RPM REDUCER

Abstract

Speed ​​reducer (1, 1A, 1B), comprising: a reduction mechanism comprising an internal gear (21, 22, 38) and an external gear (15, 28e2, 34, 36); a driven element (24, 41) that outputs a slowed rotation due to the reduction mechanism; a fixed element that is fixed against the rotation of the output element (24, 41); and a main bearing (28, 28B) that supports the attached element and the driven element (24, 41), wherein the main bearing (28, 28B) contains an inner ring (28i1, 28i2, 28i1B, 55i1, 55i2) and an outer ring (28o1, 28o2, 55o1, 55o2) formed from a plate element, and at least the inner ring (28i1, 28i2, 28i1B, 55i1, 55i2) or the outer ring (28o1, 28o2, 55o1, 55o2) is connected to the attached element or the output element (24, 41) separately from the attached element and the output element (24, 41), this inner ring (28i1, 28i2, 28i1B, 55i1, 55i2) or this outer ring (28o1, 28o2, 55o1, 55o2) contains an extension section (28e, 28e2, 55e1, 55e2, 55ep) formed from a plate element, and the extension section (28e, 28e2, 55e1, 55e2, 55ep) is a further functional component of the Speed ​​reducer (1, 1A, 1B) forms.

Description

BACKGROUND OF THE INVENTIONField of the invention

[0001] Certain embodiments of the present invention relate to a speed reducer. Description of the state of the art

[0002] In the prior art, there is a speed reducer that includes a reduction mechanism including an internal gear and an external gear, an output member that outputs decelerated rotation in the reduction mechanism, and a main bearing that supports the output member (see, for example, Japanese Unexamined Patent Publication No. JP 2020-133843 A). SUMMARY OF THE INVENTION

[0003] The speed reducer described in the prior art, which has the above-described configuration, has a problem in that the number of components is large. The present invention aims to provide a speed reducer capable of reducing the number of components.

[0004] The above-mentioned problem is solved by a speed reducer having the features of claim 1. According to one embodiment of the present invention, a speed reducer is provided including a reduction mechanism including an internal gear and an external gear, an output member that outputs rotation slowed down by the reduction mechanism, and a main bearing that supports the output member.

[0005] The main bearing contains an inner ring and an outer ring formed from a plate element.

[0006] At least one of the inner ring and the outer ring contains an extension section, and the extension section forms another functional component of the speed reducer.

[0007] According to the speed reducer of the present invention, an advantageous effect can be obtained in that the number of components can be reduced. SHORT DESCRIPTION OF THE CHARACTERS Fig. 1 is a sectional view illustrating a speed reducer according to Embodiment 1 of the present invention. Fig. 2 is a sectional view illustrating a speed reducer according to Embodiment 2 of the present invention. Fig. 3 is a sectional view illustrating a speed reducer according to Embodiment 3 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, each embodiment according to the present invention will be described in detail with reference to the figures. (Embodiment 1)

[0009] Fig. 1 is a sectional view illustrating a speed reducer according to Embodiment 1 of the present invention. In the present embodiment, a direction along a rotational axis O1 of a wave generator shaft 10 is referred to as an axial direction, a rotational direction around the rotational axis O1 is referred to as a circumferential direction, and a direction perpendicular to the rotational axis O1 is referred to as a radial direction. Furthermore, an arrangement side of an output member 24 in the axial direction is referred to as an output side, and an opposite side thereto is referred to as a counter output side.

[0010] A speed reducer 1 is a flexural meshing type gear device and includes the shaft generator shaft 10, a shaft generator bearing 11, an external gear 15, a first internal gear 21, a second internal gear 22, the output member 24, a cover member 25, bearings 26 and 27, a main bearing 28, and a stop ring 16.

[0011] The wave generator shaft 10 is a drive shaft for inputting rotational motion. The wave generator shaft 10 is a hollow cylindrical shaft that rotates around the rotation axis O1 and includes a wave generator 10A with a non-circular outer shape (for example, an elliptical shape) in a cross section perpendicular to the rotation axis O1, and shaft portions 10B and 10C provided on both sides in the axial direction of the wave generator 10A. The elliptical shape does not need to be a geometrically precise ellipse and includes a substantially elliptical shape. The shaft portions 10B and 10C are shafts with a circular outer shape in a cross section perpendicular to the rotation axis O1. A material of the wave generator shaft 10 is not particularly limited. However, in the present embodiment, the wave generator shaft 10 is formed of metal, for example, a steel material.

[0012] The external gear 15 is a flexible cylindrical member having a tooth on its outer periphery. The material of the external gear 15 is not particularly limited. However, in the present embodiment, the external gear 15 is formed of metal, for example, a steel material.

[0013] The first internal gear 21 is an annular member having a tooth provided in a portion on an inner circumference. The second internal gear 22 is an annular member having an internal tooth on the inner circumference. The internal tooth of the first internal gear 21 and the internal tooth of the second internal gear 22 are aligned in the axial direction and mesh with the external gear 15. The first internal gear 21 meshes with a portion on the counter-driven side of the external gear 15, and the second internal gear 22 meshes with a portion on the driven side of the external gear 15. Materials of the first internal gear 21 and the second internal gear 22 are not particularly limited. However, in the present embodiment, both are formed of a resin. The type of the resin is not particularly limited.However, in the present embodiment, both are formed of a polyetheretherketone (PEEK) material containing carbon fibers.

[0014] The first internal gear 21 further includes an outer peripheral portion, one end and the other end of which extend in the axial direction toward the counter-driven side and the driven side, respectively. The outer peripheral portion functions as a casing that covers an engagement portion between the external gear 15, the first internal gear 21, and the second internal gear 22 from the outside in the radial direction.

[0015] The shaft generator bearing 11 is, for example, a roller bearing and is arranged between the shaft generator 10A and the external gear 15. The shaft generator bearing 11 does not have a dedicated outer ring and inner ring. An inner peripheral portion of the external gear 15 also serves as an outer ring of the shaft generator bearing 11, and an outer peripheral portion of the shaft generator 10A also serves as an inner ring of the shaft generator bearing 11. The shaft generator bearing 11 may have the outer ring and the inner ring separately. The external gear 15 is rotatably supported by the shaft generator 10A via the shaft generator bearing 11. A material of a rolling element of the shaft generator bearing 11 is not particularly limited. However, in the present embodiment, the rolling element is formed of a metal, for example, a steel material.

