Harmonic reducer and robot

Abstract

The application provides a harmonic reducer and a robot, and relates to the field of harmonic transmission.The harmonic reducer comprises a cross bearing, a rigid gear, a flexible gear, a cross slider and a wave generator.The cross bearing comprises a bearing inner ring and a bearing outer ring, and the end face of the bearing inner ring is provided with a first groove.The flexible gear is a cup-shaped flexible gear, and the cup bottom is provided with a second groove.The cross slider comprises a connecting disc, a first protrusion and a second protrusion.The first protrusion is located on the first end face of the connecting disc, the second protrusion is located on the second end face of the connecting disc, the length direction of the first protrusion and the length direction of the second protrusion have an included angle, the first protrusion is engaged with the first groove, and the second protrusion is engaged with the second groove.The cross sections of the first protrusion and the second protrusion are both trapezoidal, and the side connected with the connecting disc is the upper base of the trapezoid.The first groove is shape-fitted with the first protrusion, and the second groove is shape-fitted with the second protrusion.The problem that the flexible gear and the bearing inner ring are connected through a screw, resulting in complicated installation and difficult concentricity adjustment, is solved.

Description

Technical Field

[0001] This application relates to the field of harmonic drive technology, specifically to a harmonic reducer and a robot. Background Technology

[0002] Harmonic reducers are typically assembled from components such as a rigid wheel, a flexible wheel, a wave generator, and crossed bearings. They are high-precision, high-torque transmission devices widely used in robotics, industrial automation, and precision equipment. Among them, cup-shaped harmonic reducers, with their cup-shaped flexible wheels, are particularly popular due to their compact structure.

[0003] In related technologies, cup-type harmonic reducers typically use screw fastening to connect the flexure and the inner ring of the cross bearing. During assembly, the holes must be precisely aligned, and the screws must be tightened one by one. Torque must be controlled using a torque wrench. This not only makes the installation process cumbersome but also easily leads to flexure eccentricity due to uneven screw tightening torque. Furthermore, screw fastening cannot compensate for radial deviations generated during assembly, requiring additional concentricity measurement and adjustment. This makes precision control difficult and affects assembly efficiency and transmission stability.

[0004] Therefore, how to solve the problem of complicated installation and difficulty in concentricity adjustment caused by the connection between the flexure and the inner ring of the cross bearing through screws in the cup-type harmonic reducer? Summary of the Invention

[0005] In view of this, this application provides a harmonic reducer and a robot to solve the problems of complicated installation and difficulty in concentricity adjustment caused by the connection of the flexible wheel and the inner ring of the cross bearing through screws in the cup-shaped harmonic reducer of the prior art.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] A harmonic reducer, comprising:

[0008] A cross bearing includes an inner ring and an outer ring, wherein the end face of the inner ring is provided with a first groove extending radially, and the first groove is provided with a pair of radially opposite grooves.

[0009] The rigid wheel is fastened to the outer ring of the bearing;

[0010] A flexible wheel is fitted inside the rigid wheel, and the outer teeth of the flexible wheel mesh with the inner teeth of the rigid wheel. The flexible wheel is a cup-shaped flexible wheel and the bottom of the cup is provided with a second groove extending radially, and the second groove is provided with a pair of radially opposite grooves.

[0011] A cross slider includes a connecting plate, a first protrusion, and a second protrusion. The first protrusion is located on a first end face of the connecting plate and extends radially with a pair of radially opposite protrusions. The second protrusion is located on a second end face of the connecting plate and extends radially with a pair of radially opposite protrusions. There is an angle between the length direction of the first protrusion and the length direction of the second protrusion. The first protrusion engages with a first groove, and the second protrusion engages with a second groove, so that the flexible wheel and the bearing inner ring are assembled and connected through the cross slider.

[0012] Wave generator, fitted inside the flexspline;

[0013] The first protrusion and the second protrusion have trapezoidal cross-sections, and the side connected to the connecting plate has a trapezoidal upper base. The first groove is adapted to the shape of the first protrusion, and the second groove is adapted to the shape of the second protrusion.

