Reduction gear

Abstract

To provide a reduction gear with improved productivity.SOLUTION: A motor with a reduction gear includes: a bracket 10 having a gear housing recess 16 into which a second surface 10c is open; a speed reduction mechanism 4 housed in the gear housing recess 16; and a guide part 56 that closes the second surface 10c of the gear storage recess 16. The speed reduction mechanism 4 includes: an internal gear 42; an eccentric shaft 41; a swing gear 43 rotationally supported at an eccentric part 45 of the eccentric shaft 41; and an output part 44. The guide part 56 and the internal gear 42 are provided with an engagement part 83 which allows the guide part 56 and the internal gear 42 to be engaged via fitting of projections and recesses. The internal gear 42 is pressed from an opening side of the gear storage recess 16 by the guide part 56.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a reduction gear device. [Background technology]

[0002] Conventionally, there has been known a motor with a reducer that obtains high rotational torque by slowing down the rotation of the motor unit with a reduction device (reduction mechanism). Some reduction mechanisms of such a motor with a reducer include an annular internal gear (ring gear) attached to a bracket (gear casing), an eccentric shaft (eccentric shaft) provided coaxially with the internal gear, an oscillating gear rotatably attached to the eccentric part of the eccentric shaft via a bearing, and an output unit meshed with the oscillating gear.

[0003] The eccentric shaft is rotated by a rotational input from the motor unit. The oscillating gear has external teeth that mesh with the internal teeth of the internal gear and internal teeth provided radially inward of the external teeth. The output unit is meshed with the internal teeth and rotates by a rotational output that is decelerated compared to the rotation of the eccentric shaft. Here, an adhesive is used to secure the internal gear to the bracket. By using an adhesive, the internal gear can be firmly secured to the bracket. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 077886 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when an adhesive is used to fix the internal gear as in the above-mentioned conventional technology, a process for applying the adhesive and time for heat curing are required, resulting in poor productivity.

[0006] SUMMARY OF THE INVENTION Therefore, the present invention provides a reduction gear transmission that can improve productivity. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, in a first aspect of the present invention, a reduction gear transmission includes a bracket having a gear accommodating recess with one surface open, a reduction mechanism accommodated in the gear accommodating recess, and a guide portion that closes the one surface of the gear accommodating recess, wherein the reduction mechanism includes an annular internal gear having first internal teeth, an eccentric shaft that is arranged coaxially with an axis of the internal gear and rotates by receiving external power, an oscillating gear that is rotatably supported by the eccentric shaft and has first external teeth that mesh with the first internal teeth and second internal teeth, and an output portion that is arranged coaxially with the axis and has second external teeth that mesh with the second internal teeth. , wherein the eccentric shaft has a shaft main body that rotates around the axis, and an eccentric portion that is provided on the shaft main body and is eccentric with respect to the axis, the oscillating gear is rotatably supported by the eccentric portion, and has at least one of a first engaging portion that is provided on the guide portion and the internal gear and that provides a recessed and projecting fit between the guide portion and the internal gear, and a second engaging portion that is provided on the bracket and the internal gear and that provides a recessed and projecting fit between the bracket and the internal gear, and the internal gear is pressed by the guide portion from the one surface side of the gear storage recess.

[0008] This configuration allows the internal gear to be fixed to the guide portion or bracket so that it cannot rotate relative to the guide portion or bracket. In addition, the guide portion presses the internal gear from one side of the gear storage recess, firmly fixing the internal gear. This eliminates the need for adhesives to fix the internal gear, as was previously required, and improves the productivity of the reduction gear.

[0009] In a second aspect of the present invention, in the reduction gear transmission of the first aspect, at least one of the first engagement portion and the second engagement portion is provided around the entire circumference of the internal gear and around the entire circumference of at least one of the guide portion and the bracket.

[0010] This configuration allows the internal gear to be fixed more firmly. The pressure load applied by the guide part to the internal gear can be distributed over the entire circumference of the internal gear, preventing the internal gear from tilting relative to the guide part or bracket.

[0011] In a third aspect of the present invention, in the reduction gear transmission of the first or second aspect, the bracket has a fixing hole provided around the gear storage recess, the guide portion has a fixing device insertion hole communicating with the fixing hole, and is provided with a fixing device that is inserted into the fixing device insertion hole from the opposite side of the guide portion from the bracket and fixed to the fixing hole, and is provided with the first engagement portion.

[0012] With this configuration, the internal gear can be pressed by the guide portion while using the fixing device. At this time, the fixing load of the fixing device can be easily managed, and by extension, the pressing load on the internal gear by the guide portion can be managed. As a result, the internal gear can be securely fixed while preventing damage to the internal gear during assembly. Furthermore, the axial thickness of the bracket can be made thinner than when the second engagement portion is provided. The impact of the axial thickness increase on the guide portion can be easily minimized. Therefore, by providing the first engagement portion, it is easier to make the reduction gear transmission thinner and more compact.

[0013] In a fourth aspect of the present invention, in the reduction gear transmission of the third aspect, the first engagement portion is provided on a guide end surface of the guide portion and a gear end surface of the internal gear, which face each other in the direction of the axis, and the first engagement portion comprises a plurality of first engaging teeth portions that protrude from the guide end surface toward the internal gear and are arranged in a row in the circumferential direction, and a plurality of second engaging teeth portions that protrude from the gear end surface toward the guide portion and are arranged in a row in the circumferential direction, wherein when the angle of the tooth flanks of the first engaging teeth portions with respect to the direction of the axis is θ1 and the angle of the tooth flanks of the second engaging teeth portions with respect to the direction of the axis is θ2, if the rigidity of the guide portion is lower than the rigidity of the internal gear, the angles θ1 and θ2 satisfy θ1<θ2, and if the rigidity of the internal gear is lower than the rigidity of the guide portion, the angles θ1 and θ2 satisfy θ1>θ2.