[0016] The stop ring 16 is arranged on the counter-drive side of the external gear 15 and the shaft generator bearing 11 and restricts the external gear 15 and the shaft generator bearing 11 from moving toward the counter-drive side. The material of the stop ring 16 is not particularly limited. However, in the present embodiment, the stop ring 16 is formed of metal, for example, a steel material.

[0017] An inner ring 28i1 of the main bearing 28 has an extension portion 28e located on the output side of the external gear 15 and the shaft generator bearing 11. The extension portion 28e functions as a movement-limiting component that limits the movement of the external gear 15 and the shaft generator bearing 11 to the output side.

[0018] The output member 24 is located on the output side of the speed reducer 1 and is connected to the second internal gear 22 to output decelerated rotation. The output member 24 may have an annular configuration with a center penetrated so as not to close a hollow portion of the wave generator shaft 10. A material of the output member 24 is not particularly limited. However, in the present embodiment, the output member 24 is formed of a resin. The type of the resin is not particularly limited. However, in the present embodiment, the output member 24 is formed of a polyoxymethylene (POM) or polyacetal material containing carbon fiber.

[0019] The wave generator 10A, the wave generator bearing 11, the external gear 15, the first internal gear 21, and the second internal gear 22 form a reduction mechanism. The first internal gear 21 is directly or indirectly connected to an external bearing member 81 that supports the speed reducer 1. The reduction mechanism reduces a rotational speed input to the wave generator 10A and outputs the decelerated rotation to the second internal gear 22. The second internal gear 22, together with the output member 24, is connected to an external counter member 82. The second internal gear 22 and the output member 24 output the rotation decelerated by the reduction mechanism to the counter member 82.

[0020] The cover member 25 is located on the counter output side of the speed reducer 1 and covers the meshing portion between the external gear 15 and the first internal gear 21 on the counter output side. The cover member 25 is connected to the first internal gear 21. A material of the cover member 25 is not particularly limited. However, in the present embodiment, the cover member 25 is formed of a resin. The type of the resin is not particularly limited. However, in the present embodiment, the cover member 25 is formed of a POM material containing carbon fiber.

[0021] Bearings 26 and 27, for example, are ball bearings, but the bearing type is not particularly limited. Bearing 26 is inserted between the cover member 25 and the shaft generator shaft 10, supporting both so that they can rotate relatively. Bearing 27 is inserted between the output member 24 and the shaft generator shaft 10, supporting both so that they can rotate relatively.

[0022] The main bearing 28 is interposed between the first internal gear 21, the second internal gear 22, and the output member 24, supporting them all for relative rotation. The main bearing 28 is a crossed roller bearing and can support a radial load and a bidirectional thrust load using a single bearing. In addition, the main bearing 28 can be configured to support a moment load using a single bearing. The single bearing means a configuration that cannot be divided into multiple components, each of which functions as a bearing if only the bearing is removed. The main bearing 28 is not limited to the crossed roller bearing. For example, other bearings that can support the radial load and the bidirectional thrust load using the single bearing, such as a four-point contact ball bearing, can be applied to the main bearing 28.Furthermore, the main bearing is not limited to the bearing that can support the radial load and the bidirectional thrust load using a single bearing, and various bearings can be applied to it. For example, the main bearing may be configured to include a pair of bearings. In this case, the present invention can be applied to both pairs of bearings, or the present invention can be applied to only one of the pairs of bearings. Furthermore, the bearing does not need to support a partial load of the radial load and the bidirectional thrust load. <drehzahlreduzierung-betrieb>

[0023] When a rotational movement is input to the wave generator shaft 10 from the outside, the rotational movement of the wave generator 10A is transmitted to the external gear 15. In this case, the external gear 15 is constrained to have a shape along an outer peripheral surface of the wave generator 10A and is bent into an elliptical shape with a major axis portion and a minor axis portion when viewed in the axial direction. Moreover, the external gear 15 meshes with the fixed first internal gear 21 at the major axis portion. Therefore, the external gear 15 does not rotate at the same speed as the wave generator 10A, and the wave generator 10A rotates relatively within the external gear 15. Then, in response to the relative rotation, the external gear 15 is bent and deformed, so that a major axis position and a minor axis position move in the circumferential direction.One period of deformation is proportional to one rotation period of the wave generator shaft 10.

[0024] When the external gear 15 is bent and deformed, the main axis position moves, so that a meshing position between the external gear 15 and the first internal gear 21 changes in the rotation direction. Here, when the number of teeth of the external gear 15 is 100 and the number of teeth of the first internal gear 21 is 102, each time the meshing position is rotated once, the meshing teeth between the external gear 15 and the first internal gear 21 are shifted. In this way, the external gear 15 is rotated (rotates). According to the number of teeth described above, the rotation of the wave generator shaft 10 is decelerated at a reduction ratio of 100:2 and transmitted to the external gear 15.

[0025] On the other hand, the external gear 15 meshes with another second internal gear 22. Accordingly, the engagement position between the external gear 15 and the second internal gear 22 is also changed in the rotational direction by the rotation of the wave generator shaft 10. On the other hand, the number of teeth of the second internal gear 22 and the number of teeth of the external gear 15 match each other. Accordingly, the external gear 15 and the second internal gear 22 are not rotated relative to each other, and the rotational movement of the external gear 15 is transmitted to the second internal gear 22 at a reduction ratio of 1:1. In this way, the rotational movement of the wave generator shaft 10 is decelerated at a reduction ratio of 100:2 and transmitted to the second internal gear 22 and the output member 24. Then, the decelerated rotational movement is output from the output member 24 to the counter member 82.

