top view of a double shear strain gauge.

[0029] Figure 13 The text shows that when using... Figure 12 The Wheatstone bridge circuit formed in the measuring device of the strain gauge.

[0030] Figure 14 This is a simplified diagram showing another example of the first internal gear component of the flexural meshing gear device according to the ninth embodiment of the present invention.

[0031] Figure 15 The text shows that in Figure 14The Wheatstone bridge circuit constituted in the measuring device for the flexural meshing gear device.

[0032] Figure 16 Is Figure 14 Another example of a Wheatstone bridge circuit constituted in a flexural meshing gear measuring device.

[0033] Figure 17 Is Figure 14 Another example of a Wheatstone bridge circuit constituted in a flexural meshing gear measuring device. Detailed Implementation

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0035] [First Implementation Method]

[0036] Figure 1 This is an axial sectional view showing the flexural meshing gear device according to the first embodiment of the present invention.

[0037] In addition, in the following description, the direction parallel to the rotation axis O1 described later is called the axial direction, the circumferential direction of the circle centered on the rotation axis O1 is called the circumferential direction, and the radial direction of the circle centered on the rotation axis O1 is called the radial direction.

[0038] The flexural gear device 1 of the first embodiment is, for example, a speed reduction device. The application of the flexural gear device 1 is not particularly limited and can be used for various purposes, such as driving the joints of a collaborative robot that works in conjunction with a human. The flexural gear device 1 includes: a vibrating body shaft 30; a vibrating body bearing 31; a first external tooth portion 32; a second external tooth portion 33; a first internal tooth portion 411; a second internal tooth portion 421; a housing 43; a first cover 44; a second cover 45; a third cover 49; bearings 46 and 47; a main bearing 48; and retaining rings 51 and 52.

[0039] The vibrating body shaft 30 is a hollow cylindrical shaft that rotates around a rotation axis O1. It comprises a vibrating body 30A with a non-circular (e.g., elliptical) cross-section perpendicular to the rotation axis O1, and shaft portions 30B and 30C disposed on both axial sides of the vibrating body 30A. The ellipse need not be geometrically precise; it can also be approximately elliptical. Shaft portions 30B and 30C are shafts with a circular cross-section perpendicular to the rotation axis O1. Alternatively, the vibrating body shaft 30 can also be a solid shaft.

[0040] The first internal tooth portion 411 is constructed by providing teeth on a portion of the inner periphery of the first internal tooth member 41, which is a rigid internal gear.

[0041] The second internal tooth portion 421 is constructed by providing teeth on a portion of the inner periphery of the rigid second internal tooth member 42.

[0042] The first external tooth portion 32 and the second external tooth portion 33 are integrally disposed on the outer periphery of a flexible, cylindrical metal base 34, and are arranged on one side and the other side in the axial direction. These first external tooth portions 32, second external tooth portions 33 and base 34 constitute an external gear.

[0043] Furthermore, the first external tooth portion 32 engages with the first internal tooth portion 411, and the second external tooth portion 33 engages with the second internal tooth portion 421.

[0044] The vibrator bearing 31 is, for example, a roller bearing, and is disposed between the vibrator 30A and the base 34 having the first external tooth portion 32 and the second external tooth portion 33. The vibrator 30A and the first external tooth portion 32 and the second external tooth portion 33 can rotate relative to each other via the vibrator bearing 31.

[0045] The vibrating bearing 31 has an outer ring 31a embedded inside the base 34, a plurality of rolling elements (rollers) 31b and a cage 31c for holding the plurality of rolling elements 31b.

[0046] The plurality of rolling elements 31b comprises a first group of rolling elements 31b arranged radially and circumferentially on the inner side of the first external tooth portion 32 and the first internal tooth portion 411, and a second group of rolling elements 31b arranged radially and circumferentially on the inner side of the second external tooth portion 33 and the second internal tooth portion 421. These rolling elements 31b roll on the outer circumferential surface of the vibrator 30A and the inner circumferential surface of the outer ring 31a. The vibrator bearing 31 may also have an inner ring separate from the vibrator 30A. Furthermore, the vibrator bearing 31 may omit the outer ring 31a and use the inner circumferential surface of the base 34 as the outer ring-side rolling surface. The type of rolling element is not particularly limited; for example, it may be a ball. Furthermore, the number of rows of rolling elements is not limited to two; it may be one row or more than three rows.

[0047] Stop rings 51 and 52 are disposed on both sides of the first external tooth portion 32 and the second external tooth portion 33 and the vibrating body bearing 31 in the axial direction, thereby restricting the first external tooth portion 32 and the second external tooth portion 33 and the vibrating body bearing 31 from moving axially.

[0048] The housing 43 covers the outer periphery of the second internal gear member 42. An outer ring portion of the main bearing 48 is formed on the inner periphery of the housing 43, and the housing 43 supports the second internal gear member 42 for free rotation via the main bearing 48. The housing 43 is connected to the first internal gear member 41, for example, via a bolt or other connecting member.

[0049] The main bearing 48 is, for example, a crossed roller bearing, and has a plurality of rolling elements disposed between an inner ring portion integrated with the second internal gear member 42 and an outer ring portion integrated with the housing 43. Alternatively, the main bearing 48 may also be composed of a plurality of bearings (angular contact ball bearings, tapered roller bearings, etc.) axially separated between the second internal gear member 42 and the housing 43.

[0050] Furthermore, an oil seal 541 is provided between the housing 43 and the second internal gear component 42, and at a position closer to the output side than the main bearing 48, which inhibits the lubricant from flowing out axially to the outside (output side).

[0051] The first cover 44 is connected to the third cover 49, for example, via a bolt or other connecting member not shown, and the third cover 49 is connected to the first internal tooth member 41 and the outer shell 43, for example, via a bolt or other connecting member not shown.

[0052] Furthermore, the first cover 44 covers the first external tooth 32 and the first internal tooth 411 from the opposite side of the output in the axial direction. The first cover 44, the third cover 49, the first internal tooth component 41, and the outer shell 43 are directly or indirectly connected to external components (e.g., the base arm component of a collaborative robot).

[0053] Furthermore, the side that connects to an external component (also known as an object component, such as one of the components in a main assembly where a flexural gear mechanism 1 is assembled as a component, and which transmits power to the external component) and outputs the decelerated motion to the external component is called the output side, and the side opposite to the output side in the axial direction is called the output opposite side. A bearing 46 is disposed between the first housing 44 and the shaft portion 30B of the vibrator shaft 30, and the vibrator shaft 30 is rotatably supported on the first housing 44. The bearing 46 is exemplified as a ball bearing, but other radial bearings may also be used.

