speed reducer

Abstract

To provide a speed reducer which avoids needs for designing an output shaft according to a shape of a flexible contact member and may transmit rotation of the flexible contact member to the output shaft effectively.SOLUTION: A speed reducer reduces a rotation speed of a motor. The speed reducer includes: an input shaft which rotates around an input center axis; a wave motion generator which has a non-circular cam having an outer diameter which is different depending on a circumferential position and rotates around the input center axis; a flexible contact member with which the wave motion generator contacts from the radial inner side; an annular contact member with which the flexible contact member contacts from the radial inner side; an output shaft which rotates around an output center axis; an annular member located between the flexible contact member and the output shaft; and a fixing member which is located on the output center axis of the output shaft and fixes the flexible contact member to the output shaft through the annular member.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a reducer. [Background technology]

[0002] In a conventional wave gear reducer, the wave generator includes a transmission cylinder and a connecting ring that are coaxially arranged (see, for example, Patent Document 1). The motor output shaft is connected to the transmission cylinder via an adjustable expansion sleeve. The connecting ring is connected to a rigid wheel via a flexible wheel. When the flexible wheel rotates in conjunction with the rotation of the motor output shaft, the rotation of the flexible wheel is transmitted to the output shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Chinese Utility Model No. 213017566 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional strain wave gear reducers, when the flexible contact member is changed, it is necessary to prepare an output shaft that corresponds to the shape of the flexible contact member, and therefore, every time the shape, such as the size, of the flexible contact member is changed, it is necessary to design an output shaft that corresponds to the shape of the flexible contact member.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide a reducer that can avoid the need to design an output shaft according to the shape of a flexible contact member and can effectively transmit the rotation of the flexible contact member to the output shaft. [Means for solving the problem]

[0006] An exemplary reducer according to the present disclosure is a reducer for reducing the rotational speed of a motor, and includes: an input shaft that rotates about an input central axis; a wave generator having a non-circular cam with an outer diameter that varies depending on a circumferential position and that rotates about the input central axis; a flexible contact member that is in contact with the wave generator from its radially inner side; an annular contact member that is in contact with the flexible contact member from its radially inner side; an output shaft that rotates about an output central axis; an annular member located between the flexible contact member and the output shaft; and a fixing member located on the output central axis of the output shaft and fixing the flexible contact member to the output shaft via the annular member. [Effects of the Invention]

[0007] According to an exemplary embodiment of the present disclosure, a reducer can be provided that can effectively transmit the rotation of the flexible contact member to the output shaft while avoiding the need to design the output shaft depending on the shape of the flexible contact member. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a reducer according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a vertical cross-sectional view of the reduction gear transmission taken along line II-II in FIG. [Figure 3] 3 is an enlarged longitudinal sectional view of a portion of the reducer shown in FIG. 2. FIG. [Figure 4] 4 is an enlarged longitudinal sectional view of a portion of the reducer shown in FIG. 2. FIG. [Figure 5] FIG. 5 is an exploded perspective view of an output rotor, an annular member, a flexible external gear, a mounting member, and an external gear fixing member in a reducer according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is an exploded perspective view of an output rotor, an annular member, a flexible external gear, a mounting member, and an external tooth fixing member in a reducer according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. In the drawings, identical or corresponding parts are designated by the same reference numerals, and descriptions thereof will not be repeated. For ease of understanding, the X-axis, Y-axis, and Z-axis of a three-dimensional Cartesian coordinate system are appropriately indicated in the drawings.

[0010] In addition, in this specification, the direction parallel to the central axis AX of the reducer and motor is referred to as the "axial direction AD," the direction perpendicular to the central axis AX is referred to as the "radial direction RD," and the direction along the arc centered on the central axis AX is referred to as the "circumferential direction CD." The "radial direction RD" may be any direction as long as it is perpendicular to the central axis AX, and is not particularly limited. In addition, in this specification, the term "parallel direction" does not mean parallel in the strict sense, but includes, for example, parallel to the extent that the effects of the present disclosure are achieved. In addition, in this specification, the term "orthogonal direction" does not mean perpendicular to the strict sense, but includes, for example, perpendicular to the extent that the effects of the present disclosure are achieved.

[0011] Furthermore, in this specification, the terms "bottomed cylindrical shape," "bottomed cylindrical shape," "bottomed square cylindrical shape," "cylindrical," "cylindrical," "annular," "annular," "ring-shaped," "elliptical," "columnar," "cylindrical," "flat plate-shaped," "flat plate-shaped," "disk-shaped," and "rectangular shape" do not refer to shapes in the strict sense, but include, for example, shapes that can realize the functions of the reduction gear device in this disclosure.

[0012] A reducer 200 according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 6. FIG. 1 is a perspective view showing a reduction gear SR including the reducer 200 of this embodiment. The reduction gear SR shown in FIG. 1 reduces the rotational speed. The rotational speed indicates, for example, the number of rotations per unit time. Specifically, the reduction gear SR converts rotational motion of a first rotational speed into rotational motion of a second rotational speed that is lower than the first rotational speed.