[0026] During a deceleration operation of the speed reducer 1, when the radial load or the bidirectional axial load is applied between the external bearing member 81 and the counter member 82, the main bearing 28 receives the load. In this way, the speed reducer 1 can continuously perform the deceleration operation without any problems. In addition, during the deceleration operation of the speed reducer 1, when the moment load is applied between the external bearing member 81 and the counter member 82, the main bearing 28 receives the moment load. In this way, an effect can be obtained so that the speed reducer 1 can continuously perform the deceleration operation without any problems. <Innenring und Außenring von Hauptlager>

[0027] The main bearing 28 includes inner rings 28i1 and 28i2 formed from a plate member, outer rings 28o1 and 28o2 formed from a plate member, and a roller-shaped rolling element 28t. When the main bearing 28 is a four-point contact ball bearing, the rolling element 28t has a spherical shape. The plate member described above can be formed from metal, for example, a steel material.

[0028] Each of the inner rings 28i1 and 28i2 and the outer rings 28o1 and 28o2 is configured such that the plate member is bent by press forming, and a plate-shaped portion having at least one rolling surface (also referred to as a trajectory surface) of a cross-sectional shape in Fig. 1, has an annular shape that is continuous in the circumferential direction. The outer rings 28o1 and 28o2 are arranged on the output side and the counter-output side, respectively, and are formed of two mutually divided elements, each of which contains the rolling surface on which the rolling element 28t rolls. Similarly, the inner rings 28i1 and 28i2 are arranged on the output side and the counter-output side, respectively, and are formed of two mutually divided elements, each of which contains the rolling surface on which the rolling element 28t rolls. A rolling element (roller) having a rotation axis x1 rolls on the rolling surfaces of the inner ring 28i1 and the outer ring 28O2, and a rolling element (roller) having a rotation axis x2 rolls on the rolling surfaces of the inner ring 28i2 and the outer ring 28O1.The inner ring 28i1 corresponds to an example of a first inner ring element according to the present invention, and the inner ring 28i2 corresponds to an example of a second inner ring element according to the present invention.

[0029] The inner rings 28i1 and 28i2 and the outer rings 28o1 and 28o2 are formed from the plate element. This allows for weight reduction and the cost of the main bearing 28 to be reduced.

[0030] The outer rings 28o1 and 28o2 further include a flange portion 28f1 extending outward in the radial direction and a communication hole (e.g., a through hole) h28o provided in the flange portion 28f1. The flange portions 28f1 may be provided continuously along an entire circumference in the circumferential direction, or may be provided at multiple locations in the circumferential direction. The communication holes h28o are provided at multiple locations in the circumferential direction.

[0031] Viewed in the axial direction, the first internal gear 21 has a flange portion 21f arranged to overlap the flange portion 28f1, and a connecting hole (e.g., a bolt hole) h21 provided in the flange portion 21f. The flange portions 21f may be provided continuously along the entire circumference in the circumferential direction, or may be provided at multiple locations in the circumferential direction. The connecting holes h21 are provided at multiple locations in the circumferential direction.

[0032] The flange portion 28f1 of the outer rings 28o1 and 28o2 and the flange portion 21f of the first internal gear 21 are connected by a connecting member B1, such as a bolt, via the connecting holes h28o and h21. Furthermore, the flange portions 28f1 and 21f may be connected to the external bearing member 81 via the connecting holes h28o and h21 by a connecting member B2, such as a bolt.

[0033] The inner rings 28i1 and 28i2 further include a flange portion 28f2 extending inward in the radial direction and a communication hole (e.g., a through hole) h28i provided in the flange portion 28f2. The flange portions 28f2 may be provided continuously along the entire circumference in the circumferential direction, or may be provided at multiple locations in the circumferential direction. The communication holes h28i are provided at multiple locations in the circumferential direction.

[0034] In the second internal gear 22, connecting holes (for example, screw holes) h22 are provided at several locations in the circumferential direction.

[0035] In the output element 24, connecting holes (for example through holes) h24a and h24b are provided at several locations in the circumferential direction.

[0036] The output member 24, the flange portion 28f2 of the inner rings 28i1 and 28i2, and the second internal gear 22 are connected to each other by a connecting member B3, such as a screw, via the connecting holes h24a, h28i, and h22. Furthermore, the external counter member 82 may be connected to the flange portion 28f2 and the second internal gear 22 by a connecting member B4, such as a screw, via the connecting holes h24b, h28i, and h22 of the output member 24.

[0037] The inner ring 28i1 further includes an extension portion 28e having a disk shape (a disk shape with the center penetrated, i.e., an annular shape) extending inward in the radial direction and continuous in the circumferential direction. The inner ring 28i1 having the extension portion 28e is located inside the device in the axial direction from the other inner ring 28i2. The inside of the device means a location near the center (center of the engagement portion between the external gear 15, the first internal gear 21, and the second internal gear 22) of the reduction mechanism in the axial direction.

[0038] As described above, the extension portion 28e forms a functional component other than the bearing, and specifically functions as a movement limiting component that limits the external gear 15 and the shaft generator bearing 11 from moving to the output side.

[0039] The plate member can easily achieve high thickness accuracy and desired surface properties. Therefore, the extension portion 28e of the inner ring 28i1 formed from the plate member can have high thickness accuracy and surface properties suitable for the movement-limiting component without costly machining.

[0040] Furthermore, the extension portion 28e extends in the axial direction to a position overlapping the outer ring of the bearing 27 and can contact an entire side surface of a retainer of the shaft generator bearing 11. This contact can stably limit the movement of the shaft generator bearing 11. Thus, a configuration that limits the movement of the shaft generator bearing 11 by contacting the entire side surface of the retainer is difficult to achieve unless an independent stop member is arranged or an extension portion is provided in one or both of the inner rings 28i1 and 28i2. For example, if a similar movement-limiting component must be provided by extending a portion of the output member 24 instead of the extension portion 28e, a difficulty arises as follows.That is, the outer ring of the bearing 27 is positioned by fitting it into an inner peripheral portion of the driven member 24 from the counter-drive side and coming into contact with a protruding portion 24a protruding inward in the radial direction of the driven member 24. Therefore, if a portion of the driven member 24 is extended to the vicinity of the shaft generator bearing 11 instead of the extension portion 28e, the bearing 27 and the driven member 24 are less likely to be installed. However, in Embodiment 1, the extension portion 28e is provided in the inner ring 28I2. In this way, a portion of the inner ring 28I2 is caused to function as the movement-limiting component. Accordingly, the inner ring 28I2 having the movement-limiting component (extension portion 28e) can be installed in the device without the difficulty described above.

