Flexure mesh type gear device and torque measuring device

Abstract

To provide a bending meshing type gear device capable of favorable torque detection.SOLUTION: A bending meshing type gear device 1 includes a wave generator 30A, an external gear 33 flexibly deformed by the wave generator, and an internal gear 41 meshing with the external gear. The internal gear includes an internal tooth ring portion 412 including an internal tooth 411 formed on an inner periphery, an external connection portion 413 connected to an external member, an easily deformable portion 414 provided between the internal tooth ring portion and the external connection portion and configured to be more easily deformable than the internal tooth ring portion, and a distortion measurer 416 provided in the easily deformable portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a flexible mesh gear device. and torque measuring device Regarding. [Background technology]

[0002] In gear devices such as a flexible mesh gear device equipped with an external gear that undergoes flexible deformation, a strain gauge is attached to the outer periphery of the fixed frame of the internal gear, and torque is detected from the detected strain (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 07-20537 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional gear device, the strain gauge is attached to the outer periphery of the fixed frame of the internal gear, and is therefore in a position where distortion caused by torque from the internal gear is unlikely to occur, so there was a risk that sufficient detection accuracy would not be achieved.

[0005] The present invention provides a flexible mesh gear device that enables good torque detection. and torque measuring device The purpose is to provide the following. [Means for solving the problem]

[0006] The present invention provides A vibrator; an external gear that is flexibly deformed by the vibrator; an internal gear that meshes with the external gear; A flexible mesh gear device comprising: The internal gear has an internally toothed ring portion having internal teeth formed on its inner circumference, an external connecting portion that is connected to an external member, an easily deformable portion that is provided between the internally toothed ring portion and the external connecting portion and that is configured to be more easily deformed than the internally toothed ring portion, and a distortion measuring means that is provided on the easily deformable portion, The easily deformable portion is circumferentially disposed between the internal tooth ring portion and the external connecting portion. At uniform intervals Intermittently installed Multiple It is composed of a support part, Each of the support portions has a first extending portion extending radially outward from an outer circumferential surface of the internal toothed ring portion, a second extending portion extending radially inward from an inner circumferential surface of the external connecting portion, and an intermediate connecting portion extending along a circumferential direction or a tangential direction to the circumferential direction, connecting an extending end portion of the first extending portion and an extending end portion of the second extending portion, The strain measuring means is a portion along the circumferential direction or a tangential direction to the circumferential direction of the support portion. The intermediate connecting portion The configuration is such that the Another invention is a torque measuring device, An inner member; An outer member; an easily deformable portion provided between the inner member and the outer member and configured to be more easily deformed than the inner member; and a strain measuring means provided on the easily deformable portion; a measurement device for specifying torque from the detected value of the strain measurement means, The easily deformable portion is formed between the inner member and the outer member in a circumferential direction. At uniform intervals Intermittently installed Multiple It is composed of a support part, Each of the support portions has a first extending portion extending radially outward from the outer peripheral surface of the inner member, a second extending portion extending radially inward from the inner peripheral surface of the outer member, and an intermediate connecting portion extending along a circumferential direction or a tangential direction to the circumferential direction, connecting an extending end portion of the first extending portion and an extending end portion of the second extending portion, The strain measuring means is a portion along the circumferential direction or a tangential direction to the circumferential direction of the support portion. The intermediate connecting portion The configuration is such that the [Effects of the Invention]

[0007] According to the present invention, a flexible mesh gear device that enables good torque detection is provided. and torque measuring device It is possible to provide the following. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an axial cross-sectional view showing a flexible mesh gear device according to a first embodiment of the present invention. [Figure 2]FIG. 2 is a perspective view of a first internal teeth member. [Figure 3] FIG. 10 is a front view of another example of the first internal gear member of the flexible mesh gear device according to the second embodiment of the present invention, as viewed from the axial direction. [Figure 4] FIG. 11 is a front view of another example of the first internal gear member of the flexible mesh gear device according to the third embodiment of the present invention, as viewed from the axial direction. [Figure 5] FIG. 11 is an enlarged partial front view of the periphery of a support member of a first internal teeth member of a third embodiment. [Figure 6] FIG. 11 is a front view of another example of the first internal gear member of the flexible mesh gear device according to the fourth embodiment of the present invention, as viewed from the axial direction. [Figure 7] FIG. 11 is a front view of another example of the first internal gear member of the flexible mesh gear device according to the fifth embodiment of the present invention, as viewed from the axial direction. [Figure 8] FIG. 13 is a perspective view showing another example of the first internal gear member of the flexible mesh gear device according to the sixth embodiment of the present invention. [Figure 9] FIG. 13 is an axial cross-sectional view of a first internal gear member according to a sixth embodiment of the present invention. [Figure 10] FIG. 13 is an axial cross-sectional view of a first internal gear member according to a seventh embodiment of the present invention. [Figure 11] FIG. 13 is a front view of a first internal teeth member according to an eighth embodiment of the present invention. [Figure 12] FIG. 1 is a plan view of a double shear strain gauge. [Figure 13] 13 shows a Wheatstone bridge circuit configured in the measurement device using the strain gauge of FIG. 12. [Figure 14] FIG. 13 is a simplified diagram showing another example of the first internal gear member of the flexible mesh gear device according to the ninth embodiment of the present invention. [Figure 15] 15 shows a Wheatstone bridge circuit configured in the flexible mesh gear device measuring device of FIG. 14. [Figure 16] 15 is one Wheatstone bridge circuit configured in another example of the flexible mesh gear device measuring device of FIG. 14. [Figure 17]15 is another Wheatstone bridge circuit configured in another example of the flexible mesh gear device measuring device of FIG. 14. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0010] [Embodiment 1] FIG. 1 is an axial cross-sectional view showing a flexible mesh gear device according to a first embodiment of the present invention. In the following description, the direction parallel to the rotation axis O1 described below is referred to as the axial direction, the direction along the circumference centered on the rotation axis O1 is referred to as the circumferential direction, and the direction along the radius of the circumference centered on the rotation axis O1 is referred to as the radial direction.

[0011] The flexible mesh gear device 1 of embodiment 1 is, for example, a reduction gear. The use of the flexible mesh gear device 1 is not particularly limited and can be used for a variety of purposes, for example, to drive the joints of a collaborative robot that works in collaboration with humans. This flexible mesh gear device 1 includes a vibrator shaft 30, a vibrator 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 casing 43, a first cover 44, a second cover 45, a third cover 49, bearings 46 and 47, a main bearing 48, and stopper rings 51 and 52.