[0013] As shown in FIG. 1, the reduction gear SR has a motor 100 and a reducer 200. The motor 100 drives the reducer 200. The reducer 200 reduces the rotational speed of the motor 100. The reducer 200 is used to reduce the rotational speed of the motor 100. Specifically, the reducer 200 converts rotational motion of a first rotational speed by the motor 100 into rotational motion of a second rotational speed that is lower than the first rotational speed.

[0014] 2 is a longitudinal cross-sectional view of the reduction gear SR taken along line II-II in FIG. 1. As shown in FIG. 2, the reduction gear SR further includes a main board SB0. Circuits and a microcomputer are arranged on the main board SB0. The main board SB0 is arranged along the axial direction AD. The main board SB0 is attached to the reducer 200.

[0015] The motor 100 includes a motor body 1, a magnetic encoder 3, a motor housing 7, a wall member 9, and a rotating shaft 21.

[0016] The motor main body 1 rotates the rotating shaft 21 about the central axis AX. More specifically, the motor main body 1 rotates the rotating shaft 21 about the input central axis AXa. The input central axis AXa is an imaginary line that passes through the center of the rotating shaft 21 along the longitudinal direction of the rotating shaft 21. The motor main body 1 has a rotor RT and a stator ST. The rotor RT rotates about the input central axis AXa. In other words, the rotor RT is the rotor of the motor main body 1. The rotor RT is fixed to the rotating shaft 21. Therefore, when the rotor RT rotates, the rotating shaft 21 rotates. In other words, the rotating shaft 21 rotates together with the rotor RT. The rotor RT is disposed about the input central axis AXa. The rotor RT is disposed radially outward of the stator ST in the radial direction RD. In other words, the motor 100 is an outer rotor type motor. Note that the motor 100 may also be an inner rotor type motor. The stator ST is the stator of the motor main body 1. The stator ST is disposed about the input central axis AXa.

[0017] When the motor body 1 is driven, the rotating shaft 21 rotates around the input central axis AXa. The rotating shaft 21 extends in the axial direction AD. The rotating shaft 21 has, for example, a substantially cylindrical shape. The rotating shaft 21 is made of, for example, metal. The material of the rotating shaft 21 is, for example, an alloy containing iron.

[0018] The magnetic encoder 3 detects the rotation of the rotary shaft 21. Then, the magnetic encoder 3 outputs rotation information indicating the rotation position or rotation angle of the rotary shaft 21 to the microcomputer on the main board SB0.

[0019] The motor housing 7 accommodates the motor main body 1. The motor housing 7 has, for example, a substantially rectangular cylindrical shape with a bottom. The motor housing 7 is fixed to the wall member 9 by a plurality of fixing members (not shown) such as screws.

[0020] The wall member 9 is disposed between the motor body 1 and the reducer 200. The wall member 9 has a substantially flat plate shape and a substantially rectangular shape.

[0021] The reducer 200 has a rigid internal gear A1, a flexible external gear A2, a wave generator A3, a plurality of internal fixing members 74, a fixing member 110, an annular member 140, an output rotor 210, a first output bearing 81, a second output bearing 85, a reducer housing 86, and a cover 87. The rigid internal gear A1 corresponds to an example of an "annular contact member." The flexible external gear A2 corresponds to an example of a "flexible contact member." The output rotor 210 corresponds to an example of an "output shaft."

[0022] The fixing member 110 includes an external teeth fixing member 120 and an attachment member 130. The external teeth fixing member 120 corresponds to an example of a "fixed shaft."

[0023] The reducer 200 is a device that reduces the speed of input rotational motion by utilizing the differential between the rigid internal gear A1 and the flexible external gear A2. In this embodiment, the rotating shaft 21 functions as the input shaft of the reducer 200. Therefore, it can also be considered that the reducer 200 has the rotating shaft 21.

[0024] The rigid internal gear A1 is substantially annular. In the example of FIG. 2, the rigid internal gear A1 is substantially circular. The rigid internal gear A1 is fixed to the reducer housing 86 by a plurality of internal tooth fixing members 74. Specifically, each internal tooth fixing member 74 passes through the rigid internal gear A1 and is screwed into the reducer housing 86. As a result, the rigid internal gear A1 is fixed to the reducer housing 86 by fastening the internal tooth fixing members 74. The internal tooth fixing members 74 are, for example, screws. The screws are, for example, bolts or screws.

[0025] A flexible external gear A2 contacts the rigid internal gear A1 from the inside in the radial direction RD. The flexible external gear A2 is flexible. A wave generator A3 contacts the flexible external gear A2 from the inside in the radial direction RD. The wave generator A3 has an outer diameter that varies depending on the position in the circumferential direction CD. A rotating shaft 21 is coupled to the wave generator A3. Therefore, as the rotating shaft 21 rotates, the wave generator A3 rotates around the central axis AX. In the example of Figure 2, the wave generator A3 is approximately elliptical. The wave generator A3 is a mechanism that flexibly deforms the flexible external gear A2.

