A harmonic reducer

Abstract

The application discloses a harmonic reducer and belongs to the technical field of reducers. The harmonic reducer comprises a flexible gear, a bearing outer ring, a rigid gear and a wave generator. The flexible gear comprises a flexible deformation part which is engaged with the inner side of the rigid gear, a driving part which is located on the outer side of the rigid gear and a connecting part which connects the flexible deformation part and the driving part. The bearing outer ring is located on the outer side of the rigid gear and is fixedly connected with the driving part. The driving part and the bearing outer ring are rotationally matched with the outer side of the rigid gear. The wave generator extends into the flexible deformation part. The harmonic reducer is simple in structure, reduces the number of parts and manufacturing cost, reduces the overall size and weight of the reducer, guarantees high transmission precision and is suitable for robots used in household, public service, scientific research and education and other scenes which pursue low cost and high practicability.

Description

Technical Field

[0001] This invention relates to the field of speed reducer technology, and specifically to a harmonic speed reducer. Background Technology

[0002] With the development and application of robots, harmonic reducers, as important actuators in robot joints, are increasingly demanding in terms of lightweighting, miniaturization, and low cost. However, existing harmonic reducers have complex structures, a large number of parts, and high manufacturing costs. In particular, the wave generator in harmonic reducers is mainly a combination of cams and flexible bearings. The outer ring of the flexible bearing needs to balance elasticity and wear resistance, resulting in high manufacturing costs and heavy weight. This makes them unsuitable for robots used in scenarios such as home use, public services, and scientific research and education where low cost and high practicality are required. Summary of the Invention

[0003] The purpose of this invention is to provide a harmonic reducer to solve the problems of high cost and heavy weight of existing harmonic reducers.

[0004] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A harmonic reducer includes: a flexible wheel, a bearing outer ring, a rigid wheel, and a wave generator; the flexible wheel includes a flexible deformable part that meshes with the inner side of the rigid wheel, a driving part located on the outer side of the rigid wheel, and a connecting part connecting the flexible deformable part and the driving part; the bearing outer ring is located on the outer side of the rigid wheel and is fixedly connected to the driving part, and the driving part and the bearing outer ring are rotatably engaged with the outer side of the rigid wheel; the wave generator extends into the flexible deformable part.

[0005] Furthermore, the inner wall of the aforementioned drive unit and bearing outer ring has a gap with the outer wall of the rigid wheel and is rolled into contact with the first roller bearing.

[0006] Furthermore, a first groove is provided on the inner side of the connection position between the drive unit and the outer ring of the bearing, and a second groove corresponding to the first groove is provided on the outer side of the rigid wheel, and the first roller bearing is disposed between the first groove and the second groove.

[0007] Furthermore, the aforementioned wave generator includes a cam, several second roller bearings, and a roller cage; a raceway is provided circumferentially on the outer side of the cam, all the second roller bearings are arranged in the raceway along the axial direction of the cam, and the roller cage is arranged on the outer side of the cam for limiting the second roller bearings, with the second roller bearings partially extending out of the roller cage.

[0008] Furthermore, a convex ring is provided on the outer side of one end of the cam, and a cover plate is connected to the other end of the cam. A raceway is formed between the convex ring, the outer wall of the cam, and the cover plate.

[0009] Furthermore, the aforementioned roller cage is circular.

[0010] Furthermore, the aforementioned second roller bearing is drum-shaped.

[0011] Furthermore, the end of the cam with the protruding ring extends into the flexible deformable part.

[0012] The present invention has the following beneficial effects: (1) Compared with existing harmonic reducers, the harmonic reducer of the present invention eliminates high-cost components such as flexible bearings and simplifies the structure of rigid wheel, flexible wheel, and crossed roller bearing. Therefore, the harmonic reducer of the present invention simplifies the structure of the harmonic reducer, reduces the number of components and manufacturing costs, reduces the overall size and weight of the reducer, and ensures high transmission accuracy.