[0012] The vibrator shaft 30 is a hollow cylindrical shaft that rotates around the rotation axis O1, and includes a vibrator 30A whose cross section perpendicular to the rotation axis O1 has a non-circular (e.g., elliptical) outer shape, and shaft portions 30B and 30C provided on both sides of the vibrator 30A in the axial direction. The elliptical shape does not have to be a strict geometric ellipse and includes an approximate ellipse. The shaft portions 30B and 30C are shafts whose cross section perpendicular to the rotation axis O1 has a circular outer shape. The vibrator shaft 30 may also be a solid shaft.

[0013] The first internally toothed portion 411 is configured by providing teeth on a part of the inner circumference of the first internally toothed member 41 as an internally toothed gear having rigidity. The second internal teeth portion 421 is configured by providing teeth on a part of the inner circumference of the second internal teeth member 42 having rigidity.

[0014] The first external toothed portion 32 and the second external toothed portion 33 are integrally provided side by side in the axial direction on the outer periphery of a single flexible metallic cylindrical base portion 34. The first external toothed portion 32, the second external toothed portion 33, and the base portion 34 constitute an external gear. The first external teeth portion 32 meshes with the first internal teeth portion 411 , and the second external teeth portion 33 meshes with the second internal teeth portion 421 .

[0015] The vibrator bearing 31 is, for example, a roller bearing, and is arranged between the vibrator 30A and a base 34 on which the first external toothed portion 32 and the second external toothed portion 33 are formed. The vibrator 30A and the first external toothed portion 32 and the second external toothed portion 33 are rotatable relative to each other via the vibrator bearing 31. The vibrator bearing 31 has an outer ring 31a fitted inside the base 34, a plurality of rolling elements (rollers) 31b, and a cage 31c that holds the plurality of rolling elements 31b. The rolling elements 31b include a first group of rolling elements 31b arranged radially inward of the first external tooth portion 32 and the first internal tooth portion 411 and aligned circumferentially, and a second group of rolling elements 31b arranged radially inward of the second external tooth portion 33 and the second internal tooth portion 421 and aligned circumferentially. These rolling elements 31b roll on the outer peripheral surface of the vibrator 30A and the inner peripheral surface of the outer ring 31a as rolling surfaces. The vibrator bearing 31 may have an inner ring separate from the vibrator 30A. Alternatively, the vibrator bearing 31 may eliminate the outer ring 31a and use the inner peripheral surface of the base 34 as the outer ring rolling surface. The type of rolling elements is not particularly limited, and may be, for example, balls. The number of rows of rolling elements is not limited to two, and may be one row, three rows, or more.

[0016] The stopper rings 51, 52 are arranged on both axial sides of the first external tooth portion 32 and the second external tooth portion 33 and the vibrator bearing 31, and regulate the axial movement of the first external tooth portion 32, the second external tooth portion 33 and the vibrator bearing 31.

[0017] The casing 43 covers the outer peripheral side of the second internal gear member 42. An outer ring portion of a main bearing 48 is formed on the inner peripheral portion of the casing 43, and the second internal gear member 42 is rotatably supported via the main bearing 48. The casing 43 is connected to the first internal gear member 41 via a connecting member such as a bolt.

[0018] The main bearing 48 is, for example, a cross roller bearing, and has a plurality of rolling elements arranged between an inner ring portion integrated with the second internal gear member 42 and an outer ring portion integrated with the casing 43. Note that the main bearing 48 may be composed of a plurality of bearings (angular contact ball bearings, tapered bearings, etc.) spaced apart in the axial direction between the second internal gear member 42 and the casing 43. Furthermore, an oil seal 541 is provided between the casing 43 and the second internal gear member 42, on the output side of the main bearing 48, to prevent the lubricant from leaking outward in the axial direction (toward the output side).

[0019] The first cover 44 is connected to the third cover 49 via connecting members such as bolts not shown, and the third cover 49 is further connected to the first internal gear member 41 and the casing 43 via connecting members such as bolts not shown. The first cover 44 covers the first external teeth portion 32 and the first internal teeth portion 411 from the axially opposite output side. The first cover 44, the third cover 49, the first internal teeth member 41, and the casing 43 are directly or indirectly connected to an external member (for example, a base-end arm member of a collaborative robot).

[0020] The side that is connected to an external member (also called a mating member, for example, one of the members of a main device that incorporates the flexible mesh gear device 1 as a component and through which power is transmitted between them) and outputs decelerated motion to the external member is called the output side, and the side opposite the output side in the axial direction is called the anti-output side. A bearing 46 is arranged between the first cover 44 and the shaft portion 30B of the vibrator shaft 30, and the vibrator shaft 30 is supported by the first cover 44 so as to be able to rotate freely. A ball bearing is shown as an example of the bearing 46, but other radial bearings may also be used. In addition, an oil seal 542 is provided between the first cover 44 and the shaft portion 30B of the vibrator shaft 30, on the anti-output side of the bearing 46, to prevent lubricant from leaking outward in the axial direction (anti-output side).

[0021] The second cover 45 is connected to the second internal teeth member 42 via a connecting member 533 such as a bolt, and covers the second external teeth portion 33 and the second internal teeth portion 421 from the axial output side. The second cover 45 and the second internal teeth member 42 are connected to an external member (for example, a distal arm member of a collaborative robot) that outputs decelerated motion (this external member rotates relative to the external member to which the first internal teeth member 41, etc. are connected). A bearing 47 is disposed between the second cover 45 and the shaft portion 30C of the vibrator shaft 30, and the vibrator shaft 30 is rotatably supported by the second cover 45. Although a ball bearing is shown as an example of the bearing 47, other radial bearings may also be used. An oil seal 543 is provided between the second cover 45 and the shaft portion 30C of the vibrator shaft 30, on the output side of the bearing 47, to prevent the lubricant from leaking outward in the axial direction (toward the output side). The second cover 45 may be formed integrally with the second internal gear member 42.

[0022] Furthermore, an O-ring 551 for sealing is interposed between the first internal teeth member 41 and the casing 43. Similarly, a sealing O-ring 554 is interposed between the first internal gear member 41 and the third cover 49, a sealing O-ring 552 is interposed between the third cover 49 and the first cover 44, and a sealing O-ring 553 is interposed between the second internal gear member 42 and the second cover 45. Therefore, the internal space of the flexible meshing gear device 1 (the meshing portion between the first external tooth portion 32 and the first internal tooth portion 411, the meshing portion between the second external tooth portion 33 and the second internal tooth portion 421, the main bearing 48, bearings 46, 47, the vibrator bearing 31, etc.) is a lubricant-filled space in which a lubricant is filled, and is sealed by oil seals 541-543 and O-rings 551-554.

