Eccentric swing type speed reducer

Abstract

The invention provides an eccentric swing type reduction gear capable of detecting torque acting on a component. An eccentric oscillating speed reducer is provided with: an eccentric body (12); an external gear (16) swingable by the eccentric body (12); an internal gear (18) that meshes with the external gear (16); and a gear carrier (20) which can be synchronized with the rotation component of the external gear (16), one of the internal gear (18) and the gear carrier (20) constitutes at least a part of a fixed body (28) fixed to the external member (26), and the fixed body (28) is provided with: a first annular part (40); a second annular part (42) provided at a distance from the first annular part (40) in the radial direction and fixed to the outer member (26); and a deformation generation part (44) provided between the first annular part (40) and the second annular part (42), the deformation generation part (44) being provided with a strain sensor (60).

Description

[0001] This application claims priority based on Japanese Patent Application No. 2023-208428 filed on December 11, 2023. The entire content of the Japanese application is incorporated herein by reference. Technical Field

[0002] The present invention relates to an eccentric swing type reduction gear. Background Art

[0003] Patent Document 1 discloses an eccentric swing type reduction gear including: an eccentric body; an outer gear swung by the eccentric body; an inner gear meshing with the outer gear; and a wheel carrier synchronized with the rotation component of the outer gear.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2023-99960

[0005] In an eccentric swing type reduction gear, it is sometimes required to detect the torque acting on its constituent members. Summary of the Invention

[0006] Therefore, one object of the present invention is to provide an eccentric swing type reduction gear capable of detecting the torque acting on its constituent members.

[0007] The eccentric swing type reduction gear of the present invention includes: an eccentric body; an outer gear swingable by the eccentric body; an inner gear meshing with the outer gear; and a wheel carrier synchronized with the rotation component of the outer gear, wherein one of the inner gear and the wheel carrier constitutes at least a part of a fixed body fixed to an external member, the fixed body includes: a first annular portion; a second annular portion radially separated from the first annular portion and fixed to the external member; and a deformation generating portion provided between the first annular portion and the second annular portion, and a strain sensor is provided in the deformation generating portion. Brief Description of the Drawings

[0008] Figure 1 It is a side cross-sectional view showing the eccentric swing type reduction gear of the first embodiment.

[0009] Figure 2 It is an exploded perspective view showing the synchronous wheel carrier and its peripheral structure of the first embodiment.

[0010] Figure 3 It is a front view showing the synchronous wheel carrier of the first embodiment.

[0011] Figure 4 It is a front view showing the synchronous wheel carrier and its peripheral structure of the first embodiment.

[0012] Figure 5 It shows Figure 1 an enlarged view of the strain sensor.

[0013] Figure 6 is a magnified view of the strain sensor indicating Figure 4 .

[0014] Figure 7 is a side cross-sectional view showing the eccentric swing type reduction gear of the second embodiment.

[0015] Figure 8 is a view when observing the eccentric swing type reduction gear of the second embodiment from the same line of sight direction as Figure 4 .

[0016] Figure 9 is a view when observing the eccentric swing type reduction gear of the third embodiment from the same line of sight direction as Figure 6 .

[0017] In the figure: 10 - eccentric swing type reduction gear, 12 - eccentric body, 16 - external gear, 18 - internal gear, 20 - wheel carrier, 22 - housing, 26 - external component, 28 - fixed body, 32 - output body, 40 - first annular portion, 42 - second annular portion, 44 - deformation generating portion, 50 - column portion, 52 - axially penetrating hole, 52a - circumferential side portion, 52b, 52c - radial side portions, 60 - strain sensor, 62 - circuit board, 62a - circumferential portion, 62b - first protruding portion, 62c - second protruding portion, 76 - conductive connection material, 80 - first recess, 82 - second recess, 90 - reinforcement portion, 92 - main bearing, 96 - load transfer path, 102 - flexible substrate. Detailed Embodiment

[0018] An embodiment for implementing the eccentric swing type reduction gear (hereinafter, also referred to as the reduction gear) of the present invention will be described. The same or equivalent elements are denoted by the same reference numerals, and repeated descriptions are omitted. In each drawing, for the sake of convenience of explanation, the constituent elements are appropriately omitted, enlarged, or reduced. Observe the drawings according to the orientation of the reference numerals.

[0019] (First Embodiment)

[0020] Refer to Figure 1。The speed reduction device 10 includes: a crankshaft 14 having at least one eccentric body 12; an external gear 16 that can be swung by the eccentric body 12; an internal gear 18 that meshes with the external gear 16; a synchronous wheel carrier 20 that can be synchronized with the rotational component of the external gear 16; a housing 22 disposed radially outside the external gear 16; and an asynchronous wheel carrier 24 provided on the side opposite to the synchronous wheel carrier 20 in the axial direction with respect to the external gear 16. In the present embodiment, a central crank type eccentric swing type speed reduction device 10 will be described. In this type of speed reduction device 10, the crankshaft 14 is disposed on the swing center C16a of the external gear 16. Hereinafter, the direction along the swing center C16a of the external gear 16 will be referred to as the axial direction, and the radial direction and the circumferential direction with the swing center C16a as the center of the circle will be referred to as the radial direction and the circumferential direction, respectively.

[0021] The speed reduction device 10 includes: a fixed body 28 fixed to an external component 26; and an output body 32 that outputs rotation to a driven component 30 outside. Here, an example will be described in which the synchronous wheel carrier 20 and the housing 22 constitute the fixed body 28 and the internal gear 18 and the asynchronous wheel carrier 24 constitute the output body 32. The external component 26 is disposed outside the speed reduction device 10 and supports the speed reduction device 10. The driven component 30 is disposed outside the speed reduction device 10 and is driven by the output of the output body 32. The driven component 30 becomes a part of various machines such as industrial machines (machine tools, construction machines, etc.), robots (industrial robots, service robots, etc.), and handling equipment (conveyors, vehicles, etc.). If rotation is input from a drive source (not shown) to the crankshaft 14, the output body 32 outputs rotation that is slower than the rotation of the crankshaft 14 to the driven component 30. The drive source is, for example, a motor, but in addition to this, it may also be a gear motor, an engine, or the like.

[0022] The eccentric body 12 is a circle eccentric with respect to the rotation center line C14 of the crankshaft 14. The eccentric body 12 can rotate about the rotation center line C14 of the crankshaft 14 to swing the external gear 16. The "swing" here means that the gear center C16b of the external gear 16 rotates around the swing center C16a. The number of eccentric bodies 12 is not particularly limited and can be any one of one and three or more.