[0054] Furthermore, an oil seal 542 is provided between the first cover 44 and the shaft portion 30B of the vibrator shaft 30, and at a position further away from the output side than the bearing 46, to prevent lubricant from flowing out axially to the outer side (the output side).

[0055] The second cover 45 is connected to the second internal tooth member 42, for example, via a connecting member 533 such as a bolt, and covers the second external tooth 33 and the second internal tooth 421 from the output side in the axial direction. The second cover 45 and the second internal tooth member 42 are connected to an external member (e.g., the front end arm member of a cooperative robot) that outputs decelerated motion (this external member is a member that rotates relative to an external member connected to the first internal tooth member 41, etc.).

[0056] A bearing 47 is disposed between the second housing 45 and the shaft portion 30C of the vibrator shaft 30, and the vibrator shaft 30 is rotatably supported on the second housing 45. The bearing 47 is exemplified as a ball bearing, but other radial bearings may also be used.

[0057] Furthermore, an oil seal 543 is provided between the second cover 45 and the shaft portion 30C of the vibrator shaft 30, and further to the output side than the bearing 47, to prevent lubricant from flowing out axially to the outer side (output side). Alternatively, the second cover 45 may be integrally formed with the second internal gear component 42.

[0058] Furthermore, a sealing O-ring 551 is installed between the first internal tooth component 41 and the outer casing 43.

[0059] Similarly, a sealing O-ring 554 is installed between the first inner tooth component 41 and the third cover 49, a sealing O-ring 552 is installed between the third cover 49 and the first cover 44, and a sealing O-ring 553 is installed between the second inner tooth component 42 and the second cover 45.

[0060] Therefore, the internal space of the flexural meshing gear device 1 (the space containing the meshing portion of the first external tooth 32 and the first internal tooth 411, the meshing portion of the second external tooth 33 and the second internal tooth 421, the main bearing 48, the bearings 46, 47 and the vibrating body bearing 31, etc.) is set as a lubricant sealing space, and is sealed by oil seals 541 to 543 and O-rings 551 to 554.

[0061] Figure 2 This is a perspective view of the first internal tooth component 41. (See attached image.) Figure 2 As shown, the first internal tooth member 41 includes an internal tooth ring-shaped portion 412 with internal teeth of the first internal tooth portion 411 formed on its inner circumference, an external connecting portion 413 connected to the external member together with the outer shell 43 and the third cover 49, and a deformable portion 414 disposed between the internal tooth ring-shaped portion 412 and the external connecting portion 413 in the radial direction and having a structure that is more easily deformed (with a larger deformation amount) than the internal tooth ring-shaped portion 412 when torque is applied to the first internal tooth member 41.

[0062] The annular portion 412 is annular, and the first internal tooth portion 411 (internal tooth) described above is formed on its inner circumferential surface.

[0063] The external connecting portion 413 is annular and located at the outermost periphery of the first internal tooth member 41. It has a plurality of mounting holes that pass through the axial direction relative to the external member at certain intervals in the circumferential direction. In addition, the external connecting portion 413 can be directly connected to the external member, or it can be connected to the external member via the first cover 44 or the third cover 49.

[0064] The deformable part 414 is composed of a plurality of columnar members 415 that are intermittently arranged in the circumferential direction between the internal toothed annular part 412 and the external connecting part 413.

[0065] The columnar member 415 extends outward in a radial direction from the outer periphery of the internal toothed annular portion 412 and is connected to the inner periphery of the external connecting portion 413. In addition, this example illustrates a case where the deformable portion 414, the internal toothed annular portion 412, and the external connecting portion 413 are formed as a single unit from the same material (e.g., metal, resin, etc.).

[0066] Furthermore, this example illustrates the case where four columnar members 415 are arranged at certain intervals in the circumferential direction. The circumferential intervals between the columnar members 415 are preferably equal, but not necessarily. Moreover, the number of columnar members 415 can be increased or decreased.

[0067] The axial width (thickness) of the external connecting portion 413 and the columnar member 415 are equal and smaller than the axial width of the internal toothed annular portion 412. Alternatively, the axial width of the columnar member 415 may differ from that of the external connecting portion 413; for example, its axial width can be set smaller than that of the external connecting portion 413, provided that sufficient strength is available to ensure torque transmission. Furthermore, the columnar member 415 may have a recess for accommodating the strain gauge 416.

[0068] Additionally, on the plane of the output side inside the radial direction of the external connection portion 413, a protrusion 413a protruding towards the output side is formed throughout the entire circumference, which is embedded (locked into) in the recess on the opposite side of the output of the housing 43.

[0069] Each columnar component 415 is equipped with a strain gauge 416, which serves as a strain measurement mechanism. Here, the strain gauge 416 is shown mounted on the surface opposite to the input of the columnar component 415, but it can also be mounted on the surface on the output side, or on the surface at one end or the other end in the circumferential direction.

[0070] The strain gauge 416 is mounted on the columnar member 415 to detect the radial strain in the columnar member 415. Furthermore, the direction of the strain detected by the strain gauge 416 is not limited to the radial direction.

[0071] When torque is applied to the first internal tooth component 41 (specifically, when the external connecting part 413 is connected to the external component, and the first internal tooth component 411 is subjected to meshing reaction force resulting in torque being applied to the first internal tooth component 411), the deformable part 414 (cylindrical component 415) deforms more significantly than the internal tooth annular part 412. As a result, the radial strain generated in the cylindrical component 415 also increases. Since the strain of this cylindrical component 415 is related to the torque, the torque can be obtained by detecting the strain using a strain gauge 416.

[0072] like Figure 2 As shown, each strain gauge 416 is connected to the measuring device 417 (in Figure 2 The diagram shows only one strain gauge 416 connected, but in reality, all strain gauges 416 are connected to the measuring device.

[0073] The measuring device 417 amplifies and records the detection signals from each strain gauge 416. Furthermore, the rotational phase of the vibrating body 30A is input to the measuring device 417 via a detection unit not shown in the diagram.

[0074] The measuring device 417 stores, for example, a data table that establishes a corresponding association between the rotation phase of the vibrating body shaft 30, the measured values ​​of each strain gauge 416, and the torque value. The measuring device 417 refers to the data table to determine the torque value corresponding to the rotation phase and the measured values ​​of each strain gauge 416 input from the detection unit. The data table is prepared in advance, for example, through experimentation. Specifically, the data table is created by acquiring the measured values ​​of each strain gauge 416 while changing the rotation phase of the vibrating body 30A and the torque applied to the first internal gear member 41. Furthermore, the method by which the measuring device 417 determines the torque based on the measured values ​​of each strain gauge 416 is not particularly limited; for example, the torque value can be calculated using a pre-prepared formula.

