Wave harmonic reducer retainer

Abstract

The application discloses a wave harmonic reducer retainer, which comprises a retainer body, the retainer body is provided with arc-shaped wave crests and arc-shaped wave troughs which are arranged in a circumferential direction continuously; the rising wave sections and the falling wave sections of the arc-shaped wave crests and the arc-shaped wave troughs constitute window beams, the adjacent window beams form pockets for accommodating balls, the pockets comprise first pockets with lower side openings and second pockets with upper side openings; during a periodic elliptical deformation of the retainer, the arc-shaped wave crests and the arc-shaped wave troughs can change the wave length through deformation, uniformly disperse stress, reduce stress concentration phenomenon, and further improve the fatigue life of the retainer. Under the driving of a wave generator, when the retainer is deformed elliptically, the wave length of the arc-shaped wave crests and the arc-shaped wave troughs is dynamically adjusted with the deformation amount, the adaptive change of the wave length makes the stress not concentrated on fixed connection points, but dispersedly borne through the whole curved surface structure.

Description

Technical Field

[0001] This application belongs to the field of harmonic reducer cages, and particularly relates to a waveform harmonic reducer cage. Background Technology

[0002] Harmonic reducers, as a crucial transmission device, are widely used in numerous industrial fields, especially in components such as robot joints. Among the core components of harmonic reducers, flexible bearings play a vital role. They not only transmit motion and power but also adapt to the unique transmission method of harmonic reducers through their elastic deformation. The cage of the harmonic reducer, as an important component of the flexible bearing, directly affects the operating performance and service life of the entire bearing and even the harmonic reducer.

[0003] In the actual operation of harmonic reducers, the wave generator is a key component that triggers a series of mechanical motion changes. When the wave generator operates, it causes the flexible bearing to undergo specific elliptical deformation. However, current harmonic reducer cage designs generally suffer from an unavoidable problem: they all include end ring structures. While the end rings play a role in enhancing structural stability and guiding the rolling elements to some extent, they face severe fatigue life issues in actual use. During periodic elliptical deformation, the bearing shape continuously changes, and the connection between the end ring and the beam experiences significant alternating stress. This stress concentration accelerates material fatigue damage. Therefore, existing technology needs further improvement and enhancement. Utility Model Content

[0004] This invention provides a retainer for a waveform harmonic reducer, which at least solves or alleviates one or more technical problems in the prior art, or at least provides a beneficial alternative.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A waveform harmonic reducer cage includes a cage body, the cage body having arc-shaped crests and arc-shaped troughs, the arc-shaped crests and arc-shaped troughs being circumferentially continuous;

[0007] The rising and falling segments of the arc-shaped peaks and troughs constitute window beams, and pockets for accommodating ball bearings are formed between adjacent window beams. The pockets include a first pocket with a lower opening and a second pocket with an upper opening.

[0008] During the periodic elliptical deformation of the cage, the arc-shaped peaks and troughs can change the wavelength through deformation, uniformly disperse stress, reduce stress concentration, and thus improve the fatigue life of the cage.

[0009] In a preferred implementation, the first pocket and the second pocket are the same size.

[0010] In a preferred implementation, the arc-shaped peaks and troughs are integrally formed.

[0011] In a preferred implementation, adjacent window beams are connected by a balancing section. The side of the balancing section facing the first pocket or the second pocket is a first arc surface that adapts to the ball bearing profile, and the side facing away from the first pocket or the second pocket is a flat surface.

[0012] In a preferred implementation, the window beam facing the first pocket or the second pocket is a second arc surface that accommodates the ball bearings, and the first arc surface and the second arc surface transition smoothly.

[0013] In the preferred implementation, the window beam and the balance section have the same wall thickness.

[0014] In the preferred implementation, the wavelengths of the arc-shaped peaks and troughs are the same.

[0015] In the preferred implementation, the wavelengths of the arc-shaped peaks and troughs are different.

[0016] In the preferred implementation, the wavelength of the arc-shaped peak is twice the wavelength of the arc-shaped trough, and a dividing beam is provided at the center of the arc-shaped peak to divide it into two first pockets.

[0017] In a preferred implementation, multiple arc-shaped peaks have the same wave height and multiple arc-shaped troughs have the same wave height, and the wave heights of the arc-shaped peaks and the arc-shaped troughs are equal.