[0023] The external gear 16 is provided corresponding to a plurality of eccentric bodies 12 and is supported by the corresponding eccentric body 12 via an eccentric bearing 34. The internal gear 18 includes an internal gear main body 18a and a plurality of internal teeth 18b provided on the inner peripheral portion of the internal gear main body 18a and meshing with the external gear 16. The plurality of internal teeth 18b can be integrally provided by the same component as the internal gear main body 18a or can be constituted by a plurality of pins rotatably supported by the internal gear main body 18a.

[0024] The pin 36 projects axially from the synchronous pulley bracket 20. A plurality of pins 36 are circumferentially arranged at intervals. The pin 36 may be formed of the same component as the synchronous pulley bracket 20 or may be formed of a component separate from the synchronous pulley bracket 20. The pin 36 axially penetrates the external gear 16 and can bear a load from the external gear 16 when the external gear 16 swings.

[0025] The synchronous pulley bracket 20 "synchronizing with the rotation component of the external gear 16" means that within the numerical range including zero, the rotation component of the synchronous pulley bracket 20 is maintained at the same magnitude relative to the rotation component of the external gear 16. For example, in the case where the internal gear 18 becomes the output body 32 and the synchronous pulley bracket 20 becomes the fixed body 28 as in the present embodiment, when the reduction gear 10 operates, the internal gear 18 rotates. At this time, since the synchronous pulley bracket 20 is fixed to the external component 26, its own rotation component is maintained at zero. And since the rotation of the external gear 16 is restricted by the synchronous pulley bracket 20 and the pin 36, the rotation component of the external gear 16 is also maintained at zero. As a result, the rotation component of the synchronous pulley bracket 20 synchronizes with the rotation component of the external gear 16. In contrast, in the case where the internal gear 18 becomes the fixed body 28 and the synchronous pulley bracket 20 becomes the output body 32, when the reduction gear 10 operates, the external gear 16 rotates. The rotation component of the external gear 16 is transmitted to the synchronous pulley bracket 20 via the pin 36. Thus, the synchronous pulley bracket 20 rotates with a rotation component of the same magnitude as the rotation component of the external gear 16, thereby synchronizing with the rotation component of the external gear 16.

[0026] The asynchronous pulley bracket 24 is not connected to the synchronous pulley bracket 20 and does not synchronize with the rotation component of the synchronous pulley bracket 20 when the reduction gear 10 operates. Consider the case where the synchronous pulley bracket 20 becomes the fixed body 28 and thus maintains the rotation component at zero as in the present embodiment. At this time, since the asynchronous pulley bracket 24 becomes the output body 32 and rotates, it does not synchronize with the rotation component of the synchronous pulley bracket 20. In contrast, consider the case where the synchronous pulley bracket 20 becomes the output body 32 and rotates. At this time, since the asynchronous pulley bracket 24 becomes the fixed body 28 and maintains the rotation component at zero, it does not synchronize with the rotation component of the synchronous pulley bracket 20.

[0027] The housing 22 of the present embodiment is separately provided from the internal gear 18. The housing 22 of the present embodiment is fixed to the synchronous pulley bracket 20 by fixing tools such as bolts (not shown), and thus is integrated with the synchronous pulley bracket 20.

[0028] An example of the operation of the above-described speed reduction device 10 will be described. When rotation is input from a drive source to the crankshaft 14, the outer gear 16 is swung by the eccentric body 12 of the crankshaft 14. When the outer gear 16 swings, the meshing position of the outer gear 16 and the inner gear 18 changes along the circumferential direction. Thus, every time the crankshaft 14 rotates once, either the outer gear 16 or the inner gear 18 (here, the inner gear 18) rotates on its own axis. The output body 32 rotates by the self-rotation component of either the outer gear 16 or the inner gear 18 and outputs the rotation to the driven member 30. At this time, the output body 32 outputs to the driven member 30 a rotation obtained by reducing the rotation input to the crankshaft 14 at a reduction ratio corresponding to the difference in the number of teeth between the outer gear 16 and the inner gear 18.

[0029] Reference Figures 1 to 3 。The speed reduction device 10 includes a strain sensor 60 provided in a deformation generating portion 44 (to be described later) provided in the fixed body 28 and a circuit board 62 electrically connected to the strain sensor 60. In addition to these, the speed reduction device 10 also has features in the structure of the fixed body 28.

[0030] The fixed body 28 includes: a first annular portion 40; a second annular portion 42, which is provided separately from the first annular portion 40 in the radial direction and fixed to the external member 26; and a deformation generating portion 44 provided between the first annular portion 40 and the second annular portion 42. The first annular portion 40, the second annular portion 42, and the deformation generating portion 44 of the present embodiment are provided on the timing pulley bracket 20. In the present embodiment, these are provided on one component constituting the timing pulley bracket 20.

[0031] The first annular portion 40 is annular. The second annular portion 42 is annular. The first annular portion 40 of the present embodiment becomes an inner annular portion provided on the radially inner side, and the second annular portion 42 becomes an outer annular portion provided on the radially outer side.

[0032] When the speed reduction device 10 is operating, torque is input to the first annular portion 40. Specifically, when the speed reduction device 10 is operating, torque is transmitted from either the outer gear 16 or the inner gear 18 to the first annular portion 40, whereby torque is input to the first annular portion 40. Consider the case where the timing pulley bracket 20 becomes at least a part of the fixed body 28 as in the present embodiment. At this time, the torque transmitted from the outer gear 16 is input to the first annular portion 40 of the fixed body 28 via the pin 36. In contrast, consider the case where the inner gear 18 becomes at least a part of the fixed body 28 as in the embodiment described later. At this time, the torque transmitted from the inner teeth 18b of the inner gear 18 is input to the first annular portion 40 of the fixed body 28. Figure 7 When the speed reduction device 10 is operating, torque is input to the first annular portion 40. Specifically, when the speed reduction device 10 is operating, torque is transmitted from either the outer gear 16 or the inner gear 18 to the first annular portion 40, whereby torque is input to the first annular portion 40. Consider the case where the timing pulley bracket 20 becomes at least a part of the fixed body 28 as in the present embodiment. At this time, the torque transmitted from the outer gear 16 is input to the first annular portion 40 of the fixed body 28 via the pin 36. In contrast, consider the case where the inner gear 18 becomes at least a part of the fixed body 28 as in the embodiment described later. At this time, the torque transmitted from the inner teeth 18b of the inner gear 18 is input to the first annular portion 40 of the fixed body 28.