[0014] This configuration ensures that either the first or second mating teeth portion is interposed with the other mating teeth portion adjacent to each other in the circumferential direction, ensuring contact between the mating teeth portions. In this case, the mating teeth portion with the lower rigidity, either the first or second mating teeth portion, can be plastically deformed. This improves the meshing and fixing force of the mating teeth portions, thereby firmly fixing the internal gear. Furthermore, by making the angle of the less rigid mating tooth portion, either the first or second mating tooth portion, smaller than the angle of the more rigid mating tooth portion, it is possible to promote plastic deformation of the less rigid mating tooth portion while suppressing tilting of the less rigid mating tooth portion during meshing, thereby reliably improving the meshing fixing force of each mating tooth portion.

[0015] In a fifth aspect of the present invention, in the reduction gear transmission of the fourth aspect, the rigidity of the guide portion is lower than the rigidity of the internal gear, and the angle θ1 and the angle θ2 satisfy θ1<θ2.

[0016] In this way, by making the rigidity of the guide part, which presses the internal gear, lower than the rigidity of the internal gear, it becomes easier for the first mating teeth to bite into the second mating teeth, thereby enabling the internal gear to be firmly fixed. Furthermore, by reducing the rigidity of the guide portion, it becomes easier to process the guide portion. For example, it becomes easier to assemble a bearing for rotatably supporting the eccentric shaft to the guide portion. As a result, it is possible to reduce the manufacturing cost of the reduction gear device and improve the productivity of the reduction gear device. [Effects of the Invention]

[0017] According to the present invention, the productivity of reduction gears can be improved. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view of a motor with a reducer according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 2 is an enlarged view of a speed reduction mechanism according to an embodiment of the present invention. [Figure 5] FIG. 2 is a perspective view of an internal gear according to an embodiment of the present invention, seen from the opposite side to the motor unit. [Figure 6] FIG. 2 is a perspective view of a guide portion according to an embodiment of the present invention, as viewed from the internal gear side. [Figure 7] FIG. 2 is a perspective view of a guide portion and an internal gear according to an embodiment of the present invention. [Figure 8] 10 is a schematic diagram illustrating a state in which a guide-side fitting tooth portion and a gear-side fitting tooth portion are fitted together in a concave-convex manner in an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] Next, an embodiment of the present invention will be described with reference to the drawings.

[0020] <Motor with reducer> Fig. 1 is a perspective view of a speed reducer-equipped motor 1. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. As shown in Figures 1 and 2, the motor with a reducer 1 comprises a flat motor section 2 configured as a so-called DC brushless motor, and a control section 3 and a reduction mechanism 4 arranged on either side of the motor section 2 in the direction of the rotation axis A of the motor section 2. The rotation axis A of the motor unit 2 coincides with the rotation center of an output unit 44 (described later) of the reduction gear mechanism 4. In the following description, the direction parallel to the rotation axis A will be referred to as the axial direction. The direction around the rotation axis A will be referred to as the circumferential direction. The radial direction of the motor unit 2, which is perpendicular to the axial and circumferential directions, will be simply referred to as the radial direction.

[0021] <Motor section> The motor unit 2 includes a disk-shaped bracket 10 and a stator 21 and a rotor 22 housed in the bracket 10. The bracket 10 is made of, for example, an aluminum alloy. The outer peripheral surface 10a of the bracket 10 has two reduced diameter portions 11a, 12a (first reduced diameter portion 11a, second reduced diameter portion 12a) whose diameter gradually decreases via two step surfaces 11b, 12b (first step surface 11b, second step surface 12b) as the bracket 10 moves away from the control unit 3. That is, the outer peripheral surface 10a of the bracket 10 has the first reduced diameter portion 11a, which is formed with a smaller diameter than the outer peripheral surface 10a, via the first step surface 11b formed closer to the control unit 3 (the right side in FIG. 2) than the center in the axial direction. The bracket 10 also has the second reduced diameter portion 12a, which is formed with a smaller diameter than the first reduced diameter portion 11a, via the second step surface 12b.

[0022] The first reduced diameter portion 11a is integrally formed with a plurality of (for example, six in this embodiment) bolt seats 17 that protrude radially outward and are arranged on the first stepped surface 11b. The bolt seats 17 are arranged at equal intervals in the circumferential direction. Of these bolt seats 17, for example, three bolt seats 17 each have a stator female thread portion (not shown) formed therein. The stator female thread portion is formed on one surface (back surface) of the corresponding bolt seat 17 that faces the control unit 3. These stator female thread portions are arranged at equal intervals in the circumferential direction. The stator female thread portion is used to fasten and fix the stator 21 to the bracket 10.

[0023] Of the bolt seats 17, for example, three bolt seats 17 that do not have a female thread portion for a stator are each formed with a female thread portion for an external device 17a. The female thread portion for an external device 17a is formed on the other surface (front surface) 17b opposite to the one surface of the corresponding bolt seat 17. The female thread portion for an external device 17a is used to fasten and fix an external device (not shown).

