A gear meshing structure and a harmonic reducer formed thereby

Abstract

The application provides a gear meshing structure and a harmonic reducer formed by the gear meshing structure, wherein the gear meshing structure comprises a flexspline and a rigid spline, an inner side wall of the rigid spline is provided with a rigid gear, an outer side wall of the flexspline is provided with a flexible gear, and the rigid gear and the flexible gear are meshed; an arc-shaped protrusion is arranged at a tooth meshing position in the flexible gear, and the arc-shaped protrusion is distributed along an axial line direction of the flexible gear; an arc-shaped recess is arranged at a tooth groove meshing position in the rigid gear, and the arc-shaped recess is matched with the arc-shaped protrusion. The compatible matching between the arc-shaped protrusion arranged at the tooth meshing position in the flexible gear and the arc-shaped recess arranged at the tooth groove meshing position in the rigid gear improves the meshing error between the flexspline and the rigid spline, and solves the wear and noise problems caused by the meshing error.

Description

Technical Field

[0001] This invention relates to the technical field of harmonic reducers, and more particularly to a gear meshing structure and the harmonic reducer formed therefrom. Background Technology

[0002] The working principle of a harmonic reducer: When the wave generator is inserted into the inner circle of the flexure, it forces the flexure to undergo elastic deformation into an elliptical shape. This causes the flexure gear at its major axis to insert into the tooth groove of the rigid wheel, achieving a fully meshed state; while at its minor axis, the two gear teeth are completely disengaged. As the wave generator rotates continuously, it forces the flexure to deform continuously, causing the two gear teeth to constantly change their working states during engagement, disengagement, and retraction, generating a staggered tooth motion, thereby achieving motion transmission.

[0003] During the assembly of a harmonic reducer, it is crucial to ensure the coaxiality between the flex wheel and the rigid wheel to guarantee that the reducer rotates coaxially under the drive of the motor. Currently, coaxiality is primarily ensured through complex tooling and high machining precision. However, despite repeated adjustments and measurements, coaxiality errors often persist during actual assembly, preventing the rigid wheel's axis from perfectly aligning with the flex wheel's axis. This can lead to poor meshing between the rigid and flex wheel teeth during operation, exacerbating tooth wear, generating abnormal noise, and affecting the overall reliability of the reducer. Summary of the Invention

[0004] To overcome the problems existing in related technologies, one of the objectives of this invention is to provide a gear meshing structure that improves the meshing error between the flexible gear and the rigid gear by the compatible fit between the arc-shaped protrusions provided in the meshing part of the teeth in the flexible gear and the arc-shaped recesses provided in the meshing part of the tooth groove in the rigid gear, thereby solving the wear and noise problems caused by the meshing error.

[0005] A gear meshing structure includes a flexible gear and a rigid gear. A rigid gear is provided on the inner sidewall of the rigid gear, and a flexible gear is provided on the outer sidewall of the flexible gear. The rigid gear and the flexible gear mesh. An arc-shaped protrusion is provided at the meshing part of the teeth of the flexible gear, and the arc-shaped protrusion is distributed along the axis of the flexible gear.

[0006] The rigid gear has an arc-shaped recess at the tooth meshing part, which is adapted to the arc-shaped protrusion.

[0007] In this application, the flexible gear with arc-shaped protrusions and the rigid gear with arc-shaped recesses maintain their meshing structure. However, the meshing surface changes from planar meshing to arc-shaped meshing. Arc-shaped meshing ensures that even with coaxiality errors between the flexible and rigid gears, they can still mesh. This avoids the problem in existing technologies where planar meshing only maintains meshing within a single plane, leading to poor meshing if coaxiality errors exist. In this application, arc-shaped meshing can accommodate a certain range of coaxiality errors, requiring only that the arc-shaped protrusions and recesses contact each other within the arc surface. The gear meshing structure in this application can accommodate a certain range of coaxiality errors, reducing wear and noise caused by coaxiality errors and extending service life.

[0008] As a specific embodiment, the size of the arc-shaped recess is x1 in the direction of the axis of the rigid gear; the maximum size of the arc-shaped recess is y1 in the direction parallel to the diameter of the rigid gear; the maximum size of the arc-shaped recess is located at the center of the arc-shaped recess.