[0033] The second annular portion 42 has a first fixing portion 46 fixed to the external component 26. The first fixing portion 46 of the present embodiment is directly fixed to the external component 26 by a fixing tool 48 such as a bolt. In Figure 1 only the center line of the bolt serving as the fixing tool 48 is illustrated. In Figure 1 the center lines are also illustrated only in the same manner at the usage positions of the other bolts. In the first fixing portion 46 of the present embodiment, first through holes 46a for passing the fixing tool 48 therethrough are formed at intervals in the circumferential direction. In addition, the first fixing portion 46 may be fixed to the external component 26 via other components (for example, the housing 22) of the fixing body 28.

[0034] The deformation generating portion 44 connects the first annular portion 40 and the second annular portion 42. The deformation generating portion 44 can deform while transmitting the torque transmitted to the first annular portion 40 to the second annular portion 42. The deformation generating portion 44 is configured to be more deformable in the circumferential direction than the first annular portion 40 and the second annular portion 42 when such torque is applied. It can also be said that the amount of deformation of the deformation generating portion 44 in the circumferential direction becomes larger than that of the first annular portion 40 and the second annular portion 42.

[0035] Thus, in order to increase the amount of deformation of the deformation generating portion 44, the deformation generating portion 44 of the present embodiment is composed of a plurality of column portions 50 provided at intervals in the circumferential direction. Thus, a specific example for increasing the amount of deformation of the deformation generating portion 44 is not particularly limited. When achieving this, for example, the axial dimension of the deformation generating portion 44 may be reduced with respect to the axial dimensions of both the first annular portion 40 and the second annular portion 42. At this time, the deformation generating portion 44 may also be formed as a circumferentially continuous ring.

[0036] When viewed from the axial direction, the plurality of column portions 50 of the present embodiment are radially and extendingly provided. The specific shape of the column portion 50 is not particularly limited. When viewed from the axial direction, the column portion 50 may be, for example, linear, curved, crank-shaped, or the like.

[0037] The fixing body 28 has axial through holes 52 formed between adjacent column portions 50. The axial through holes 52 penetrate the fixing body 28 along the axial direction. A plurality of the axial through holes 52 of the present embodiment are formed at intervals in the circumferential direction. The axial through holes 52 include: paired circumferential side portions 52a formed by adjacent column portions 50; and paired radial side portions 52b, 52c formed by the first annular portion 40 and the second annular portion 42. The paired radial side portions 52b, 52c include: an inner radial side portion 52b formed by the outer peripheral portion of the annular portion 40 located radially inward; and an outer radial side portion 52c formed by the inner peripheral portion of the annular portion 42 located radially outward.

[0038] Reference Figure 4 、 Figure 5 andFigure 6 The strain sensor 60 is used to detect the torque acting on the fixed body 28. The strain sensor 60 is disposed on the axial side surface of the deformation occurrence portion 44 by bonding or the like. The strain sensor 60 detects an electric signal corresponding to the strain when the deformation occurrence portion 44 of the fixed body 28 is deformed. The electric signal detected by the strain sensor 60 represents the strain of the deformation occurrence portion 44. The strain sensor 60 of the present embodiment detects an electric signal representing the shear strain of the deformation occurrence portion 44 in a direction orthogonal to the axial direction.

[0039] The strain sensor 60 of the present embodiment is a strain gauge, but its specific example is not particularly limited. The strain gauge may be a uniaxial strain gauge using a single strain element formed of a resistance wire, or may be a multi-axis strain gauge such as a rosette gauge using a plurality of strain elements. Here, as the strain gauge, a biaxial strain gauge using two strain elements 64A and 64B is illustrated, but its specific example is not particularly limited. The strain elements 64A and 64B are deformed together with the deformation occurrence portion 44 of the fixed body 28, thereby detecting an electric signal representing the strain in the detection direction corresponding to each of the strain elements 64A and 64B. The strain elements 64A and 64B of the present embodiment include: a first strain element 64A for detecting the shear strain in the first detection direction D1; and a second strain element 64B for detecting the shear strain in the second detection direction D2 orthogonal to the first detection direction D1.

[0040] The strain sensor 60 includes sensor electrodes 66 for outputting the detected electric signal. The sensor electrodes 66 of the present embodiment are pad electrodes provided on the main surface (axial side surface) of the strain sensor 60, but their specific examples are not particularly limited. The sensor electrodes 66 of the present embodiment are provided corresponding to the respective strain elements 64A and 64B, and are provided at both ends of each of the strain elements 64A and 64B.

[0041] A plurality of the strain sensors 60 of the present embodiment are provided at intervals in the circumferential direction. Specifically, in the present embodiment, a total of four strain sensors 60 are provided at intervals in the circumferential direction. The strain sensors 60 are wired in a prescribed wiring method (such as a single strain gauge method, a double strain gauge method, a four strain gauge method, etc.) to form a bridge circuit (not shown). Here, a wiring method of the four strain gauge method using four strain sensors 60 is illustrated. In addition to this, the connection method may be any one of the single strain gauge method using one strain sensor 60, the double strain gauge method using two strain sensors 60, etc. The number and arrangement positions of the strain sensors 60 are not limited thereto, and can be changed appropriately.

[0042] The strain sensor 60 is electrically connected to a processing device 68 for detecting torque via a circuit board 62. The processing device 68 is, for example, a combination of a CPU such as a microcomputer, a ROM, and a RAM, and is constituted by, for example, a processing chip or the like. The processing device 68 may be mounted on the circuit board 62 or may be present outside the reduction gear 10.

[0043] The strain sensor 60 outputs an electric signal representing the strain of the deformation occurrence portion 44 to the processing device 68 via the above-described bridge circuit. The processing device 68 can process the electric signal output from the strain sensor 60 to detect the torque acting on the fixed body 28. As a processing method for detecting torque based on the electric signal of the strain sensor 60, in addition to known methods, methods that can be utilized in the future can also be used, and detailed description thereof is omitted herein.

[0044] Circuit elements 70 for processing the electric signal of the strain sensor 60 are mounted on the circuit board 62. The circuit elements 70 are, for example, an amplifier for amplifying the electric signal of the strain sensor 60, a processing chip constituting the processing device 68, an A / D converter, and the like. The circuit elements 70 are mounted on a mounting surface 62d provided on the main surface of the circuit board 62.