[0024] An outer flange portion 13 that protrudes radially outward is integrally formed on the outer peripheral surface 10a of the bracket 10 at the end on the side of the control unit 3. The outer flange portion 13 is used to fasten and fix the bracket 10 to a control case 5 of the control unit 3, which will be described later. A motor accommodating recess 15 is formed in a large portion of the radial center of the bracket 10, with a first surface 10b on the control unit 3 side opening toward the control unit 3 side relative to the axial center. A gear accommodating recess 16 is formed in a large portion of the radial center of the bracket 10, with a second surface (an example of a surface in the claims) 10c on the speed reduction mechanism 4 side opening toward the speed reduction mechanism 4 side relative to the axial center.

[0025] The bracket 10 has a partition wall 14 formed between the motor housing recess 15 and the gear housing recess 16. The partition wall 14 is formed in a stepped shape that gradually shifts toward the motor unit 2 as it extends radially inward. That is, the partition wall 14 has an annular first partition wall 91 formed at the outermost periphery, an annular second partition wall 92 formed on the inner circumferential edge of the first partition wall 91, and a disk-shaped third partition wall 93 formed radially inward of the second partition wall 92. The second partition wall 92 is positioned closer to the motor unit 2 than the first partition wall 91, via a step 91a from the inner circumferential edge of the first partition wall 91. The third partition wall 93 is positioned closer to the motor unit 2 than the second partition wall 92, via a step 92a from the inner circumferential edge of the second partition wall 92. A cylindrical bearing housing 19 is integrally formed in the radial center of the third partition wall 93. The bearing housing 19 is provided with a rolling bearing 20 for supporting the rotor 22 so that it can rotate freely.

[0026] The stator 21 is housed in the motor housing recess 15. The stator 21 has an annular stator core 23 formed by laminating multiple electromagnetic steel sheets or by pressure molding soft magnetic powder. The stator core 23 is fastened to the motor housing recess 15 of the bracket 10 by bolts and female threads for the stator (not shown).

[0027] A plurality of teeth 24 protruding radially inward are arranged in a circumferential direction on the inner peripheral surface of the stator core 23. Coils 25 are wound around these teeth 24. When power is supplied to the coils 25, a predetermined interlinkage magnetic flux is generated in the stator 21.

[0028] The rotor 22 is disposed radially inside the stator 21. The rotor 22 includes a rotor shaft 31 rotatably supported by the partition wall 14 via a rolling bearing 20, a rotor core 32 fitted onto the rotor shaft 31, and a ring magnet 33 fixed to the rotor core 32. The axis of the rotor shaft 31 coincides with the rotation axis A.

[0029] The rotor shaft 31 includes a support shaft 34 supported by the rolling bearing 20, an attachment shaft 35 extending axially from the end of the support shaft 34 on the control unit 3 side, and a flange portion 34a integrally formed with the end of the support shaft 34 opposite to the attachment shaft 35. The outer diameter of the flange portion 34a is larger than the inner diameter of the rolling bearing 20. This restricts axial displacement of the rotor shaft 31.

[0030] The mounting shaft 35 is formed to have a smaller diameter than the support shaft 34. The rotor core 32 is fitted onto the mounting shaft 35. The rotor core 32 has a disk-shaped core body 36 arranged along the radial direction. A cylindrical inner peripheral wall 37 is formed at the radial center of the core body 36. The inner peripheral wall 37 protrudes axially toward the rolling bearing 20. The inner peripheral wall 37 is fitted onto the support shaft 34.

[0031] An axially extending cylindrical outer peripheral wall 38 is integrally formed on the outer periphery of the core body 36. The axial height of the outer peripheral wall 38 is greater than the axial thickness of the stator core 23. The entire radially inner end faces of the teeth 24 of the stator core 23 face the outer peripheral wall 38 of the rotor core 32 in the radial direction.

[0032] A ring magnet 33 is fitted onto the outer peripheral surface of the outer peripheral wall 38. The ring magnet 33 is formed in a cylindrical shape so as to correspond to the outer peripheral wall 38. The ring magnet 33 is magnetized with a plurality of north and south poles alternately arranged in the circumferential direction. The magnet fixed to the outer peripheral wall 38 is not limited to the ring magnet 33, but may be a magnet divided in the circumferential direction. In this case, the magnet is fixed to the outer peripheral wall 38 so that the magnetic poles are in order in the circumferential direction.

[0033] <Deceleration mechanism> FIG. 3 is a cross-sectional view taken along line III-III in FIG. As shown in Figures 2 and 3, an eccentric shaft 41 is integrally molded with the end of the rotor shaft 31 on the side of the reduction mechanism 4 (the left side in Figure 2). The eccentric shaft 41 constitutes a part of the reduction mechanism 4. The reduction mechanism 4 is configured as a so-called hypocycloid reduction mechanism. In addition to the eccentric shaft 41, the reduction mechanism 4 includes an internal gear 42 fixed to the gear housing recess 16 of the bracket 10, an oscillating gear 43 meshed with the internal gear 42, an output section 44 meshed with the oscillating gear 43, and a guide section 56 that rotatably supports the output section 44 and presses the internal gear 42 from the side opposite to the motor section 2.

[0034] The eccentric shaft 41 includes an eccentric portion 45 formed on the flange portion 34a of the rotor shaft 31, and a shaft main body 46 extending axially from the end of the eccentric portion 45 opposite the flange portion 34a. The eccentric portion 45 is formed in a cylindrical shape. The outer peripheral surface 45a of the eccentric portion 45 is formed as a cylindrical surface with a center C at a position eccentric to the rotation axis A. The shaft main body 46 is formed so that its axis coincides with the rotation axis A.

