Wave generator, speed reducer and robot

Abstract

The invention discloses a wave generator, a speed reducer and a robot, the wave generator comprises a cam, the cam is provided with a guide part, and the guide part comprises at least one groove and at least one guide surface; and the cam is at least partially located in the flexible transmission piece. According to the wave generator provided by the embodiment of the invention, the flexible transmission part can be guided through the guide part on the cam when being mounted, so that the flexible transmission part is easier to deform, and the mounting efficiency is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of speed reducers, and more particularly, to a wave generator, a speed reducer, and a robot. Background Art

[0002] A harmonic reducer is a high-precision, high-efficiency reduction gear that provides precise angular displacement control, ensuring the equipment's operational accuracy and stability. The wave generator plays a key role in harmonic transmission devices. The wave generator causes the flexspline to produce periodic elastic deformation waves according to a specific deformation pattern. This deformation enables the teeth of the flexspline to mesh with the rigid gear, thereby transmitting motion and power.

[0003] In the related art, the cam is elliptical, and the flexible transmission part is sleeved outside the cam. Before installation, the flexible transmission part is circular, and the inner diameter of the flexible transmission part is smaller than the length of the long axis of the cam. During installation, a pressing jig is first used to deform the circular flexible transmission part into an elliptical shape that matches the cam, and then another pressing jig is used to press the cam into the flexible transmission part. Therefore, two complexly designed jigs are required to complete the assembly of the wave generator. Summary of the Invention

[0004] The present invention provides a wave generator, a reducer and a robot, which can make the flexible transmission part more convenient to install and at least solve one of the shortcomings in the related art.

[0005] In a first aspect, an embodiment of the present application provides a wave generator, characterized in that the wave generator includes:

[0006] A cam, wherein the cam is provided with a guide portion, wherein the guide portion comprises at least one groove and at least one guide surface;

[0007] A flexible transmission member, wherein the cam is at least partially located within the flexible transmission member.

[0008] Optionally, the cam includes a supporting portion, and the flexible transmission member is located around the supporting portion.

[0009] Optionally, the support portion and the flexible transmission member are interference fit.

[0010] Optionally, the guide portion includes two grooves and two guide surfaces, the support portion has a longest outer diameter and a shortest outer diameter, the two guide surfaces are arranged at both ends of the longest outer diameter, and the two grooves are arranged at both ends of the shortest outer diameter.

[0011] Optionally, the cam includes a limiting portion, and the guide portion is located on a side of the cam away from the limiting portion.

[0012] Optionally, the guide surface has a first guide surface and a second guide surface, the cam has a rotation center line, and the first guide surface is arranged on a side of the second guide surface close to the rotation center line.

[0013] Optionally, at least one of the two ends of the first guide surface along the direction of the rotation center line has an arc-shaped edge.

[0014] Optionally, the shortest outer diameter of the first guide surface is smaller than the inner diameter of the flexible transmission member.

[0015] Optionally, the width of the second guide surface gradually decreases in a direction away from the rotation center line toward the rotation center line.

[0016] Optionally, the groove is provided with a third guide surface.

[0017] In a second aspect, an embodiment of the present application proposes a reducer, characterized in that it includes a flexspline, a rigid spline and the above-mentioned wave generator, wherein the flexspline is located between the rigid spline and the wave generator.

[0018] Optionally, the reducer further includes a fixing seat, and the fixing seat and the rigid wheel are connected via fasteners.

[0019] Optionally, the reducer further includes a flange, the flange is located outside the fixing seat, and the flange and the flexible wheel are connected by fasteners.

[0020] In a third aspect, an embodiment of the present application proposes a robot comprising the above-mentioned wave generator or the above-mentioned reducer.

[0021] In an embodiment of the present application, a wave generator includes a cam having a guide portion including at least one groove and at least one guide surface; and a flexible transmission member, wherein the cam is at least partially located within the flexible transmission member. During installation, the flexible transmission member needs to be deformed into a shape that matches the cam. The guide surface provides guidance for the installation and deformation of the flexible transmission member, and the groove provides space for deformation of the flexible transmission member. Therefore, the cam's guide portion can assist in the installation of the flexible transmission member, eliminating the need for an additional flexible bearing deformation jig. Flexible bearing installation can be completed using only a single upper and lower pressing jig, improving assembly efficiency and reducing costs.