[0013] (2) The wave generator of the present invention uses multiple cylindrical drum rollers to replace flexible bearings, which simplifies the structure of the wave generator, reduces its manufacturing cost, and reduces the difficulty of assembly, allowing the wave generator to be assembled manually.

[0014] (3) The rigid wheel and flexible wheel of the present invention are integrated with the inner and outer rings of the cross roller bearing (first roller bearing). Compared with the three being independent components, the flange structure of the steel wheel and flexible wheel can be eliminated, resulting in a more compact structure, lighter weight, and smaller size.

[0015] (4) The outer ring of the cross roller bearing (first roller bearing) of the present invention is separated into a flexible wheel and a bearing outer ring, which provides machining space for the tool for machining the flexible wheel teeth; the outer ring of the cross roller bearing (first roller bearing) is split, which can accurately adjust the clearance of the entire bearing and improve the transmission accuracy of the reducer; the outer ring is split, the bearing rollers can be easily installed, the reducer is easy to disassemble as a whole, and it is convenient to maintain and replace parts. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the external structure of a harmonic reducer provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of a harmonic reducer provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the wave generator provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the connection between the cam and the cover plate provided in an embodiment of the present invention.

[0017] In the figure: 10-flexible wheel; 11-flexible deformation part; 12-drive part; 13-connecting part; 20-bearing outer ring; 30-rigid wheel; 40-wave generator; 41-cam; 42-second roller bearing; 43-roller cage; 44-raceway; 45-convex ring; 46-cover plate; 50-first roller bearing. Detailed Implementation

[0018] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0019] like Figure 1 and Figure 2 As shown, this embodiment provides a harmonic reducer, including: a flexible wheel 10, a bearing outer ring 20, a rigid wheel 30, and a wave generator 40. The flexible wheel 10 includes a flexible deformable portion 11, a driving portion 12, and a connecting portion 13. The flexible deformable portion 11 meshes with the inner side of the rigid wheel 30 via teeth. The driving portion 12 is located on the outer side of the rigid wheel 30. The connecting portion 13 connects the flexible deformable portion 11 and the driving portion 12. The bearing outer ring 20 is located on the outer side of the rigid wheel 30 and connected to the driving portion 12. After the driving portion 12 is connected to the bearing outer ring 20, it can rotate with the outer side of the rigid wheel 30. The wave generator 40 extends into the flexible deformable portion 11. When the wave generator 40 is working, it causes the flexible deformable portion 11 to deform, and the relative rotation between the flexible deformable portion 11 and the wave generator 40 is achieved through the difference in the number of teeth, thus realizing a high reduction ratio.

[0020] In this embodiment, there are gaps between the drive unit 12, the connecting part 13, and the bearing outer ring 20 and the rigid wheel 30. The drive unit 12 and the bearing outer ring 20 are rotatably engaged with the outer side of the rigid wheel 30 through a plurality of first roller bearings 50. Specifically, a first groove is provided on the inner side of the connection between the drive unit 12 and the bearing outer ring 20, that is, part of the first groove is formed on the inner side of the drive unit 12 and another part is formed on the inner side of the bearing outer ring 20. A second groove is provided on the outer side of the steel wheel 30. The second groove is arranged opposite to the first groove to form a space for installing the first roller bearings 50.

[0021] Preferably, both the first and second roller grooves are V-shaped, with the apex of the first roller groove located at the connection between the drive unit 12 and the outer ring 20 of the bearing. This arrangement facilitates the installation of the first roller bearing 50.

[0022] Preferably, the drive unit 12 is detachably connected to the bearing outer ring 20; more preferably, the drive unit 12 is detachably connected to the bearing outer ring 20 by bolts.