[0075] [Deceleration action]

[0076] If the vibrator shaft 30 rotates via rotational motion input from a motor (not shown), the motion of the vibrator 30A is transmitted to the first external tooth 32 and the second external tooth 33. At this time, the first external tooth 32 and the second external tooth 33 are constrained to conform to the shape of the outer circumferential surface of the vibrator 30A, and when viewed axially, they flex into an elliptical shape having a major axis portion and a minor axis portion. Furthermore, the first external tooth 32 meshes with the first internal tooth 411 of the fixed first internal tooth member 41 at its major axis portion. Therefore, the first external tooth 32 and the second external tooth 33 do not rotate at the same speed as the vibrator 30A; instead, the vibrator 30A rotates relative to the inside of the first external tooth 32 and the second external tooth 33. Moreover, accompanying this relative rotation, the first external tooth 32 and the second external tooth 33 flex and deform by moving circumferentially at their major axis and minor axis positions. The deformation period is proportional to the rotation period of the vibrating body shaft 30.

[0077] When the first external tooth 32 and the second external tooth 33 flex and deform, their long axis positions shift, thus changing the meshing position of the first external tooth 32 and the first internal tooth 411 in the rotational direction. Here, if the number of teeth in the first external tooth 32 is set to 100 and the number of teeth in the first internal tooth 411 is set to 102, then with each rotation of the meshing position, the meshing teeth of the first external tooth 32 and the first internal tooth 411 sequentially shift, thereby causing the first external tooth 32 to rotate (self-rotate). With the aforementioned number of teeth, the rotational motion of the vibrating body shaft 30 is reduced to a reduction ratio of 100:2 before being transmitted to the first external tooth 32.

[0078] On the other hand, the second external tooth 33, which shares a base 34 with the first external tooth 32, meshes with the second internal tooth 421. Therefore, the rotation of the vibrator shaft 30 causes the meshing position of the second external tooth 33 and the second internal tooth 421 to change in the rotational direction. Furthermore, the number of teeth in the second internal tooth 421 is the same as the number of teeth in the second external tooth 33, so the second external tooth 33 and the second internal tooth 421 do not rotate relative to each other. The rotational motion of the second external tooth 33 is transmitted to the second internal tooth 421 with a reduction ratio of 1:1. Thus, the rotational motion of the vibrator shaft 30 is reduced to a reduction ratio of 100:2 and then transmitted to the second internal tooth component 42 and the second cover 45. Moreover, this reduced rotational motion is output to the external components.

[0079] In the aforementioned deceleration action, in the first internal tooth portion 411, torque is transmitted from the internal tooth annular portion 412 to the external connecting portion 413 via the deformable portion 414.

[0080] At this time, the strain in the radial direction detected by the strain gauges 416 respectively installed on the columnar components 415 of the deformable part 414 is input to the measuring device 417, and the torque value is derived based on these strains.

[0081] Furthermore, the torque values ​​obtained through these structures can be input into, for example, the control device of the main assembly in which the flexural gear mechanism 1 is assembled as a component, and can be used to detect abnormalities in the torque values ​​of the control device. For example, when the flexural gear mechanism 1 is assembled into the joint of a collaborative robot, an abnormal increase in torque value can be detected to indicate contact between the robot arm and the human, thereby enabling the robot to stop or perform an avoidance action.

[0082] [Technical Effects of the Implementation Method]

[0083] As described above, in the flexural meshing gear device 1 according to this embodiment, the first internal tooth component 41 has a deformable portion 414 with a structure that is more easily deformable than the internal tooth annular portion 412, and a strain gauge 416 provided on the deformable portion 414.

[0084] Therefore, when transmitting torque, strain can be detected in the deformable portion 414 of the first internal tooth component 41, which is more inward than the external connecting portion 413 and more easily deformable than the internal tooth annular portion 412. Thus, the strain gauge 416 detects strain at a location where strain caused by torque is easily generated, thereby enabling higher precision torque detection.

[0085] Furthermore, when strain is detected in the outer periphery where it is difficult to generate strain caused by torque, countermeasures such as forming the first internal gear component as a whole from a non-hard material are needed to improve the detection accuracy, so that strain caused by torque can be easily generated in the outer periphery. However, this countermeasure has the disadvantage of easily causing gear meshing errors.

[0086] In contrast, for the first internal gear member 41 of the flexural meshing gear device 1 of this embodiment, it is only necessary to make a portion composed of the deformable part 414 easily deformable, so that the meshing error of the gear can be suppressed.

[0087] Furthermore, since the strain gauge 416 is located inside the flexural meshing gear device 1 rather than on its outer periphery, the device can be miniaturized.

[0088] Furthermore, the deformable part 414 is composed of a columnar member 415 that is intermittently provided circumferentially between the internal toothed annular part 412 and the external connecting part 413. Therefore, the structure of the deformable part 414 can be easily realized without the need for special methods such as adding new parts.

[0089] [Second Implementation]

[0090] Figure 3 This is a front view of another example of the first internal gear component of the flexural meshing gear device according to the second embodiment of the present invention, viewed from the axial direction.

[0091] The difference between the first internal gear member 41A of the second embodiment and the first internal gear member 41 described above is that the number of columnar members 415 constituting the deformable portion 414A is different. That is, the deformable portion 414A of the first internal gear member 41A has eight columnar members 415 evenly spaced in the circumferential direction. In addition, the structure and size of each columnar member 415 are the same as those of the columnar members 415 of the first internal gear member 41 described above.

[0092] Furthermore, strain gauges 416 are installed on each columnar component 415.

[0093] Thus, in the first internal gear member 41A, by increasing the number of columnar members 415, the internal gear annular portion 412 can be supported from the outside, thereby suppressing the deflection of the internal gear annular portion 412. As a result, gear meshing errors can be reduced.

[0094] Furthermore, it can increase the number of strain gauges 416.

[0095] [Third Implementation Method]

[0096] Figure 4 This is a front view of another example of the first internal gear component of the flexural meshing gear device according to the third embodiment of the present invention, viewed from the axial direction.

[0097] The difference between the first internal tooth component 41B of the third embodiment and the first internal tooth component 41 described above is that it has four support components 418B.

[0098] Each support member 418B is disposed in the radial direction between the internal toothed annular portion 412 and the external connecting portion 413, and in the circumferential direction between two adjacent columnar members 415.

[0099] like Figure 5 As shown, these support members 418B extend radially between the internal toothed annular portion 412 and the external connecting portion 413, with one end (e.g., the end on the side of the internal toothed annular portion 412) fixed, while the other end (e.g., the end on the side of the external connecting portion 413) can slidably contact the inner circumference of the external connecting portion 413. Alternatively, the external connecting portion 413 side can be fixed, while the internal toothed annular portion 412 side can slidably contact it.