[0045] The circuit board 62 includes a plurality of board electrodes 72 for electrically connecting to the strain sensor 60. The board electrodes 72 in the present embodiment are end face through-hole electrodes provided on the end face (the end face of the first protruding portion 62b described later) of the circuit board 62. The type of the board electrodes 72 is not particularly limited, and may also be pad electrodes provided on the main surface of the circuit board 62. The plurality of board electrodes 72 constitute an electrode group 74 composed of a plurality (here, four) of board electrodes 72. The circuit board 62 in the present embodiment includes a plurality of sets of electrode groups 74. The plurality of sets of electrode groups 74 are provided at intervals in the circumferential direction of the circuit board 62. The electrode group 74 corresponds to one strain sensor 60, and each board electrode 72 belonging to the electrode group 74 is electrically connected to each sensor electrode 66 of the corresponding strain sensor 60. In addition, the number and position of the sensor electrodes 66 and the board electrodes 72 are not particularly limited.

[0046] The strain sensor 60 is electrically connected to the circuit board 62 via a conductive connection material 76 that contacts these. Specifically, the sensor electrode 66 of the strain sensor 60 to be electrically connected to each other and the substrate electrode 72 of the circuit board 62 are electrically connected via the conductive connection material 76 that contacts these. The conductive connection material 76 of the present embodiment is solder, but it may also be a conductive resin or the like. The circuit board 62 and the strain sensor 60 of the present embodiment are directly connected by the conductive connection material 76, but wires such as bonding wires and the conductive connection material 76 may also be used for connection. The electrical signal output from the strain sensor 60 is sequentially transmitted to other parts such as the circuit element 70 via the substrate electrode 72 of the circuit board 62 → the conductor pattern 78 of the circuit board 62 (refer to Figure 6 ).

[0047] The effects of the speed reduction device 10 described above will be described.

[0048] (A) When torque is input to the first annular portion 40 during the operation of the speed reduction device 10, the deformation generating portion 44 of the fixed body 28 transmits the torque and deforms at the same time. A strain sensor 60 is provided in the deformation generating portion 44 of the fixed body 28. Therefore, by using the electrical signal corresponding to the strain of the deformation generating portion 44 detected by the strain sensor 60, the torque acting on the fixed body 28 can be detected.

[0049] As described above, the processing device 68 processes the electrical signal, so that the torque can be detected. In solving the problem of providing the eccentric swing type speed reduction device 10 capable of detecting torque, the processing device 68 is not essential, and the speed reduction device 10 does not need to include the processing device 68.

[0050] The deformation generating portion 44 of the fixed body 28 is configured to be more deformable than the annular portions 40 and 42 of the fixed body 28, and is likely to increase the strain when torque acts. By providing the strain sensor 60 at such a portion where the strain is likely to increase, compared with the case where the strain sensor 60 is provided on the annular portions 40 and 42 of the fixed body 28, the electrical signal detected by the strain sensor 60 can be increased. Furthermore, compared with this case, even if the torque acting on the first annular portion 40 of the fixed body 28 is small, the torque can be easily detected using this electrical signal.

[0051] Next, other features of the speed reduction device 10 of the present embodiment will be described. Refer to Figure 3 and Figure 5The deformation generating portion 44 of the fixing body 28 includes a first recess 80 that houses the strain sensor 60. The first recess 80 is provided on the axial side surface of the fixing body 28. The first recess 80 is provided between the first annular portion 40 and the second annular portion 42, and is recessed axially with respect to the axial side surface of at least one of the first annular portion 40 and the second annular portion 42 (here, the first annular portion 40). The first recess 80 of the present embodiment is also recessed axially with respect to the axial side surface of a reinforcing portion 90 provided in the deformation generating portion 44 described later. The strain sensor 60 is provided on the bottom surface portion of the first recess 80 by bonding or the like.

[0052] One of the first annular portion 40 and the second annular portion 42 of the fixing body 28 includes a second recess 82 that houses at least a part of the circuit board 62. The second recess 82 is provided on the axial side surface of the fixing body 28. In the present embodiment, the second recess 82 is provided on the axial side surface of the second annular portion 42, and is recessed axially with respect to the axial outer side surface 42a of the second annular portion 42 that is axially outside the second recess 82. The circuit board 62 is provided on the bottom surface portion of the second recess 82 by bonding or the like. The internal space of the second recess 82 of the present embodiment is continuous with the internal space of the first recess 80. The bottom surface portion of the second recess 82 of the present embodiment is continuously in the same plane as the bottom surface portion of the first recess 80.

[0053] The second recess 82 includes: a circumferentially extending portion 82a that extends along the circumferential direction when viewed axially; a first radially extending portion 82b that extends from the circumferentially extending portion 82a along the radial direction toward the deformation generating portion 44 side; and a second radially extending portion 82c that extends from the circumferentially extending portion 82a along the radial direction toward the axially penetrating hole 52 side. Here, for the sake of explanation, in Figure 3 the positions of the respective portions are indicated by double-dot dash lines. For the circumferentially extending portion 82a, only a part is shown. The circumferentially extending portion 82a of the present embodiment extends continuously in a ring shape, but may be provided only in a part of the circumferential range. The first radially extending portions 82b of the present embodiment are provided corresponding to the plurality of column portions 50 respectively. The first radially extending portions 82b are provided at intervals in the circumferential direction. The second radially extending portions 82c of the present embodiment are provided corresponding to the plurality of axially penetrating holes 52 respectively. The second radially extending portions 82c are provided at intervals in the circumferential direction.

[0054] Reference Figure 4 and Figure 5。The circuit board 62 includes: a circumferential portion 62a that faces one of the first annular portion 40 and the second annular portion 42 in the axial direction; a first protruding portion 62b that protrudes radially from the circumferential portion 62a; and a second protruding portion 62c that protrudes radially from the circumferential portion 62a. The mounting surface 62d of the circuit board 62 is mainly provided on the circumferential portion 62a of the circuit board 62, and is also provided on the second protruding portion 62c in addition.