[0014] Optionally, the mating clearance between the first protrusion and the first groove, and the mating clearance between the second protrusion and the second groove are both δ, 0.015mm≤δ≤0.035mm.

[0015] Optionally, both the first protrusion and the second protrusion have isosceles trapezoidal cross sections with a base angle of α, wherein:

[0016] 76°≤α≤80°; and / or,

[0017] The cross-sections of the first groove and the second groove are both isosceles trapezoids with a base angle of α´, and the fit tolerance between α´ and α is ±0.5°.

[0018] Optionally, the height of the first protrusion and the second protrusion relative to the connecting disk is both H, where 1.3mm≤H≤2mm.

[0019] Optionally, the diameter of the connecting disk is D, and the span of a pair of first protrusions in the radial direction of the connecting disk and the span of a pair of second protrusions in the radial direction of the connecting disk are both L, with 0.68×D≤L≤0.72×D.

[0020] Optionally, the height of the first protrusion and the second protrusion relative to the connecting disk is both H;

[0021] The cross-sections of the first protrusion and the second protrusion are both isosceles trapezoids. The width of the upper base of the cross-sections of the first protrusion and the second protrusion is b1, and the width of the lower base of the cross-sections of the first protrusion and the second protrusion is b2. 0.8×H≤b1≤0.9×H, 0.8mm≤b2-b1≤1.2mm;

[0022] The depth of both the first groove and the second groove in the axial direction of the harmonic reducer is h, where 0.03mm≤hH≤0.05mm;

[0023] The bottom width of the first groove and the second groove is b3, b3=b2+2×δ, 0.015mm≤δ≤0.035mm.

[0024] Optionally, the radially outer ends of both the first and second protrusions have rounded corners with a radius of r, where 0.2 mm ≤ r ≤ 0.4 mm.

[0025] Optionally, the average surface roughness of the first bump and the second bump is less than or equal to 0.4 μm; and / or,

[0026] The average surface roughness of the first groove and the second groove is less than or equal to 0.4 μm.

[0027] Optionally, the bottom of the flexible wheel has a connecting boss, the second groove is formed on the connecting boss, and the diameter of the connecting disc is adapted to the diameter of the connecting boss and the diameter tolerance is H7;

[0028] The end face runout tolerance of the connecting plate is less than or equal to 0.003 mm.

[0029] Optionally, the tops of the first bump and the second bump are configured to be elastic; or,

[0030] The bottom of the first groove and the bottom of the second groove are configured to be elastic.

[0031] A robot comprising any of the harmonic reducers described above.