[0041] In Embodiment 1, an example was described in which the outer ring of the main bearing 28 is formed of two elements (outer rings 28o1 and 28o2) and the inner ring is formed of two elements (inner rings 28i1 and 28i2). However, the outer ring may be formed of a single plate member by press forming, or the inner ring may be formed of a single plate member by press forming. Furthermore, the configuration of Embodiment 1 may include an extension portion extending to the counter driven side and then to an end portion of any of the outer rings 28o1 and 28o2. Then, the extension portion may function as a housing covering an outer side in the radial direction of the engagement portion between the external gear 15, the first internal gear 21, and the second internal gear 22.The outer ring containing the extension portion in this way may be the outer ring 28o1 located inside the device in the axial direction. In this case, the extension portion may be small in size, and the extension portion may function as a housing without being machined into a complicated shape.

[0042] As described above, according to the speed reducer 1 of Embodiment 1, the reduction mechanism including the first internal gear 21, the second internal gear 22, and the external gear 15, the output member 24 that outputs the rotation decelerated by the reduction mechanism, and the main bearing 28 that supports the output member 24 are provided. Furthermore, the main bearing 28 includes the inner rings 28i1 and 28i2 and the outer rings 28o1 and 28o2 formed from the plate member. The inner ring 28i1 includes the extension portion 28e, and the extension portion 28e constitutes another functional component of the speed reducer 1. Therefore, the inner ring 28i1 and another functional component can be integrated with each other, and the number of components can be reduced. In addition, the inner rings 28i1 and 28i2 and the outer rings 28o1 and 28o2 of the main bearing 28 are formed from the plate element.In this way, compared with the main bearing including a block-shaped inner ring and outer ring, weight reduction of the main bearing 28 can be achieved, and weight reduction of the speed reducer 1 can be achieved.

[0043] In particular, the extension portion 28e functions as the movement-limiting component that limits the movement of the other elements. The inner ring 28i1 is formed from the plate element. Accordingly, the extension portion 28e can maintain high thickness accuracy and, moreover, can easily obtain desired surface properties. Therefore, the extension portion 28e satisfactorily functions as the movement-limiting component.

[0044] More specifically, the extension portion 28e limits the movement of the external gear 15 toward the output side. The extension portion 28e limits the movement of the external gear 15 after the external gear 15 slides. Accordingly, the surface properties are required to withstand the sliding. However, since the inner ring 28i1 is formed of the plate member, the surface properties can be easily obtained.

[0045] Furthermore, according to the speed reducer 1 of Embodiment 1, the inner rings 28i1 and 28i2 are formed from the two elements divided from each other, and one inner ring 28i2 includes the extension portion 28e. The inner rings 28i1 and 28i2 are formed from the two elements. In this way, the rolling surface of the rolling element 28t can be easily machined, and one inner ring 28i1 includes the extension portion 28e. Accordingly, the extension portion 28e can be easily formed, and the extension portion 28e can be easily installed, compared to a case where the extension portions are provided in both inner rings 28i1 so that two extension portions are overlapped and used.

[0046] Furthermore, according to the speed reducer 1 of Embodiment 1, among the inner rings 28i1 and 28i2, the extension portion 28e is provided in the inner ring 28i1, which is arranged inside the device in the axial direction. Therefore, the extension portion 28e can be small in size and can be arranged as a functional component of the reduction mechanism without requiring a complicated shape that avoids other components.

[0047] Furthermore, according to the speed reducer 1 of Embodiment 1, the main bearing 28 is configured to support the radial load and the bidirectional axial load using a single bearing. Therefore, compared with a configuration in which two main bearings are arranged differently in the axial direction, the total number of components of the speed reducer 1 can be reduced. Moreover, the bearing that supports the load in this way can be easily formed from the two inner rings 28i1 and 28i2 divided from each other and the two outer rings 28o1 and 28o2 divided from each other. Accordingly, in addition to the above-described advantageous effect obtained by the configuration in which the inner rings 28i1 and 28i2 are divided into each other, the inner rings 28i1 and 28i2 are formed from two mutually divided members.In this way, an advantageous effect is achieved in that the bearing for receiving the load described above can be easily formed.

[0048] Furthermore, according to the speed reducer 1 of Embodiment 1, the inner rings 28i1 and 28i2 and the outer rings 28o1 and 28o2 are formed from the plate member bent by press forming. Therefore, the manufacturing costs of the inner rings 28i1 and 28i2 and the outer rings 28o1 and 28o2 can be reduced, and the cost of components of the speed reducer 1 can be reduced. (Embodiment 2)

[0049] Fig. 2 is a sectional view illustrating a speed reducer according to Embodiment 2 of the present invention. In Embodiment 2, the direction along the rotational axis O1 of an eccentric body shaft 31 is referred to as the axial direction, the rotational direction around the rotational axis O1 is referred to as the circumferential direction, and the direction perpendicular to the rotational axis O1 is referred to as the radial direction. Moreover, the arrangement side of a carrier body 41 (the side of the carrier body 41 as viewed from the external gears 34 and 36) that outputs the rotational motion decelerated in the axial direction is referred to as the output side, and the opposite side thereto is referred to as the counter output side.

[0050] A speed reducer 1A of Embodiment 2 is an eccentric oscillating type speed reducer in which the external gears 34 and 36 eccentrically oscillate, and includes the eccentric body shaft 31 including two eccentric bodies 31b and 31c, the two external gears 34 and 36, an internal gear 38 meshing with the external gears 34 and 36, eccentric body bearings 51 and 52, an internal pin 55ep meshing with the external gears 34 and 36, the carrier body 41 connected to the internal pin 55ep, a cover member 46 covering a position where the external gears 34 and 36 oscillate from the counter output side, and a main bearing 55 interposed between the carrier body 41 and the internal gear 38. The carrier body 41 corresponds to an example of an output element according to the present invention. The inner pin 55ep corresponds to an example of a pin element according to the present invention.