[0026] The flexible external gear A2 rotates relative to the rigid internal gear A1 in response to the rotation of the wave generator A3. In the example of Fig. 2, the flexible external gear A2 is located on the output shaft side of the reducer 200. As a result, the reducer 200 reduces the speed of the rotational motion input from the rotating shaft 21, which functions as the input shaft, and outputs the reduced rotational motion from the flexible external gear A2, which functions as the output shaft.

[0027] The rigid internal gear A1 has a higher rigidity than the cylindrical portion A21 of the flexible external gear A2, and therefore the rigid internal gear A1 can be considered to be substantially a rigid body.

[0028] The flexible external gear A2 is fixed to the output rotor 210 by the external gear fixing member 120 via the mounting member 130. The flexible external gear A2 is fixed between the mounting member 130 and the annular member 140 by a plurality of fixing members (not shown) such as screws.

[0029] The mounting member 130 is, for example, a bushing. The mounting member 130 is made of, for example, metal. The material of the mounting member 130 is, for example, an alloy containing iron. The external tooth fixing member 120 is screwed into the end of the output rotor 210 in the axial direction AD via the mounting member 130. As a result, the flexible external gear A2 is fastened between the mounting member 130 and the end of the output rotor 210, and the flexible external gear A2 is fixed to the output rotor 210. The external tooth fixing member 120 is, for example, a screw. The screw is, for example, a bolt or a screw. Furthermore, as will be described later, the flexible external gear A2 is restricted from rotating relative to the output rotor 210 in the circumferential direction CD.

[0030] The flexible external gear A2, which functions as the output shaft, is fixed to the output rotor 210, and the relative rotation of the flexible external gear A2 with respect to the output rotor 210 is restricted, so that the rotation of the flexible external gear A2 is transmitted to the output rotor 210. Therefore, the output rotor 210 rotates about the output central axis AXb at the same rotational speed as the rotational speed of the flexible external gear A2.

[0031] The first output bearing 81 is substantially annular. The first output bearing 81 is disposed between the outer peripheral surface 210s of the output rotor 210 and the inner peripheral surface 86a of the reducer housing 86. The first output bearing 81 has an inner ring 82, an outer ring 83, and a plurality of balls 84. The inner ring 82 is fixed to the outer peripheral surface 210s of the output rotor 210. The outer ring 83 is fixed to the inner peripheral surface 86a of the reducer housing 86. The plurality of balls 84 are interposed between the inner ring 82 and the outer ring 83 and arranged along the circumferential direction CD. The first output bearing 81 is, for example, a ball bearing.

[0032] The second output bearing 85 and the first output bearing 81 are arranged side by side in the axial direction AD. The second output bearing 85 is substantially annular. The second output bearing 85 is arranged between the outer peripheral surface 210s of the output rotor 210 and the inner peripheral surface 86a of the reducer housing 86. The second output bearing 85 has an inner ring 82, an outer ring 83, and a plurality of balls 84. Otherwise, the configuration of the second output bearing 85 is the same as the configuration of the first output bearing 81.

[0033] By providing the first output bearing 81 and the second output bearing 85, the output rotor 210 can rotate relative to the reducer housing 86.

[0034] The reducer housing 86 accommodates the rigid internal gear A1, the flexible external gear A2, the wave generator A3, the external tooth fixing member 120, the mounting member 130, the first output bearing 81, the second output bearing 85, and a portion of the output rotor 210. In the example of FIG. 2, the reducer housing 86 has an outer shape that is a substantially rectangular parallelepiped. The reducer housing 86 also has a substantially cylindrical accommodation space Sp. The reducer housing 86 is fixed to the wall member 9 by a plurality of fixing members (not shown), such as screws.

[0035] The reducer housing 86 has a first housing 86p and a second housing 86q. The first housing 86p accommodates the external gear fixing member 120, the mounting member 130, the first output bearing 81, the second output bearing 85, and a portion of the output rotor 210. The second housing 86q accommodates the rigid internal gear A1, the flexible external gear A2, and the wave generator A3.

[0036] The cover 87 covers the end portion in the axial direction AD of the reducer housing 86. The output rotor 210 passes through the cover 87 and protrudes from the cover 87 to the outside.

[0037] In this embodiment, the reducer 200 includes a rotating shaft 21, a wave generator A3, a flexible external gear A2, a rigid internal gear A1, a fixed member 110, an annular member 140, and an output rotor 210. The rotating shaft 21 rotates about an input central axis AXa. The wave generator A3 has a non-circular cam 62 (FIG. 3) having an outer diameter that varies depending on the circumferential position, and rotates about the input central axis AXa. The wave generator A3 contacts the flexible external gear A2 from the radially inner side. The flexible external gear A2 contacts the rigid internal gear A1 from the radially inner side. The output rotor 210 rotates about an output central axis AXb. The annular member 140 is located between the flexible external gear A2 and the output rotor 210. The external gear fixing member 120 is located on the output central axis AXb of the output rotor 210 and fixes the flexible external gear A2 to the output rotor 210 via the annular member 140.