[0032] The harmonic reducer provided in this application includes a cross bearing, a rigid wheel, a flexible wheel, a cross slider, and a wave generator. The cross bearing includes an inner bearing ring and an outer bearing ring. The end face of the inner bearing ring has a first groove extending radially, and the first groove has a pair of radially opposite grooves. The rigid wheel is fastened to the outer bearing ring. The flexible wheel is fitted inside the rigid wheel, and the external teeth of the flexible wheel mesh with the internal teeth of the rigid wheel. The flexible wheel is a cup-shaped flexible wheel, and the bottom of the cup has a second groove extending radially, and the second groove has a pair of radially opposite grooves. The cross slider includes a connecting plate, a first protrusion, and a second protrusion. The first protrusion is located on the first end face of the connecting plate. A first protrusion extends radially and has a pair of radially opposite protrusions. A second protrusion is located on the second end face of the connecting plate. The second protrusion extends radially and has a pair of radially opposite protrusions. There is an angle between the length direction of the first protrusion and the length direction of the second protrusion. The first protrusion engages with the first groove, and the second protrusion engages with the second groove, so that the flexible wheel and the inner ring of the bearing are connected by a cross slider assembly. The wave generator is fitted inside the flexible wheel. The cross-section of the first protrusion and the second protrusion are both trapezoidal, and the side connected to the connecting plate is the upper base of the trapezoid. The first groove is adapted to the shape of the first protrusion, and the second groove is adapted to the shape of the second protrusion. With this configuration, the flex wheel is a cup-shaped flex wheel, meaning the harmonic reducer provided in this application is a cup-shaped harmonic reducer. This application no longer uses the traditional method of fastening the flex wheel and the bearing inner ring with screws; instead, it uses a cross-slider to form a plug-in connection. During assembly, the first protrusion of the cross-slider slides into the first groove of the bearing inner ring from the side (i.e., radially), and then the flex wheel is connected to the cross-slider. That is, the second groove at the bottom of the flex wheel cup slides onto the second protrusion. All protrusions and corresponding grooves are trapezoidal in shape, making operation simple and installation convenient, improving assembly efficiency, and avoiding the uneven torque caused by screw fastening. The cross-slider provided in this application has a dual-function design: because the first... The cross-sections of the protrusion and the first groove are both trapezoidal with a narrower root and are compatible. The cross-sections of the second protrusion and the second groove are also trapezoidal with a narrower root and are compatible. This prevents the cross slider from moving axially without additional fasteners. It not only prevents the flexure and the cross bearing from separating axially, making it suitable for high-speed operation scenarios of harmonic reducers, but also, since all the protrusions and corresponding grooves have trapezoidal inclined surfaces, the position of the flexure can be automatically fine-tuned during assembly through the guide of the trapezoidal inclined surfaces. This achieves automatic centering and concentricity adjustment to meet the concentricity requirements of the harmonic reducer transmission. This solves the problem in the existing cup-type harmonic reducers where the flexure and the inner ring of the cross bearing are connected by screws, resulting in cumbersome installation and difficulty in concentricity adjustment. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0034] Figure 1 This is a schematic diagram illustrating the assembly process of the cross bearing and cross slider provided in an embodiment of this application.

[0035] Figure 2 This is a cross-sectional view of a harmonic reducer provided in an embodiment of this application.

[0036] Figure 3 The front view of the cross slider provided in the embodiment of this application.

[0037] Figure 4 A side view of the cross slider provided in an embodiment of this application.

[0038] Figure 5 A cross-sectional view of a flexible wheel provided in an embodiment of this application.

[0039] Figure 6 A front view of the flexible wheel provided in an embodiment of this application.

[0040] exist Figures 1-6 middle:

[0041] 1. Inner ring of bearing; 2. Outer ring of bearing; 3. Rigid wheel; 4. Flexible wheel; 5. Cross slide block; 6. Flexible bearing; 7. Cam; 8. First screw;

[0042] 51. First protrusion; 52. Second protrusion; 53. Connecting disc;

[0043] 101. First groove;

[0044] 41. Connecting boss;

[0045] 401. Second groove. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] In the structural design of harmonic reducers, the cross-slider coupling is widely used due to its simple structure and ability to compensate for radial displacement. The cross-slider coupling achieves torque transmission and deviation compensation through the sliding of the middle slider within a groove. However, the applicant has found that the middle slider of conventional cross-slider couplings has a rectangular cross-section, which is prone to axial detachment and lacks dimensional optimization for the assembly requirements of harmonic reducers. For cup-type harmonic reducers, it cannot directly adapt to the connection scenario between the flexure and the inner ring of the cross bearing. Therefore, there is an urgent need to design a connection structure that adapts to cup-type harmonic reducers and combines anti-detachment and concentricity adjustment functions to solve the problems of cumbersome installation and difficult concentricity adjustment caused by screw connections between the flexure and the inner ring of the cross bearing.