[0009] x1 and y1 satisfy the following relationship:

[0010] 0.05x1≥y1>0.042x1.

[0011] The arc-shaped protrusion in this application has a protrusion amplitude that is related to its height and satisfies the above formula. This ensures that the formed arc-shaped meshing surface can be compatible with a large range of coaxiality errors. It also reduces the machining and installation difficulty of the teeth in the flexible gear, ensuring that even when the axes of the rigid gear and the flexible gear intersect, the teeth can still maintain good meshing, reduce tooth wear, and reduce abnormal noise caused by poor meshing.

[0012] As a specific embodiment, the size of the arc-shaped protrusion is x2 in the direction of the axis of the flexible gear; the maximum size of the arc-shaped protrusion is y2 in the direction parallel to the diameter of the flexible gear; the maximum size of the arc-shaped protrusion is located at the center of the arc-shaped protrusion.

[0013] x² and y² satisfy the following relationship:

[0014] 0.05x² ≥ y² > 0.01x².

[0015] The convexity of the arc-shaped recess in this application is related to its height and satisfies the above formula. This ensures that the formed arc-shaped meshing surface can accommodate a large range of coaxiality errors. It also reduces the machining and installation difficulty of the tooth groove in rigid gears, ensuring that even when the axes of the rigid gear and the flexible gear intersect, the teeth can still maintain good meshing, reducing tooth wear and abnormal noise caused by poor meshing.

[0016] As a specific embodiment, y1 and y2 satisfy the following relationship:

[0017] 1.18y2≥y1>y2.

[0018] This application limits the dimensions of the arc-shaped protrusions and concave sections, thereby increasing the tolerance of the rigid gear located outside the flexible gear to the teeth of the flexible gear. This ensures that meshing between the teeth of the flexible gear and the tooth grooves of the rigid gear can still be achieved even with large coaxiality errors. Simultaneously, it ensures the installation stability of both the flexible and rigid gears, guaranteeing stable operation after assembly and preventing operational instability caused by significant dimensional differences between the arc-shaped protrusions and concave sections.

[0019] In one specific embodiment, x1 equals 13mm, x2 equals 11mm, y1 equals 0.64mm, and y2 equals 0.55mm.

[0020] As a specific embodiment, the arc-shaped protrusions of each tooth in the flexible gear form a spherical structure, and the arc-shaped recesses of each tooth groove in the rigid gear form a spherical structure.

[0021] This application incorporates the arc-shaped protrusions and concave depressions as part of a spherical structure. This increases the tolerance of the rigid gear located outside the flexible gear to the teeth in the flexible gear, ensuring meshing between the teeth in the flexible gear and the tooth grooves in the rigid gear even with significant coaxiality errors. Simultaneously, it ensures the installation stability of both the flexible and rigid gears, guaranteeing stable operation after assembly and preventing operational instability caused by significant dimensional differences between the arc-shaped protrusions and concave depressions.

[0022] As a specific embodiment, the spherical radius of the arc-shaped protrusion is 30mm, and the spherical radius of the arc-shaped depression is 32.5mm.

[0023] The specific dimensions described above satisfy all the relationships and eliminate the poor meshing effect caused by coaxiality within 0.05mm. In this application, the arc-shaped meshing can accommodate a certain range of coaxiality errors; it is only necessary to ensure that the arc-shaped protrusions and concave areas can contact each other within the arc surface. The gear meshing structure in this application can accommodate a certain range of coaxiality errors, reducing wear and noise caused by coaxiality errors, improving service life, and reducing the requirements for coaxiality of the flexible and rigid gear assembly.

[0024] A second objective of this invention is to provide a harmonic reducer, including the gear meshing structure described above.

[0025] In one specific embodiment, the number of rigid gears is greater than the number of flexible gears.

[0026] As a specific embodiment, it also includes a rigid bearing, a flexible bearing, and a cam, with a flexible gear provided at the top of the flexible wheel and a flange surface provided at the bottom of the flexible wheel;

[0027] The cam is located inside the flexible wheel, and a flexible bearing is provided between the cam and the flexible wheel. The rigid wheel is fixedly connected to the rigid bearing, and the rigid bearing is fixedly connected to the flange face of the flexible wheel.