[0100] Each support member 418B is composed of a component different from the internal toothed annular portion 412 and the external connecting portion 413, and is fixed at one end by welding, bonding or other joining methods. Furthermore, each support member 418B only needs to be fixed relative to the internal toothed annular portion 412 or the external connecting portion 413 at least in the circumferential direction. Moreover, each support member 418B can be formed, for example, of a material different from the first internal toothed member 41, such as resin, or it can be formed of the same material.

[0101] Thus, by providing a support member 418B in the first internal gear member 41B, the internal gear annular portion 412 can be supported from the outside, thereby suppressing the deflection of the internal gear annular portion 412. As a result, gear meshing errors can be reduced.

[0102] Furthermore, the support member 418B is fixed in the circumferential direction only at one end relative to the external connecting part 413 or the internal toothed ring part 412, while the other end is not fixed. Therefore, it can not only support the internal toothed ring part 412 from the outside, but also does not suppress the expansion and contraction strain of the columnar member 415 caused by torque, thus enabling good torque detection.

[0103] [Fourth Implementation Method]

[0104] Figure 6 This is a front view of another example of the first internal gear component of the flexural meshing gear device according to the fourth embodiment of the present invention, viewed from the axial direction.

[0105] The deformable portion 414 of the first internal tooth component 41 described above is composed of four columnar components 415 extending straight along the radial direction, but is not limited to this.

[0106] The deformable portion 414C of the first internal tooth component 41C in the fourth embodiment has a plurality of support portions 415C that connect the internal tooth ring portion 412 and the external connection portion 413 in the radial and circumferential directions.

[0107] Multiple support portions 415C are evenly spaced circumferentially between the internal toothed annular portion 412 and the external connecting portion 413. Each support portion 415C can be integrally formed from the same material as the internal toothed annular portion 412 and the external connecting portion 413, or it can be formed from a different material. Furthermore, both ends of each support portion 415C are fixed to the internal toothed annular portion 412 and the external connecting portion 413, respectively. This example illustrates a case with four support portions 415C, but the number is not limited to four. In the fourth embodiment, each support portion 415C corresponds to a columnar member.

[0108] Each support portion 415C is crank-shaped. That is, each support portion 415C has a first extension portion 415Ca extending outward in a radial direction from the outer periphery of the internal toothed annular portion 412, a second extension portion 415Cb extending inward in a radial direction from the inner periphery of the external connecting portion 413, and an intermediate connecting portion 415Cc extending circumferentially or in a tangential direction relative to the circumferential direction along the extension end of the first extension portion 415Ca and the extension end of the second extension portion 415Cb.

[0109] Furthermore, the strain gauge 416 is mounted on the intermediate connection portion 415Cc of each support portion 415C in the direction of detecting the expansion and contraction strain in the length direction of the intermediate connection portion 415Cc.

[0110] Thus, in the first internal gear member 41C, a strain gauge 416 is provided on the intermediate connection portion 415Cc of the support portion 415C which has a portion extending along the circumferential direction or in a tangential direction relative to the circumferential direction (i.e., intermediate connection portion 415Cc).

[0111] Therefore, during torque transmission in the flexural gear mechanism, the portion along the circumferential direction or the tangential direction relative to the circumferential direction (i.e., the intermediate connection 415Cc) experiences more significant expansion and contraction strain, thus enabling higher precision torque detection.

[0112] [Fifth Implementation Method]

[0113] Figure 7 This is a front view of another example of the first internal gear component of the flexural meshing gear device according to the fifth embodiment of the present invention, viewed from the axial direction.

[0114] The deformable portion 414 of the first internal tooth component 41 described above is composed of four columnar components 415 extending straight along the radial direction, but is not limited to this.

[0115] The deformable portion 414D of the first internal tooth member 41D in the fifth embodiment has a plurality of support portions 415D that are fixed to the outer periphery of the internal tooth annular portion 412 and extend along a tangential direction relative to the circumferential direction.

[0116] Both ends of each support portion 415D are fixed to the inner circumference of the outer connecting portion 413, and the middle portion is fixed to the outer circumference of the internal toothed annular portion 412.

[0117] Furthermore, an example is shown here with four support portions 415D. In the four support portions 415D, the two ends of one support portion 415D are connected to the ends of another support portion 415D, so that when viewed from the axial direction, the four support portions 415D form a single unit and a square frame shape.

[0118] Furthermore, a strain gauge 416 is installed between the end of each support portion 415D that is fixed to the inner periphery of the external connecting portion 413 and the middle portion that is fixed to the outer periphery of the internal toothed ring portion 412. Each strain gauge 416 is installed in the direction of detecting the expansion and contraction strain in the length direction of the support portion 415D.

[0119] Each support portion 415D can be formed integrally from the same material as the internal toothed annular portion 412 and the external connecting portion 413, or it can be formed from different materials.

[0120] Furthermore, this example illustrates a case with four support portions 415D, but the number is not limited to four, as long as they can be evenly spaced around the internal toothed annular portion 412 in the circumferential direction.

[0121] Thus, the deformable portion 414D of the first internal gear component 41D has the support portion 415D with the above-described structure, but the deformable portion 414D, like the deformable portion 414, is also capable of performing high-precision torque detection.

[0122] [Sixth Implementation Method]

[0123] Figure 8 This is a perspective view showing another example of the first internal gear component of the flexural meshing gear device according to the sixth embodiment of the present invention.

[0124] The deformable portion 414 of the first internal tooth component 41 described above is composed of four columnar components 415 intermittently arranged along the circumference, but is not limited to this.

[0125] The deformable portion 414E of the first internal tooth member 41E in the sixth embodiment is formed by a circumferentially continuous annular plate between the internal tooth annular portion 412 and the external connecting portion 413.

[0126] However, as Figure 9 As shown in the axial cross-sectional view, the axial thickness d3 of the deformable part 414E is set to be smaller than the axial thickness d1 of the internal toothed annular part 412 and the axial thickness d2 of the external connecting part 413.

[0127] Furthermore, multiple strain gauges 416 are mounted at equal intervals along the circumference on any plane of the deformable portion 414E. An example is shown here with four strain gauges 416. Alternatively, there can be only one strain gauge 416; for example, an annular strain gauge can be arranged in a ring along the deformable portion 414E.

[0128] Each strain gauge 416 is installed in the direction of detecting the expansion and contraction strain in the radial direction.