[0048] Based on the above research approach, such as Figures 1-6 As shown, this application embodiment provides a harmonic reducer, including a cross bearing, a rigid wheel 3, a flexible wheel 4, a cross slider 5, and a wave generator; the cross bearing includes an inner bearing ring 1 and an outer bearing ring 2, the end face of the inner bearing ring 1 is provided with a first groove 101 extending radially, and the first groove 101 is provided with a pair of radially opposite grooves; the rigid wheel 3 is fastened to the outer bearing ring 2 by a first screw 8; the flexible wheel 4 is fitted inside the rigid wheel 3, and the external teeth of the flexible wheel 4 mesh with the internal teeth of the rigid wheel 3, the flexible wheel 4 is a cup-shaped flexible wheel and the bottom of the cup is provided with a second groove 401 extending radially, and the second groove 401 is provided with a pair of radially opposite grooves; the cross slider 5 includes a connecting plate 53, a first protrusion 51, and a second protrusion 52, the first protrusion 51 is located on the first end face of the connecting plate 53, the first protrusion 51 extends radially and is provided with a pair of radially opposite grooves, the second protrusion 52 ... The second end face of the receiving plate 53 has a second protrusion 52 extending radially and having a pair of radially opposite protrusions. The length direction of the first protrusion 51 and the length direction of the second protrusion 52 form an angle. The first protrusion 51 engages with the first groove 101, and the second protrusion 52 engages with the second groove 401, so that the flexible wheel 4 and the inner ring of the bearing 1 are connected by a cross slider 5 to achieve torque transmission. The wave generator is fitted inside the flexible wheel 4. The wave generator includes a flexible bearing 6 and a cam 7 fitted inside the flexible bearing 6. The cross-sections of the first protrusion 51 and the second protrusion 52 are both trapezoidal. The side of the first protrusion 51 / second protrusion 52 connected to the connecting plate 53 is the upper base of the trapezoid, and the other side is the lower base of the trapezoid. The size of the lower base of the trapezoid is larger than that of the upper base of the trapezoid. The shape of the first groove 101 is adapted to the shape of the first protrusion 51, and the shape of the second groove 401 is adapted to the shape of the second protrusion 52. That is, the cross-sections of the first protrusion 51 and the second protrusion 52 are configured to have a limiting characteristic in the axial direction of the connecting disk 53, so that they cannot be separated from the first groove 101 and the second groove 401 in the axial direction.

[0049] With this configuration, the flexible wheel 4 is a cup-shaped flexible wheel, meaning the harmonic reducer provided in this application is a cup-shaped harmonic reducer. This application no longer uses the traditional method of fastening the flexible wheel 4 and the bearing inner ring 1 with screws; instead, it uses a cross slider 5 to form a plug-in connection. During assembly, the first protrusion 51 of the cross slider 5 is slid into the first groove 101 of the bearing inner ring 1 from the side (i.e., radially), and then the flexible wheel 4 is connected to the cross slider 5. That is, the second groove 401 at the bottom of the flexible wheel 4 slides onto the second protrusion 52. All protrusions and corresponding grooves are trapezoidal in shape, making operation simple and installation convenient, improving assembly efficiency, and avoiding the uneven torque caused by screw fastening. The cross slider 5 provided in this application has a dual-function design: [The text abruptly ends here, so the translation stops here as well.] Since the cross sections of the first protrusion 51 and the first groove 101 are both trapezoidal with a narrower root and are compatible, and the cross sections of the second protrusion 52 and the second groove 401 are also trapezoidal with a narrower root and are compatible, the cross slider 5 can be prevented from moving axially without additional fasteners. This not only prevents the flexure 4 and the cross bearing from separating axially, adapting to the high-speed operation scenario of the harmonic reducer, but also, since all the protrusions and corresponding grooves have trapezoidal inclined surfaces, the position of the flexure 4 can be automatically fine-tuned during assembly through the trapezoidal inclined surfaces, achieving automatic centering and concentricity adjustment to meet the concentricity requirements of the harmonic reducer transmission. This solves the problem in the existing cup-shaped harmonic reducer where the flexure 4 and the inner ring 1 of the cross bearing are connected by screws, resulting in cumbersome installation and difficulty in concentricity adjustment.

[0050] It should be noted that the specific connection method between the inner ring 1 and the outer ring 2 of the cross bearing is existing technology and will not be described in detail here.