[0055] The circumferential portion 62a is in a circumferential shape extending along the circumferential direction. In achieving this, the circumferential portion 62a of the present embodiment is continuously annular, but may also be provided only within a part of the circumferential range. In the present embodiment, after the circumferential portion 62a is opposed to the second annular portion 42 in the axial direction, it is provided on the opposed second annular portion 42 by an adhesive or the like. The circumferential portion 62a of the present embodiment is axially opposed to the second annular portion 42 in the second concave portion 82 of the second annular portion 42. The circuit board 62 is provided on the fixing body 28 at the annular portion 42 at a position different from the deformation generating portion 44 that is the installation position of the strain sensor 60. The circumferential portion 62a is accommodated in the circumferential extension portion 82a of the second concave portion 82 of the fixing body 28.

[0056] The first protruding portion 62b protrudes radially from the circumferential portion 62a toward the side where the deformation generating portion 44 of the fixing body 28 is located. The first protruding portion 62b of the present embodiment protrudes from the circumferential portion 62a into the first concave portion 80 where the deformation generating portion 44 is located. The first protruding portion 62b is accommodated not only in the first concave portion 80 of the fixing body 28 but also in the first radial extension portion 82b of the second concave portion 82. A substrate electrode 72 is provided on the first protruding portion 62b. As described above, the first protruding portion 62b is connected to the strain sensor 60 through the conductive connection material 76.

[0057] The second protruding portion 62c protrudes radially from the circumferential portion 62a toward the same side as the first protruding portion 62b. When viewed from the axial direction, the second protruding portion 62c is provided at a position overlapping with the internal space of the axial through hole 52 of the fixing body 28. When viewed from the axial direction, the second protruding portion 62c protrudes from the circumferential portion 62a of the circuit board 62 so as to be located between adjacent column portions 50. The second protruding portion 62c protrudes radially from the circumferential portion 62a more than the first protruding portion 62b. A part of the second protruding portion 62c is accommodated in the second radial extension portion 82c of the second concave portion 82 of the fixing body 28 (refer to Figure 3 ).

[0058] The effects of the above features will be described.

[0059] (B) The deformation-occurring portion 44 has a first recess 80 that houses the strain sensor 60. Accordingly, compared with the case where the deformation-occurring portion 44 does not have the first recess 80, it is possible to make it difficult for the strain sensor 60 to interfere with other components.

[0060] (C) The second annular portion 42 of the fixing body 28 has a second recess 82 that houses the circuit board 62. Accordingly, compared with the case where the second annular portion 42 does not have the second recess 82, it is possible to make it difficult for the circuit board 62 to interfere with other components. The same effect can also be obtained in the case where the first annular portion 40 has the second recess 82 instead of the second annular portion 42.

[0061] (D) The circuit board 62 has a first protruding portion 62b that protrudes into the first recess 80 of the fixing body 28 and is electrically connected to the strain sensor 60. Accordingly, compared with the case where the circuit board 62 does not have the first protruding portion 62b, it is possible to make the first protruding portion 62b, which is part of the circuit board 62, exist near the strain sensor 60 located within the first recess 80. Furthermore, it is easy to electrically connect the circuit board 62 and the strain sensor 60 using the first protruding portion 62b.

[0062] (E) The circuit board 62 has: a circumferential portion 62a that faces the second annular portion 42 in the axial direction; and a first protruding portion 62b that protrudes radially from the circumferential portion 62a and is connected to the strain sensor 60. Accordingly, compared with the case where the circuit board 62 does not have the first protruding portion 62b, it is possible to make the first protruding portion 62b, which is part of the circuit board 62, exist near the strain sensor 60 provided in the deformation-occurring portion 44 of the fixing body 28. Furthermore, it is easy to connect the circuit board 62 and the strain sensor 60 using the first protruding portion 62b. The same effect can also be obtained in the case where the first annular portion 40 faces the circumferential portion 62a of the circuit board 62 in the axial direction instead of the second annular portion 42.

[0063] (F) The circuit board 62 has a second protruding portion 62c that protrudes so as to be located between adjacent column portions 50 of the fixing body 28. Accordingly, it is possible to make a part of the circuit board 62 exist between adjacent column portions 50 of the fixing body 28, which is advantageous for increasing the area of the mounting surface 62d for mounting the circuit element 70.

[0064] Reference Figure 3 and Figure 5。The fixing body 28 includes a reinforcing portion 90 provided on the column portion 50. The reinforcing portion 90 of the present embodiment is provided in pairs on both circumferential side portions of the column portion 50. The reinforcing portion 90 is composed of convex portions that project outward in the axial direction in the column portion 50. The reinforcing portion 90 is provided to reinforce the column portion 50. The reinforcing portion 90 of the present embodiment is provided to increase the rigidity of the column portion 50 against bending deformation and thus suppress the bending strain of the column portion 50. Here, the bending deformation and bending strain refer to the deformation and strain generated by a moment load acting in a manner that inclines the rotation center line of the output body 32. Thus, it is advantageous when accurately detecting torque using an electric signal representing the shear strain of the deformation occurrence portion 44. To achieve this, the reinforcing portion 90 of the present embodiment includes a radially extending portion 90a provided on the circumferential side portion of the column portion 50 and extending along the radial direction. In addition, the reinforcing portion 90 of the present embodiment further includes a circumferentially extending portion 90b provided on the annular portion 42 and extending along the circumferential direction from the end portion of the radially extending portion 90a. The circumferentially extending portion 90b extends outward in the circumferential direction from the end portion of the radially extending portion 90a with respect to the column portion 50 where the reinforcing portion 90 is provided.

[0065] The reinforcing portion 90 of the present embodiment projects along the axial direction from the bottom surface portions of the first recess 80 and the second recess 82. The radially extending portion 90a of the reinforcing portion 90 forms a part of the first radially extending portion 82b of the first recess 80 and the second recess 82. The circumferentially extending portion 90b of the reinforcing portion 90 forms a part of the circumferentially extending portion 82a of the second recess 82.

[0066] The above-described reinforcing portions 90 are respectively provided in pairs on the paired circumferential side portions 52a of the axially penetrating hole 52. The paired reinforcing portions 90 are truncated at the outer radial side portion 52c that is on the second recess 82 side of the fixing body 28 in the radial direction with respect to the axially penetrating hole 52 among the paired radial side portions 52b and 52c of the axially penetrating hole 52. In Figure 3 this, the truncated portion S1 of the paired reinforcing portions 90 is indicated by a double-dot chain line. Here, "truncated" means that, when viewed axially, in the mentioned radial side portion 52c, the paired reinforcing portions 90 are not continuous and are provided at intervals. A second radially extending portion 82c that forms a part of the second recess 82 is provided at the radial side portion 52c of the axially penetrating hole 52 located at the truncated portion S1 of the paired reinforcing portions 90. When viewed axially, the second protruding portion 62c of the circuit board 62 protrudes in such a manner as to pass through the truncated portion S1 of the paired reinforcing portions 90 and be located between adjacent column portions 50.