[0023] 2 is a perspective view of the first internal teeth member 41. As shown in the figure, the first internal teeth member 41 includes an internal teeth ring portion 412 having the internal teeth of the first internal teeth portion 411 formed on its inner periphery, an external coupling portion 413 that is coupled to an external member together with the casing 43 and the third cover 49, and an easily deformable portion 414 that is provided between the internal teeth ring portion 412 and the external coupling portion 413 in the radial direction and configured to be more easily deformed (have a larger amount of deformation) than the internal teeth ring portion 412 when torque is applied to the first internal teeth member 41.

[0024] The internal tooth ring portion 412 is ring-shaped, and the first internal tooth portion 411 (internal teeth) described above is formed on the inner circumferential surface thereof. The external coupling portion 413 is ring-shaped and located on the outermost periphery of the first internal gear member 41, and has a plurality of mounting holes formed therethrough in the axial direction at regular intervals in the circumferential direction for attachment to an external member. The external coupling portion 413 may be directly coupled to the external member, or may be coupled to the external member via the first cover 44 or the third cover 49.

[0025] The easily deformable portion 414 is composed of a plurality of pillar members 415 provided intermittently in the circumferential direction between the internal tooth ring portion 412 and the external connecting portion 413 . The pillar members 415 extend radially outward from the outer periphery of the internal toothed ring portion 412 and are connected to the inner periphery of the external connecting portion 413. Note that, here, an example is shown in which the easily deformable portion 414, the internal toothed ring portion 412, and the external connecting portion 413 are integrally formed from the same material (for example, a metal material, a resin material, etc.). In addition, the example shows a case where four pillar members 415 are provided at regular intervals in the circumferential direction. It is preferable, but not essential, that the intervals between the pillar members 415 in the circumferential direction be uniform. The number of pillar members 415 can also be increased or decreased.

[0026] The external coupling portion 413 and the pillar member 415 have the same axial width (thickness), and the axial width is smaller than that of the internal toothed ring portion 412. The axial width of the pillar member 415 may be different from that of the external coupling portion 413, and for example, the axial width of the pillar member 415 may be smaller than that of the external coupling portion 413 as long as the strength is sufficient to ensure the torque transmission function. The pillar member 415 may also have a recess for accommodating a strain gauge 416. In addition, a convex rib 413a that convexly faces the output side is formed around the entire circumferential circumference on the output side flat surface on the radially inner side of the external connecting portion 413, and is fitted (spigot-fitted) into a concave portion on the opposite output side of the casing 43.

[0027] A strain gauge 416 serving as strain measuring means is attached to each pillar member 415. Although the strain gauge 416 is attached to the surface of the pillar member 415 on the side opposite to the output side in the illustrated example, it may be attached to the surface on the output side, or to a surface on one end or the other end side in the circumferential direction.

[0028] The strain gauge 416 is attached to the column member 415 in a direction that detects strain due to expansion and contraction in the radial direction of the column member 415. Note that the direction of strain detected by the strain gauge 416 is not limited to the radial direction. When torque acts on the first internal teeth member 41 (specifically, when torque acts on the first internal teeth member 41 as a result of the first internal teeth member 411 receiving a meshing reaction force while the external connecting portion 413 is connected to an external member), the easily deformable portion 414 (pillar member 415) deforms more than the internal teeth ring portion 412. As a result, the radial expansion and contraction strain generated in the pillar member 415 also becomes large. Since this strain of the pillar member 415 correlates with torque, the torque can be obtained by detecting it with a strain gauge 416.

[0029] As shown in FIG. 2, each strain gauge 416 is connected to a measuring device 417 (although FIG. 2 shows only one strain gauge 416 connected, in reality all strain gauges 416 are connected). The measuring device 417 amplifies and records the detection signal of each strain gauge 416. Furthermore, the measuring device 417 receives the rotation phase of the vibrator 30A from a detection unit (not shown). The measuring device 417 holds, for example, a data table that associates the rotational phase of the vibrator shaft 30 with the detection values ​​and torque values ​​of each strain gauge 416. The measuring device 417 refers to the data table to identify the torque values ​​corresponding to the rotational phase input from the detection unit and the detection values ​​of each strain gauge 416. The data table is prepared in advance, for example, through experiments. Specifically, the data table is created by acquiring the detection values ​​of each strain gauge 416 while changing the rotational phase of the vibrator 30A and the torque applied to the first internal gear member 41. Note that the method by which the measuring device 417 identifies the torque from the detection values ​​of each strain gauge 416 is not particularly limited, and for example, the measuring device 417 may be configured to calculate the torque value by calculation using a pre-prepared arithmetic expression.

[0030] [Deceleration operation] When rotational motion is input from a motor (not shown) or the like and the vibrator shaft 30 rotates, the motion of the vibrator 30A is transmitted to the first external toothed portion 32 and the second external toothed portion 33. At this time, the first external toothed portion 32 and the second external toothed portion 33 are constrained to a shape that conforms to the outer peripheral surface of the vibrator 30A and are bent into an elliptical shape having a major axis portion and a minor axis portion when viewed from the axial direction. Furthermore, the first external toothed portion 32 is meshed with the first internal toothed portion 411 of the fixed first internal toothed member 41 at the major axis portion. Therefore, the first external toothed portion 32 and the second external toothed portion 33 do not rotate at the same rotational speed as the vibrator 30A, and the vibrator 30A rotates relatively inside the first external toothed portion 32 and the second external toothed portion 33. Then, with this relative rotation, the first external toothed portion 32 and the second external toothed portion 33 are bent and deformed such that the major axis position and the minor axis position move in the circumferential direction. The period of this deformation is proportional to the rotation period of the vibrator shaft 30.

[0031] When the first external toothed portion 32 and the second external toothed portion 33 flexibly deform, their major axis positions move, causing the meshing position between the first external toothed portion 32 and the first internal toothed portion 411 to change in the rotational direction. If the number of teeth of the first external toothed portion 32 is 100 and the number of teeth of the first internal toothed portion 411 is 102, the meshing teeth of the first external toothed portion 32 and the first internal toothed portion 411 will shift each time the meshing position makes one rotation, causing the first external toothed portion 32 to rotate (spin on its axis). With the above number of teeth, the rotational motion of the vibrator shaft 30 is decelerated at a reduction ratio of 100:2 and transmitted to the first external toothed portion 32.

[0032] Meanwhile, the second external toothed portion 33, which shares the base 34 with the first external toothed portion 32, meshes with the second internal toothed portion 421, and therefore the meshing position between the second external toothed portion 33 and the second internal toothed portion 421 also changes in the rotational direction as the vibrator shaft 30 rotates. Meanwhile, because the number of teeth of the second internal toothed portion 421 matches the number of teeth of the second external toothed portion 33, the second external toothed portion 33 and the second internal toothed portion 421 do not rotate relative to each other, and the rotational motion of the second external toothed portion 33 is transmitted to the second internal toothed portion 421 at a reduction ratio of 1:1. As a result, the rotational motion of the vibrator shaft 30 is decelerated at a reduction ratio of 100:2 and transmitted to the second internal toothed member 42 and the second cover 45. This decelerated rotational motion is then output to an external member.