[0051] In terms of some adaptive design aspects, in order to adapt to the assembly environment of the harmonic reducer, the connecting plate 53 is undoubtedly annular and allows the shaft to pass through. The first groove 101 is connected to the shaft hole of the inner ring 1 of the bearing, and the second groove 401 is connected to the shaft hole of the flexible wheel 4.

[0052] Preferably, the connecting disc 53, the first protrusion 51, and the second protrusion 52 are integrally formed. In addition, it is preferred that the angle between the length direction of the first protrusion 51 and the length direction of the second protrusion 52 is a right angle, that is, in a cross shape.

[0053] In some preferred embodiments, the mating clearance between the first protrusion 51 and the first groove 101, and the mating clearance between the second protrusion 52 and the second groove 401 are both δ, 0.015mm≤δ≤0.035mm.

[0054] This configuration, after testing and verification, ensures that the minimal clearance δ compensates for assembly deviations while preventing radial movement caused by excessive clearance. In addition, it helps ensure the compatibility of the cross slider 5 with the bearing inner ring 1 and the flexible wheel 4, and also facilitates the low-vibration and high-precision operation of the harmonic reducer.

[0055] In some preferred embodiments, the cross-sections of the first protrusion 51 and the second protrusion 52 are both isosceles trapezoids with a base angle of α, where 76°≤α≤80°. This configuration, after testing and verification, helps ensure the assembly compatibility between the cross slider 5 and the inner ring 1 of the bearing and the flexible wheel 4. Simultaneously, it facilitates low-vibration and high-precision operation of the harmonic reducer. For example, α is taken as 78°.

[0056] In some preferred embodiments, the cross-sections of the first protrusion 51 and the second protrusion 52 are both isosceles trapezoids with a base angle α, and the cross-sections of the first groove 101 and the second groove 401 are both isosceles trapezoids with a base angle α´. α´ and α match, and the fit tolerance between α´ and α is ±0.5°. This configuration, after testing and verification, helps ensure the assembly compatibility between the cross slider 5 and the inner ring 1 of the bearing and the flexible wheel 4. Simultaneously, it facilitates the low-vibration, high-precision operation of the harmonic reducer. In particular, when combined with the aforementioned embodiments, the harmonic reducer exhibits even better low-vibration, high-precision operation performance.

[0057] In some preferred embodiments, the height of the first protrusion 51 and the second protrusion 52 relative to the connecting disc 53 is both H, where 1.3mm ≤ H ≤ 2mm. The height of the protrusion is also its axial dimension. This arrangement provides dimensional constraints on the first protrusion 51 and the second protrusion 52, and after testing and verification, it is beneficial for the low-vibration and high-precision operation of the harmonic reducer. In particular, when combined with the aforementioned embodiments, the harmonic reducer exhibits even better low-vibration and high-precision operation performance.

[0058] In some preferred embodiments, the diameter of the connecting disk 53 is D, and the radial span of the pair of first protrusions 51 and the radial span of the pair of second protrusions 52 on the connecting disk 53 are both L, where 0.68 × D ≤ L ≤ 0.72 × D. This arrangement provides dimensional constraints on the first protrusions 51 and the second protrusions 52, and through testing and verification, it is beneficial for the low-vibration, high-precision operation of the harmonic reducer. In particular, when combined with the aforementioned embodiments, the harmonic reducer exhibits even better low-vibration, high-precision operation performance. For example, L is taken as 0.70 × D.