[0035] The oscillating gear 43 is rotatably supported on the eccentric portion 45 via a rolling bearing 47. The oscillating gear 43 includes a disk-shaped oscillating gear main body 48 arranged along the radial direction, a cylindrical bearing housing 49 integrally molded at the radial center of the oscillating gear main body 48, and a cylindrical tooth wall 50 integrally molded on the outer periphery of the oscillating gear main body 48. The bearing housing 49 protrudes from the oscillating gear main body 48 in the axial direction toward the opposite side to the motor portion 2. The tooth wall 50 protrudes from the oscillating gear main body 48 in the same direction as the bearing housing 49 protrudes.

[0036] With this configuration, a recess 43a is formed in the oscillating gear 43 between the bearing housing 49 and the tooth wall 50, the recess 43a being open on the side opposite to the motor unit 2 (the left side in FIG. 2). The recess 43a is formed in an annular shape when viewed in the axial direction. A bearing housing 49 of the oscillating gear 43 is rotatably supported on the eccentric part 45 via a rolling bearing 47. External teeth 50a are formed on the outer peripheral surface of the tooth wall 50, and internal teeth 50b are formed on the inner peripheral surface. The axial centers of the external teeth 50a, the internal teeth 50b, and the rolling bearing 47 are located on the same plane P in the radial direction. The external teeth 50a of the oscillating gear 43 are meshed with the internal teeth 42a of the internal gear 42.

[0037] Fig. 4 is an enlarged view of the reduction mechanism 4, showing half of it centered around the rotation axis A. Fig. 5 is a perspective view of the internal gear 42 as seen from the opposite side to the motor unit 2. As shown in Figures 2 to 5, the internal gear 42 is made of, for example, iron and has an annular gear body 81. The gear body 81 is disposed concentrically with the rotation axis A. An outer peripheral surface 81a of the gear body 81 is lightly press-fitted into the inner peripheral surface 16a of the gear accommodating recess 16. The gear body 81 is placed on the first partition wall 91. An inner peripheral surface 81b of the gear body 81 is formed with internal teeth 82.

[0038] A plurality of gear-side mating teeth portions (an example of second mating teeth portions) 84 are integrally molded on an end face (an example of a gear end face in the claims) 81c of the gear body 81 opposite the partition wall 14. The gear-side mating teeth portions 84, together with guide-side mating teeth portions 62 described below, constitute an engagement portion (an example of a first engagement portion in the claims) 83 that fits the internal gear 42 and the guide portion 56 in a concave-convex manner (details will be described later).

[0039] The gear-side fitting teeth 84 protrude from the end face 81c of the gear body 81 toward the opposite side from the partition wall 14. The multiple gear-side fitting teeth 84 are arranged at equal intervals around the entire circumference. Each gear-side fitting tooth 84 is formed in a tapered shape such that its circumferential width gradually narrows toward the tip face 84a. In other words, both circumferential tooth flanks (side faces) 84b of each gear-side fitting tooth 84 are inclined with respect to the axial direction. Details of the inclination angle of the tooth flanks 84b will be described later.

[0040] The output unit 44 has a disk-shaped output unit main body 51 arranged along the radial direction. A bearing housing recess 52 is formed in the radial center of one surface 51a of the output unit main body 51 facing the motor unit 2. A rolling bearing 40 is housed in the bearing housing recess 52. A shaft main body 46 of the eccentric shaft 41 is rotatably supported by the output unit main body 51 via this rolling bearing 40.

[0041] An externally toothed ring 53 is formed on one surface 51a of the output portion main body 51 so as to protrude radially outward from the bearing accommodating recess 52. The externally toothed ring 53 is formed in a cylindrical shape to correspond to the recess 43a of the oscillating gear 43. The externally toothed ring 53 faces this recess 43a. On the outer circumferential surface of the externally toothed ring 53, external teeth 53a are formed which mesh with the internal teeth 42a of the internal gear 42 and are concentric with the rotation axis A. The external teeth 53a mesh with the internal teeth 50b of the oscillating gear 43.

[0042] Here, the axial center of the meshing range between the internal teeth 42a of the internal gear 42 and the external teeth 50a of the oscillating gear 43 substantially coincides with the axial center of these internal teeth 42a and external teeth 50a. Also, the axial center of the meshing range between the internal teeth 50b of the oscillating gear 43 and the external teeth 53a of the output portion 44 substantially coincides with the axial center of these internal teeth 50b and external teeth 53a. In other words, the axial center of the meshing range between the internal teeth 42a of the internal gear 42 and the external teeth 50a of the oscillating gear 43, the axial center of the meshing range between the internal teeth 50b of the oscillating gear 43 and the external teeth 53a of the output portion 44, and the axial center of the rolling bearing 47 are located on substantially the same plane P in the radial direction.

[0043] A plurality of (for example, four in this embodiment) female screw portions 54 are formed on the other surface 51b opposite to the one surface 51a of the output portion main body 51. These female screw portions 54 are used to fasten and fix an external device (not shown) to the output portion 44.

[0044] The output section 44 has an output section main body 51 rotatably supported on a guide section 56 via a rolling bearing 55. An inner ring 55a of the rolling bearing 55 is fitted onto the outer peripheral surface of the output section main body 51. An outer bearing flange section 58 that protrudes radially outward from the outer peripheral surface is integrally formed on the end of the output section main body 51 on the oscillating gear 43 side. The outer bearing flange section 58 is abutted by the end of the inner ring 55a of the rolling bearing 55 on the oscillating gear 43 side. This allows the rolling bearing 55 to be positioned axially with respect to the output section 44.