[0022] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0024] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same drawing numbers represent the same parts in the following description.

[0025] Figure 1 This is one of the schematic diagrams of the cam in the embodiment of the present application;

[0026] Figure 2 This is the second schematic diagram of the cam in the embodiment of the present application;

[0027] Figure 3 This is a schematic diagram of the flexible transmission member in the first shape according to an embodiment of the present application;

[0028] Figure 4 is a schematic diagram of a wave generator according to an embodiment of the present application;

[0029] Figure 5 is a schematic diagram of a reducer according to an embodiment of the present application;

[0030] Figure 6 This is one of the cross-sectional views of the reducer according to an embodiment of the present application;

[0031] Figure 7 This is the second cross-sectional view of the reducer according to the embodiment of the present application;

[0033] Reference numerals:

[0034] Cam 100;

[0035] guide surface 110;

[0036] a first guide surface 111;

[0037] a second guide surface 112;

[0038] groove 120;

[0039] A third guide surface 121;

[0040] Support portion 130;

[0041] Limiting portion 140;

[0042] Flexible transmission member 200;

[0043] Flexspline 300;

[0044] Ganglun 400;

[0045] Fixed seat 500;

[0046] Flange 600;

[0047] Crossed roller bearing 700;

[0048] Sealing ring 800. DETAILED DESCRIPTION

[0049] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0050] In the description of the present invention, it should be understood that the terms "upper," "lower," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the mechanisms or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, features defined as "first" or "second" may explicitly or implicitly include one or more of such features.

[0051] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted" and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0052] A wave generator is a component that causes the flexible wheel 300 to generate periodic elastic deformation waves according to a certain deformation law. The wave generator is usually composed of a flexible transmission member 200 and a cam 100. The flexible transmission member 200 is generally a flexible bearing. Under the action of the cam 100, the flexible transmission member 200 will undergo elastic deformation, thereby driving the flexible wheel to generate corresponding deformation waves. In the related art, during installation, it is necessary to first use a pressing jig to press the circular flexible transmission member 200 into an ellipse, and then use another pressing jig to press the cam 100 into the flexible transmission member 200. This type of cam 100 means that the flexible transmission member 200 lacks deformation space and is not easy to deform. The assembly of the wave generator requires the use of two complex jigs.

[0053] To address the aforementioned issues with the aforementioned technologies, the present application provides a wave generator, a speed reducer, and a robot that utilize a guide surface 110 and a groove 120 to assist in the installation of a flexible transmission member 200. The guide surface 110 provides guidance for the installation and deformation of the flexible transmission member 200, while the groove 120 provides space for the deformation of the flexible transmission member 200. Therefore, no additional flexible bearing deformation jig is required; only a single upper and lower pressing jig is required to complete the flexible bearing installation, improving assembly efficiency, saving materials, and reducing costs.

[0054] like Figure 1-4 As shown, a wave generator according to an embodiment of the present invention includes: a cam 100, the cam 100 is provided with a guide portion, the guide portion includes at least one groove 120 and at least one guide surface 110; a flexible transmission member 200, and the cam 100 is at least partially located in the flexible transmission member 200.

[0055] The wave generator typically has a cam 100 with an elliptical or other outer contour. The wave generator includes a cam 100 connected to the input shaft. As the cam 100 rotates, it causes the transmission member 200 to undergo periodic elastic deformation. This deformation is then transmitted to the flexspline 300, causing the flexspline 300 to generate corresponding elastic deformation waves. This deformation wave propagates within the flexspline 300, causing relative motion between the flexspline 300 and the rigid wheel 400, thereby achieving transmission. The cam 100 typically has a major axis and a minor axis. The contour of the cam 100 determines the deformation pattern and transmission performance of the flexspline 300. By varying the shape of the cam 100, the degree and frequency of deformation of the flexspline 300 can be adjusted, thereby varying the transmission ratio and speed. The major axis diameter of the cam 100 is larger than the inner diameter of the flexible transmission member 200, while the minor axis diameter is smaller than the inner diameter of the flexible transmission member 200. This design enables the cam 100 to force the flexible transmission member 200 to produce elastic deformation when rotating, thereby achieving waveform changes of the flexible wheel 300.