[0051] In addition, the speed reducer 1A includes a stop ring 44 disposed between the external gear 34 and the cover member 46, a stop ring 45 disposed between the two external gears 34 and 36, a collar 48 fixed to a shaft portion 31a1 of the eccentric body shaft 31, a seal 47 disposed between the collar 48 and the cover member 46, and high-speed bearings 53 and 54 supporting the eccentric body shaft 31.

[0052] The eccentric body shaft 31 includes shaft sections 31a1, 31a2, and 31a3, in which the rotation axis O1 overlaps a central axis, and eccentric bodies 31b and 31c arranged eccentrically from the rotation axis O1. The eccentric bodies 31b and 31c have a circular cross-section perpendicular to the rotation axis O1 and are eccentrically rotated in mutually different phases by the rotation of the eccentric body shaft 31.

[0053] The external gear 34 is installed in the eccentric body 31b via an eccentric body bearing 51 and oscillates via the rotation of the eccentric body shaft 31. The other external gear 36 is installed in the eccentric body 31c via an eccentric body bearing 52 and oscillates in a different phase than the external gear 34 via the rotation of the eccentric body shaft 31. The external gear 34 is provided with an inner pin hole 34h through which the inner pin 55ep is inserted. Similarly, the external gear 36 is provided with an inner pin hole 36h through which the inner pin 55ep is inserted.

[0054] The inner pin 55ep and the inner pin holes 34h and 36h may be provided one after the other or may be provided at multiple locations in the circumferential direction.

[0055] The inner pin 55ep contacts an inner peripheral surface of the inner pin holes 34h and 36h via a sleeve 49 and moves (including stopping) in synchronization with the movement (rotational movement) of the external gears 34 and 36. More specifically, the inner pin 55ep revolves in synchronization with the rotation of the external gears 34 and 36, causing the carrier body 41 to rotate axially. When the rotation of the external gears 34 and 36 is restricted, the rotation is restricted, and the axial rotation of the carrier body 41 is also restricted.

[0056] The carrier body 41 is arranged on the output side of the two external gears 34 and 36 and is connected to the inner rings 55i1 and 55i2 and the inner pin 55ep of the main bearing 55.

[0057] Although the bearing type is not particularly limited, the high-speed bearings 53 and 54 are, for example, ball bearings. One high-speed bearing 53 is interposed between the cover member 46 and the shaft portion 31a2 of the eccentric body shaft 31, supporting them so that they can rotate relatively. The other high-speed bearing 54 is interposed between the support body 41 and the shaft portion 31a3 of the eccentric body shaft 31, supporting them so that they can rotate relatively.

[0058] The main bearing 55 supports the internal gear 38 and the carrier body 41 so that they can rotate relatively. The main bearing 55 is a crossed roller bearing and can support radial loads and bidirectional thrust loads using a single bearing. Furthermore, the main bearing 55 can be configured to support moment loads using a single bearing. The main bearing 55 is not limited to the crossed roller bearing. For example, other bearings that can support radial loads and bidirectional thrust loads using a single bearing, such as a four-point contact ball bearing, can be applied to the main bearing 55. <drehzahlreduzierung-betrieb>

[0059] In the speed reducer 1A having the above-described configuration, the internal gear 38 is directly or indirectly connected to the external bearing member 81 through a connecting member B13 such as a screw, and the support body 41 is directly or indirectly connected to the external counter member 82 through a connecting member B12 such as a screw. Then, when the rotational movement is input from the outside to the eccentric body shaft 31, the speed reducer 1A decelerates the input rotation and outputs the decelerated rotation to the counter member 82 from the support body 41.

[0060] Specifically, when the eccentric body shaft 31 rotates, the eccentric bodies 31b and 31c rotate eccentrically, and one external gear 34 and the other external gear 36 oscillate with a phase difference of 180 degrees. Since the two external gears 34 and 36 are provided, transmission capacity can be increased and strength can be maintained. Furthermore, rotational balance of the speed reducer 1A can be maintained. The external gears 34 and 36 internally mesh with the internal gear 38, and the internal gear 38 is connected to the bearing member 81. Therefore, every time the eccentric body shaft 31 rotates once, the external gears 34 and 36 are relatively rotated (rotated) with respect to the internal gear 38 by a difference in the number of teeth. A rotational component of the external gears 34 and 36 is transmitted to the carrier body 41 via the inner pin 55ep.As a result, the rotational movement of the eccentric body shaft 31 is decelerated at a reduction ratio of (the difference in the number of teeth between the internal gear 38 and the external gears 34 and 36) / (the number of common teeth of the external gear 34 and the external gear 36) and is transmitted to the carrier body 41. Then, the decelerated rotation is output from the carrier body 41 to the counter member 82.

[0061] During a deceleration operation of the speed reducer 1A, when the radial load or the bidirectional axial load is applied between the external bearing member 81 and the counter member 82, the main bearing 55 receives the load. In this way, the speed reducer 1A can continuously perform the deceleration operation without any problems. In addition, during the deceleration operation of the speed reducer 1A, when the moment load is applied between the external bearing member 81 and the counter member 82, the main bearing 55 receives the moment load. In this way, an effect can be enabled so that the speed reducer 1A can continuously perform the deceleration operation without any problems.

[0062] The speed reducer 1A can be used as follows. The support body 41 is directly or indirectly connected to the bearing element, the internal gear 38 is directly or indirectly connected to the counter element, and the decelerated rotation is output to the counter element via the internal gear 38. In this case, the internal gear 38 or the cover member 46 connected to the internal gear 38 corresponds to an example of an output member according to the present invention. <Innenring und Außenring von Hauptlager>

[0063] The main bearing 55 includes inner rings 55i1 and 55i2 formed from a plate member, outer rings 55o1 and 55o2 formed from a plate member, and a roller-shaped rolling element 55t. When the main bearing 55 is a four-point contact ball bearing, the rolling element 55t has a spherical shape.