[0033] During the deceleration operation, in the first internal toothed portion 411 , torque is transmitted from the internal toothed ring portion 412 to the external connecting portion 413 via the easily deformable portion 414 . At this time, the radial strain detected by the strain gauges 416 provided on each of the pillar members 415 of the easily deformable portion 414 is input to a measuring device 417, and a torque value is derived based on this. The torque values ​​obtained by these configurations can be input to, for example, a control device of a main body device incorporating the flexible mesh gear device 1 as a component, and can be used to detect abnormalities in the torque value in the control device. For example, if the flexible mesh gear device 1 is incorporated into a joint of a collaborative robot, an abnormal increase in torque value can be detected as contact between the robot arm and a person, allowing the robot to stop or take evasive action.

[0034] [Technical Effects of the Embodiments] As described above, according to the flexible mesh gear device 1 of this embodiment, the first internal tooth member 41 has an easily deformable portion 414 that is configured to be more easily deformed than the internal tooth ring portion 412, and a strain gauge 416 provided in the easily deformable portion 414. Therefore, when torque is transmitted, the first internal tooth member 41 can detect strain in the easily deformable portion 414, which is located inside the external connecting portion 413 and is more easily deformed than the internal tooth ring portion 412.Therefore, by having the strain gauge 416 detect strain at a position where distortion due to torque is likely to occur, more accurate and better torque detection can be performed. Furthermore, when detecting distortion in the outer periphery where distortion due to torque is unlikely to occur, measures must be taken to improve detection accuracy, such as forming the entire first internal gear member from a non-hard material so that distortion due to torque is more likely to occur in the outer periphery. However, such measures have the drawback of making it more likely for gear meshing errors to occur. In contrast, the first internal tooth member 41 of the flexible mesh gear device 1 of this embodiment only needs to be made deformable in a portion consisting of the easily deformable portion 414, making it possible to suppress the occurrence of gear meshing errors. Furthermore, since the strain gauge 416 is installed inside the flexible mesh gear device 1 rather than on its outer periphery, the device can be made smaller.

[0035] Furthermore, since the easily deformable portion 414 is composed of pillar members 415 arranged intermittently in the circumferential direction between the internal tooth ring portion 412 and the external connecting portion 413, no special method such as adding a new member is required, and the configuration of the easily deformable portion 414 can be easily realized.

[0036] [Embodiment 2] FIG. 3 is a front view of another example of the first internal gear member of the flexible mesh gear device according to the second embodiment of the present invention, as viewed from the axial direction. The first internal teeth member 41A of embodiment 2 differs from the above-described first internal teeth member 41 in the number of post members 415 that make up the easily deformable portion 414A. That is, the easily deformable portion 414A of this first internal teeth member 41A includes eight post members 415 spaced evenly apart in the circumferential direction. The structure and dimensions of each of the post members 415 are the same as those of the post members 415 of the above-described first internal teeth member 41. A strain gauge 416 is attached to each of the pillar members 415 individually.

[0037] In this way, in the first internal toothed member 41A, by increasing the number of pillar members 415, it is possible to support the internal toothed ring portion 412 from the outside and suppress deflection of the internal toothed ring portion 412. This makes it possible to reduce meshing errors of the gears. Moreover, the number of strain gauges 416 can be increased.

[0038] [Embodiment 3] FIG. 4 is a front view of another example of the first internal gear member of the flexible mesh gear device according to the third embodiment of the present invention, as viewed from the axial direction. The first internal teeth member 41B of the third embodiment differs from the first internal teeth member 41 described above in that it includes four support members 418B.

[0039] Each support member 418B is provided between the internal toothed ring portion 412 and the external coupling portion 413 in the radial direction, and is provided midway between two adjacent pillar members 415 in the circumferential direction. 5, each of these support members 418B extends radially between the internal toothed ring portion 412 and the external coupling portion 413, with one end thereof, for example, the internal toothed ring portion 412 side, being fixed, and the other end thereof, for example, the external coupling portion 413 side, being able to make sliding contact or slide on the inner periphery of the external coupling portion 413. Note that the external coupling portion 413 side may be fixed, and the internal toothed ring portion 412 side may be able to make sliding contact or slide. Each support member 418B is formed from a separate material from the internal toothed ring portion 412 and the external connecting portion 413, and one end side is fixed by welding, adhesive, or other joining method. It is sufficient that each support member 418B is fixed at least in the circumferential direction to the internal toothed ring portion 412 or the external connecting portion 413. Furthermore, each support member 418B may be formed from a material different from that of the first internal toothed member 41, such as resin, or may be formed from the same material.

[0040] In this way, by providing the support member 418B in the first internally toothed member 41B, the internally toothed ring portion 412 can be supported from the outside, and deflection of the internally toothed ring portion 412 can be suppressed. This makes it possible to reduce meshing errors of the gears. Furthermore, only one end of the support member 418B is fixed circumferentially to the external connecting portion 413 or the internal toothed ring portion 412, and the other end is not fixed. Therefore, while supporting the internal toothed ring portion 412 from the outside, it does not suppress the expansion and contraction distortion of the pillar member 415 due to torque, making it possible to perform good torque detection.

[0041] [Embodiment 4] FIG. 6 is a front view of another example of the first internal gear member of the flexible mesh gear device according to the fourth embodiment of the present invention, as viewed from the axial direction. In the above-described first internal teeth member 41, the easily deformable portion 414 is configured by four pillar members 415 extending straight in the radial direction, but is not limited to this.

[0042] In the first internal teeth member 41C of the fourth embodiment, the easily deformable portion 414C includes a plurality of support portions 415C that connect the internal teeth ring portion 412 and the external connecting portion 413 in the radial and circumferential directions. The plurality of support portions 415C are provided at uniform intervals in the circumferential direction between the internal toothed ring portion 412 and the external connecting portion 413. Each support portion 415C may be formed integrally with the internal toothed ring portion 412 and the external connecting portion 413 using the same material, or may be formed using a different material. Each support portion 415C has both ends fixed to the internal toothed ring portion 412 and the external connecting portion 413. Although the case where four support portions 415C are provided is illustrated here, any number may be used as long as there is a plurality, and the number is not limited to four. In the fourth embodiment, each support portion 415C corresponds to a pillar member.