[0129] Thus, in the first internal gear component 41E, the deformable portion 414E is designed as a continuous flat plate along the circumferential direction, and its axial thickness d3 is set to be smaller than the axial thickness d1 of the internal gear annular portion 412 and the axial thickness d2 of the external connecting portion 413. Therefore, when the flexural meshing gear device transmits torque, the deformable portion 414E is more easily deformed than the internal gear annular portion 412. As a result, it is also easier to generate expansion and contraction strain in the radial direction. Similar to the deformable portion 414, higher accuracy torque detection is possible. In addition, the axial thickness d3 of the deformable portion 414E only needs to be at least smaller than the axial thickness d1 of the internal gear annular portion 412, and can be the same as or greater than the axial thickness d2 of the external connecting portion 413.

[0130] Furthermore, the deformable portion 414E is continuous along the circumference, thus supporting the internal tooth annular portion 412 from the outside throughout the entire circumference, thereby suppressing the deflection of the internal tooth annular portion 412. As a result, gear meshing errors can be reduced.

[0131] [Seventh Implementation Method]

[0132] Figure 10 This is an axial sectional view of the first internal tooth component according to the seventh embodiment of the present invention.

[0133] In the above embodiments, the shape of the deformable portion 414 is designed to make it more easily deformable than the internal toothed annular portion 412; however, the method for making the deformable portion 414 easily deformable is not particularly limited. For example, like... Figure 10 As shown in the first internal tooth component 41F, the deformable portion 414F can be formed from a material that is softer than the internal tooth annular portion 412 or even the external connecting portion 413, thereby making it more easily deformable than the internal tooth annular portion 412. For example, it is preferable to form the deformable portion 414F from a metal material that is softer than the internal tooth annular portion 412 and the external connecting portion 413, or from a resin material that is softer.

[0134] At this time, the axial thickness of the internal tooth ring portion 412, the deformable portion 414F and the external connecting portion 413 can be the same, or the thickness of the deformable portion 414F can be set to be greater than the thickness of the internal tooth ring portion 412 and the external connecting portion 413.

[0135] Furthermore, the deformable portion 414F can be provided intermittently or continuously along the circumference. In the case of intermittent provision, it can be configured to be the same as the deformable portions 414, 414A, 414C, and 414D described above. Moreover, the support member 418B described above can also be added.

[0136] [Eighth Implementation Method]

[0137] Figure 11 This is a front view showing another example of the first internal gear member of the flexural meshing gear device according to the eighth embodiment of the present invention. Additionally, in Figure 11 In the diagram, the first external tooth 32 is simplified using an ellipse to indicate the position of the major axis.

[0138] In the first internal gear member 41 described above, the deformable part 414 has two sets of columnar members 415 respectively disposed on both sides of the first internal gear member 41 in the diametrical direction. Moreover, the four columnar members 415 composed of these two sets are equally spaced in the circumferential direction, and a strain gauge 416 is mounted on each columnar member 415.

[0139] In contrast, in the flexural meshing gear device according to the eighth embodiment, the deformable portion 414 of the first internal gear member 41G has two sets of columnar members 415 arranged on both sides of the first internal gear member 41G in the diametrical direction, and the columnar members 415 are equally spaced in the circumferential direction, which is the same as the first internal gear member 41. Moreover, in the first internal gear member 41G, strain gauges 56-1 and 56-2 are respectively provided on one of the columnar members 415 in the two sets.

[0140] Furthermore, the structure of strain gauge 56-1 is the same as that of strain gauge 56-2. In the following description, when there is no need to distinguish between them, they will be referred to as strain gauge 56.

[0141] Furthermore, in Figure 11 In the above, the strain gauges 56-3 and 56-4, indicated by double-dotted lines, are another example of the first internal gear component described later. In the first internal gear component 41G of this eighth embodiment, strain gauges 56-3 and 56-4 are not provided.

[0142] Figure 12 This is a top view of strain gauge 56. (Example) Figure 12 As shown, the strain gauge 56 is a dual-shear strain gauge, which has strain gauges formed on the plane of the substrate of the insulator respectively. Figure 12 The left and right measuring parts 56A and 56B are in the middle.

[0143] Each measuring section 56A and 56B has a grid section 561A and 561B with several layers of resistance wires folded back in parallel, and leads 562A and 562B extending from both ends of the grid section 561A and 561B.

[0144] Figure 12 The resistance line of the grid section 561A of the left measuring section 56A extends in a right-downward direction, and the resistance line of the grid section 561B of the right measuring section 56B extends in a left-downward direction.

[0145] As can be seen from this structure, the strain gauge 56 is essentially a structure with two strain gauges that have different strain detection directions and can obtain detection signals from these two strain gauges respectively.

[0146] Each measuring unit 56A and 56B has a structure that is highly sensitive to the shrinkage strain in the extension direction of the resistance wires of each grid unit 561A and 561B. Moreover, the extension direction of the resistance wires of the grid unit 561A of the measuring unit 56A is orthogonal to the extension direction of the resistance wires of the grid unit 561B of the measuring unit 56B.

[0147] The strain gauge 56 uses the combined direction of the extension directions of each resistance wire in the grid sections 561A and 561B of the two measuring sections 56A and 56B as the reference direction. Figure 12(arrow G). Moreover, the strain gauge 56 is mounted on the cylindrical member 415 in such a way that the reference direction G is orthogonal to the direction in which the flexural meshing gear device 1 generates shear force on the cylindrical member 415 when it operates. More specifically, the reference direction G of the strain gauge 56 is set to be parallel to the length direction (i.e., the radial direction) of the cylindrical member 415.

[0148] In the above situation, if the rotation of the vibrating body shaft 30 in a clockwise direction causes the first external tooth portion 32 to rotate counterclockwise relative to the first internal tooth component 41G (hereinafter referred to as forward rotation), then the internal tooth ring portion 412 of the first internal tooth component 41G bears a torque in a clockwise direction relative to the external connecting portion 413. The resulting shear force mainly acts on the grid portion 561A of the measuring unit 56A, thereby enabling the measurement unit 56A to obtain a detection signal corresponding to the torque.

[0149] Furthermore, if the oscillator shaft 30 rotates counterclockwise, causing the first external tooth portion 32 to rotate clockwise relative to the first internal tooth component 41G (hereinafter referred to as counterclockwise rotation), then the internal tooth ring portion 412 of the first internal tooth component 41G bears a torque in the counterclockwise direction relative to the external connecting portion 413. The resulting shear force mainly acts on the grid portion 561B of the measuring unit 56B, thereby enabling the measurement unit 56B to obtain a detection signal corresponding to the torque.