[0064] Each of the inner rings 55i1 and 55i2 and the outer rings 55o1 and 55o2 is such that the plate member is bent by press forming, and a plate-shaped portion having at least one rolling surface (also referred to as a trajectory surface) of a cross-sectional shape in Fig. 1 has an annular shape that is continuous in the circumferential direction. The outer rings 55o1 and 55o2 are formed of two elements, respectively arranged on the output side and the counter-driven side, each of which includes the rolling surface on which the rolling element 55t rolls. Similarly, the inner rings 55i1 and 55i2 are formed of two elements, respectively arranged on the output side and the counter-driven side, each of which includes the rolling surface on which the rolling element 55t rolls. A rolling element (roller) having the rotation axis x1 rolls on the rolling surfaces of the inner ring 55i1 and the outer ring 55o2, and a rolling element (roller) having the rotation axis x2 rolls on the rolling surfaces of the inner ring 55i2 and the outer ring 55o1.

[0065] The inner rings 55i1 and 55i2 and the outer rings 55o1 and 55o2 are formed from the plate element. This allows for weight reduction and lower costs for the main bearing 55.

[0066] The outer rings 55o1 and 55o2 further include a flange portion 55f1 extending outward in the radial direction and a communication hole (e.g., a through hole) h55o provided in the flange portion 55f1. The flange portions 55f1 may be provided continuously along the entire circumference in the circumferential direction, or may be provided at multiple locations in the circumferential direction. The communication holes h55o are provided at multiple locations in the circumferential direction.

[0067] In the internal gear 38, connecting holes (for example screw holes) h38 are provided at several locations in the circumferential direction.

[0068] The flange portion 55f1 of the outer rings 55o1 and 55o2 and the internal gear 38 are connected by a connecting element B11, such as a bolt, via the connecting holes h55o and h38. The flange portion 55f1 can be used to connect the external bearing element. In this case, the bearing element is connected by the connecting element, such as the bolt, via the connecting holes h55o and h38.

[0069] The inner rings 55i1 and 55i2 further include a flange portion 55f2 extending inward in the radial direction and a communication hole (e.g., a through hole) h55i provided in the flange portion 55f2. The flange portions 55f2 may be provided continuously along the entire circumference in the circumferential direction, or may be provided at multiple locations in the circumferential direction. The communication holes h55i are provided at multiple locations in the circumferential direction.

[0070] In the carrier body 41, connecting holes (for example through holes) h41 are provided at several locations in the circumferential direction.

[0071] The flange portion 55f2 of the inner rings 55i1 and 55i2 and the support body 41 are connected by a connecting member B12, such as a bolt, via the connecting holes h55i and h41. Furthermore, the external counter member 82 may be connected by the connecting member B12, such as a bolt, via the connecting holes h55i and h41 of the flange portion 55f2 and the support body 41.

[0072] The inner ring 55i1 further includes an extension portion 55e1 extending inward in the radial direction. The inner ring 55i1, including the extension portion 55e1, is located inside (inside in the axial direction) of the other inner ring 55i2. Furthermore, the extension portion 55e1 includes the hollow inner pin 55ep projecting in a pin shape toward the counter driven side. The inner pin 55ep is formed from a plate material subjected to deep drawing. The extension portion 55e1 may have a disk shape (disk shape with the center penetrated) that is continuous in the circumferential direction, or may have a configuration that partially includes a cutout in the circumferential direction. The inner pin 55ep is provided at one location or at multiple locations in the circumferential direction.The inner pin 55ep passes through the through hole of the carrier body 41 from the output side to the counter output side and projects toward the side of the external gears 34 and 36.

[0073] Similarly, the other inner ring 55i2 has an extension portion 55e2 extending inward in the radial direction. The extension portion 55e2 may have a disk shape (a disk shape with a center penetration) that is continuous in the circumferential direction, or may have a configuration that partially includes a cutout in the circumferential direction. The extension portion 55e2 closes a base opening portion of the inner pin 55ep.

[0074] As described above, according to the speed reducer 1A of Embodiment 2, the reduction mechanism including the internal gear 38 and the external gears 34 and 36, the support body (output member) 41 that outputs the rotation decelerated by the reduction mechanism, and the main bearing 55 that supports the support body 41 are provided. Furthermore, the main bearing 55 includes the inner rings 55i1 and 55i2 and the outer rings 55o1 and 55o2 formed from the plate member. The inner ring 55i1 has the extension portion 55e1 (including the inner pin 55ep). The extension portion 55e1 constitutes another functional component (inner pin 55ep) of the speed reducer 1A. Therefore, the inner ring 55i1 and another functional component can be integrated with each other, and the number of components can be reduced.Furthermore, the inner rings 55i1 and 55i2 and the outer rings 55o1 and 55o2 of the main bearing 55 are formed from the plate member. Accordingly, compared to the main bearing including the block-shaped inner ring and outer ring, weight reduction of the main bearing 55 can be achieved, and weight reduction of the speed reducer 1A can be achieved.

[0075] Specifically, the extended portion 55e1 of the inner ring 55i1 forms the inner pin 55ep, which is synchronized with the rotational component of the external gears 34 and 36. Therefore, one or more inner pins 55ep can be integrated, and an assembly process of the inner pin 55ep can be simplified.

[0076] Furthermore, in the speed reducer 1A of Embodiment 2, as in Embodiment 1, the inner rings 55i1 and 55i2 are also formed of two members divided from each other, and the main bearing 55 receives the radial load and the bidirectional thrust load using a single bearing. Furthermore, the inner rings 55i1 and 55i2 and the outer rings 55o1 and 55o2 are formed of the plate member bent by press forming. Therefore, the above-described advantageous effect obtained by the same configuration of Embodiment 1 can be achieved in the same way. (Embodiment 3)

[0077] Fig. 3 is a sectional view illustrating a speed reducer according to Embodiment 3. Embodiment 3 is a partial modification of Embodiment 1. The same reference numerals are assigned to the same configurations as those in Embodiment 1, and detailed descriptions thereof are omitted. A speed reducer 1B of Embodiment 3 is a flexural meshing type gear device having a so-called top hat type. The reduction mechanism thereof includes an external gear 28e2 having a flange portion 28f3, an internal gear 21B, and a wave generator bearing 11B corresponding to an internal gear 21B. Furthermore, the speed reducer 1B of Embodiment 3 includes a main bearing 28B in which an extended portion of an inner ring 28i1B functions as the external gear 28e2.

[0078] The internal gear 21B has the same configuration as the first internal gear 21 of Embodiment 1. The speed reducer 1B of Embodiment 3 does not include the second internal gear.