[0018] The above structure has the following beneficial effects:

[0019] The cage body of this application adopts a sinusoidal waveform continuous curved surface design, with the arc-shaped peaks and troughs seamlessly connected circumferentially. Driven by a wave generator, when the cage undergoes elliptical deformation, the wavelengths of the arc-shaped peaks and troughs dynamically adjust with the amount of deformation. When stretched along the major axis, the wavelength increases; when compressed along the minor axis, the wavelength decreases. This adaptive wavelength variation prevents stress concentration at fixed connection points, instead distributing the load across the entire curved surface structure. The lower opening of the first pocket and the upper opening of the second pocket are used for ball bearing assembly, and this structure with openings on both the upper and lower sides enhances lubricant flow. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain this application and do not constitute an undue limitation of the present invention. In the drawings:

[0021] Figure 1A schematic three-dimensional structural diagram of one embodiment of the waveform harmonic reducer cage of this application is shown;

[0022] Figure 2 A three-dimensional structural schematic diagram of another illustrative embodiment of the waveform harmonic reducer cage of this application is shown;

[0023] Label Explanation:

[0024] 10. Curved crest; 100. First pocket; 101. Divider beam; 11. Curved trough; 110. Second pocket; 12. Window beam; 120. Second curved surface; 13. Balance section; 130. First curved surface. Detailed Implementation

[0025] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit and scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0026] In the description of this utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In this utility model, unless otherwise expressly specified and limited, the first feature being "upper" or "lower" than the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium.

[0027] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral unit; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. However, specifying a direct connection indicates that the two connected entities do not have a connecting structure to establish a connection relationship, but are simply connected to form a whole through a connecting structure. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0028] In this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0029] The present invention will now be described with reference to the accompanying drawings.

[0030] The specific solution adopted is as follows:

[0031] like Figure 1-2 As shown, this utility model provides a waveform harmonic reducer cage, including a cage body, the cage body having arc-shaped peaks 10 and arc-shaped valleys 11, the arc-shaped peaks and arc-shaped valleys being circumferentially continuous;

[0032] The rising and falling segments of the arc-shaped peaks and troughs constitute the window beam 12, and pockets for accommodating balls are formed between adjacent window beams. The pockets include a first pocket 100 with a lower opening and a second pocket 110 with an upper opening.

[0033] During the periodic elliptical deformation of the cage, the arc-shaped peaks and troughs can change the wavelength through deformation, uniformly disperse stress, reduce stress concentration, and thus improve the fatigue life of the cage.

[0034] The cage body of this application adopts a sinusoidal waveform continuous curved surface design, with the arc-shaped peaks 10 and troughs seamlessly connected circumferentially. Driven by a wave generator, when the cage undergoes elliptical deformation, the wavelengths of the arc-shaped peaks and troughs dynamically adjust with the amount of deformation. When stretched along the major axis, the wavelength increases; when compressed along the minor axis, the wavelength decreases. This adaptive wavelength variation ensures that stress is no longer concentrated at the fixed connection point, but is distributed throughout the entire curved surface structure. The lower opening of the first pocket and the upper opening of the second pocket are used for ball bearing assembly, and this structure with openings on both the upper and lower sides enhances the flow of lubricating oil.

[0035] In addition, for applications with small cage sizes (such as 10mm), elliptical deformation is a minor deformation. Even if the wavelength changes and the pocket changes, the ball displacement is still controlled within a reasonable range, effectively preventing the balls from falling out.

[0036] In a preferred embodiment of this application, the first pocket 100 and the second pocket 110 are of the same size, and the wavelengths and heights of the arc-shaped peaks and troughs are the same. This allows the first and second pockets to accommodate balls of the same size. During elliptical deformation, the contact stress distribution at each pocket is more uniform, and the balls of uniform size exhibit synchronous motion characteristics during elliptical deformation, reducing motion lag or lead caused by differences in ball size. During assembly, there is no need to distinguish between balls and pockets of different sizes. In maintenance scenarios, maintenance personnel can quickly replace balls of uniform size.

[0037] As a preferred embodiment of this application, the arc-shaped peaks and troughs are integrally formed. If injection molding is used, continuous seamless forming of the peak and trough surfaces can be achieved, ensuring good deformation matching of each part of the frame body, improving continuous operating life, and making it particularly suitable for robot joint scenarios.

[0038] See Figure 2 Adjacent window beams are connected by a balancing section. The side of the balancing section 13 facing the first pocket or the second pocket is a first arc surface 130 that adapts to the ball profile, while the side facing away from the first pocket or the second pocket is a flat surface. This balancing section serves as a transition section between adjacent window beams. By setting the arc transition of the first arc surface and the rigid support of the flat surface, the stress distribution presents a continuous and smooth transition. At the same time, the first arc surface is also a limiting position for the axial direction of the ball. In addition, the annular raceway set on the inner and outer rings of the bearing restricts the movement of the ball within a certain spatial range. This first arc surface adapts to the ball, allowing for better contact with the ball, reducing friction and collisions caused by abrupt changes in shape, and providing better encapsulation for the ball. The flat surface can reduce the overall height of the cage, making it suitable for use in small gaps. Furthermore, the spacing between the window beams on the opening side can be set to be smaller than the ball diameter to prevent the ball from axially dislodging from the opening side. The spacing between the window beams near the first arc surface is larger than the ball diameter, allowing the ball to rotate at this position.