[0045] Fig. 6 is a perspective view of the guide portion 56 as seen from the side of the internal gear 42. Fig. 7 is a perspective view of the guide portion 56 and the internal gear 42. 2 to 7, the guide portion 56 is integrally formed with a cylindrical guide body 57, a portion of which is housed in the gear accommodating recess 16 and which is provided so as to close the opening of the gear accommodating recess 16 (the second surface 10c of the bracket 10), and a flange portion 59 which protrudes radially outward from an outer circumferential surface 57a of the guide body 57. The guide portion 56 is made of, for example, an aluminum alloy.

[0046] The flange portion 59 abuts against the second surface 10c of the bracket 10. A plurality of (for example, four in this embodiment) bolt insertion holes 59a are formed in the flange portion 59 at equal intervals in the circumferential direction. A bolt 60 is inserted into each bolt insertion hole 59a from the side opposite to the bracket 10. Each bolt 60 is screwed into a female thread portion 10d formed in the bracket 10, thereby fastening and fixing the guide portion 56 to the bracket 10.

[0047] The guide main body 57 is disposed on the opposite side of the internal gear 42 from the control section 3. An outer ring 55b of the rolling bearing 55 is fitted onto the inner peripheral surface of the guide main body 57. Furthermore, an inner bearing flange portion 61 that protrudes radially inward from the inner peripheral surface is integrally formed on the end of the guide main body 57 opposite the internal gear 42. The inner bearing flange portion 61 abuts against the end of the outer ring 55b of the rolling bearing 55 opposite the oscillating gear 43. This positions the rolling bearing 55 relative to the guide section 56 in the axial direction. As a result, the guide section 56 and the output section 44 are positioned in the axial direction via the rolling bearing 55.

[0048] A plurality of guide-side mating teeth 62 (an example of first mating teeth in the claims) are integrally formed on an end face 57b (an example of a guide end face in the claims) of the guide body 57 on the internal gear 42 side. The guide-side mating teeth 62 constitute an engagement portion 83 together with a gear-side mating teeth 84 of the internal gear 42.

[0049] The guide-side fitting teeth 62 are arranged on the outer periphery of the end face 57b of the guide body 57. The guide-side fitting teeth 62 protrude from the end face 57b of the guide body 57 toward the internal gear 42. The multiple guide-side fitting teeth 62 are arranged at equal intervals around the entire circumference. Each guide-side fitting tooth 62 is formed in a tapered shape such that its circumferential width gradually narrows toward the tip face 62a. In other words, both circumferential tooth surfaces (side surfaces) 62b of each guide-side fitting tooth 62 are inclined with respect to the axial direction.

[0050] 7, the guide-side fitting teeth 62 and the gear-side fitting teeth 84 are fitted together in a concave-convex manner. In other words, the guide-side fitting teeth 62 and the gear-side fitting teeth 84 are meshed together so that they are alternately arranged in the circumferential direction.

[0051] FIG. 8 is a schematic diagram showing a state in which the guide-side fitting teeth portion 62 and the gear-side fitting teeth portion 84 are fitted together. As shown in FIG. 8, when the inclination angle of the tooth surface 62b of the guide-side fitted tooth portion 62 with respect to the axial direction is θ1 and the inclination angle of the tooth surface 84b of the gear-side fitted tooth portion 84 with respect to the axial direction is θ2, the inclination angles θ1 and θ2 are θ1<θ2 (1) Meet the following.

[0052] Therefore, the corners of the tip end surface 62a of the guide-side fitting teeth portion 62 (hereinafter simply referred to as the corners of the guide-side fitting teeth portion 62) come into contact with the tooth surface 84b of the gear-side fitting teeth portion 84. As a result, gaps G are formed between the tip end surface 62a of the guide-side fitting teeth portion 62 and the end face 81c of the gear main body 81, and between the tip end surface 84a of the gear-side fitting teeth portion 84 and the end face 57b of the guide main body 57. A lubricant (not shown) is filled in the gaps G. As a result, the meshing resistance between the internal teeth 42a of the internal gear 42 and the external teeth 50a of the oscillating gear 43, and the meshing resistance between the internal teeth 50b of the oscillating gear 43 and the external teeth 53a of the output portion 44 are reduced, and the sliding resistance of the rolling bearing 55 is also reduced.

[0053] Here, the guide portion 56 is made of, for example, an aluminum alloy. The internal gear 42 is made of, for example, iron. That is, the rigidity of the guide portion 56 is lower than the rigidity of the internal gear 42. Furthermore, due to the tightening force (axial force) of the bolt 60 when fastening the guide portion 56 to the bracket 10, the guide portion 56 presses the internal gear 42 from the second surface 10c of the bracket 10 (the surface on which the gear storage recess 16 is open). That is, the guide-side mating teeth 62 are pressed against the gear-side mating teeth 84. Therefore, the corners of the guide-side mating teeth 62 are pressed against the tooth surfaces 84b of the gear-side mating teeth 84. As a result, the corners of the guide-side mating teeth 62 are slightly crushed. Therefore, the internal gear 42 is firmly fixed without any rattle in the circumferential and axial directions.

[0054] The rolling bearing 55 is exposed to the outside through an opening on the inner peripheral edge side of the bearing inner flange portion 61 of the guide portion 56. For this reason, it is desirable to provide a seal at least on the surface of the rolling bearing 55 facing the bearing inner flange portion 61. This makes it possible to prevent dust and other foreign matter from entering the rolling bearing 55 from the outside.