[0038] Because the fixed member 110 fixes the flexible external gear A2 on the output central axis AXb of the output rotor 210 via the annular member 140, the rotation of the flexible external gear A2 can be effectively transmitted to the output rotor 210 via the annular member 140. Furthermore, because the flexible external gear A2 can be fixed to the output rotor 210 via the annular member 140, it is possible to avoid the need to design the output rotor 210 according to the shape of the flexible external gear A2.

[0039] The fixing member 110 has an external teeth fixing member 120 and an attachment member 130. The attachment member 130 is attached to the flexible external gear A2. The external teeth fixing member 120 is attached to the attachment member 130 on the output central axis AXb of the output rotor 210. The external teeth fixing member 120 is fixed to the output rotor 210. Because the external teeth fixing member 120 is fixed to the output rotor 210 via the attachment member 130 attached to the flexible external gear A2, the external teeth fixing member 120 can be firmly fixed to the output rotor 210, which is rotatable around the output central axis AXb.

[0040] Next, the motor 100 will be described in detail with reference to Fig. 3. Fig. 3 is an enlarged longitudinal cross-sectional view of a portion of the reducer 200 and the motor 100 shown in Fig. 2. As shown in Fig. 3, the motor 100 has a substrate SB1, a magnet holding member 5, a first bearing 30, a second bearing 35, and a plurality of support members 93.

[0041] A circuit is formed on the substrate SB1. The substrate SB1 has, for example, a substantially rectangular shape. The substrate SB1 is substantially perpendicular to the axial direction AD. The substrate SB1 is supported by a plurality of support members 93.

[0042] A portion of the magnetic encoder 3 is disposed on the substrate SB1. The magnetic encoder 3 has a magnet 91 and a magnetic sensor 92. The magnet 91 is, for example, a permanent magnet. The magnet 91 has, for example, a substantially cylindrical shape. The magnet holding member 5 holds the magnet 91. Specifically, the magnet 91 is fixed to the magnet holding member 5. The magnet holding member 5 holding the magnet 91 is then fixed to the first end E1 of the rotating shaft 21. The magnet holding member 5 is made of a non-magnetic material. For example, the magnet holding member 5 is made of aluminum or synthetic resin.

[0043] The rotating shaft 21 has a first end E1 and a second end E2. The first end E1 is one end in the axial direction AD of the rotating shaft 21. The second end E2 is the other end in the axial direction AD of the rotating shaft 21. The second end E2 is coupled to the reducer 200.

[0044] The magnetic encoder 3 detects the rotation of the rotary shaft 21 based on changes in the magnetic field of the magnet 91 that rotates together with the rotary shaft 21 .

[0045] Specifically, the magnet 91 is disposed at a distance from the magnetic sensor 92 in the axial direction AD. The magnetic sensor 92 detects changes in the magnetic field caused by the magnet 91 rotating together with the rotating shaft 21. In other words, the magnetic sensor 92 detects the rotational position or rotational angle of the rotating shaft 21 as changes in the magnetic field, and outputs rotation information indicating the rotational position or rotational angle of the rotating shaft 21 to the microcomputer on the main board SB0. The magnetic sensor 92 includes, for example, a Hall element. The magnetic sensor 92 is disposed on the board SB1.

[0046] The stator ST is disposed about the central axis AX. The stator ST includes, for example, a stator core made of laminated steel plates in which thin electromagnetic steel sheets are stacked in the axial direction AD, an insulator, and a coil. The insulator electrically insulates the stator core from the coil. The insulator is made of an insulating material. The insulator covers at least a portion of the stator core. The insulator is disposed in a substantially annular shape surrounding the central axis AX. The insulator may be formed of multiple separate members or may be formed of a single member. The coil is formed by winding a conducting wire around the stator core via the insulator.

[0047] The rotor RT includes a rotor yoke 41 and a magnet 42. The magnet 42 is, for example, a permanent magnet. The magnet 42 has, for example, a substantially annular shape. Note that, for example, the rotor RT may include a plurality of magnets arranged in the circumferential direction CD. The rotor yoke 41 is, for example, made of a magnetic material. The rotor yoke 41 has a substantially cylindrical shape with a bottom. The rotor yoke 41 also has a hole through which the rotating shaft 21 passes. The rotor yoke 41 is fixed to the rotating shaft 21.

[0048] The magnet 42 is fixed to the inner side of the rotor yoke 41 in the radial direction RD. In other words, the motor 100 is an SPM (Surface Permanent Magnet) motor. The magnet 42 may also be fixed inside the rotor yoke 41. In other words, the motor 100 may be a so-called IPM (Interior Permanent Magnet) motor. The magnet 42 and the stator core face each other with a gap in the radial direction RD.

