Novel lightweight harmonic speed reducer

Abstract

The utility model provides a novel light-weight harmonic speed reducer, which relates to the technical field of speed reducers and comprises a flexible gear, and the flexible gear is respectively connected with a wave generator and an inner structural body of a crossed roller bearing through an elastic meshing interface; an inner gear matched with the flexible gear in tooth shape is arranged on the inner side of the inner structure body. And the crossed roller bearing is also provided with an outer ring structure linked with the inner structure body. The utility model has the beneficial effects that through the integrated design of the internal gear and the crossed roller bearing, the number of assembly components is obviously reduced, the volume of parts is reduced, the axial size is reduced, the structural rigidity is improved, the stress distribution of a transmission interface is more uniform, the service life of the components is effectively prolonged, and the assembly difficulty is reduced; due to the design of the axial hollow pin rollers, elasticity is increased, part precision errors and assembly errors can be absorbed, gaps between the rollers and a track are eliminated through elastic deformation of the axial hollow pin rollers, and back-clearance-free transmission is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a speed reducer technical field especially a novel lightweight harmonic speed reducer. BACKGROUND

[0002] The harmonic reducer is a high-precision transmission device based on elastic deformation principle, and its core structure is composed of a rigid gear, a flexible gear and a wave generator. The rigid gear, as a rigid internal gear, forms a tooth number difference (usually 2 teeth) meshing base with the flexible gear outer gear made of high-strength thin-walled alloy material. The wave generator, as a power input mechanism, drives the flexible gear to produce periodic elastic deformation through the synergistic effect of the elliptical cam and the flexible bearing, realizes the dynamic adjustment of the tooth surface contact area, and thus completes the high reduction ratio (up to 100:1 or more) transmission. Its transmission error can be controlled within 1 arc minute, and it has a transmission efficiency of more than 90%, meeting the industrial demand for high precision and low energy consumption.

[0003] In the application level, the harmonic reducer has become the preferred transmission scheme for load below 20 kg due to its compact structure and lightweight characteristics, especially in the wrist, elbow joint of industrial robot and SCARA robot, and its application field has extended to high-end fields such as aerospace (satellite attitude adjustment), medical equipment (surgical robot precision driving), semiconductor manufacturing (wafer positioning system), etc., showing multi-scene adaptability.

[0004] In the engineering practice of the harmonic reducer, lightweight design is the key technical path to reduce the inertia load of the system and improve the dynamic response capability. By optimizing the mass distribution of the transmission system, the motor driving energy consumption can be significantly reduced and the equipment motion flexibility can be enhanced.

[0005] The technical content disclosed in Chinese patent document (publication number: CN105840766A, patent name: a lightweight harmonic reducer) is: including a wave generator, a rigid gear, a four-point contact bearing, a flexible gear, a bearing support, a load plate, the wave generator is arranged in the flexible gear, the flexible gear is engaged in the rigid gear, the four-point contact bearing is arranged between the bearing support and the load plate, the rigid gear is fixed with the bearing support on the outer side of the four-point contact bearing, and the flexible gear is fixed with the load plate on the inner side of the four-point contact bearing.

[0006] From the above embodiment and the corresponding drawing display, it can be known that the lightweight harmonic reducer reduces the weight through the four-point contact bearing layout of structural simplification, but does not reduce the number of components of the harmonic reducer, so it does not form a great optimization in structure and weight. UTILITY MODEL CONTENT

[0007] The utility model overcomes the defects in the prior art and provides a novel lightweight harmonic speed reducer, which is structurally more stable and lighter as a whole by virtue of structural design of the flexspline and the internal gear to reduce the number of parts and enhance the rigidity of each part.

[0008] To solve the above technical problems, the utility model is realized by the following technical solutions:

[0009] A novel lightweight harmonic speed reducer, comprising a flexspline, which is connected to an internal structure of a wave generator and a cross roller bearing through an elastic engagement interface respectively;

[0010] The internal structure is internally provided with an internal gear matched with the flexspline;

[0011] The cross roller bearing is further provided with an outer ring structure linked with the internal structure;

[0012] The flexspline comprises flexspline teeth arranged in a ring shape, and a flexspline disc extending outward from one end of the flexspline teeth;

[0013] The flexspline is connected to the outer ring structure.

[0014] Further, the cross roller bearing comprises cross-arranged rollers, each of which is provided with an axially-through hollow weight-reducing cavity, and the rollers can be elastically deformed under extrusion.

[0015] Further, the rollers are provided with axially-through hollow weight-reducing cavities, and are allowed to have an elastic deformation of 0.05-0.1 mm within a rated load range.