[0056] The wave generator also includes a flexible transmission member 200, which can withstand multi-directional loads and deformation during movement, including axial, radial, and tilting loads. This reduces friction and wear between the flexible transmission member 200 and the cam 100, thereby improving the durability and reliability of the wave generator. The flexible transmission member 200 deforms under the pressure of the cam 100 and transmits this deformation to the flexible gear, which is closely connected to the wave generator. This deformation enables the flexible gear 300 to mesh with the internal teeth of the rigid gear 400, thus achieving transmission.

[0057] like Figure 3As shown, the flexible transmission member 200 is in a first shape when separated from the cam. During installation, the cam 100 is at least partially located within the flexible transmission member 200, and the flexible transmission member 200 deforms from the first shape to a second shape that matches the cam. The cam 100 is provided with a guide portion comprising a guide surface 110 and a groove 120. The guide surface 110 supports and guides the flexible transmission member 200. The design of the guide surface 110 ensures that the flexible transmission member 200 moves stably and accurately along a predetermined path, preventing deviation or shaking. This increases the contact area between the flexible transmission member 200 and the guide portion, thereby improving the overall stability of the system. Therefore, the flexible transmission member 200 can be installed with the aid of the guide portion. The guide surface 110 provides guidance for the installation and deformation of the flexible transmission member 200, while the groove 120 reserves space for deformation of the flexible transmission member 200, avoiding excessive assembly stress. During assembly, no additional deformation jig for the flexible transmission member 200 is required; only a single upper and lower pressing jig is required to complete the installation of the flexible transmission member 200, improving assembly efficiency and reducing costs.

[0058] It is understandable that the guide surface 110 may be a curved surface or a flat surface, and the guide surface 110 and the groove 120 may be one or more, which is not limited in this embodiment.

[0059] Therefore, in the wave generator of the embodiment of the present application, the flexible transmission part 200 can be guided by the guide part on the cam 100 during installation, and the guiding function is realized by cooperating with the guide surface 110 and the groove 120 to increase the assembly gap and guide the assembly, thereby simplifying the assembly process and improving assembly efficiency and accuracy.

[0060] In some embodiments, the cam 100 includes a support portion 130 , and the flexible transmission member 200 is located around the support portion 130 .

[0061] The cam 100 includes a support portion 130, and a flexible transmission member 200 is positioned around the support portion 130. Under the support of the support portion 130, the flexible transmission member 200 deforms from a first shape to a second shape that matches the support portion 130. It will be appreciated that a guide portion is positioned on the support portion 130 to allow the flexible transmission member 200 to be quickly fitted around the support portion 130 during installation.

[0062] In some embodiments, the support portion 130 and the flexible transmission member 200 are interference fit.

[0063] The support part 130 and the flexible transmission part 200 are interference fit, so the support part 130 and the flexible transmission part 200 are tightly connected. The interference fit reduces the gap and deformation between the two during the transmission process. A large clamping force is generated between the support part 130 and the flexible transmission part 200, and the energy loss during the transmission process is also reduced. It can effectively transmit torque and load, thereby improving the transmission efficiency.

[0064] In some embodiments, the guide portion includes two grooves 120 and two guide surfaces 110 , the support portion 130 has a longest outer diameter and a shortest outer diameter, the two guide surfaces 110 are located at both ends of the longest outer diameter, and the two grooves 120 are located at both ends of the shortest outer diameter.

[0065] The cam 100 is generally elliptical, that is, the support part 130 has the longest outer diameter and the shortest outer diameter. The guide surface 110 is located at both ends of the longest outer diameter of the support part 130, and the groove 120 is located at both ends of the shortest outer diameter. Therefore, the guide part provides guidance for the position with the largest deformation, which is convenient for installation at the position with the largest deformation. At the same time, the groove 120 is set at the position with the smallest deformation, which can reserve space for the position with larger deformation. Through the reasonable setting of the guide part, the entire installation process is made more convenient.