[0079] The external gear 28e2 is a metal member including a cylindrical portion and a flange portion 28f3 extending outward in the radial direction from one end of the cylindrical portion, and having flexibility at least at the cylindrical portion. The cylindrical portion has an external tooth G1 provided in a region facing the internal gear 21B (the internal tooth portion thereof).

[0080] The shaft generator bearing 11B is interposed between the shaft generator 10A and the external gear 28E2, and supports the shaft generator 10A and the external gear 28E2 so that they are relatively rotatable. The shaft generator bearing 11B is provided at a position (within the engagement portion in the radial direction) corresponding to the engagement portion between the external gear 28E2 and the internal gear 21B.

[0081] In addition to the same configuration as in Embodiment 1, the wave generator shaft 10 has a protrusion 10e located near an end portion of the wave generator bearing 11B. The protrusion 10e restricts the wave generator bearing 11B from moving to the output side.

[0082] The flange portion 28f3 of the external gear 28e2 is connected to the output element 24.

[0083] The main bearing 28B is interposed between the internal gear 21B, the driven member 24, and the flange portion 28f3 of the external gear 28e2, and supports the internal gear 21B and the driven member 24, and the internal gear 21B and the external gear 28e2 so that they are relatively rotatable. The main bearing 28B is configured in the same way as the main bearing 28 of Embodiment 1, except that the extension portion of the inner ring 28i1B is different. <drehzahlreduzierung-betrieb>

[0084] When the rotational movement is input from the outside to the wave generator shaft 10, the rotational movement of the wave generator 10A is transmitted to the external gear 28e2. In this case, an external tooth portion of the external gear 28e2 is limited to have a shape along an outer peripheral surface of the wave generator 10A and is bent into an elliptical shape with a major axis portion and a minor axis portion, as viewed in the axial direction. Furthermore, the external gear 28e2 meshes with the fixed internal gear 21B at the major axis portion. Therefore, the external gear 28e2 does not rotate at the same speed as the wave generator 10A, and the wave generator 10A rotates relatively within the external gear 28e2. The external gear 28e2 is bent and deformed, so that a major axis position and a minor axis position of the external gear 28e2 move in the circumferential direction.As the main axis position moves, the meshing position between the external gear 28e2 and the internal gear 21B changes in the rotation direction. Here, if the number of teeth of the external gear 28e2 is 100 and the number of teeth of the internal gear 21B is 102, each time the meshing position is rotated once, the meshing teeth of the external gear 28e2 and the internal gear 21B shift. Thus, the external gear 28e2 rotates (rotates). According to the number of teeth described above, the rotational motion of the wave generator shaft 10 is decelerated at a reduction ratio of 100:2 and transmitted to the external gear 28e2. Then, the rotation of the external gear 28e2 is transmitted to the output member 24 via the flange portion 28f3, and the decelerated rotation is output from the output member 24 to the external counter member 82.

[0085] During the deceleration operation of the speed reducer 1B, when the radial load or the bidirectional axial load is applied between the external bearing member 81 and the counter member 82, the main bearing 28B receives the load. In this way, the speed reducer 1B can continuously perform the deceleration operation without any problems. In addition, during the deceleration operation of the speed reducer 1B, when the moment load is applied between the external bearing member 81 and the counter member 82, the main bearing 28B receives the moment load. In this way, an effect can be enabled so that the speed reducer 1B can continuously perform the deceleration operation without any problems. <Innenring und Außenring von Hauptlager>

[0086] The main bearing 28B includes inner rings 28i1B and 28i2, which are formed of two elements, and outer rings 28o1 and 28o2, which are formed of two elements. Furthermore, the inner ring 28i1B, located inside the device, has the extension portion (external gear 28e2), which forms another functional component. The extension portion is a tubular portion extending in the axial direction. As described above, the extension portion forms the external gear 28e2, which has a top hat type.

[0087] Furthermore, a screw hole h28B is provided in the flange portion 28f3 of the inner ring 28i1B, in which a screw is formed by a thread cutter, and connecting members B6 and B7 such as bolts are screwed therein. Then, the driven member 24 and the inner rings 28i1B and 28i2 are connected by the connecting member B6, such as the screw, via connecting holes h24a and h28i and the screw hole h28B. According to this configuration, a nut for connecting the inner rings 28i1B and 28i2 and the driven member 24 is not required, and the number of components can be further reduced. Furthermore, the driven member 24 and the external counterpart member 82 are connected by the connecting member B7, such as the screw, via the connecting holes h24b and h28i and the screw hole h28B.According to this configuration, a nut for connecting the counter member 82 and the output member 24 is not required, and the number of components can be further reduced.

[0088] The speed reducer 1B can also be used as follows. The inner rings 28i1B and 28i2 and the external gear 28e2 are connected to the external bearing element, and the outer rings 28o1 and 28o2 and the internal gear 21B are connected to the external counter element. In this case, the rotational motion input to the shaft generator shaft 10 is slowed down and transmitted to the internal gear 21B, and is output from the internal gear 21B to the external counter element. In this case, the internal gear 21B acts as the output element, outputting the slowed-down rotation.

[0089] Furthermore, in the configuration where the internal gear 21B functions as the driven member, the connecting hole h28o of the outer ring 28o2 may be formed from a screw hole in which a screw is formed by a threaded cutter. In contrast, the connecting hole h21 of the internal gear 21B may be formed from a through hole. Then, the screw may be caused to pass from the connecting hole (for example, the through hole) h21 of the internal gear 21B through the connecting hole h28o of the outer rings 28o1 and 28o2, and may be screwed to the connecting hole h28o (screw hole) of one outer ring 28o2. In this way, the internal gear 21B serving as the driven member and the outer rings 28o1 and 28o2 can be connected to each other.

[0090] As described above, according to the speed reducer 1B of Embodiment 3, the reduction mechanism including the internal gear 21B and the external gear 15, the output member 24 that outputs the rotation decelerated by the reduction mechanism, and the main bearing 28B that supports the output member 24 are provided. Furthermore, the main bearing 28B includes the inner rings 28i1B and 28i2 and the outer rings 28o1 and 28o2 formed from the plate member. The inner ring 28i1B has the extension portion (28e2), and the extension portion forms another functional component. Therefore, the inner ring 28i1B and another functional component can be integrated with each other, and the number of components can be reduced. In addition, the inner rings 28i1B and 28i2 and the outer rings 28o1 and 28o2 of the main bearing 28B are formed from the plate member.Accordingly, compared with the main bearing including the block-shaped inner ring and outer ring, weight reduction of the main bearing 28B can be achieved, and weight reduction of the speed reducer 1B can be achieved.