[0043] Each support portion 415C is crank-shaped and includes a first extending portion 415Ca extending radially outward from the outer periphery of the internal toothed ring portion 412, a second extending portion 415Cb extending radially inward from the inner periphery of the external connecting portion 413, and an intermediate connecting portion 415Cc extending in the circumferential direction or in a tangential direction to the circumferential direction and connecting the extending end of the first extending portion 415Ca to the extending end of the second extending portion 415Cb. The strain gauges 416 are attached to the intermediate connecting portions 415Cc of the respective support portions 415C in a direction that detects expansion and contraction strain in the longitudinal direction of the intermediate connecting portions 415Cc.

[0044] In this way, in the first internal gear member 41C, the strain gauge 416 is provided at the intermediate connecting portion 415Cc of the support portion 415C having the intermediate connecting portion 415Cc that is a portion along the circumferential direction or a tangential direction to the circumferential direction. As a result, when torque is transmitted from a flexible mesh gear device, the intermediate connecting portion 415Cc, which is located along the circumferential direction or a tangential direction to the circumferential direction, experiences more pronounced expansion and contraction distortion, making it possible to perform torque detection with higher accuracy.

[0045] [Embodiment 5] FIG. 7 is a front view of another example of the first internal gear member of the flexible mesh gear device according to the fifth embodiment of the present invention, as viewed from the axial direction. In the above-described first internal teeth member 41, the easily deformable portion 414 is configured by four pillar members 415 extending straight in the radial direction, but is not limited to this.

[0046] In the first internal teeth member 41D of the fifth embodiment, an easily deformable portion 414D is fixed to the outer periphery of the internal teeth ring portion 412 and includes a plurality of support portions 415D extending in a tangential direction relative to the circumferential direction. Each support portion 415D has both ends fixed to the inner periphery of the external connection portion 413 and a middle portion fixed to the outer periphery of the internal tooth ring portion 412. Here, an example is shown in which four support portions 415D are provided. Both ends of the four support portions 415D are connected to the ends of other support portions 415D, and when viewed in the axial direction, the four support portions 415D are integrated to form a square frame shape.

[0047] Furthermore, each support portion 415D has one strain gauge 416 attached between its end portion fixed to the inner periphery of the external connection portion 413 and its middle portion fixed to the outer periphery of the internal tooth ring portion 412. Each strain gauge 416 is attached in a direction that detects expansion and contraction strain in the longitudinal direction of the support portion 415D.

[0048] Each support portion 415D may be formed integrally with the inner tooth ring portion 412 and the outer connecting portion 413 using the same material, or may be formed using a different material. Further, although the case where four support portions 415D are provided is illustrated here, the number is not limited to four as long as they can surround the internal tooth ring portion 412 at uniform intervals in the circumferential direction.

[0049] In this way, in the first internal tooth member 41D, the easily deformable portion 414D is configured to have a support portion 415D of the above-mentioned structure, and like the easily deformable portion 414, this easily deformable portion 414D is also capable of performing more accurate and better torque detection.

[0050] [Embodiment 6] FIG. 8 is a perspective view showing another example of the first internal gear member of the flexible mesh gear device according to the sixth embodiment of the present invention. In the first internal teeth member 41 described above, the easily deformable portion 414 is configured by four pillar members 415 spaced apart in the circumferential direction, but the present invention is not limited to this.

[0051] In the first internal teeth member 41E of the sixth embodiment, the easily deformable portion 414E is formed from a ring-shaped flat plate that is continuous in the circumferential direction between the internal teeth ring portion 412 and the external connection portion 413. However, as shown in the axial cross-sectional view of Figure 9, the axial thickness d3 of this easily deformable portion 414E is set to be smaller than both the axial thickness d1 of the internal tooth ring portion 412 and the axial thickness d2 of the external connecting portion 413.

[0052] A plurality of strain gauges 416 are attached at equal intervals in the circumferential direction on one of the flat surfaces of easily deformable portion 414E. Here, an example is shown in which four strain gauges 416 are provided. However, the number of strain gauges 416 may be one, or for example, a ring-shaped strain gauge may be arranged along the ring shape of easily deformable portion 414E. Each strain gauge 416 is attached in a direction that detects expansion and contraction strain along the radial direction.

[0053] As described above, in the first internal teeth member 41E, the easily deformable portion 414E is formed in the shape of a circumferentially continuous flat plate, and its axial thickness d3 is set smaller than the axial thickness d1 of the internal toothed ring portion 412 and the axial thickness d2 of the external connecting portion 413. For this reason, the easily deformable portion 414E is more easily deformed than the internal toothed ring portion 412 when torque is transmitted from the flexible mesh gear device, and as a result, expansion and contraction strain is more likely to occur in the radial direction, making it possible to perform more accurate and satisfactory torque detection, similar to the easily deformable portion 414. Note that the axial thickness d3 of the easily deformable portion 414E only needs to be smaller than the axial thickness d1 of the internal toothed ring portion 412, and may be equal to or larger than the axial thickness d2 of the external connecting portion 413. Furthermore, since the easily deformable portion 414E is continuous in the circumferential direction, it is possible to support the internal toothed ring portion 412 from the outside over the entire circumference, thereby suppressing deflection of the internal toothed ring portion 412. This makes it possible to reduce meshing errors of the gears.

[0054] [Embodiment 7] FIG. 1 is an axial cross-sectional view of a first internal gear member according to a seventh embodiment of the present invention. In each of the above-described embodiments, the shape of the easily deformable portion 414 is devised to make it easier to deform than the internal toothed ring portion 412, but the method for making the easily deformable portion 414 easier to deform is not particularly limited. For example, as in the first internal toothed member 41F shown in Fig. 10, the easily deformable portion 414F may be made of a softer material than the internal toothed ring portion 412 and the external coupling portion 413, thereby making it easier to deform than the internal toothed ring portion 412. For example, it is preferable that the easily deformable portion 414F be made of a metal material that is softer than the internal toothed ring portion 412 and the external coupling portion 413, or a softer resin material. In this case, the axial thicknesses of the internal toothed ring portion 412, the easily deformable portion 414F, and the external connecting portion 413 may be the same, or the easily deformable portion 414F may be thicker than the internal toothed ring portion 412 and the external connecting portion 413. Furthermore, the easily deformable portions 414F may be intermittent or continuous along the circumferential direction. If they are intermittent, they may have the same form as the easily deformable portions 414, 414A, 414C, and 414D described above. Furthermore, the support member 418B described above may be added.

[0055] [Embodiment 8] Fig. 11 is a front view showing another example of the first internal teeth member of the flexible mesh gear device according to embodiment 8 of the present invention. In Fig. 11, the first external teeth portion 32 is simply illustrated by an ellipse indicating the position of the major axis.