[0049] The first bearing 30 is substantially annular. The first bearing 30 is disposed between the outer peripheral surface of the rotating shaft 21 and the inner peripheral surface 52a of the bracket 52. The first bearing 30 has an inner ring 32, an outer ring 33, and a plurality of balls 34. The inner ring 32 is fixed to the outer peripheral surface of the rotating shaft 21. The outer ring 33 is fixed to the inner peripheral surface 52a of the bracket 52. The plurality of balls 34 are interposed between the inner ring 32 and the outer ring 33, and arranged along the circumferential direction CD. The first bearing 30 is, for example, a ball bearing.

[0050] The second bearing 35 and the first bearing 30 are disposed with a gap therebetween in the axial direction AD.

[0051] The second bearing 35 is substantially annular. The second bearing 35 is disposed between the outer peripheral surface of the rotating shaft 21 and the inner peripheral surface 51a of the bracket 51. The second bearing 35 has an inner ring 32, an outer ring 33, and a plurality of balls 34. Otherwise, the configuration of the second bearing 35 is the same as the configuration of the first bearing 30.

[0052] By providing the first bearing 30 and the second bearing 35, the rotary shaft 21 can rotate relative to the motor housing 7.

[0053] The wave generator A3 is fixed to the rotating shaft 21. The wave generator A3 has a wave bearing 61 and a non-circular cam 62. The wave bearing 61 is flexible. The wave bearing 61 is located inside the cylindrical portion of the flexible external gear A2 in the radial direction RD. The non-circular cam 62 extends in an annular shape centered on the central axis AX. The non-circular cam 62 is approximately elliptical. The non-circular cam 62 has an outer diameter that varies depending on the position in the circumferential direction CD. The wave bearing 61 is arranged along the outer peripheral surface of the non-circular cam 62 and is bent in an approximately elliptical shape.

[0054] A second end E2 of the rotary shaft 21 is coupled to the non-circular cam 62. Specifically, the reducer 200 has a fixing portion 70. The fixing portion 70 fixes the non-circular cam 62 to the rotary shaft 21.

[0055] The fixing portion 70 has a connecting member 71 and an annular member 72. The connecting member 71 is arranged on a central axis AX. The connecting member 71 has a head 71a and a shaft portion 71b. The head 71a has a generally cylindrical shape. The head 71a protrudes in the radial direction RD relative to the shaft portion 71b. The shaft portion 71b has a generally cylindrical shape. The shaft portion 71b extends from the head 71a in the axial direction AD. The shaft portion 71b is arranged on the central axis AX. A screw thread (not shown) is formed on the shaft portion 71b. The connecting member 71 functions as a male screw. The connecting member 71 is, for example, a bolt or a screw. The connecting member 71 is made of, for example, a metal. For example, the material of the connecting member 71 is an alloy containing iron.

[0056] The annular member 72 has a generally truncated cone shape tapering toward the second end E2 of the rotating shaft 21. The annular member 72 has a through hole 72a. The through hole 72a penetrates the annular member 72 in the axial direction AD on the central axis AX. The shaft portion 71b of the connecting member 71 penetrates the through hole 72a in the axial direction AD. The through hole 72a is a generally cylindrical space. The annular member 72 is made of, for example, metal. For example, the material of the annular member 72 is an alloy containing iron. The annular member 72 is, for example, a bushing.

[0057] A bracket 51 is provided on the motor body side of the wall member 9. The bracket 51 has a cylindrical shape. The second bearing 35 is disposed in a through hole of the bracket 51.

[0058] Bracket 52 is provided on the motor body side relative to bracket 51. Bracket 52 has a cylindrical shape. The outer diameter of bracket 52 is smaller than that of bracket 51. Furthermore, the length of bracket 52 along the axial direction AD is greater than the length of bracket 51 along the axial direction AD. First bearing 30 is disposed in a through hole in bracket 52.

[0059] Next, the reducer 200 will be described in detail with reference to Fig. 4. Fig. 4 is an enlarged vertical cross-sectional view of the reducer 200 shown in Fig. 2.

[0060] As shown in Fig. 4, the reducer 200 includes a flexible external gear A2, a rigid internal gear A1, a fixed member 110, an annular member 140, and an output rotor 210. The output rotor 210 rotates around an output central axis AXb. The annular member 140 is located between the flexible external gear A2 and the output rotor 210. The fixed member 110 is located on the output central axis AXb of the output rotor 210, and fixes the flexible external gear A2 to the output rotor 210 via the annular member 140.

[0061] Because the fixed member 110 fixes the flexible external gear A2 on the output central axis AXb of the output rotor 210 via the annular member 140, the rotation of the flexible external gear A2 can be effectively transmitted to the output rotor 210 via the annular member 140. Furthermore, because the flexible external gear A2 can be fixed to the output rotor 210 via the annular member 140, it is possible to avoid the need to design the output rotor 210 according to the shape of the flexible external gear A2.

[0062] The fixing member 110 has an external teeth fixing member 120 and an attachment member 130. The attachment member 130 is attached to the flexible external gear A2. The external teeth fixing member 120 is attached to the attachment member 130 on the output central axis AXb of the output rotor 210. The external teeth fixing member 120 is fixed to the output rotor 210. Because the external teeth fixing member 120 is fixed to the output rotor 210 via the attachment member 130 attached to the flexible external gear A2, the external teeth fixing member 120 can be firmly fixed to the output rotor 210, which is rotatable around the output central axis AXb.