[0016] Further, the outer ring structure comprises a first outer ring and a second outer ring, and the first outer ring and the second outer ring wrap one side of the rollers.

[0017] The internal structure is provided with an inner ring on a side opposite to the internal gear, and the inner ring wraps a side of the rollers away from the outer ring structure.

[0018] Further, the first outer ring, the second outer ring and the inner ring form a dynamic gap compensation zone through the elastic structure of the rollers.

[0019] Further, the first outer ring, the second outer ring, the internal structure and the rollers are made of PEEK material or resin material, and the arrangement direction of the rollers forms an angle of 45°±0.1° with the bearing axial direction.

[0020] Further, a sealing ring is arranged between the first outer ring and the internal structure.

[0021] Further, the wave generator comprises a cam, the cam is connected to a flexspline bearing, and the flexspline bearing is sleeved at the center of the flexspline.

[0022] Compared with the prior art, the harmonic reducer has the advantages that:

[0023] 1. The inner gear and the cross roller bearing are designed in an integrated manner, the number of assembly components is significantly reduced, the volume of the components is reduced, the axial dimension is reduced, the structural rigidity is improved, the stress distribution of the transmission interface is more uniform, the service life of the assembly is effectively prolonged, and the assembly difficulty is reduced.

[0024] 2. The integrated structure design of the flexspline and the inner gear reduces the number of parts and enhances the rigidity of each component, so that the harmonic reducer structure is more stable and the overall is more lightweight. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present application, together with the embodiments of the present application, to explain the present application, and do not constitute a limitation on the present application, in which:

[0026] Fig. 1 is a schematic diagram of the overall structure of the harmonic reducer of the embodiment of the present application;

[0027] Fig. 2 is a sectional view of the harmonic reducer of the embodiment of the present application;

[0028] Fig. 3 is an exploded view of the harmonic reducer of the embodiment of the present application;

[0029] Fig. 4 is a half-sectional view of the harmonic reducer of the embodiment of the present application.

[0030] In the figure: 1, flexspline; 101, flexspline disc; 102, flexspline tooth; 2, cross roller bearing; 201, roller; 202, first outer ring; 203, second outer ring; 204, inner structure; 2041, inner gear; 2042, inner ring; 3, sealing ring; 4, wave generator; 401, cam; 402, flexspline bearing. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and do not limit the present application.

[0032] As Figs. 1 to 4As shown, a kind of lightweight harmonic reducer, including flexspline 1, flexspline 1 is connected the inner structure body 204 of wave generator 4 and cross roller bearing 2 respectively by elastic engagement interface;The inner side of inner structure body 204 is equipped with the inner gear 2041 matched with the tooth profile of flexspline 1;The inner gear and cross roller bearing are integrated in the utility model, significantly reduce the number of assembly components, the volume of component is reduced, reduce axial dimension and improve structural rigidity, the design makes transmission interface stress distribution more uniform, effectively prolongs the service life of component, reduces the difficulty of assembly.

[0033] Wave generator 4 includes cam 401, cam 401 is connected flexspline bearing 402, flexspline bearing 402 is sleeved in the center of flexspline 1.Flexspline 1 includes annularly arranged flexspline tooth 102, and flexspline disc 101 is outwardly extended along one end of flexspline tooth 102.

[0034] Cross roller bearing 2 is also provided with outer ring structure linked with inner structure body 204, cross roller bearing 2 is made of high polymer composite material, compared with traditional metal material, and the weight is reduced by 30%-50%, so that the weight of harmonic reducer can be greatly reduced, so that the harmonic reducer is more light when being applied, thereby reducing the burden of driving motor, prolonging the service life of driving motor.

[0035] Cross roller bearing 2 includes cross-arranged roller 201, each roller 201 is provided with hollow weight-reducing cavity passing through axially, and the roller 201 can be elastically deformed by extrusion, the hollow weight-reducing cavity has the functions of light weight and elastic deformation buffering, and also makes the roller 201 can absorb part of the part precision error and dynamic load in the application process, so that the manufacturing cost of parts can be reduced, the roller 201 can also be elastically deformed to eliminate the gap between the roller 201 and the running track, so as to achieve gapless transmission, improve the transmission accuracy, reduce the vibration generated by the gap in the transmission process, so that each part of the reducer can still maintain close connection after long running time.

[0036] In the embodiment, the roller 201 is provided with hollow weight-reducing cavity passing through axially, and the elastic deformation amount of 0.05-0.1mm is allowed within the rated load range, the friction coefficient is reduced, and plastic deformation is inhibited.