[0055] <Control unit> The control unit 3 includes a cylindrical control case 5 with a bottom, and a control board 6 housed within the control case 5. The control case 5 is arranged with its opening 5a facing the motor unit 2. An outer flange 71 that protrudes radially outward is formed at the opening 5a of the control case 5. An end face 71a of this outer flange 71 on the motor unit 2 side abuts against the outer flange 13 of the bracket 10. The outer flange 71 of the control case 5 and the outer flange 13 of the bracket 10 are fastened together with a plurality of bolts 72 (see FIG. 1).

[0056] An O-ring groove 73 is formed around the entire periphery of the end face 71a of the outer flange portion 71 of the control case 5. By fitting an O-ring (not shown) into this O-ring groove 73, sealing is ensured between the outer flange portion 71 of the control case 5 and the outer flange portion 13 of the bracket 10. Furthermore, a cylindrical power outlet 77 and a cylindrical sensor outlet 78 are formed to protrude outward from the control case 5. A power harness 75 (described below) connected to the control board 6 is pulled out from the power outlet 77. A sensor harness 76 is pulled out from the sensor outlet 78.

[0057] The control board 6 is a so-called epoxy board on which a plurality of conductive patterns (not shown) are formed. The control board 6 is disposed so that one surface thereof faces the stator 21 and the rotor 22 in the axial direction. A plurality of magnetic detection elements 74 are mounted on the control board 6 at positions facing the ring magnet 33 of the rotor 22 in the axial direction. The magnetic detection elements 74 detect magnetic changes in the ring magnet 33, thereby detecting the rotational position of the rotor 22.

[0058] An end portion of the coil 25 of the stator 21 is connected to the control board 6, as well as an end portion of a power harness 75 and an end portion of a sensor harness 76. The power harness 75 is connected to an external power source (not shown), and the sensor harness 76 is connected to an external control device (not shown). The control board 6 is mounted with a capacitor (not shown) and the like that smooths the voltage applied to the control board 6. The control board 6 may also be mounted with a power module (not shown) that is made up of a switching element such as a FET (Field Effect Transistor) that controls the current supplied to the coil 25.

[0059] <Operation of a motor with a reducer> Next, the operation of the speed reducer-equipped motor 1 will be described. When a predetermined current is supplied to the coil 25 of the motor unit 2 via the control unit 3, a predetermined interlinkage magnetic flux is formed in the stator 21. Then, magnetic attraction and repulsion are generated between this interlinkage magnetic flux and the ring magnet 33 of the rotor 22, causing the rotor 22 to rotate.

[0060] When the rotor 22 rotates, the eccentric shaft 41, which is integrally formed with the rotor shaft 31 of the rotor 22, rotates. When the eccentric shaft 41 rotates, the oscillating gear 43 rotates in response to the rotation. The oscillating gear 43 is rotatably mounted on the eccentric portion 45 of the eccentric shaft 41 via a rolling bearing 47, and its external teeth 50a mesh with the internal teeth 42a of the internal gear 42. Therefore, the oscillating gear 43 revolves around the rotation axis A and rotates around the center C of the eccentric portion 45 at a reduced speed relative to the eccentric shaft 41. The oscillating rotation of the oscillating gear 43 transmits power to the output portion 44, which meshes with the internal teeth 50b of the oscillating gear 43. This causes the output portion 44 to rotate.

[0061] In the above-described embodiment, the reducer-equipped motor 1 includes an engagement portion 83 that allows the internal gear 42 and the guide portion 56 to be fitted together. In addition, the internal gear 42 is pressed by the guide portion 56 from the second surface 10c of the bracket 10 (the surface on which the gear storage recess 16 is open). This allows the internal gear 42 to be fixed to the guide portion 56 so as not to rotate relative to it. This eliminates the need for adhesive to fix the internal gear 42 as in the past, improving the productivity of the reducer-equipped motor 1.

[0062] The engagement portion 83 is provided around the entire circumference of the internal gear 42 and the guide portion 56. This allows for more firmly fixing the internal gear 42. The pressing load on the internal gear 42 by the guide portion 56 can be dispersed around the entire circumference of the internal gear 42, preventing the internal gear 42 from tilting relative to the guide portion 56 or bracket 10.

[0063] The guide portion 56 is fastened and fixed to the bracket 10 by the bolt 60. By providing an engagement portion 83 between this guide portion 56 and the internal gear 42, the internal gear 42 can be pressed by the guide portion 56 while utilizing the tightening force of the bolt 60. At this time, the tightening force of the bolt 60 can be easily controlled. As a result, the pressing load on the internal gear 42 by the guide portion 56 can be controlled. Therefore, the internal gear 42 can be reliably fixed while preventing damage to the internal gear 42 during assembly.

[0064] For example, if the bracket 10 is to be provided with the engaging portion 83, the partition wall 14 must be thickened to accommodate the gear-side fitting tooth portion 84. This would result in a particularly thick first partition wall 91. Compared to this case, if the guide portion 56 is provided with the engaging portion 83, the impact on the axial thickening of the guide portion 56 is small. Therefore, by providing the engaging portion 83 between the guide portion 56 and the internal gear 42, the reducer-equipped motor 1 can be made thinner and more compact.