[0066] In some embodiments, the cam includes a limiting portion 140 , and the guide portion is located on a side of the cam 100 away from the limiting portion 140 .

[0067] The cam includes a stopper 140, and the guide portion is located on the side of the cam 100 facing away from the stopper 140. The stopper 140 limits the axial displacement of the flexible transmission member 200 toward the stopper 140, preventing the flexible transmission member 200 from being fitted onto the support portion during press-fitting and thus from being detached from the support portion 130. The guide portion is located on the side of the support portion 130 facing away from the stopper 140, meaning that the installation direction of the flexible transmission member 200 is from the guide portion to the stopper 140.

[0068] In some embodiments, the guide surface 110 has a first guide surface 111 and a second guide surface 112 , the cam 100 has a rotation center line, and the first guide surface is provided on a side of the second guide surface close to the rotation center line.

[0069] The cam 100 is connected to the input shaft, so the cam has a rotation center line. The guide surface 110 has a first guide surface 111 and a second guide surface 112. The first guide surface 111 is located on the side of the second guide surface 112 away from the limiting portion 140. The two guide surfaces 110 can be set to different shapes respectively, so that the flexible transmission part 200 can move along a predetermined trajectory when installed in different positions. The guide surfaces 110 matching them are set at different positions to further increase the stability and accuracy during assembly and improve the overall performance and reliability.

[0070] The guide portion is located on the installation side of the support portion 130 to facilitate guiding the flexible transmission member 200 during installation. Therefore, during installation, the guide portion is first used for guidance, the support portion 130 is used for support, and finally the position limiting portion 140 is used for positioning.

[0071] In some embodiments, at least one of the two ends of the first guide surface 111 along the direction of the rotation center line has an arc-shaped edge.

[0072] The edge of at least one end of the first guide surface 111 along the direction of the rotation center line is arc-shaped. Therefore, when the flexible transmission member 200 is assembled along the first guide surface 111, the deformation of each part of the flexible transmission member 200 is uniform, which facilitates the installation of the support part 130 in the flexible transmission member 200.

[0073] In some embodiments, the shortest outer diameter of the first guide surface 111 is smaller than the inner diameter of the flexible transmission member 200 in the first shape.

[0074] The shortest outer diameter of the first guide surface 111 is smaller than the inner diameter of the flexible transmission member 200 in the first shape, so that the cam 100 can quickly correspond to the flexible transmission member 200 at the beginning of installation, ensuring that the flexible transmission member 200 can be correctly and smoothly installed during assembly.

[0075] In some embodiments, the width of the second guide surface 112 gradually decreases from away from the rotation centerline to closer to the rotation centerline.

[0076] The width of the second guide surface 112 gradually decreases from the rotation centerline to the rotation centerline. Therefore, a longer guide distance is provided at the place where the support part 130 is far from the centerline, so that the place with large deformation can also be easily assembled.

[0077] In some embodiments, the groove 120 is provided with a third guide surface 121 .

[0078] The groove 120 is provided with a third guide surface 121 to prevent the groove 120 from blocking the groove 120 when assembled to the bottom of the groove 120. The third guide surface 121 further guides the installation, making the assembly process simpler and faster.

[0079] The present application also provides a speed reducer, comprising a flexspline 300, a rigid spline 400, and the aforementioned wave generator, wherein the flexspline 300 is located between the rigid spline 400 and the wave generator. The speed reducer has all the beneficial effects of the aforementioned wave generator, which will not be further elaborated in this disclosure.

[0080] As shown in 5-7, the reducer also includes a flexspline 300, a rigid wheel 400 and the above-mentioned wave generator. The flexspline 300 is located between the rigid wheel 400 and the wave generator. The flexspline 300 produces elastic deformation according to the shape of the wave generator, so that the flexspline 300 produces a long axis and a short axis. The outer teeth on both sides of the long axis of the flexspline 300 are fully engaged with the inner teeth of the rigid wheel 400, and the teeth in the short axis direction are completely disengaged from the inner teeth of the rigid wheel 400. The deceleration is achieved by the tooth difference movement between the flexspline 300 and the rigid wheel 400.