[0039] Furthermore, the window beam facing the first pocket or the second pocket is a second arc surface 120 that is adapted to the ball bearing. The first arc surface and the second arc surface are smoothly transitioned. The smooth transition arc surface reduces the collision of the ball bearing due to abrupt shape changes in the pocket, reduces vibration, and significantly improves dynamic stability.

[0040] As a preferred embodiment of this application, the window beam 12 and the balance section 13 have the same wall thickness and are integrally formed with the same wall thickness. During the elliptical deformation process of the harmonic reducer, the geometric abrupt change at the joint is completely eliminated through continuous material distribution, so that the stress transmission path is a continuous and smooth transition. The same wall thickness design allows the window beam and the balance section to deform together. The consistent wall thickness of the two avoids the local plastic deformation or connection failure caused by stiffness differences in traditional structures.

[0041] In a preferred embodiment of this application, the wavelengths of the arc-shaped crests 10 and troughs 11 are different; for example, the wavelength of the arc-shaped crest is twice the wavelength of the arc-shaped trough. A dividing beam 101 is provided at the center of the arc-shaped crest to divide it into two first pockets. The combination of long and short wavelengths makes the structure of the cage more varied, and the height of the crests can also be designed, such as alternating long and short crests. This arrangement can make the stress distribution of the cage more uniform when subjected to elliptical variable stress. The long and short crests complement and restrain each other during deformation, avoiding stress concentration in a certain area, thereby improving the overall strength and stability of the cage. Locally setting 1-2 long crests / troughs: Setting long crests or troughs locally on the cage can optimize the design for stress concentration problems in specific parts, improve the strength and stability of the cage, and prevent excessive overall deformation. Long crests or troughs can cover a larger circumferential range, bear a larger range of periodic deformation, disperse local high stress to a larger area, and reduce deformation and damage caused by local stress concentration.

[0042] For any parts not mentioned in this utility model, existing technologies can be used or referenced.

[0043] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this utility model, and these should all be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A cage for a waveform harmonic reducer, characterized in that, include: The cage body has arc-shaped crests and arc-shaped troughs, which are continuously arranged circumferentially. The rising and falling segments of the arc-shaped peaks and troughs form window beams, and pockets for accommodating balls are formed between adjacent window beams. The pockets include a first pocket with a lower opening and a second pocket with an upper opening. During the periodic elliptical deformation of the cage, the arc-shaped peaks and troughs can change the wavelength through deformation, uniformly disperse stress, reduce stress concentration, and thus improve the fatigue life of the cage.

2. The waveform harmonic reducer cage according to claim 1, characterized in that, The first pocket and the second pocket are the same size.

3. The waveform harmonic reducer cage according to claim 1, characterized in that, The arc-shaped peaks and troughs are integrally formed.

4. The waveform harmonic reducer cage according to claim 1, characterized in that, Adjacent window beams are connected by a balancing section. The side of the balancing section facing the first pocket or the second pocket is a first arc surface that adapts to the ball bearing profile, while the side facing away from the first pocket or the second pocket is a flat surface.

5. The waveform harmonic reducer cage according to claim 4, characterized in that, The window beam facing the first pocket or the second pocket is a second arc surface that is adapted to the ball bearing, and the first arc surface and the second arc surface are smoothly transitioned.

6. The waveform harmonic reducer cage according to claim 4, characterized in that, The window beam and the balance section have the same wall thickness.

7. The waveform harmonic reducer cage according to claim 1, characterized in that, The wavelengths of the arc-shaped crests and troughs are the same.

8. The waveform harmonic reducer cage according to claim 1, characterized in that, The wavelengths of the crests and troughs of an arc are different.

9. The waveform harmonic reducer cage according to claim 7, characterized in that, The wavelength of the arc-shaped peak is twice that of the arc-shaped trough, and a dividing beam is provided at the center of the arc-shaped peak to divide it into two first pockets.

10. The waveform harmonic reducer cage according to claim 1, characterized in that, Multiple arc-shaped peaks have the same wave height, and multiple arc-shaped troughs have the same wave height. The wave heights of the arc-shaped peaks and the arc-shaped troughs are equal.

Images