[0067] (G) Thus, the portion S1 where the pair of reinforcing portions 90 are cut off can be used as a mounting space for the circuit board 62 accommodated in the second recess 82 of the fixed body 28, which is beneficial for enlarging the area of the mounting surface for mounting the circuit elements 70. And in this way, while ensuring the mounting space for the circuit board 62, the column portion 50 of the fixed body 28 can be reinforced by the pair of reinforcing portions 90.

[0068] Reference Figure 1 . A main bearing 92 is disposed between the fixed body 28 and the output body 32. The main bearing 92 of the present embodiment is disposed between the housing 22 and the internal gear 18. In addition to this, the main bearing 92 can also be disposed between the housing 22 and the asynchronous wheel carrier 24. The main bearing 92 can transfer the torque load input to the output body 32 from the driven member 30 to the fixed body 28. To achieve this, the main bearing 92 of the present embodiment is constituted by a crossed roller bearing, but it can also be constituted by a four-point contact ball bearing or the like. In addition to this, to achieve this, a plurality of main bearings 92 can be provided at intervals in the axial direction. At this time, the main bearing 92 can be constituted by various bearings such as a deep groove ball bearing and an angular contact ball bearing.

[0069] The fixed body 28 includes fixing portions 46, 94 fixed to the external member 26. In addition to the above-mentioned first fixing portion 46 provided on the second annular portion 42 of the synchronous wheel carrier 20, the fixing portions 46, 94 further include a second fixing portion 94 provided on the housing 22. The first fixing portion 46 of the synchronous wheel carrier 20 and the second fixing portion 94 of the housing 22 of the present embodiment are fixed to the external member 26 by a common fixing tool 48. The second fixing portion 94 of the housing 22 is formed at a position where the second through hole 94a and the first through hole 46a for passing the fixing tool 48 overlap in the axial direction.

[0070] The speed reduction device 10 is provided with a load transfer path 96 from the output body 32 via the main bearing 92 and the fixed body 28 to the external member 26. Here, an arrow is marked on a part of the load transfer path 96 to indicate. The load transfer path 96 can transfer the load input to the output body 32 from the driven member 30 to the external member 26. This "load" is mainly a torque load, but in addition to this, it can also include an axial load and a radial load. In the present embodiment, on this load transfer path 96, in addition to the second fixing portion 94 of the housing 22 provided with the fixed body 28, the first fixing portion 46 of the second annular portion 42 of the synchronous wheel carrier 20 is also provided.

[0071] The deformation generating portion 44 of the fixing body 28 is provided at a position different from the load transmission path 96. In addition to the deformation generating portion 44, the first annular portion 40 of the fixing body 28 is also provided at a position different from the load transmission path 96. Regarding the deformation generating portion 44, when the speed reduction device 10 operates, although the torque is transmitted from the first annular portion 40 to the deformation generating portion 44, it is provided at a position different from the load transmission path 96 for transmitting torque loads and the like. To satisfy this condition, the deformation generating portion 44 of the present embodiment is provided at a part of the synchronizer carrier 20 where the torque is transmitted from the external gear 16 via the pin 36 and integrated with the housing 22. Thus, when integrating the housing 22 and the synchronizer carrier 20, the second annular portion 42 of the synchronizer carrier 20 can be directly fixed to the external component 26 as in the present embodiment, or can be fixed to the external component 26 via the housing 22 directly fixed to the external component 26. And, to be provided at a position different from the load transmission path 96, the deformation generating portion 44 of the present embodiment is provided at a position radially inwardly offset from the second annular portion 42 fixed to the external component 26.

[0072] It is known that if a moment load acts on the deformation generating portion 44 of the fixing body 28 and the bending strain generated in the deformation generating portion 44 becomes large, the detection accuracy will decrease when detecting the torque using the electrical signal of the strain sensor 60 representing the shear strain of the deformation generating portion 44. The deformation generating portion 44 of the fixing body 28 is provided at a position different from the load transmission path 96 for transmitting the moment load that causes such a decrease in detection accuracy. Thereby, it is difficult to generate bending strain in the deformation generating portion 44, which is advantageous for accurately detecting the torque as described above.

[0073] (Second Embodiment)

[0074] Reference Figure 7 . In the subsequent embodiments, the following unstated constituent elements among the constituent elements described in the first embodiment can be applied with the same content as the first embodiment.

[0075] In Figure 1 In the speed reduction device 10 of the embodiment, the housing 22 and the internal gear 18 are separately provided. In contrast, the speed reduction device 10 of the present embodiment is different from the first embodiment in that the housing 22 and the internal gear 18 are integrated. In terms of satisfying this condition, it is sufficient that at least the internal gear main body 18a of the internal gear 18 and the plurality of internal teeth 18b are integrated with the housing 22.

[0076] In Figure 1In the speed reduction device 10 of the embodiment, a synchronous wheel holder 20 and an asynchronous wheel holder 24 are respectively provided on both axial sides of the external gear 16. In contrast, in the speed reduction device 10 of the present embodiment, a pair of synchronous wheel holders 20 are provided on both axial sides of the external gear 16. Each synchronous wheel holder 20 is connected together via a pin 36, and both can be synchronized with the rotation component of the external gear 16.

[0077] In Figure 1 the embodiment, the fixed body 28 is composed of the synchronous wheel holder 20 and the housing 22, and the output body 32 is composed of the asynchronous wheel holder 24 and the internal gear 18. In contrast, in the present embodiment, the fixed body 28 is composed of the internal gear 18 and the housing 22, and the output body 32 is composed of each synchronous wheel holder 20. Different from Figure 1 the embodiment, between the output body 32 and the fixed body 28, a pair of main bearings 92 are arranged at intervals in the axial direction. The pair of main bearings 92 are respectively arranged between each synchronous wheel holder 20 and the housing 22.