[0081] In some embodiments, the reducer further includes a fixing seat 500 , and the fixing seat 500 and the rigid wheel 400 are connected via fasteners.

[0082] In some embodiments, the reducer further includes a flange 600 . The flange 600 is located outside the fixing seat 500 . The flange 600 and the flexible spline 300 are connected by fasteners.

[0083] In some embodiments, a flange 600 is mounted on the outside of the fixed seat 500 of the rigid wheel 400, with rollers inserted between the two to form a cross-roller bearing 700. The structural features of the cross-roller bearing 700 enable it to simultaneously withstand radial, axial, and momentary loads. During the deceleration process of the reducer, forces may be generated from different directions simultaneously. The multi-directional load-bearing capacity of the cross-roller bearing 700 effectively shares these loads, ensuring stable operation of the reducer. The cross-roller bearing 700, through its high-precision transmission characteristics, ensures the output accuracy of the reducer and improves the service life and reliability of the harmonic reducer. A sealing ring 800 seals the underside of the flange 600 with the upper surface of the bottom of the flexspline 300 to prevent grease leakage from the meshing area between the flexspline 300 and the rigid wheel 400 and the rollers of the cross-roller bearing 700. The main function of grease is to form a lubricating film between the gears and bearings within the harmonic reducer, thereby reducing direct contact and friction between them. This lubrication effectively prevents wear caused by friction and extends the service life of the reducer.

[0084] The present application also provides a robot, comprising the above-mentioned wave generator or the above-mentioned reducer. The robot has all the beneficial effects of the above-mentioned wave generator, which will not be described in detail in this disclosure.

[0085] In the description of this specification, reference to the terms "one embodiment", "some embodiments" or "example" means that a specific feature, structure or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention.

[0086] In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and purpose of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A wave generator, characterized in that: The wave generator comprises: A cam, wherein the cam is provided with a guide portion, wherein the guide portion comprises at least one groove and at least one guide surface; A flexible transmission member, wherein the cam is at least partially located within the flexible transmission member.

2. The wave generator according to claim 1, characterized in that The cam comprises a supporting portion, and the flexible transmission member is located at a peripheral side of the supporting portion.

3. The wave generator according to claim 2, characterized in that The support portion is interference fit with the flexible transmission member.

4. The wave generator according to claim 2, characterized in that The guide portion includes two grooves and two guide surfaces, the support portion has a longest outer diameter and a shortest outer diameter, the two guide surfaces are arranged at two ends of the longest outer diameter, and the two grooves are arranged at two ends of the shortest outer diameter.

5. The wave generator according to claim 1, characterized in that The cam comprises a limiting portion, and the guiding portion is located at a side of the cam away from the limiting portion.

6. The wave generator according to claim 1, characterized in that The guide surface comprises a first guide surface and a second guide surface, the cam comprises a rotation center line, and the first guide surface is arranged on a side of the second guide surface close to the rotation center line.

7. The wave generator according to claim 6, characterized in that At least one of the two ends of the first guide surface along the direction of the rotation center line has an arc-shaped edge.

8. The wave generator according to claim 6, characterized in that The shortest outer diameter of the first guide surface is smaller than the inner diameter of the flexible transmission member.

9. The wave generator according to claim 6, characterized in that The width of the second guide surface gradually decreases in a direction away from the rotation center line toward approaching the rotation center line.

10. The wave generator according to claim 1, characterized in that The groove is provided with a third guide surface.

11. A reducer, characterized in that: It comprises a flexible spline, a rigid spline and the wave generator according to any one of claims 1 to 10, wherein the flexible spline is located between the rigid spline and the wave generator.

12. The reducer according to claim 11, characterized in that: The reducer also includes a fixing seat, and the fixing seat and the rigid wheel are connected via a fastener.

13. The reducer according to claim 12, characterized in that: The reducer further comprises a flange, which is located outside the fixing seat, and the flange and the flexible wheel are connected via fasteners.

14. A robot, characterized in that: It comprises the wave generator as described in any one of claims 1 to 10 or the reducer as described in any one of claims 11 to 13.

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