[0037] The outer ring structure comprises a first outer ring 202 and a second outer ring 203, and the first outer ring 202 and the second outer ring 203 wrap one side of the roller 201; the inner structure 204 is provided with an inner ring 2042 on the side opposite to the inner gear 2041, and the inner ring 2042 wraps the side of the roller 201 away from the outer ring structure; the dynamic gap compensation area is formed through the elastic structure of the roller between the first outer ring 202, the second outer ring 203 and the inner ring 2042. Thus, when the harmonic reducer is subjected to external impact, and when the harmonic reducer vibrates, the cross roller bearing 2 can absorb the vibration through the dynamic gap compensation area, so that the vibration absorption capacity is improved.

[0038] In the embodiment, the first outer ring 202, the second outer ring 203, the inner structure 204 and the roller 201 are all made of PEEK (polyether ether ketone composite) material or resin material, wherein the arrangement direction of the roller 201 is at an angle of 45°±0.1° with the bearing axial direction, and the optimization matching of the axial bearing and the radial deformation is realized through anisotropic mechanical design, so as to ensure the elastic compensation capacity under the condition of high rigidity.

[0039] The sealing ring 3 is arranged between the first outer ring 202 and the inner structure 204, and the sealing ring 3 can ensure that the grease is retained in the cross roller bearing 2, and can also prevent dust and other impurities from entering the cross roller bearing 2, so that the smooth operation of the roller 201 can be ensured.

[0040] The harmonic reducer of the utility model realizes that the axial size is reduced by 15%-20%, the overall quality is reduced by 25%-40%, the transmission precision is maintained within 60 arc seconds, the component vibration is reduced to 2-3 times of the traditional design through the structure integration, material compounding and mechanical optimization design, and the harmonic reducer is especially suitable for the humanoid robot scene which is limited in space and weight and needs to suppress vibration.

[0041] Finally, it should be noted that: the above is only the preferred embodiment of the utility model, and is not used for limiting the utility model, although the utility model is described in detail with reference to the embodiment, for the person skilled in the art, still can modify the technical scheme recorded in each embodiment, or equivalent replacement is carried out to part of technical features, but any modification, equivalent replacement, improvement, etc. within the spirit and principle of the utility model should be contained in the protection scope of the utility model.

Claims

1. A novel lightweight harmonic speed reducer, characterized by, The flexible gear (1) is connected to the wave generator (4) and the inner structure (204) of the cross roller bearing (2) through the elastic engagement interface respectively. The inner structure (204) is provided with an internal gear (2041) matched with the tooth shape of the flexible gear (1) on the inner side. The cross roller bearing (2) is further provided with an outer ring structure linked with the inner structure (204). The flexible gear (1) comprises a flexible gear tooth (102) arranged in a ring shape, and a flexible gear disc (101) extending outward along one end of the flexible gear tooth (102). The flexible gear (1) is connected with the outer ring structure.

2. The novel lightweight harmonic speed reducer according to claim 1, characterized by, The cross roller bearing (2) comprises cross-arranged rollers (201), each roller (201) is provided with an axially-through hollow weight-reducing cavity, and the roller (201) can be elastically deformed under extrusion.

3. The novel lightweight harmonic speed reducer according to claim 2, characterized by The roller (201) is provided with an axially-through hollow weight-reducing cavity, and the elastic deformation amount is 0.05-0.1mm within the rated load range.

4. The novel lightweight harmonic speed reducer according to claim 3, characterized by The outer ring structure comprises a first outer ring (202) and a second outer ring (203), the first outer ring (202) and the second outer ring (203) wrap one side of the roller (201). The inner structure (204) is provided with an inner ring (2042) on the side away from the internal gear (2041), and the inner ring (2042) wraps the side of the roller (201) away from the outer ring structure.

5. The novel lightweight harmonic speed reducer according to claim 4, characterized by The dynamic gap compensation area is formed between the first outer ring (202), the second outer ring (203) and the inner ring (2042) through the elastic structure of the roller.

6. The novel lightweight harmonic speed reducer according to claim 5, characterized by The first outer ring (202), the second outer ring (203), the inner structure (204) and the roller (201) are all made of PEEK material or resin material, and the arrangement direction of the roller (201) is at an angle of 45°±0.1° with the bearing axial direction.

7. The novel lightweight harmonic speed reducer according to claim 6, characterized by The sealing ring (3) is arranged between the first outer ring (202) and the inner structure (204).

8. The novel lightweight harmonic speed reducer according to any one of claims 1 to 7, characterized by The wave generator (4) comprises a cam (401), the cam (401) is connected with a flexible gear bearing (402), and the flexible gear bearing (402) is sleeved at the center of the flexible gear (1).

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