[0078] The first annular portion 40, the second annular portion 42, and the deformation generating portion 44 of the fixed body 28 of the present embodiment are provided on the housing 22 integrated with the internal gear 18. Similar to Figure 1 the embodiment, these are provided on one component constituting the housing 22. The first annular portion 40 of the fixed body 28 constitutes the inner annular portion, and the second annular portion 42 constitutes the outer annular portion. A plurality of internal teeth 18b are provided on the inner peripheral portion of the first annular portion 40 of the present embodiment. And, the main bearing 92 is arranged on the inner peripheral portion of the first annular portion 40 of the present embodiment. When the internal gear 18 becomes at least a part of the fixed body 28 as in the present embodiment, the torque transmitted from the internal teeth 18b of the internal gear 18 is input to the first annular portion 40 of the fixed body 28.

[0079] Refer to Figure 8 . The deformation generating portion 44 of the fixed body 28 of the present embodiment also has a first recess 80 for accommodating the strain sensor 60. And, the second annular portion 42 of the fixed body 28 of the present embodiment also has a second recess 82 for accommodating the circuit board 62. The circuit board 62 of the present embodiment also has a first protrusion 62b protruding into the first recess 80 of the fixed body 28.

[0080] Thus, the speed reduction device 10 of the present embodiment has the constituent elements described in the above (A) to (E), and thus can obtain the effects corresponding to these descriptions. And, the speed reduction device 10 of the present embodiment has the features related to the second protrusion 62c of the circuit board 62 of the above (F) in addition to the features related to the reinforcement portion 90 of the fixed body 28 of (G), and thus can obtain the effects corresponding to these descriptions.

[0081] In addition, in the speed reduction device 10 of the present embodiment, different from the first embodiment, the deformation generating portion 44 of the fixed body 28 is provided on the load transmission path 96 that reaches the external member 26 from the output body 32 via the main bearing 92 and the fixed body 28. At this time, different from the first embodiment, the moment load is transmitted to the deformation generating portion 44 of the fixed body 28, and when detecting the torque using the electric signal of the strain sensor 60 indicating the shear strain of the deformation generating portion 44, the detection accuracy may be decreased. As a countermeasure, in order to suppress the influence of the bending strain generated in the deformation generating portion 44, various methods including well-known methods can be adopted.

[0082] As this method, for example, a dedicated strain sensor for detecting the bending strain generated in the fixed body 28 can be provided on the fixed body 28. At this time, the electric signal of the strain sensor 60 indicating the shear strain of the deformation generating portion 44 can be corrected according to the electric signal of the dedicated strain sensor indicating the bending strain of the deformation generating portion 44, thereby reducing the bending strain component included in the electric signal of the strain sensor 60.

[0083] In addition to this, as this method, strain sensors 60 can be respectively provided on both axial sides of the deformation generating portion 44 of the fixed body 28, and each strain sensor 60 can be arranged on the opposite sides of the bridge circuit, thereby canceling the bending strain component included in the electric signal of each strain sensor 60.

[0084] In addition to this, in order to suppress the influence of the bending strain component included in the electric signal of the strain sensor 60, a machine learning model can also be used. The machine learning model is learned in the following manner: when the electric signal of the strain sensor 60 indicating the shear strain of the deformation generating portion 44 is input, the torque with the influence of the bending strain component included in the electric signal of the strain sensor 60 reduced is output. The machine learning model is, for example, a neural network such as an artificial neural network (ANN: Artificial Neuronal Network).

[0085] (Third Embodiment)

[0086] Reference Figure 9 The entire circuit board 62 of the first embodiment is composed of a rigid board. In the present embodiment, the circumferential portion 62a of the circuit board 62 is composed of a rigid board 100, and the first protruding portion 62b is composed of a flexible board 102. The flexible board 102 is connected to the rigid board 100 by various connection methods including well-known methods. The second protruding portion 62c is composed of the same rigid board 100 as the circumferential portion 62a, but may also be composed of a flexible board 102. And both the circumferential portion 62a and the first protruding portion 62b of the circuit board 62 may be composed of a flexible board 102.

[0087] If the deformation-occurring portion 44 deforms more than the respective annular portions 40 and 42 under the torque applied to the fixed body 28, the strain sensor 60 provided in the deformation-occurring portion 44 and the circuit board 62 provided in the annular portion 42 tend to move relative to each other in the circumferential direction. The flexible substrate 102 can flexibly deform along with this relative movement of the circuit board 62 and the strain sensor 60. At this time, the flexible substrate 102 of the present embodiment can mainly shear-deform in the circumferential direction, but can also deform in the axial direction. Although not shown, the flexible substrate 102 is provided at a slight interval from the axial side surface of the fixed body 28 to allow its own flexible deformation, and is not fixed to the fixed body 28 by an adhesive or the like. In contrast, the circumferential portion 62a of the circuit board 62 formed of the rigid substrate 100 is fixed to the annular portion 42 of the fixed body 28 by an adhesive or the like.

[0088] Thus, when the strain sensor 60 and the circuit board 62 tend to move relative to each other in the circumferential direction, the flexible substrate 102 deforms, thereby being able to avoid a situation where a large load acts locally on the connection portion between the strain sensor 60 and the circuit board 62 and the conductive connection material 76. Furthermore, it is possible to suppress the occurrence of a connection failure in which either the sensor electrode 66 of the strain sensor 60 or the substrate electrode 72 of the circuit board 62 is separated from the conductive connection material 76, resulting in the inability to electrically connect the strain sensor 60 and the circuit board 62. Such a connection failure may be caused, for example, by the conductive connection material 76 being damaged due to a local large load.

[0089] Also, when thermal expansion occurs in the deformation-occurring portion 44 of the fixed body 28 or vibration is input to the deformation-occurring portion 44, etc., the strain sensor 60 provided in the deformation-occurring portion 44 is displaced relative to the rigid substrate 100 of the circuit board 62. At this time, since the flexible substrate 102 of the circuit board 62 can flexibly deform, it is possible to avoid a situation where a large load acts on the connection portion between the circuit board 62 and the conductive connection material 76. Also, the thickness of the flexible substrate 102 in the axial direction becomes thinner than that of the rigid substrate 100. Thereby, it is possible to reduce the axial dimension from the main surface on the axial outer side of the circuit board 62 (the main surface of the flexible substrate 102) to the main surface of the strain sensor 60. Thereby, there is also an advantage that it is easy to dispose the conductive connection material 76 so as to cover the main surface side portion of the substrate electrode 72 located on the main surface of the circuit board 62 while covering the sensor electrode 66 located on the main surface of the strain sensor 60.

[0090] Next, a modification example of each of the above-described constituent elements will be described.