[0150] The first internal gear component 41G is a structure in which one end of a pair of columnar components 415 is symmetrical to the other end in the diametrical direction. At this time, when the flexural meshing gear device 1 is in operation, as long as no bending moment relative to the axial direction is generated, equal shear forces due to torque are generated in one of the two columnar components 415 and the other columnar component 415 in the pair.

[0151] Therefore, even if strain gauges 56 are not installed on both columnar components 415 in a pair, the required strain can be detected by installing strain gauge 56 on only one columnar component 415, and the torque can be calculated based on the detection of each strain gauge 56.

[0152] That is, the flexural meshing gear device 1 of the eighth embodiment is particularly good at obtaining torque in environments where it is difficult to generate bending moment relative to the axial direction.

[0153] Figure 13 The diagram shows the Wheatstone bridge circuit 57 constructed in the measuring device using the strain gauges 56 described above.

[0154] The Wheatstone bridge circuit 57 has paths 1 to 4, 571 to 574.

[0155] Furthermore, one end of the first path 571 and one end of the second path 572 are both connected to the positive side of the voltage supply source and the positive side of the transmitter. Additionally, one end of the third path 573 and one end of the fourth path 574 are both connected to the negative side of the voltage supply source and the negative side of the transmitter.

[0156] Furthermore, the other end of the first path 571 is connected to the other end of the third path 573, and the connection point becomes the positive side output of the detection signal. Also, the other end of the second path 572 is connected to the other end of the fourth path 574, and the connection point becomes the negative side output of the detection signal.

[0157] like Figure 13 As shown, a measuring section 56A of a strain gauge 56-2 is provided on the first path 571 (in... Figure 13 The middle part is “2A”), and the measuring part 56B of the strain gauge 56-2 is set on the second path 572 (in Figure 13 The middle part is "2B"), and the measuring part 56B of the strain gauge 56-1 is installed on the third path 573 (in Figure 13 The middle part is “1B”), and the measuring part 56A of the strain gauge 56-1 is installed on the fourth path 574 (in Figure 13 (The middle part is "1A").

[0158] In addition, Figure 13 In the text, “3A”, “3B”, “4A”, and “4B”, indicated by double-dotted lines, represent the measuring parts 56A and 56B of strain gauges 56-3 and 56-4 in another example of the first internal gear component described later. “3A”, “3B”, “4A”, and “4B” are not provided in the Wheatstone bridge circuit 57 of this eighth embodiment.

[0159] In the aforementioned Wheatstone bridge circuit 57, when the first external tooth 32 rotates in the forward direction, a detection signal can be obtained based on the movement of the major axis position of each vibrating element 30A via the measuring sections 56A of strain gauge 56-1 and strain gauge 56-2. This detection signal can be obtained from the potential difference between the positive and negative outputs of the Wheatstone bridge circuit 57. Furthermore, since the shear detection signal detected from each columnar member 415 is related to the torque of the flexural gear mechanism, the torque of the flexural gear mechanism can be obtained based on the shear detection signal.

[0160] As described above, in the flexural meshing gear device according to the eighth embodiment, the number of strain gauges 56 can be reduced relative to the number of columnar members 415, thereby reducing the production cost of the device.

[0161] In addition, the eighth embodiment illustrates a case where the deformable portion 414 of the first internal tooth member 41G has two sets (four) of columnar members 415, but a structure having one or more sets of columnar members 415 may also be adopted.

[0162] Furthermore, while a double-shear strain gauge is exemplified as strain gauge 56, strain gauge 416, which measures strain in the longitudinal direction (radial direction) of columnar member 415 as described above, can also be used.

[0163] Furthermore, strain gauge 56 can be used instead of strain gauge 416 in the first to seventh embodiments described above.

[0164] Furthermore, in the eighth embodiment, a dual-shear strain gauge is exemplified. However, for example, if the flexural meshing gear device rotates only in either the forward or reverse direction, a strain gauge having only one of the measuring units 56A and 56B can also be used.

[0165] Furthermore, as in the first embodiment, strain gauges 56-1 to 56-4 are provided on all columnar members 415, such as Figure 11 and Figure 13 As shown by the double-dotted line, the measuring part 56A of the strain gauge 56-2 is connected in series on the first path 571 of the Wheatstone bridge circuit 57. Figure 13 The measuring section 56A of the strain gauge 56-4 (marked as "2A") is located in the middle. Figure 13 (The middle part is "4A").

[0166] Furthermore, the measuring section 56B of the strain gauge 56-2 is connected in series on the second path 572 (in... Figure 13 The middle part is "2B") and the measuring part 56B of the strain gauge 56-4 (in Figure 13 (The middle part is "4B").

[0167] Furthermore, the measuring section 56B of the strain gauge 56-1 is connected in series on the third path 573 (in Figure 13 The measuring section 56B of strain gauge 56-3 (with "1B" in the middle) and the measuring section 56B of strain gauge 56-3 (in Figure 13 (The middle part is "3B").

[0168] Furthermore, the measuring section 56A of the strain gauge 56-1 is connected in series on the fourth path 574 (in... Figure 13 The middle part is “1A”) and the measuring part 56A of the strain gauge 56-3 (in Figure 13 (The middle part is "3A").

[0169] Therefore, the torque of the flexural meshing gear device can be obtained based on the detection signal of the shear detected from each columnar component 415.

[0170] [Ninth Implementation Method]

[0171] Figure 14 This is a simplified diagram showing another example of the first internal gear component of the flexural meshing gear device according to the ninth embodiment of the present invention. Additionally, in Figure 14 In the diagram, the first external tooth 32 is also simplified using an ellipse to indicate the position of the major axis.

[0172] In the first embodiment described above, the deformable portion 414 is illustrated by having a structure in which an even number of columnar members 415 are arranged at equal intervals in the circumferential direction.

[0173] In contrast, in the first internal gear member 41H of the flexural meshing gear device according to the ninth embodiment, the deformable portion 414 is illustrated with a structure in which a plurality of odd-numbered columnar members 415 are arranged at equal intervals in the circumferential direction. In the ninth embodiment, a case with seven columnar members 415 is illustrated, but the number of columnar members 415 is only required to be a plurality of odd-numbered members and can be arbitrarily changed.

[0174] On all columnar components 415, strain gauges 56-1 to 56-7, identical to the strain gauges 56 described above, are sequentially arranged along the circumference.

[0175] When the number of columnar components 415 in the first internal tooth component 41H is odd, such as Figure 14 As shown by the solid line, if one end of the long shaft of the first external tooth 32 is engaged in a position consistent with any one of the columnar members 415 in the circumferential direction, then the other end of the long shaft of the first external tooth 32 is engaged in a position between the other two columnar members 415.