[0065] The engagement portion 83 is composed of the gear-side fitting teeth portion 84 and the guide-side fitting teeth portion 62. The rigidity of the guide-side fitting teeth portion 62 is lower than that of the gear-side fitting teeth portion 84. The inclination angle θ1 of the tooth surface 62b of the guide-side fitting teeth portion 62 and the inclination angle θ2 of the tooth surface 84b of the gear-side fitting teeth portion 84 satisfy the above formula (1). This configuration ensures that the guide-side fitting teeth portion 62 is reliably interposed between the gear-side fitting teeth portions 84 adjacent to each other in the circumferential direction. The corners of the guide-side fitting teeth portion 62 can be reliably abutted against the tooth surface 84b of the gear-side fitting teeth portion 84. The corners of the guide-side fitting teeth portion 62, which have low rigidity, are crushed and plastically deformed, thereby improving the meshing and fixing force of the fitting teeth portions 62, 84. This allows the internal gear 42 to be firmly fixed.

[0066] Furthermore, by making the inclination angle θ1 of the guide-side fitting teeth 62, which has low rigidity, smaller than the inclination angle θ2 of the gear-side fitting teeth 84, which has high rigidity, it is possible to promote plastic deformation of the guide-side fitting teeth 62 while preventing the guide-side fitting teeth 62 from tipping and deforming when the fitting teeth 62, 84 mesh with each other. This ensures an improved meshing fixing force between the fitting teeth 62, 84.

[0067] Furthermore, by making the rigidity of the guide portion 56, which presses the internal gear 42, lower than the rigidity of the internal gear 42, it is possible to make it easier for the guide-side fitting teeth portion 62 to bite into the gear-side fitting teeth portion 84. This allows the internal gear 42 to be reliably fixed. Furthermore, by reducing the rigidity of the guide portion 56, it becomes easier to process the guide portion 56. For example, it becomes easier to assemble the rolling bearing 55 for rotatably supporting the eccentric shaft 41 to the guide portion 56. As a result, the manufacturing cost of the speed reducer motor 1 can be reduced and the productivity of the speed reducer motor 1 can be improved.

[0068] By improving the productivity of the geared motor 1, it will be possible to contribute to Goal 7 of the United Nations-led Sustainable Development Goals (SDGs), "Ensure access to affordable, reliable, sustainable and modern energy for all," and Goal 9, "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation."

[0069] The present invention is not limited to the above-described embodiment, and includes various modifications to the above-described embodiment without departing from the spirit of the present invention.

[0070] For example, in the above embodiment, a case has been described in which the guide portion 56 is formed with the guide-side fitting teeth portion 62, and the internal gear 42 is formed with the gear-side fitting teeth portion 84. A case has been described in which the guide-side fitting teeth portion 62 and the gear-side fitting teeth portion 84 form the engagement portion 83 that provides a concave-convex fit between the guide portion 56 and the internal gear 42. However, this is not limiting, and an engagement portion (a second engagement portion in the claims) that provides a concave-convex fit between the bracket 10 and the internal gear 42 may also be provided.

[0071] In this case, the engaging portion may be provided on the first partition wall 91 and the end face of the gear main body 81 placed on the first partition wall 91. The engaging portion may also be provided on the outer peripheral surface 81a of the gear main body 81 and the inner peripheral surface 16a of the gear accommodating recess 16. For example, the outer peripheral surface 81a of the gear main body 81 and the inner peripheral surface 16a of the gear accommodating recess 16 may be spline-fitted together. With this configuration, it is sufficient that the internal gear 42 is pressed by the guide portion 56 from the second surface 10c of the bracket 10 (one surface of the gear accommodating recess 16).

[0072] In the above embodiment, the engaging portion 83 is provided around the entire circumference of the internal gear 42 and the guide portion 56. However, this is not limited to this, and it is sufficient that the engaging portion 83 is provided in at least one location. For example, a key may be provided on either the internal gear 42 or the guide portion 56, and a key groove may be provided on the other, and these key and key groove may be fitted together. This also applies to the case where the internal gear 42 and the bracket 10 are fitted together.

[0073] In the above embodiment, the case where the guide portion 56 is fastened to the bracket 10 using the bolt 60 has been described. However, this is not limited to this, and any fastener that is inserted into the bolt insertion hole 59a of the guide portion 56 and fastens the guide portion 56 to the bracket 10 may be used. For example, a crimping pin may be used as the fastener instead of the bolt 60. Even in this configuration, the fixing load of the fastener (for example, the crimping pin) can be easily managed, and in turn, the pressing load applied by the guide portion 56 to the internal gear 42 can be managed.

[0074] In the above embodiment, the rigidity of the guide-side fitting teeth portion 62 is lower than the rigidity of the gear-side fitting teeth portion 84. The inclination angle θ1 of the tooth surface 62b of the guide-side fitting teeth portion 62 and the inclination angle θ2 of the tooth surface 84b of the gear-side fitting teeth portion 84 satisfy the above formula (1). However, this is not limiting, and the rigidity of the guide-side fitting teeth portion 62 may be higher than the rigidity of the gear-side fitting teeth portion 84.

[0075] In this case, the inclination angles θ1 and θ2 are θ1>θ2 (2) That is, the relationship between the fitting teeth 62, 84 and the inclination angles θ1, θ2 should be such that the inclination angle θ1, θ2 of the fitting teeth 62, 84 with the lower rigidity is smaller than the inclination angle θ1, θ2 of the fitting teeth 62, 84 with the higher rigidity. This also applies to the case where the internal gear 42 and the bracket 10 are fitted together.