[0063] The mounting member 130 has a flat portion 130a and a cylindrical portion 130b. The flat portion 130a contacts the flexible external gear A2. The cylindrical portion 130b protrudes from the flat portion 130a and faces the inner circumferential surface of the annular member 140. The flat portion 130a and the cylindrical portion 130b are provided with a through hole 130h through which the external teeth fixing member 120 passes. With the cylindrical portion 130b of the mounting member 130 positioned within the annular member 140 and the external teeth fixing member 120 passing through the through hole 130h of the flat portion 130a and the cylindrical portion 130b, the external teeth fixing member 120 can be firmly fixed to the output rotor 210, which is rotatable about the output central axis AXb.

[0064] The end of the mounting member 130 on the output rotor 210 side protrudes further toward the output rotor 210 than the bottom surface of the annular member 140 on the output rotor 210 side. As a result, the mounting member 130 protrudes further toward the output rotor 210 than the bottom surface of the annular member 140, allowing the external gear fixing member 120 to be aligned with the output central axis AXb of the output rotor 210 with high precision, and eccentricity can be suppressed.

[0065] A recess 210q is provided in the output rotor 210. Portions of the external teeth fixing member 120 and the mounting member 130 are positioned within the recess 210q of the output rotor 210. As a result, by having portions of the external teeth fixing member 120 and the mounting member 130 positioned within the recess 210q of the output rotor 210, the external teeth fixing member 120 can be aligned with high precision with respect to the output central axis AXb of the output rotor 210, and eccentricity can be suppressed.

[0066] The outermost diameter of the output rotor 210 relative to the output central axis AXb is smaller than the outermost diameter of the annular member 140 relative to the output central axis AXb. This reduces the amount of cutting required when manufacturing the output rotor 210, and prevents the output rotor 210 from becoming too large.

[0067] 1 to 6, the output rotor, annular member, flexible external gear, mounting member, and external tooth fixing member in the reducer 200 will be described. Figures 5 and 6 are exploded perspective views of the output rotor 210, annular member 140, flexible external gear A2, mounting member 130, and external tooth fixing member 120 in the reducer 200 according to an embodiment of the present disclosure.

[0068] As shown in FIGS. 5 and 6, in the reducer 200, the external tooth fixing member 120, the mounting member 130, the flexible external gear A2, the annular member 140, and the output rotor 210 are arranged in this order.

[0069] The external teeth fixing member 120 has a flat portion 120a and a protruding portion 120b. The flat portion 120a extends from the protruding portion 120b. The outermost diameter of the flat portion 120a relative to the output center axis AXb is larger than the outermost diameter of the protruding portion 120b relative to the output center axis AXb. Furthermore, the length of the protruding portion 120b along the axial direction AD is larger than the outermost diameter of the flat portion 120a along the axial direction AD.

[0070] The mounting member 130 has a flat portion 130a and a cylindrical portion 130b. The cylindrical portion 130b extends from the flat portion 130a in the axial direction AD. The outermost diameter of the flat portion 130a relative to the output central axis AXb is larger than the outermost diameter of the cylindrical portion 130b relative to the output central axis AXb. Furthermore, the length of the cylindrical portion 130b along the axial direction AD is larger than the outermost diameter of the flat portion 130a along the axial direction AD.

[0071] A through hole 130h is provided in the flat portion 130a and the cylindrical portion 130b along the output center axis AXb. The protrusion 120b of the external teeth fixing member 120 is inserted into the through hole 130h. The length of the cylindrical portion 130b along the axial direction AD is shorter than the length of the protrusion 120b of the external teeth fixing member 120. Therefore, when the protrusion 120b of the external teeth fixing member 120 is inserted into the through hole 130h, a portion of the protrusion 120b of the external teeth fixing member 120 protrudes from the mounting member 130.

[0072] The flat portion 130a is provided with through holes 130he extending parallel to the axial direction AD. Here, six through holes 130he are provided at equal intervals in the circumferential direction around the through hole 130h.

[0073] The flat portion 130a is provided with a recess 130q centered on the through hole 130h. The outer diameter of the recess 130q relative to the output central axis AXb is larger than that of the through hole 130h. The outer diameter of the recess 130q relative to the output central axis AXb is larger than that of the flat portion 120a of the external gear fixing member 120.

[0074] The flexible external gear A2 has a generally cylindrical shape with one side open. The flexible external gear A2 has a bottom portion A2a and a side portion A2s. The side portion A2s extends parallel to the axial direction AD from the outer edge of the bottom portion A2a. The side portion A2s has a generally cylindrical shape.

[0075] A protrusion A2p is provided on the bottom A2a of the flexible external gear A2 on the output rotor 210 side. The protrusion A2p has a substantially circular shape centered on the output central axis AXb. The protrusion A2p protrudes from the bottom A2a toward the annular member 140.