[0059] In some preferred embodiments, the height of the first protrusion 51 and the second protrusion 52 protruding relative to the connecting plate 53 is both H; the cross-sections of the first protrusion 51 and the second protrusion 52 are both isosceles trapezoids, the upper base width of the cross-sections of the first protrusion 51 and the second protrusion 52 is b1, the lower base width of the cross-sections of the first protrusion 51 and the second protrusion 52 is b2, 0.8×H≤b1≤0.9×H, 0.8mm≤b2-b1≤1.2mm; the depth of the first groove 101 and the second groove 401 in the axial direction of the harmonic reducer is both h, 0.03mm≤hH≤0.05mm; the bottom width of the first groove 101 and the second groove 401 is b3, b3=b2+2×δ, 0.015mm≤δ≤0.035mm, that is, the bottom width of the first groove 101 is designed to satisfy the existence of a fitting clearance δ with the first protrusion 51, and the bottom width of the second groove 401 is designed to satisfy the existence of a fitting clearance δ with the second protrusion 52. This configuration provides dimensional constraints on the first protrusion 51 and the second protrusion 52, as well as axial dimensional fit constraints between the first protrusion 51 and the second protrusion 52 and the corresponding first groove 101 and second groove 401. Through testing and verification, this configuration is beneficial for the low-vibration, high-precision operation of the harmonic reducer. In particular, when combined with the aforementioned embodiments, the harmonic reducer exhibits even better low-vibration, high-precision operation performance.

[0060] In some preferred embodiments, the radially outer ends of the first protrusion 51 and the second protrusion 52 both have rounded corners with a radius of r, where 0.2 mm ≤ r ≤ 0.4 mm.

[0061] In some preferred embodiments, the average surface roughness of the first bump 51 and the second bump 52 is less than or equal to 0.4 μm.

[0062] In some preferred embodiments, the average surface roughness of the first groove 101 and the second groove 401 is less than or equal to 0.4 μm.

[0063] This configuration provides surface precision constraints for the first protrusion 51 and the second protrusion 52, as well as the first groove 101 and the second groove 401. Through testing and verification, this design is beneficial for the low-vibration, high-precision operation of the harmonic reducer. In particular, when combined with the aforementioned embodiments, the harmonic reducer exhibits even better low-vibration, high-precision operation performance.

[0064] In some preferred embodiments, the bottom of the flexible wheel 4 has a connecting boss 41, a second groove 401 is formed on the connecting boss 41, the diameter of the connecting plate 53 is adapted to the diameter of the connecting boss 41 and the diameter tolerance is H7; the end face runout tolerance of the connecting plate 53 is less than or equal to 0.003mm.

[0065] In some optional embodiments, the tops of the first protrusion 51 and the second protrusion 52 are configured to be elastic. Alternatively, the tops of the first protrusion 51 and the second protrusion 52 may be described as having elastic structures. The tops of the first protrusion 51 and the second protrusion 52 are located on the side of the first protrusion 51 and the second protrusion 52 away from the connecting disc 53, which is the side where the lower base of the trapezoidal cross-section of the first protrusion 51 and the second protrusion 52 is located. With this configuration, during installation, the trapezoidal inclined surface cooperation between the first protrusion 51 and the first groove 101, and between the second protrusion 52 and the second groove 401, along with the interaction of the elastic structures of the tops of the first protrusion 51 and the second protrusion 52, makes it easier for the cross slider 5 to be fine-tuned during installation, automatically adjusting the concentricity of the flexible wheel 4 and the inner ring 1 of the bearing without the need for additional adjustment tools.

[0066] Furthermore, regarding how the top of the first protrusion 51 and the top of the second protrusion 52 are constructed to be elastic, for example, at least the top of the first protrusion 51 and the top of the second protrusion 52 are provided with a plating layer, specifically a nickel layer or an additional layer with elastic buffering properties such as a molybdenum disulfide layer. Such a plating layer also has the effect of reducing noise and vibration, as well as high wear resistance and high hardness. Moreover, the first protrusion 51 and the second protrusion 52 are protruding structures, and this design has the advantage of facilitating the control of materials and plating treatment.

[0067] In some optional embodiments, the bottom of the first groove 101 and the bottom of the second groove 401 are constructed to be elastic. Alternatively, the bottom of the first groove 101 and the bottom of the second groove 401 can be described as having an elastic structure. With this configuration, during installation, the first protrusion 51 and the first groove 101, and the second protrusion 52 and the second groove 401, interact through the trapezoidal inclined surface fit characteristics, as well as the elastic structure of the bottom of the first groove 101 and the bottom of the second groove 401. This facilitates fine-tuning of the cross slider 5 during installation, automatically adjusting the concentricity of the flexible wheel 4 and the inner ring 1 of the bearing, without the need for additional adjustment tools.