[0091] As a specific type of the eccentric swing type reduction device 10, the center crank type in which the crankshaft 14 is disposed on the swing center C16a of the external gear 16 has been described. The specific type is not particularly limited. For example, it may be a distributive type in which a plurality of crankshafts 14 are disposed at positions radially offset from the swing center C16a of the external gear 16.

[0092] In the first embodiment, the fixed body 28 is constituted by at least the timing pulley bracket 20, and the output body 32 is constituted by at least the internal gear 18. And, in the second embodiment, the fixed body 28 is constituted by at least the internal gear 18, and the output body 32 is constituted by the timing pulley bracket 20. Thus, as long as one of the internal gear 18 and the timing pulley bracket 20 constitutes at least a part of the fixed body 28 and the other constitutes at least a part of the output body 32.

[0093] When one of the internal gear 18 and the timing pulley bracket 20 constitutes at least a part of the fixed body 28, there may or may not be other constituent elements of the fixed body 28, and specific examples of such constituent elements are not particularly limited. Similarly, when the other of the internal gear 18 and the timing pulley bracket 20 constitutes at least a part of the output body 32, there may or may not be other constituent elements of the output body 32, and specific examples of such constituent elements are not particularly limited.

[0094] As described above, an example in which the first annular portion 40 of the fixed body 28 constitutes the inner annular portion and the second annular portion 42 constitutes the outer annular portion has been described. Instead, the first annular portion 40 may also constitute the outer annular portion, and the second annular portion 42 may also constitute the inner annular portion.

[0095] The deformation generating portion 44 of the fixed body 28 may not have the first concave portion 80. Both the first annular portion 40 and the second annular portion 42 of the fixed body 28 may not have the second concave portion 82. The first annular portion 40 may be provided with the second concave portion 82 instead of the second annular portion 42 of the fixed body 28.

[0096] The circuit board 62 may not have the first protrusion 62b and the second protrusion 62c, or may have only one of them. And, the number of the first protrusion 62b and the second protrusion 62c is not particularly limited.

[0097] The pair of reinforcing portions 90 may not be truncated at the radial side portions 52b, 52c of the pair of axial through holes 52 that are on the second concave portion 82 side of the circuit board 62 in the radial direction.

[0098] When the deformation generating portion 44 of the fixed body 28 is provided at a position different from the above-described load transmission path 96, the fixed body 28 may not be constituted by at least the timing pulley bracket 20 and the housing 22 as in the first embodiment.

[0099] The above embodiments and modification examples are illustrative. The technical ideas abstracted from them should not be construed restrictively as the contents of the embodiments and modification examples. Many design changes such as changes, additions, and deletions of constituent elements can be made to the contents of the embodiments and modification examples. In the above embodiments, for the contents that can undergo such design changes, the mark "Embodiment" is marked and emphasized. However, it does not mean that design changes are not allowed for the contents without such a mark. The hatching lines in the cross-sections shown in the drawings are not used to limit the material of the object with the hatching lines marked.

[0100] Any combination of the above constituent elements is also effective. For example, any explanatory matter of other embodiments can be combined with the embodiments, and any explanatory matter of the embodiments and other modification examples can be combined with the modification examples. A constituent element that is composed of one component in the embodiments can also be composed of multiple components. Similarly, a constituent element that is composed of multiple components in the embodiments can also be composed of one component.

Claims

1. An eccentric swing type reduction gear device, comprising: eccentric body; an external gear capable of being swung by the eccentric body; an internal gear meshing with the external gear; and a wheel carrier capable of synchronizing with the rotation component of the external gear, The eccentric oscillating type reduction gear device is characterized in that: One of the internal gear and the wheel carrier constitutes at least a part of a fixed body fixed to an external member. The fixed body comprises: a first annular portion; a second annular portion which is radially separated from the first annular portion and fixed to the outer member; and a deformation generating portion which is disposed between the first annular portion and the second annular portion. A strain sensor is provided at the deformation generating portion.

2. The eccentric oscillating type reduction gear device according to claim 1, characterized in that: The strain generating portion includes a first recessed portion for accommodating the strain sensor.

3. The eccentric oscillating type reduction gear device according to claim 1, characterized in that: A circuit board electrically connected to the strain sensor is provided.

4. The eccentric oscillating type reduction gear device according to claim 3, characterized in that: One of the first annular portion and the second annular portion includes a second recessed portion that accommodates at least a portion of the circuit board.

5. The eccentric oscillating type reduction gear device according to claim 3, characterized in that: The strain generating portion includes a first recess for accommodating the strain sensor. The circuit board includes a first protrusion that protrudes into the first recess and is connected to the strain sensor.

6. The eccentric oscillating type reduction gear device according to claim 3, characterized in that: The circuit board includes: a circumferential portion axially opposed to one of the first annular portion and the second annular portion; and a first protruding portion radially protruding from the circumferential portion and electrically connected to the strain sensor.

7. The eccentric oscillating speed reduction device according to claim 5 or 6, characterized in that: The first protrusion is electrically connected to the strain sensor via a conductive connecting material. The first protrusion is formed of a flexible substrate.

8. The eccentric oscillating speed reduction device according to claim 3, characterized in that: The strain generating portion includes a plurality of columnar portions disposed at intervals in a circumferential direction.

9. The eccentric oscillating type reduction gear device according to claim 8, characterized in that: The circuit board includes a second protruding portion that protrudes so as to be located between the adjacent columnar portions when viewed in the axial direction.

10. The eccentric oscillating type reduction gear device according to claim 8, characterized in that: The fixing body comprises: an axial through hole formed between adjacent columnar portions; and a pair of reinforcing portions respectively disposed on a pair of circumferential side portions of the axial through hole. One of the first annular portion and the second annular portion includes a second recessed portion for accommodating at least a portion of the circuit board. The pair of reinforcing portions is cut off at a radial side portion of the axial through hole located on the second recessed portion side in the radial direction with respect to the axial through hole.

11. The eccentric oscillating speed reduction device according to claim 1, characterized in that: The other of the internal gear and the wheel carrier constitutes at least a part of an output body that outputs the rotation. A main bearing is arranged between the output body and the fixed body. The strain generating portion is provided at a position different from a load transmission path from the output body to the external member via the main bearing and the fixed body.

12. The eccentric oscillating speed reduction device according to claim 11, characterized in that: A housing is provided on the radially outer side of the external gear. At least a part of the fixed body is composed of the housing and the wheel frame, The deformation generating portion is arranged on the wheel frame.

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