[0091] Specifically, the extension portion (28e2) of the inner ring 28i1B forms the external gear 28e2, which is bent and deformed. According to the extension portion of the inner ring 28i1B serving as the plate member, it is easy to obtain a property that the external gear 28e2 is bent and deformed.

[0092] Furthermore, according to the speed reducer 1B of Embodiment 3, the inner ring 28i1B has the screw hole h28B into which the connecting members B6 and B7, such as screws, are screwed. Therefore, when the inner rings 28i1B and 28i2 are connected, or when the inner rings 28i1B and 28i2 are connected to other members (output member 24 or external gear 28e2), in a case where there is no member acting as a nut, the nut is not required, and the number of components can be reduced.

[0093] So far, each embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiments. For example, in the above-described embodiment, the flexural meshing type gear device having a so-called cylindrical type, the center-crank type eccentric oscillating speed reducer, and the flexural meshing type gear device having a so-called cylinder hat type were described as examples. However, the present invention is applicable to various types of speed reducers, such as a flexural meshing type gear device having a so-called pot shape, a so-called sorting type eccentric oscillating speed reducer in which two or more eccentric shafts including the eccentric body are arranged to be offset from the axial center of the speed reducer, or a simple planetary gear device.When the present invention is applied to the simple planetary gear device, a configuration as follows can be used. The pin member is configured to have the inner ring extension portion as in Embodiment 2, and the pin member is synchronized with a rotation component of a planetary gear (external gear). In addition, details in the above-described embodiments can be appropriately changed within the scope that does not deviate from the concept of the invention. Brief description of the reference symbols 1, 1A, 1B speed reducer 10 Shaft generator shaft 10A wave generator 11 Shaft generator bearings 15 External gear 16 Stop ring 21 first internal gear 22 second internal gear 24 Output element 28, 28B main bearing 28i1, 28i2, 28i1B, 55i1, 55i2 inner ring 28o1, 28o2, 55o1, 55o2 outer ring 28e Extension section (movement-limiting component) 28e2 External gear (extension section) 31 Eccentric body shaft 31b, 31c eccentric body 34, 36 external gear 38 internal gear 41 Carrier body (output element) 55 main bearings 55e1, 55e2 extension section 55ep inner pin (pin element, extension section)

Claims

[1] Speed ​​reducer (1, 1A, 1B), comprising: a reduction mechanism including an internal gear (21, 22, 38) and an external gear (15, 28e2, 34, 36); an output member (24, 41) outputting rotation slowed down by the reduction mechanism; a fixed member mounted against rotation of the output member (24, 41); and a main bearing (28, 28B) supporting the fixed element and the driven element (24, 41), wherein the main bearing (28, 28B) includes an inner ring (28i1, 28i2, 28i1B, 55i1, 55i2) and an outer ring (28o1, 28o2, 55o1, 55o2) formed from a plate member, and at least the inner ring (28i1, 28i2, 28i1B, 55i1, 55i2) or the outer ring (28o1, 28o2, 55o1, 55o2) is connected to the fixed element or the driven element (24, 41) separately from the fixed element and the driven element (24, 41), this inner ring (28i1, 28i2, 28i1B, 55i1, 55i2) or this outer ring (28o1, 28o2, 55o1, 55o2) contains an extension section (28e, 28e2, 55e1, 55e2, 55ep) formed from a plate element, and the extension section (28e, 28e2, 55e1, 55e2, 55ep) has a further functional component of the speed reducer (1, 1A, 1B). [2] The speed reducer (1, 1A, 1B) according to claim 1, wherein the extension portion (28e, 28e2, 55e1, 55e2, 55ep) forms a movement-limiting component (28e) that limits movement of other elements. [3] The speed reducer (1, 1A, 1B) according to claim 2, wherein the extension portion (28e, 28e2, 55e1, 55e2, 55ep) limits movement of the external gear (15, 28e2, 34, 36) in an axial direction. [4] The speed reducer (1B) according to claim 1, wherein the speed reducer (1B) is a bending engagement type speed reducer in which the external gear (28e2) is bent and deformed, and the extension portion forms the external gear (28e2). [5] The speed reducer (1A) according to claim 1, wherein the extension portion (55e1, 55e2, 55ep) forms a pin member (55ep) synchronized with a rotation component or a revolution component of the external gear (34, 36). [6] Speed ​​reducer (1, 1A, 1B) according to one of claims 1 to 5, wherein the inner ring (28i1, 28i2, 28i1B, 55i1, 55i2) includes a first inner ring element and a second inner ring element which are separated from each other, and the first inner ring element or the second inner ring element contains the extension section (28e, 28e2, 55e1, 55e2, 55ep). [7] Speed ​​reducer (1, 1A, 1B) according to claim 6, wherein the first inner ring element is arranged inwardly of the second inner ring element in an axial direction of the speed reducer (1, 1A, 1B), and the first inner ring element contains the extension section (28e, 28e2, 55e1, 55e2, 55ep). [8] A speed reducer (1, 1A, 1B) according to any one of claims 1 to 7, wherein the main bearing (28, 28B) is configured to support a radial load and a bidirectional axial load using a single bearing. [9] Speed ​​reducer (1, 1A, 1B) according to one of claims 1 to 8, wherein the inner ring (28i1, 28i2, 28i1B, 55i1, 55i2) and the outer ring (28o1, 28o2, 55o1, 55o2) are formed from a plate member bent by press forming. [10] Speed ​​reducer (1, 1A, 1B) according to one of claims 1 to 9, wherein the inner ring (28i1, 28i2, 28i1B, 55i1, 55i2) or the outer ring (28o1, 28o2, 55o1, 55o2) contains a screw hole (h28B) into which a connecting element (B6, B7) for connecting to the output element (24, 41) is screwed.

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