[0068] Furthermore, regarding how the bottom of the first groove 101 and the bottom of the second groove 401 are constructed to be elastic, for example, based on the bearing inner ring 1 body, the bottom of the first groove 101 has a plated molybdenum disulfide layer, which can exhibit recoverable elasticity; the bottom of the flexible wheel 4 can be designed to be injection molded from high-performance engineering plastics such as PEEK (Polyetheretherketone), PPS (Polyphenylene sulfide), and PPA (Polyphthalamide), and due to the material characteristics, the bottom of the second groove 401 can have a certain degree of elasticity.

[0069] In summary, this application focuses on the concentricity of the flexible wheel 4 and the inner ring 1 of the cross bearing. It constrains the dimensions of the first protrusion 51 and second protrusion 52 of the cross slider 5 with the first groove 101 of the inner ring 1 and the second groove 401 of the flexible wheel 4 through three principles: "reducing clearance, precise dimensional correlation, and strict control of geometric tolerances." Specifically, this manifests in two ways: firstly, by compensating for assembly deviations through extremely small mating clearance δ, while avoiding radial movement caused by excessive clearance; secondly, by ensuring balanced torque transmission and reducing vibration caused by stress concentration through dimensional correlation between the first protrusion 51, the second protrusion 52, and the connecting disc 53; and thirdly, by combining high-precision surfaces and geometric tolerances, reducing frictional noise.

[0070] The harmonic reducer obtained from the aforementioned embodiments has at least the following advantages: First, it is easy to install because the screw fastening connection is eliminated; during assembly, only the corresponding protrusions and grooves need to slide and engage, simplifying the operation and improving assembly efficiency. Second, it can automatically adjust concentricity; through the trapezoidal cross-section design of the protrusions and grooves, automatic concentric adjustment between the flexure 4 and the inner ring 1 of the bearing is achieved, improving the transmission accuracy of the harmonic reducer. Third, it can prevent the cross slider 5 from axially disengaging from the flexure 4 and the cross bearing due to the design of the root side of the protrusion being narrower than the other side. Fourth... Noise and vibration are reduced. Through the precise fit between the protrusion of the cross slider 5 and the groove of the bottom of the flexible wheel 4 cup and the groove of the inner ring 1 of the bearing, as well as the automatic centering function brought by the trapezoidal cross section design, the vibration caused by assembly deviation and operation eccentricity is greatly reduced, thus reducing noise at the source and achieving low-vibration and quiet operation of the harmonic reducer. Fifth, service life is extended. Through reasonable size design and material selection, the wear resistance and fatigue resistance between the protrusion of the cross slider 5 and the groove of the bottom of the flexible wheel 4 cup and the groove of the inner ring 1 of the bearing are improved, thus extending the service life of the harmonic reducer.

[0071] Based on the aforementioned harmonic reducer, this application also provides a robot that includes the aforementioned harmonic reducer. Since the robot has the aforementioned harmonic reducer, the beneficial effects of the harmonic reducer on the robot are described above and will not be repeated here.