[0076] A through hole A2h is provided in the bottom portion A2a and the protruding portion A2p of the flexible external gear A2. The through hole A2h extends in a circular shape centered on the output central axis AXb.

[0077] Furthermore, through holes A2he are provided in the bottom portion A2a and the protruding portion A2p of the flexible external gear A2. Six through holes A2he are provided at equal intervals in the circumferential direction around the through hole A2h as the center.

[0078] The annular member 140 has a substantially cylindrical shape. The annular member 140 has a bottom portion 140a, a bottom portion 140b, and a side portion 140s. The bottom portion 140a faces the flexible external gear A2. The bottom portion 140a has a substantially annular shape. The bottom portion 140b faces the output rotor 210. The bottom portion 140b has a substantially annular shape.

[0079] A through-hole 140h is provided in the annular member 140. The through-hole 140h passes through the center of the bottom portion 140a and the center of the bottom portion 140b from the bottom portion 140a to the bottom portion 140b. The protrusion portion 120b of the external teeth fixing member 120 and the cylindrical portion 130b of the mounting member 130 are inserted into the through-hole 140h. The length of the through-hole 140h along the axial direction AD is shorter than the length of the protrusion portion 120b of the external teeth fixing member 120 and the length of the cylindrical portion 130b of the mounting member 130.

[0080] Depressions 140d are provided in the bottom portion 140a of the annular member 140. Here, six depressions 140d are provided at equal intervals in the circumferential direction around the through-hole 140h.

[0081] The recess 140d of the annular member 140, the through hole A2he of the flexible external gear A2, and the through hole 130he of the mounting member 130 are aligned linearly in the axial direction AD. Therefore, the annular member 140, the flexible external gear A2, and the mounting member 130 are fixed together with screws. The screws are, for example, bolts or screws.

[0082] As described above, the flexible external gear A2 has a bottom A2a and a protrusion A2p extending from the bottom A2a toward the output rotor 210. A through hole A2he is provided in the protrusion A2p. A recess 140d connected to the through hole A2he of the protrusion A2p is provided in the annular member 140. This makes it easy to fasten the flexible external gear A2 to the annular member 140. Furthermore, it is possible to avoid an increase in the size of the output rotor 210.

[0083] A protrusion 140p is provided on the bottom 140b of the annular member 140. Here, the protrusion 140p extends in the circumferential direction CD around the output central axis AXb. Two notches 140q are provided on the protrusion 140p. The two notches 140q face each other across a through hole 140h.

[0084] The output rotor 210 has a flat portion 210a and a protruding portion 210b. The flat portion 210a extends from the protruding portion 210b. The outermost diameter of the flat portion 210a relative to the output central axis AXb is larger than the outermost diameter of the protruding portion 210b relative to the output central axis AXb. Furthermore, the length of the protruding portion 210b along the axial direction AD is larger than the length of the flat portion 210a along the axial direction AD.

[0085] The flat portion 210a is provided with a recess 210q1 and a recess 210q2 centered on the output central axis AXb. The recess 210q1 is recessed in a cylindrical shape relative to the output central axis AXb, and the recess 210q2 is recessed in an annular shape radially outward from the recess 210q1 and centered on the output central axis AXb.

[0086] The depth of the recess 210q1 relative to the flat portion 210a is greater than the depth of the recess 210q2 relative to the flat portion 210a. The outermost diameter of the recess 210q1 relative to the output center axis AXb is smaller than the outermost diameter of the recess 210q2 relative to the output center axis AXb.

[0087] The protrusion 120b of the external teeth fixing member 120 is positioned in the recess 210q1 of the output rotor 210. The tip of the protrusion 120b of the external teeth fixing member 120 is fixed to the output rotor 210 inside the recess 210q1 of the output rotor 210.

[0088] In the recess 210q2 of the output rotor 210, the cylindrical portion 130b of the mounting member 130 and the protruding portion 140p of the annular member 140 are positioned.

[0089] The annular member 140 has, on its surface (bottom 140b) facing the output rotor 210, protrusions 140p extending in the circumferential direction CD around the output central axis AXb. Notches 140q are provided in the protrusions 140p. The output rotor 210 has, on its surface (flat portion 210a) facing the annular member 140, protrusions 210p that correspond to the notches 140q in the protrusions 140p of the annular member 140. As a result, the notches 140q in the protrusions 140p of the annular member 140 correspond to the protrusions 210p of the output rotor 210, and therefore the rotation of the flexible external gear A2 can be transmitted to the output rotor 210 via the annular member 140 with high precision.

[0090] 2 to 6, the output rotor 210 is provided with the convex portion 210p, the annular member 140 is provided with the notch 140q, and the convex portion 210p of the output rotor 210 is fitted into the notch 140q of the annular member 140. However, this embodiment is not limited to this. The annular member 140 may be provided with the convex portion, and the output rotor 210 may be provided with the notch, and the convex portion of the output rotor 210 may be fitted into the notch 140q of the annular member 140.