[0056] In the first internal teeth member 41 described above, the easily deformable portion 414 has two pairs of pillar members 415 provided individually on both sides in the diameter direction of the first internal teeth member 41. The four pillar members 415 made up of these two sets are provided at equal intervals in the circumferential direction, and strain gauges 416 are attached to all of the pillar members 415. In contrast to this, in the flexible mesh gear device of embodiment 8, the easily deformable portion 414 of the first internal teeth member 41G has two pairs of pole members 415 on both diametrical sides of the first internal teeth member 41G, and the pole members 415 are arranged at equal intervals in the circumferential direction, which is the same as the first internal teeth member 41. In the first internal teeth member 41G, strain gauges 56-1 and 56-2 are provided on only one of each pair of pole members 415.

[0057] The strain gauges 56-1 and 56-2 have the same structure, and in the following description, they will be referred to as strain gauges 56 when there is no need to distinguish between them. Moreover, the strain gauges 56-3 and 56-4 indicated by the two-dot chain lines in FIG. 11 are other examples of the first internal gear member described later, and the first internal gear member 41G of the eighth embodiment is not provided with the strain gauges 56-3 and 56-4.

[0058] 12 is a plan view of a strain gauge 56. As shown in the figure, this strain gauge 56 is a double shear type strain gauge, and has measuring sections 56A and 56B formed individually on the left and right sides in FIG. 12 on the plane of an insulating substrate. Each of the measuring sections 56A and 56B has a grid section 561A, 561B in which a resistance wire is folded back multiple times in parallel, and leads 562A, 562B extending from both ends of the grid section 561A, 561B. In FIG. 12, the resistance wire of grid portion 561A of measuring portion 56A on the left side extends diagonally downward to the right, and the resistance wire of grid portion 561B of measuring portion 56B on the right side extends diagonally downward to the left. As can be seen from this structure, the strain gauge 56 essentially has two strain gauges that detect strain in different directions, and is structured such that detection signals can be obtained individually from these two strain gauges.

[0059] Each of measuring units 56A and 56B has a structure that is highly sensitive to contraction strain in the direction along the extension direction of each of grid units 561A and 561B. The extension direction of grid unit 561A of measuring unit 56A and the extension direction of grid unit 561B of measuring unit 56B are perpendicular to each other. The strain gauge 56 has a reference direction that is a combined direction of the extension directions of the grid portions 561A and 561B of the two measuring units 56A and 56B (arrow G in FIG. 12). The strain gauge 56 is attached to the pillar member 415 so that the reference direction G is perpendicular to the direction in which a shear force is generated in the pillar member 415 when the flexible mesh gear device 1 is in operation. More specifically, the reference direction G of the strain gauge 56 is set so as to be parallel to the longitudinal direction of the pillar member 415, that is, the radial direction.

[0060] In the above case, when the first external teeth portion 32 rotates counterclockwise relative to the first internal teeth member 41G due to clockwise rotation of the vibrator shaft 30 (hereinafter referred to as forward rotation), the internal teeth ring portion 412 of the first internal teeth member 41G receives clockwise torque with respect to the external connection portion 413. The shear force generated thereby acts mainly on the grid portion 561A of the measuring unit 56A, and a detection signal corresponding to the torque can be obtained from the measuring unit 56A. Furthermore, when the first external teeth portion 32 rotates clockwise relative to the first internal teeth member 41G due to counterclockwise rotation of the vibrator shaft 30 (hereinafter referred to as "reverse rotation"), the internal teeth ring portion 412 of the first internal teeth member 41G receives counterclockwise torque with respect to the external connection portion 413. The shear force generated thereby acts mainly on the grid portion 561B of the measuring unit 56B, and a detection signal corresponding to the torque can be obtained from the measuring unit 56B.

[0061] The first internal gear member 41G has a structure in which one end and the other end in the diameter direction of a pair of pole members 415 are symmetrical. In this case, when the flexible mesh gear device 1 is in operation, the same shear force caused by torque is generated in both one pole member 415 and the other pole member 415 of the pair, unless a bending moment in the axial direction is generated. Therefore, it is not necessary to provide strain gauges 56 on both of the pair of pillar members 415; by providing a strain gauge 56 on only one of the pillar members 415, the necessary strain can be detected, and the torque can be calculated from the detection of each strain gauge 56. In other words, the flexible mesh gear device 1 of the eighth embodiment can obtain torque particularly effectively when used in an environment where bending moments in the axial direction are unlikely to occur.

[0062] FIG. 13 shows a Wheatstone bridge circuit 57 configured in a measurement device using the above-mentioned strain gauges 56. The Wheatstone bridge circuit 57 has first to fourth paths 571 to 574. One end of the first path 571 and one end of the second path 572 are both connected to the positive electrode of the voltage supply source and the positive electrode of the transmitter, while one end of the third path 573 and one end of the fourth path 574 are both connected to the negative electrode of the voltage supply source and the negative electrode of the transmitter. Furthermore, the other end of the first path 571 and the other end of the third path 573 are connected to each other, and the connection point serves as a positive output for the detection signal. Also, the other end of the second path 572 and the other end of the fourth path 574 are connected to each other, and the connection point serves as a negative output for the detection signal.

[0063] As shown in FIG. 13, the first path 571 is provided with a measuring section 56A ("2A" in FIG. 13) of strain gauge 56-2, the second path 572 is provided with a measuring section 56B ("2B" in FIG. 13) of strain gauge 56-2, the third path 573 is provided with a measuring section 56B ("1B" in FIG. 13) of strain gauge 56-1, and the fourth path 574 is provided with a measuring section 56A ("1A" in FIG. 13) of strain gauge 56-1.

[0064] In the case of Figure 13, "3A", "3B", "4A", and "4B" indicated by dashed double-dashed lines indicate the measuring sections 56A and 56B of the strain gauges 56-3 and 56-4 in other examples of the first internal gear member described later, and "3A", "3B", "4A", and "4B" are not provided in the Wheatstone bridge circuit 57 of this embodiment 8.

[0065] In the Wheatstone bridge circuit 57, when the first external teeth portion 32 rotates forward, the measuring portion 56A of the strain gauge 56-1 and the measuring portion 56A of the strain gauge 56-2 can each obtain a detection signal in response to the movement of the longitudinal position of the vibrator 30A. The detection signal is obtained from the potential difference between the positive output and the negative output of the Wheatstone bridge circuit 57. Furthermore, since the detection signal based on the shear strain detected from each pillar member 415 correlates with the torque of the flexible mesh gear device, it is possible to obtain the torque of the flexible mesh gear device from the detection signal based on the shear strain.