[0176] At this time, on one end side of the long shaft of the first external tooth 32, the shear of the first internal tooth 41H decreases due to the rigidity of the columnar member 415, while on the other end side of the long shaft of the first external tooth 32, the shear of the first internal tooth 41H increases.

[0177] Here, the strain gauges 56-1 to 56-7 that detected strain are mainly those located near the long axis of the first external tooth section 32. Figure 14In the example shown by the solid line, strain gauges 56-4, 56-5, 56-1, 56-2, and 56-7 detect strain, but because strain gauges 56-2 and 56-7 are far from the long axis, the detected strain is small. As mentioned above, on the other end side of the long axis of the first external tooth 32, the shear generated in the first internal tooth member 41H becomes larger, therefore, the detected values ​​of strain gauges 56-4 and 56-5 become larger. On the other hand, on the end side of the long axis of the first external tooth 32, the shear generated in the first internal tooth member 41H becomes smaller, therefore, the detected value of strain gauge 56-1 becomes smaller than the detected values ​​of strain gauges 56-4 and 56-5. However, because the Wheatstone bridge circuit 57H (refer to the following description) is connected in series by each measuring unit 56A and each measuring unit 56B, the strain is significantly reduced. Figure 15 The measurement is performed, and thus the outputs of all strain gauges are averaged at one end and the other end of the long shaft of the first external tooth 32, thereby outputting a moderate level of detection signal.

[0178] And, as Figure 14 As shown by the double-dotted line, if both ends of the long shaft of the first external tooth 32 are not aligned with each columnar member 415 in the circumferential direction but engage with each columnar member 415 at a position close to the columnar member 415, then the shearing generated in the first internal tooth member 41H is of a moderate degree on both one end side and the other end side of the long shaft of the first external tooth 32.

[0179] Therefore, if the detection values ​​of each strain gauge 56-1 to 56-7 are combined, a moderate level of detection signal will still be output.

[0180] Therefore, by setting the number of columnar components to a plurality and an odd number, the variation width (total value, average value) of the detection signals obtained from each strain gauge 56-1 to 56-7 is reduced when the long axis of the first external tooth 32 rotates circumferentially. To address this problem, the Wheatstone bridge circuit 57H constructed in the measuring device using the aforementioned strain gauges 56-1 to 56-7 is configured as follows: Figure 15 As shown.

[0181] In addition, Figure 15 In the text, “1A” to “7A” represent the measuring section 56A of strain gauges 56-1 to 56-7, respectively, and “1B” to “7B” represent the measuring section 56B of strain gauges 56-1 to 56-7, respectively.

[0182] like Figure 15 As shown, a resistor R1 is provided on the first path 571, a resistor R2 is provided on the second path 572, the measuring parts 56A of strain gauges 56-1 to 56-7 are connected in series on the third path 573, and the measuring parts 56B of strain gauges 56-1 to 56-7 are connected in series on the fourth path 574.

[0183] The resistance values ​​of resistors R1 and R2 are equal to the resistance values ​​of the seven measuring units 56A connected in series when no strain is generated (and also equal to the resistance values ​​of the seven measuring units 56B connected in series).

[0184] Thus, in the Wheatstone bridge circuit 57H, each measuring part 56A or each measuring part 56B of the strain gauges 56-1 to 56-7 is connected in series on any one of the four paths 571 to 574.

[0185] Therefore, even if the individual detection signals obtained from each strain gauge 56-1 to 56-7 decrease when the long axis of the first external tooth 32 rotates circumferentially, the total detection signal can still be obtained, thereby increasing the detection signal. Furthermore, by setting the number of columnar members to be multiple and odd, the fluctuation of the detection signal (total value) caused by the circumferential position of the long axis of the first external tooth 32 can be reduced.

[0186] Furthermore, the Wheatstone bridge circuit constructed in the measuring apparatus using the aforementioned strain gauges 56-1 to 56-7 can also be... Figure 16 The Wheatstone bridge circuit 57H-1 shown is as follows: Figure 17 The Wheatstone bridge circuit shown is composed of these two Wheatstone bridge circuits, 57H-2.

[0187] like Figure 16 As shown, the Wheatstone bridge circuit 57H-1 has a resistor R1 on the first path 571, a resistor R2 on the second path 572, and the measuring parts 56A of the strain gauges 56-1 to 56-7 connected in series on the third path 573. A resistor R3 is provided on the fourth path 574.

[0188] The resistance values ​​of resistors R1 to R3 are equal to the resistance values ​​of the seven measuring units 56A connected in series when no strain is generated (and also equal to the resistance values ​​of the seven measuring units 56B connected in series).

[0189] like Figure 17 As shown, the Wheatstone bridge circuit 57H-2 has a resistor R5 on the first path 571, a resistor R6 on the second path 572, a resistor R4 on the third path 573, and the measuring parts 56B of the strain gauges 56-1 to 56-7 are connected in series on the fourth path 574.

[0190] The resistance values ​​of resistors R4 to R6 are equal to the resistance values ​​of the seven measuring units 56B connected in series when no strain is generated.

[0191] In the Wheatstone bridge circuits 57H-1 and 57H-2, one end of the first path 571 and the second path 572 are connected to the positive side of the voltage supply source and the positive side of the transmitter, respectively, and one end of the third path 573 and the fourth path 574 are connected to the negative side of the voltage supply source and the negative side of the transmitter, respectively. Furthermore, the other end of the first path 571 and the third path 573 becomes the positive side output of the detection signal, and the other end of the second path 572 and the fourth path 574 becomes the negative side output of the detection signal.

[0192] Moreover, each of the Wheatstone bridge circuits 57H-1 and 57H-2 receives voltage from the same power source, and different (independent) detection signals can be obtained from each of the Wheatstone bridge circuits 57H-1 and 57H-2.

[0193] Based on this structure, two detection signals that can be compared for diagnosing safety levels can be obtained from each of the Wheatstone bridge circuits 57H-1 and 57H-2.

[0194] [other]

[0195] The minor details shown in the above embodiments can be appropriately modified without departing from the spirit of the invention.

[0196] Furthermore, in the above embodiments, a structure in which a deformable portion and a strain gauge are provided on the first internal tooth component is illustrated, but a deformable portion and a strain gauge may also be provided on the second internal tooth component. In this case, the second internal tooth component should be configured to have an internal tooth ring-shaped portion with internal teeth formed on its inner circumference and an external connecting portion that connects to an external component, and a structure in which a deformable portion and a strain gauge are provided between them.