[0076] In the above embodiment, the rolling bearings 20, 40, and 47 are used as the bearings used in the speed reducer motor 1. However, this is not limited to this, and various bearings can be used. [Explanation of symbols]

[0077] DESCRIPTION OF SYMBOLS 1...motor with reducer (reduction device), 2...motor section, 3...control section, 4...reduction mechanism, 5...control case, 5a...opening, 6...control board, 10...bracket, 10a...outer surface, 10b...first surface, 10c...second surface (one surface), 10d...female thread section (fixing hole), 11a...first reduced diameter section, 11b...step surface, 12a...second reduced diameter section, 12b...second step surface, 13...outer flange section, 14...partition wall, 15...motor storage recess, 16...gear storage recess, 16a...inner surface, 17...bolt seat, 17a...female thread section for external device, 17b...other surface, 19...bearing housing, 20...rolling bearing, 21...stator , 22... rotor, 23... stator core, 24... teeth, 25... coil, 31... rotor shaft, 32... rotor core, 33... ring magnet, 34... support shaft, 34a... flange portion, 35... mounting shaft, 36... core body, 37... inner peripheral wall, 38... outer peripheral wall, 40... rolling bearing, 41... eccentric shaft, 42... internal gear, 42a... internal teeth (first internal teeth), 43... oscillating gear, 43a... recess, 44... output portion, 45... eccentric portion, 45a... outer peripheral surface, 46... shaft body, 47... rolling bearing, 48... oscillating gear body, 49... bearing housing, 50... tooth wall, 50a... external teeth (first external teeth), 50b...internal teeth (second internal teeth), 51...output portion body, 51a...one surface, 51b...other surface, 52...bearing accommodating recess, 53...external tooth ring, 53a...external teeth (second external teeth), 54...female thread portion, 55...rolling bearing, 55a...inner ring, 55b...outer ring, 56...guide portion, 57...guide body, 57a...outer peripheral surface, 57b...end face (guide end face), 58...bearing outer flange portion, 59...flange portion, 59a...bolt insertion hole (fixing device insertion hole), 60...bolt (fixing device), 61...bearing inner flange portion, 62...guide side mating teeth portion (first mating teeth portion), 62a...tip surface, 62b...tooth surface, 71...outer flange 1. Gear portion, 71a...end face, 72...bolt, 73...ring groove, 74...magnetic detection element, 75...power harness, 76...sensor harness, 77...power outlet, 78...sensor outlet, 81...gear body, 81a...outer peripheral surface, 81b...inner peripheral surface, 81c...end face (gear end face), 82...internal teeth, 83...engagement portion (first engagement portion), 84...gear side mating tooth portion (second mating tooth portion), 84a...tip face, 84b...tooth surface, 91...first partition wall, 91a...step portion, 92...second partition wall, 92a...step portion, 93...third partition wall, A...rotation axis, C...center, G...gap, P...plane, θ1...inclination angle, θ2...inclination angle

Claims

1. a bracket having a gear storage recess with one side open; a reduction mechanism housed in the gear housing recess; a guide portion that closes the one surface of the gear accommodating recess; Equipped with The reduction mechanism is an annular internal gear having first internal teeth; an eccentric shaft that is arranged coaxially with the axis of the internal gear and that rotates by receiving external power; an oscillating gear rotatably supported by the eccentric shaft, having first external teeth meshing with the first internal teeth, and having second internal teeth; an output portion disposed coaxially with the axis and having second external teeth meshed with the second internal teeth; Equipped with The eccentric shaft a shaft body that rotates around the axis; an eccentric portion provided on the shaft body and eccentric with respect to the axis; and the oscillating gear is rotatably supported by the eccentric portion, a first engagement portion provided on the guide portion and the internal gear for recess-and-protrusion engagement between the guide portion and the internal gear, and a second engagement portion provided on the bracket and the internal gear for recess-and-protrusion engagement between the bracket and the internal gear, the internal gear is pressed from the one surface side of the gear accommodating recess by the guide portion; A reduction gear device characterized by:

2. At least one of the first engaging portion and the second engaging portion is provided on the entire circumference of the internal gear and the entire circumference of at least one of the guide portion and the bracket. The reduction gear according to claim 1 .

3. The bracket has fixing holes provided around the gear housing recess, the guide portion has a fastener insertion hole communicating with the fixing hole, a fixture that is inserted into the fixture insertion hole from the opposite side of the guide portion to the bracket and fixed to the fixing hole, The first engaging portion is provided.

3. The reduction gear transmission according to claim 1 or 2.

4. the first engagement portion is provided on a guide end surface of the guide portion and a gear end surface of the internal gear that face each other in the direction of the axis, The first engagement portion is a plurality of first engagement teeth portions that protrude from the guide end surface toward the internal gear and are arranged side by side in a circumferential direction; a plurality of second engagement teeth protruding from the gear end surface toward the guide portion and arranged side by side in the circumferential direction; Equipped with When the angle of the tooth flank of the first fitting teeth portion with respect to the direction of the axis is θ1 and the angle of the tooth flank of the second fitting teeth portion with respect to the direction of the axis is θ2, When the rigidity of the guide portion is lower than the rigidity of the internal gear, the angles θ1 and θ2 are θ1<θ2 Fulfilling When the rigidity of the internal gear is lower than the rigidity of the guide portion, the angles θ1 and θ2 are θ1>θ2 fulfill, The reduction gear according to claim 3 .

5. The rigidity of the guide portion is lower than the rigidity of the internal gear, and the angles θ1 and θ2 are θ1<θ2 fulfill, The reduction gear according to claim 4 .

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