[0091] In this way, one of the annular member 140 and the output rotor 210 may have a convex portion extending in the circumferential direction about the output central axis AXb on a surface facing the other of the annular member 140 and the output rotor 210. A notch is provided in this convex portion. On the other of the annular member 140 and the output rotor 210, a convex portion corresponding to the notch in the convex portion of one of the annular member 140 and the output rotor 210 is provided on a surface facing the one of the annular member 140 and the output rotor 210. In this way, the notch in the convex portion of one of the output rotor 210 and the annular member 140 corresponds to the convex portion of the other, and therefore the rotation of the flexible external gear A2 can be transmitted to the output rotor 210 via the annular member 140 with high precision.

[0092] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments and can be implemented in various forms without departing from the spirit of the present invention. Furthermore, the components disclosed in the above embodiments can be modified as appropriate. For example, some of the components shown in one embodiment may be added to the components of another embodiment, or some of the components shown in one embodiment may be deleted from the embodiment.

[0093] Furthermore, the drawings mainly show each component in a schematic manner to facilitate understanding of the invention, and the thickness, length, number, spacing, etc. of each component shown in the drawings may differ from the actual ones due to the convenience of creating the drawings. Furthermore, the configuration of each component shown in the above embodiment is merely an example and is not particularly limited, and it goes without saying that various modifications are possible within a range that does not substantially deviate from the effects of the present invention.

[0094] In the reducer 200 described with reference to FIGS. 2 to 4, the flexible external gear A2 is described as an example of a "flexible contact member," and the rigid internal gear A1 is described as an example of an "annular contact member." However, the "flexible contact member" and the "annular contact member" are not particularly limited as long as they can convert rotational motion at a first rotational speed into rotational motion at a second rotational speed lower than the first rotational speed. For example, when the reducer 200 performs deceleration using traction (friction), the "flexible contact member" may be flexible but may not have external teeth, and the "annular contact member" may be elastic but may not have internal teeth. In this case, the outer circumferential surface of the "flexible contact member" contacts the inner circumferential surface of the "annular contact member" via an oil film of lubricating oil.

[0095] 2 to 6, the fixing member 110 is composed of two separable parts, the external gear fixing member (fixed shaft) 120 and the mounting member 130, but this embodiment is not limited to this. The fixing member 110 may be composed of a single part. [Industrial Applicability]

[0096] The present disclosure can be used in, for example, a reducer. [Explanation of symbols]

[0097] 21 Rotating shaft (input shaft) 62 Non-circular cam 62a through hole 70 Fixed part 71 Connecting member 72 Annular member 100 motor 110 Fixing member 120 External tooth fixing member 130 Mounting member (fixed shaft) 140 Annular member 200 reducer A1 Rigid internal gear (annular contact member) A2 Flexible external gear (flexible contact member) A3 Wave Generator

Claims

1. A reducer for reducing the rotational speed of a motor, an input shaft that rotates around an input central axis; a wave generator having a non-circular cam having an outer diameter that varies depending on a position in a circumferential direction, the wave generator rotating about the input central axis; a flexible contact member with which the wave generator comes into contact from a radially inner side; an annular contact member that the flexible contact member contacts from a radially inner side; an output shaft that rotates around an output central shaft; an annular member positioned between the flexible contact member and the output shaft; a fixing member located on the output central axis of the output shaft and fixing the flexible contact member to the output shaft via the annular member; Equipped with The fixing member is a mounting member attached to the flexible contact member; a fixed shaft attached to the mounting member on the output central axis of the output shaft and fixed to the output shaft; A reducer having

2. The mounting member is a flat portion that contacts the flexible contact member; a cylindrical portion that protrudes from the flat portion and faces the inner peripheral surface of the annular member; and The reducer according to claim 1 , wherein the flat portion and the cylindrical portion are provided with a through-hole through which the fixed shaft passes.

3. The reducer according to claim 1 or 2, wherein an end portion of the mounting member on the output shaft side protrudes toward the output shaft beyond a bottom surface of the annular member on the output shaft side.

4. The output shaft is provided with a recess, The reducer according to claim 1 , wherein the fixed shaft and a portion of the mounting member are located within a recess in the output shaft.

5. The reducer according to claim 1 , wherein an outermost diameter of the output shaft relative to the output central axis is smaller than an outermost diameter of the annular member relative to the output central axis.

6. The flexible contact member comprises: The bottom and a protrusion extending from the bottom toward the output shaft; and The protrusion has a through hole, The reducer according to claim 1 , wherein the annular member is provided with a recess that is connected to the through hole of the protrusion.

7. one of the annular member and the output shaft has a convex portion extending in a circumferential direction about the output central axis on a surface facing the other of the annular member and the output shaft, The protrusion is provided with a notch, 7. The reducer according to claim 6, wherein the other of the annular member and the output shaft has a convex portion on a surface facing the one of the annular member and the output shaft, the convex portion corresponding to the notch in the convex portion of the one of the annular member and the output shaft.

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