[0023] like Figure 3 and Figure 4As shown, the wave generator 40 includes a cam 41, a plurality of second roller bearings 42, and a roller cage 43. The cam 41 is elliptical, and a raceway 44 is provided circumferentially on the outer side of the cam 41. The raceway 44 is also elliptical. All the second roller bearings 42 are arranged parallel to each other and spaced apart in the raceway 44 along the axial direction of the cam 41. The roller cage 43 is located on the outer side of the cam 41, that is, on the outer side of the raceway 44, to confine the second roller bearings 42 within the raceway 44 and prevent contact between adjacent second roller bearings 42. Specifically, the raceway 44 is provided with a plurality of through holes, and the second roller bearings 42 partially protrude from the through holes for contact with the flexible wheel 10. The size of the through holes is such that the second roller bearings 42 will not fall out.

[0024] In this embodiment, a convex ring 45 is provided on the outer side of one end of the cam 41, and a cover plate 46 is connected to the other end of the cam 41. A raceway 44 is formed between the convex ring 45, the cover plate 46 and the outer side wall of the cam 41.

[0025] In this embodiment, the roller retainer 43 can be circular or elliptical, depending on whether it affects the deformation when inserted into the flexspline 10.

[0026] Preferably, the second roller bearing 42 is drum-shaped, that is, the middle part of the second roller bearing 42 protrudes outward.

[0027] When the wave generator 40 is inserted into the flexure 10, the flexure 10 is spread out to form an angle. When the second roller bearing 42 is drum-shaped, after the second roller bearing 42 is inserted into the flexure 10, one end of it is pressed and tilts up, which can automatically compensate for the deformation of the flexure 10 and increase the contact area between the second roller bearing 42 and the flexure 10. When the cam 41 is rotated, the second roller bearing 42 rolls between the cam 41 and the flexure 10, forcing the flexure 10 to produce periodic deformation.

[0028] Preferably, one end of the cam 41 with a protruding ring 45 extends into the flexible deformable portion 11 of the flexure 10.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A harmonic reducer characterized by, include: The device comprises a flexible wheel (10), a bearing outer ring (20), a rigid wheel (30), and a wave generator (40). The flexible wheel (10) includes a flexible deformable part (11) that meshes with the inner side of the rigid wheel (30), a drive part (12) located on the outer side of the rigid wheel (30), and a connecting part (13) that connects the flexible deformable part (11) and the drive part (12). The bearing outer ring (20) is located on the outer side of the rigid wheel (30) and is fixedly connected to the drive part (12). The drive part (12) and the bearing outer ring (20) are rotatably engaged with the outer side of the rigid wheel (30). The wave generator (40) extends into the flexible deformable part (11).

2. The harmonic reducer of claim 1, wherein, The inner wall of the drive unit (12) and the outer ring (20) of the bearing has a gap with the outer wall of the rigid wheel (30) and is rolled in contact with the first roller bearing (50).

3. The harmonic reducer of claim 2, wherein, The drive unit (12) has a first groove on the inner side of the connection position with the outer ring (20) of the bearing, and the outer side of the rigid wheel (30) has a second groove corresponding to the first groove. The first roller bearing (50) is disposed between the first groove and the second groove.

4. The harmonic reducer of any one of claims 1 to 3, wherein, The wave generator (40) includes a cam (41), a plurality of second roller bearings (42), and a roller cage (43); a raceway (44) is provided circumferentially on the outer side of the cam (41), all the second roller bearings (42) are arranged in the raceway (44) along the axial direction of the cam (41), and the roller cage (43) is arranged on the outer side of the cam (41) for limiting the second roller bearings (42), and the second roller bearings (42) partially extend out of the roller cage (43).

5. The harmonic reducer of claim 4, wherein, The outer side of one end of the cam (41) is provided with a convex ring (45), and the other end of the cam (41) is connected to a cover plate (46). The raceway (44) is formed between the convex ring (45), the outer side wall of the cam (41) and the cover plate (46).

6. The harmonic reducer of claim 4, wherein, The roller cage (43) is circular.

7. The harmonic reducer of claim 4, wherein, The second roller bearing (42) is drum-shaped.

8. The harmonic reducer of claim 4, wherein, The cam (41) has a protruding ring (45) at one end which extends into the flexible deformable part (11).

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