[0197] Furthermore, regardless of whether deformable portions and strain gauges are provided on the first and second internal gear components, either the first or second internal gear component can be located on the non-rotational side or upstream in the power transmission direction. In the first to ninth embodiments described above (except for the eighth embodiment), strain gauges 416 and 56 are installed on all columnar components 415, but this is not a limitation; strain gauges 416 and 56 may be installed on only a portion of the columnar components 415. Furthermore, in the above embodiments, strain gauges 416 are disposed on the axial end face of the columnar component 415, but this is not a limitation; for example, strain gauges may be disposed on the circumferential surface of the columnar component 415.

[0198] Furthermore, in the above embodiments, examples of flexural meshing gear devices 1 being cylindrical meshing gear devices have been provided. However, the present invention is also well applicable to flexural meshing gear devices other than cylindrical ones, such as cup-shaped or top-hat-shaped ones.

[0199] Industrial availability

[0200] This invention has industrial applicability to flexural meshing gear devices.

[0201] Symbol Explanation

[0202] 1-Flexible meshing gear device; 30-Vibration body shaft; 30A-Vibration body; 32-First external tooth (external gear); 33-Second external tooth (external gear); 41, 41A, 41B, 41C, 41D, 41E, 41F-First internal tooth component (internal gear); 411-First internal tooth (internal tooth); 412-Internal tooth annular portion; 413-External connecting portion; 414, 414A, 414C, 414D, 414E, 414F-Easy-to-connect Deformation section, 415-columnar component, 415C, 415D-support section, 416-strain gauge (strain measurement mechanism), 56, 56-1 to 56-7-strain gauge (double shear strain gauge), 56A, 56B-measuring section, 417-measuring device, 418B-support component, 57, 57H-1, 57H-2-Wheatstone bridge circuit, 571-first path, 572-second path, 573-third path, 574-fourth path.

Claims

1. A flexspline-engaging gear device, comprising: a vibration generator; an outer gear deformed in flexure by the vibration generator; and an inner gear engaged with the outer gear, the flexspline-engaging gear device characterized in that the inner gear has an inner-tooth annular portion in which inner teeth are formed on an inner periphery, an outer-portion linking portion linked with an outer-portion member, a deformable portion provided between the inner-tooth annular portion and the outer-portion linking portion and having a structure that is more easily deformed than the inner-tooth annular portion, and a strain measuring mechanism provided on the deformable portion, an axial thickness of the deformable portion is smaller than an axial thickness of the inner-tooth annular portion, and the deformable portion is formed by a ring-shaped flat plate that is continuous in a circumferential direction between the inner-tooth annular portion and the outer-portion linking portion.

2. A flexspline-engaging gear device, comprising: a vibration generator; an outer gear deformed in flexure by the vibration generator; and an inner gear engaged with the outer gear, the flexspline-engaging gear device characterized in that the inner gear has an inner-tooth annular portion in which inner teeth are formed on an inner periphery, an outer-portion linking portion linked with an outer-portion member, a deformable portion provided between the inner-tooth annular portion and the outer-portion linking portion and having a structure that is more easily deformed than the inner-tooth annular portion, and a strain measuring mechanism provided on the deformable portion, the deformable portion includes a plurality of support portions linking the inner-tooth annular portion and the outer-portion linking portion in a radial direction and a circumferential direction, the plurality of support portions are provided at equal intervals in a circumferential direction between the inner-tooth annular portion and the outer-portion linking portion, and the strain measuring mechanism is provided on an intermediate linking portion of the support portion extending in the circumferential direction or a tangential direction with respect to the circumferential direction.

3. A flexspline-engaging gear device, comprising: a vibration generator; an outer gear deformed in flexure by the vibration generator; and an inner gear engaged with the outer gear, the flexspline-engaging gear device characterized in that the inner gear has an inner-tooth annular portion in which inner teeth are formed on an inner periphery, an outer-portion linking portion linked with an outer-portion member, a deformable portion provided between the inner-tooth annular portion and the outer-portion linking portion and having a structure that is more easily deformed than the inner-tooth annular portion, and a strain measuring mechanism provided on the deformable portion, the deformable portion includes a plurality of support portions fixed to an outer periphery of the inner-tooth annular portion and extending in a tangential direction with respect to a circumferential direction, and the strain measuring mechanism is provided on the support portion.

4. The flexspline-engaging gear device according to claim 2, characterized in that the support portion includes a first extension portion extending from an outer periphery of the inner-tooth annular portion to a radial direction outer side, a second extension portion extending from an inner periphery of the outer-portion linking portion to a radial direction inner side, and an intermediate linking portion extending in the circumferential direction or the tangential direction with respect to the circumferential direction linking an extension end portion of the first extension portion and an extension end portion of the second extension portion, and the strain measuring mechanism is provided on the intermediate linking portion.

5. The flexspline-engaging gear device according to claim 3, characterized in that both end portions of the support portion are fixed to the inner periphery of the outer-portion linking portion, and a middle portion of the support portion is fixed to the outer periphery of the inner-tooth annular portion.

6. The flexspline-engaging gear device according to claim 5, characterized in that ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The deformable portion includes a plurality of the support portions, and the plurality of the support portions are circumferentially equally spaced around the inner tooth ring portion as viewed in the axial direction.

7. The flexspline of claim 6 wherein, The deformable portion includes four of the support portions, and the four of the support portions are integrated and in a square frame shape as viewed in the axial direction.

8. The flexspline of claim 7 wherein, One strain gauge is attached between each end portion of each support portion constituting the deformable portion, which is fixed to the inner periphery of the outer link portion, and the intermediate portion fixed to the outer periphery of the inner tooth ring portion.

9. The flexspline of claim 2 wherein, The strain measuring mechanism is a double-shear strain gauge having a measurement portion for each of two directions of strain, and the double-shear strain gauges are provided on the plurality of the support portions, The flexspline has a Wheatstone bridge circuit configured such that the measurement portions for one direction of strain of the plurality of the double-shear strain gauges are connected in series and assembled on one path, and the measurement portions for the other direction of strain of the plurality of the double-shear strain gauges are connected in series and assembled on another path.

10. The flexspline of claim 2 wherein, The strain measuring mechanism is a double-shear strain gauge having a measurement portion for each of two directions of strain, and the double-shear strain gauges are provided on the plurality of the support portions, The flexspline has: a Wheatstone bridge circuit configured such that the measurement portions for one direction of strain of the plurality of the double-shear strain gauges are connected in series and assembled on one path; and another Wheatstone bridge circuit configured such that the measurement portions for the other direction of strain of the plurality of the double-shear strain gauges are connected in series and assembled on another path.

11. The flexspline of claim 1 or 2 or 3 wherein, The deformable portion has a structure that is more easily deformed than the outer link portion. ​

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