[0066] As described above, in the flexible mesh gear device according to the eighth embodiment, the number of strain gauges 56 can be reduced relative to the number of pillar members 415, which makes it possible to reduce the production cost of the device.

[0067] In the eighth embodiment, the easily deformable portion 414 of the first internal teeth member 41G has two sets (four) of pillar members 415, but it may have one set or three or more sets of pillar members 415. Furthermore, although a double shear strain gauge is exemplified as the strain gauge 56, it is also possible to use the strain gauge 416 that detects strain in the longitudinal direction (radial direction) of the column member 415 described above. Moreover, instead of the strain gauge 416 in each of the first to seventh embodiments described above, the strain gauge 56 can also be used. Furthermore, in embodiment 8, a double shear type strain gauge is exemplified, but for example, if the flexible mesh gear device is used in an environment where it is only used in either forward or reverse rotation, a strain gauge having only one of the measuring units 56A, 56B may be used.

[0068] Furthermore, when strain gauges 56-1 to 56-4 are provided on all pillar members 415 as in embodiment 1, the measurement unit 56A of strain gauge 56-2 ("2A" in FIG. 13) and the measurement unit 56A of strain gauge 56-4 ("4A" in FIG. 13) are provided in series in the first path 571 of the Wheatstone bridge circuit 57, as shown by the two-dot chain lines in FIGS. 11 and 13. Also, in the second path 572, a measuring section 56B of the strain gauge 56-2 ("2B" in FIG. 13) and a measuring section 56B of the strain gauge 56-4 ("4B" in FIG. 13) are provided in series. Further, in the third path 573, the measuring section 56B of the strain gauge 56-1 ("1B" in FIG. 13) and the measuring section 56B of the strain gauge 56-3 ("3B" in FIG. 13) are provided in series. Further, in the fourth path 574, a measuring section 56A of the strain gauge 56-1 ("1A" in FIG. 13) and a measuring section 56A of the strain gauge 56-3 ("3A" in FIG. 13) are provided in series. This makes it possible to obtain the torque of the flexible mesh gear device from a detection signal based on the shear strain detected from each pillar member 415.

[0069] [Embodiment 9] Fig. 14 is a simplified diagram showing another example of the first internal teeth member of the flexible mesh gear device according to the ninth embodiment of the present invention. Note that in Fig. 14 as well, the first external teeth portion 32 is simply illustrated by an ellipse indicating the position of the major axis.

[0070] In the above-described first embodiment, the easily deformable portion 414 has an even number of pillar members 415 arranged at equal intervals in the circumferential direction. In contrast, the first internal tooth member 41H of the flexible mesh gear device according to embodiment 9 illustrates a configuration in which the easily deformable portion 414 has a plurality of odd number of pole members 415 spaced at equal intervals in the circumferential direction. In embodiment 9, the case in which there are seven pole members 415 is illustrated as an example, but the number of pole members 415 can be changed as long as it is a plurality and an odd number. All the pillar members 415 are provided with strain gauges 56-1 to 56-7, which are the same as the strain gauge 56 described above, in order in the circumferential direction.

[0071] When the first internal tooth member 41H has an odd number of pillar members 415, as shown by the solid line in Figure 14, when one end of the long axis of the first external tooth portion 32 meshes with a position that coincides with one of the pillar members 415 in the circumferential direction, the other end of the long axis of the first external tooth portion 32 meshes with a position midway between the other two pillar members 415. In this case, at one end side of the long axis of the first external tooth portion 32, the shear strain generated in the first internal tooth member 41H due to the rigidity of the pillar member 415 is small, and at the other end side of the long axis of the first external tooth portion 32, the shear strain generated in the first internal tooth member 41H is large. Here, among the strain gauges 56-1 to 56-7, strain is detected primarily by strain gauges located near the major axis of the first external teeth portion 32. In the example shown by the solid lines in FIG. 14, strain is detected by 56-4, 56-5, 56-1, 56-2, and 56-7, but the strain detected by strain gauges 56-2 and 56-7 is small because they are located away from the major axis. As described above, at the other end of the major axis of the first external teeth portion 32, the shear strain generated in the first internal teeth member 41H is large, so the detected values ​​of strain gauges 56-4 and 56-5 are large. On the other hand, at one end of the major axis of the first external teeth portion 32, the shear strain generated in the first internal teeth member 41H is small, so the detected value of strain gauge 56-1 is smaller than the detected values ​​of strain gauges 56-4 and 56-5. However, since the measurement is performed through a Wheatstone bridge circuit 57H (see Figure 15 described below) in which each measuring unit 56A is connected in series and each measuring unit 56B is connected in series, a medium detection signal is output by averaging (by adding up the outputs of all the strain gauges) between one end and the other end of the long axis of the first external tooth portion 32.

[0072] Furthermore, as shown by the dotted line in Figure 14, when neither end of the long axis of the first external toothing portion 32 coincides with each pillar member 415 in the circumferential direction but meshes with a position close to the pillar member 415, the shear strain generated in the first internal toothing member 41H at both one end side and the other end side of the long axis of the first external toothing portion 32 is moderate. Therefore, when the detection values ​​of the strain gauges 56-1 to 56-7 are added together, a medium level detection signal is also output.

[0073] Therefore, by using a plurality of odd-numbered pillar members, the fluctuation range (of the total value or average value) of the detection signals obtained from the strain gauges 56-1 to 56-7 is reduced when the long axis of the first external teeth portion 32 rotates in the circumferential direction. To address this, a Wheatstone bridge circuit 57H configured in a measurement device using the strain gauges 56-1 to 56-7 is configured as shown in FIG. In FIG. 15, "1A" to "7A" respectively indicate measuring units 56A of strain gauges 56-1 to 56-7, and "1B" to "7B" respectively indicate measuring units 56B of strain gauges 56-1 to 56-7.

[0074] As shown in FIG. 15, a resistor R1 is provided in the first path 571, a resistor R2 is provided in the second path 572, measuring units 56A of strain gauges 56-1 to 56-7 are connected in series in the third path 573, and measuring units 56B of strain gauges 56-1 to 56-7 are connected in series in the fourth path 574. The resistors R1 and R2 have a resistance value equal to the resistance of the seven measuring parts 56A connected in series when no strain is occurring (also equal to the resistance value of the seven measuring parts 56B connected in series).

[0075] In this way, in the Wheatstone bridge circuit 57H, the measuring units 56A or 56B of the strain gauges 56-1 to 56-7 are connected in series to any one of the four paths 571 to 574. Therefore, even if the individual detection signals obtained from the individual strain gauges 56-1 to 56-7 become small when the long axis of the first external teeth portion 32 rotates in the circumferential direction, it is possible to obtain a sum of the detection signals and increase the detection signal. Furthermore, by using a plurality of odd-numbered pillar members, it is possible to reduce variations in the (sum of) detection signals caused by the circumferential position of the long axis of the first external teeth portion 32.