[0072] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0073] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0074] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0075] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0076] It should be understood that the qualifying terms “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0077] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A harmonic reducer characterized by, The cross bearing comprises a bearing inner ring (1) and a bearing outer ring (2), an end surface of the bearing inner ring (1) is provided with a first groove (101) extending in the radial direction, and the first groove (101) is provided with a pair of radially opposite grooves; A rigid wheel (3) is tightly connected with the bearing outer ring (2); A flexible wheel (4) is sleeved in the rigid wheel (3), and the outer teeth of the flexible wheel (4) are engaged with the inner teeth of the rigid wheel (3), the flexible wheel (4) is a cup-shaped flexible wheel, and the bottom of the cup is provided with a second groove (401) extending in the radial direction, and the second groove (401) is provided with a pair of radially opposite grooves; A cross slider (5) comprises a connecting disc (53), a first protrusion (51) and a second protrusion (52), the first protrusion (51) is located on the first end surface of the connecting disc (53), the first protrusion (51) extends in the radial direction and is provided with a pair of radially opposite protrusions, the second protrusion (52) is located on the second end surface of the connecting disc (53), the second protrusion (52) extends in the radial direction and is provided with a pair of radially opposite protrusions, the length direction of the first protrusion (51) and the length direction of the second protrusion (52) have an included angle, the first protrusion (51) is engaged with the first groove (101), and the second protrusion (52) is engaged with the second groove (401), so that the flexible wheel (4) and the bearing inner ring (1) are assembled and connected through the cross slider (5); A wave generator is sleeved in the flexible wheel (4); The cross section of the first protrusion (51) and the second protrusion (52) is trapezoidal, and the side connected with the connecting disc (53) is the upper base of the trapezoid, the first groove (101) is matched with the shape of the first protrusion (51), and the second groove (401) is matched with the shape of the second protrusion (52). The matching gap of the first protrusion (51) and the first groove (101) and the matching gap of the second protrusion (52) and the second groove (401) are all δ, and 0.015mm≤δ≤0.035mm.

2. The harmonic reducer of claim 1, wherein, The cross section of the first protrusion (51) and the second protrusion (52) is isosceles trapezoidal, and the base angle is α, wherein:

3. The harmonic reducer of claim 1, wherein, 76°≤α≤80°; and / or, The cross section of the first groove (101) and the second groove (401) is isosceles trapezoidal, and the base angle is α', and the matching tolerance of α' and α is ±0.5°. The height of the first protrusion (51) and the second protrusion (52) protruding relative to the connecting disc (53) is H, and 1.3mm≤H≤2mm.

4. The harmonic reducer of claim 1, wherein, The diameter of the connecting disc (53) is D, the span of a pair of first protrusions (51) in the radial direction of the connecting disc (53) and the span of a pair of second protrusions (52) in the radial direction of the connecting disc (53) are both L, and 0.68×D≤L≤0.72×D.

5. The harmonic reducer of claim 1, wherein, The height of the first protrusion (51) and the second protrusion (52) protruding relative to the connecting disc (53) is H; 6. The harmonic reducer of claim 1, wherein, ​ The first protrusion (51) and the second protrusion (52) are isosceles trapezoidal in cross section, the upper base width of the cross section of the first protrusion (51) and the second protrusion (52) is b1, the lower base width of the cross section of the first protrusion (51) and the second protrusion (52) is b2, 0.8×H≤b1≤0.9×H, 0.8mm≤b2-b1≤1.2mm; The first groove (101) and the second groove (401) are 0.03mm≤h-H≤0.05mm in depth in the axial direction of the harmonic reducer; The first groove (101) and the second groove (401) are 0.015mm≤δ≤0.035mm in groove bottom width b3, b3=b2+2×δ.

7. The harmonic reducer of claim 1, wherein, The end portion of the first protrusion (51) and the second protrusion (52) on the radially outer side has a rounded corner structure with a radius r, 0.2mm≤r≤0.4mm.

8. The harmonic reducer of claim 1, wherein, The surface average roughness of the first protrusion (51) and the second protrusion (52) is less than or equal to 0.4μm; and / or, The surface average roughness of the first groove (101) and the second groove (401) is less than or equal to 0.4μm.

9. The harmonic reducer of claim 1, wherein, The cup bottom of the flexspline (4) has a connecting boss (41), the second groove (401) is formed in the connecting boss (41), the connecting disc (53) is in diameter adaptation with the connecting boss (41) and the diameter tolerance is H7; The end face circle runout tolerance of the connecting disc (53) is less than or equal to 0.003mm.

10. The harmonic reducer of claim 1, wherein, The top of the first protrusion (51) and the top of the second protrusion (52) are configured to have elasticity; or, The groove bottom of the first groove (101) and the groove bottom of the second groove (401) are configured to have elasticity.

11. A robot, characterized in that The harmonic reducer comprising any one of claims 1-10.

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