[0076] Furthermore, the Wheatstone bridge circuit configured in a measurement device using the strain gauges 56-1 to 56-7 may be configured with two Wheatstone bridge circuits: a Wheatstone bridge circuit 57H-1 shown in FIG. 16 and a Wheatstone bridge circuit 57H-2 shown in FIG. 17.

[0077] As shown in FIG. 16, the Wheatstone bridge circuit 57H-1 has a resistor R1 provided on the first path 571, a resistor R2 provided on the second path 572, measuring units 56A of strain gauges 56-1 to 56-7 connected in series on the third path 573, and a resistor R3 provided on the fourth path 574. The resistors R1 to R3 have a resistance value equal to the resistance of the seven measuring units 56A connected in series when no distortion occurs (and also equal to the resistance of the seven measuring units 56B connected in series).

[0078] As shown in FIG. 17, the Wheatstone bridge circuit 57H-2 has a resistor R5 provided on the first path 571, a resistor R6 provided on the second path 572, a resistor R4 provided on the third path 573, and measuring units 56B of strain gauges 56-1 to 56-7 connected in series on the fourth path 574. The resistors R4 to R6 have resistance values ​​equal to the resistances of the seven measuring units 56B connected in series when no distortion occurs.

[0079] In both of the Wheatstone bridge circuits 57H-1 and 57H-2, one end of the first path 571 and the second path 572 is connected to the positive side of the voltage supply source and the positive side of the transmitter, and one end of the third path 573 and the fourth path 574 is connected to the negative side of the voltage supply source and the negative side of the transmitter. Furthermore, the other end of the first path 571 and the third path 573 serves as a positive output for the detection signal, and the other end of the second path 572 and the fourth path 574 serves as a negative output for the detection signal.

[0080] The Wheatstone bridge circuits 57H-1 and 57H-2 are both supplied with voltage from the same supply source, and it is possible to obtain different (independent) detection signals from the Wheatstone bridge circuits 57H-1 and 57H-2. With this configuration, it is possible to obtain two detection signals individually from each of the Wheatstone bridge circuits 57H-1 and 57H-2 that can be compared for diagnosing the safety level.

[0081] [others] The details shown in the above embodiments can be modified as appropriate without departing from the spirit of the invention.

[0082] In addition, while the above embodiments have exemplified a configuration in which the easily deformable portion and the strain gauge are provided in the first internal teeth member, the easily deformable portion and the strain gauge may be provided in the second internal teeth member. In that case, too, the second internal teeth member should have an internal teeth ring portion having internal teeth formed on its inner circumference and an external connecting portion that is connected to an external member, and the easily deformable portion and the strain gauge should be provided between them. Furthermore, regardless of whether the easily deformable portion and the strain gauge are provided on the first internal teeth member or the second internal teeth member, either the first internal teeth member or the second internal teeth member may be on the non-rotation side or the upstream side in the power transmission direction. Furthermore, in each of the above-mentioned Embodiments 1 to 9 (except for Embodiment 8), the strain gauges 416, 56 are attached to all of the post members 415, but this is not limited thereto, and the strain gauges 416, 56 may be attached to only some of the post members 415. Furthermore, in each of the above-mentioned embodiments, the strain gauge 416 is arranged on the axial end surface of the post member 415, but this is not limited thereto, and the strain gauge 416, 56 may be arranged on the circumferential surface of the post member 415, for example.

[0083] In addition, in the above embodiments, a cylindrical meshing gear device has been described as an example of the flexible meshing gear device 1. However, the present invention can also be suitably applied to flexible meshing gear devices other than cylindrical types, such as cup types and top hat types. [Industrial Applicability]

[0084] The present invention has industrial applicability to flexible mesh gear devices. [Explanation of symbols]

[0085] 1. Flexible mesh gear device 30 Vibrator axis 30A vibrator 32 First external tooth part (external tooth gear) 33 Second external tooth part (external tooth gear) 41, 41A, 41B, 41C, 41D, 41E, 41F First internal gear member (internal gear) 411 First internal tooth part (internal tooth) 412 Internal tooth ring part 413 External connection part 414, 414A, 414C, 414D, 414E, 414F Easy-to-deform part 415 Column members 415C,415D Bearing part 416 Strain gauge (strain measurement means) 56, 56-1 to 56-7 Strain gauges (double shear type strain gauges) 56A,56B Measuring section 417 Measuring Equipment 418B Support material 57, 57H-1, 57H-2 Wheatstone bridge circuit 571 Route 1 572 Route 2 573 Route 3 574 Route 4

Claims

1. A vibrator; an external gear that is flexibly deformed by the vibrator; an internal gear that meshes with the external gear; A flexible mesh gear device comprising: The internal gear has an internally toothed ring portion having internal teeth formed on its inner circumference, an external connecting portion that is connected to an external member, an easily deformable portion that is provided between the internally toothed ring portion and the external connecting portion and that is configured to be more easily deformed than the internally toothed ring portion, and a distortion measuring means that is provided on the easily deformable portion, the easily deformable portion is constituted by a plurality of support portions provided intermittently at uniform intervals in the circumferential direction between the internal toothed ring portion and the external connecting portion, Each of the support portions has a first extending portion extending radially outward from an outer circumferential surface of the internal toothed ring portion, a second extending portion extending radially inward from an inner circumferential surface of the external connecting portion, and an intermediate connecting portion extending along a circumferential direction or a tangential direction to the circumferential direction, connecting an extending end portion of the first extending portion and an extending end portion of the second extending portion, The distortion measuring means is provided at the intermediate connecting portion, which is a portion along the circumferential direction of the support portion or along a direction tangential to the circumferential direction.

2. An inner member; An outer member; an easily deformable portion provided between the inner member and the outer member and configured to be more easily deformed than the inner member; and a strain measuring means provided on the easily deformable portion; a measurement device for specifying torque from the detected value of the strain measurement means, the easily deformable portion is constituted by a plurality of support portions provided intermittently at uniform intervals in the circumferential direction between the inner member and the outer member, Each of the support portions has a first extending portion extending radially outward from the outer peripheral surface of the inner member, a second extending portion extending radially inward from the inner peripheral surface of the outer member, and an intermediate connecting portion extending along a circumferential direction or a tangential direction to the circumferential direction, connecting an extending end portion of the first extending portion and an extending end portion of the second extending portion, The strain measuring means is a torque measuring device provided at the intermediate connecting portion, which is a portion along the circumferential direction of the support portion or along a direction tangential to the circumferential direction.

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