[0028] In this application, the arc-shaped meshing can accommodate a certain range of coaxiality errors, as long as the arc-shaped protrusions and concave surfaces can contact each other within the arc surface. This application uses a spherical tooth structure to solve the problem of inter-tooth meshing errors caused by coaxiality errors between the rigid and flexible gears in the reducer, thereby improving inter-tooth meshing, reducing inter-tooth wear, lowering abnormal noise caused by poor meshing, and enhancing the performance and reliability of the harmonic reducer. Simultaneously, it can reduce the precision requirements of parts, decrease the use of complex assembly tooling, reduce processing costs, save assembly time, and thus improve assembly efficiency.

[0029] The beneficial effects of this invention are as follows:

[0030] This invention provides a gear meshing structure, comprising a flexible gear and a rigid gear. A rigid gear is disposed on the inner sidewall of the rigid gear, and a flexible gear is disposed on the outer sidewall of the flexible gear. The rigid gear and the flexible gear mesh. Specifically, the flexible gear has teeth, and the rigid gear has grooves. The teeth of the flexible gear and the grooves of the rigid gear mesh to form a complete meshing structure. The meshing portion of the teeth has an arc-shaped protrusion, which is distributed along the axis of the flexible gear. That is, in the direction of the axis of the flexible gear, the two ends of the arc-shaped protrusion are flush with the two ends of the teeth, and the middle portion of the arc-shaped protrusion protrudes away from the axis of the flexible gear. Simultaneously, the meshing portion of the tooth groove in the rigid gear has an arc-shaped recess that matches the arc-shaped protrusion. The flexible gear with arc-shaped protrusions and the rigid gear with arc-shaped recesses still maintain a meshing structure, but the meshing surface changes from planar meshing to arc-shaped meshing. Arc-shaped meshing ensures that even if there is a coaxiality error between the flexible and rigid gears, they can still mesh. This avoids the situation in the prior art where planar meshing can only maintain a meshing state within a single plane, and poor meshing will occur once a coaxiality error exists. In this application, arc-shaped meshing can accommodate a certain range of coaxiality errors, as long as the arc-shaped protrusions and concave surfaces can contact each other within the arc surface. The gear meshing structure in this application can accommodate a certain range of coaxiality errors, reducing wear and noise caused by coaxiality errors, increasing service life, and reducing the requirements for the coaxiality of the flexible and rigid gear assembly.

[0031] This application also provides a harmonic reducer including the above-mentioned gear meshing structure. By changing the gear meshing structure, even if the axes of the rigid wheel and the flexible wheel intersect, the teeth can still maintain good meshing; reduce wear and noise caused by axis intersection problems and improve service life; at the same time, reduce the requirements of the whole machine for assembly coaxiality, reduce the use of complex assembly tooling, and thus improve the assembly efficiency of the whole machine. Attached Figure Description

[0032] Figure 1 This is a cross-sectional view of the harmonic reducer after coaxial assembly in this application;

[0033] Figure 2 This is a cross-sectional schematic diagram of the harmonic reducer after assembly, which has coaxiality error in this application.

[0034] Figure 3 This is a schematic diagram of the overall structure of the harmonic reducer in this application;

[0035] Figure 4 This is a top view of the harmonic reducer in this application;

[0036] Figure 5 This is a schematic diagram of the flexible wheel structure in this application;

[0037] Figure 6 This is a schematic diagram of the rigid wheel in this application;

[0038] Figure 7 This is a cross-sectional schematic diagram of the rigid wheel in this application.

[0039] Figure label:

[0040] 1. Rigid bearing; 2. Rigid wheel; 21. Arc-shaped recess; 3. Cam; 4. Flexible bearing; 5. Screw; 6. Flexible wheel; 61. Arc-shaped protrusion; 62. Flange face. Detailed Implementation

[0041] Preferred embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0042] Example 1

[0043] This application provides a gear meshing structure, including a flexible gear 6 and a rigid gear 2. The inner sidewall of the rigid gear 2 is provided with a rigid gear, and the outer sidewall of the flexible gear 6 is provided with a flexible gear. The rigid gear and the flexible gear mesh.

[0044] like Figure 1 The diagram shows the structure of the flexure 6 and rigid wheel 2 in the harmonic reducer when they are coaxially installed. At this time, the axis of the flexure 6 and rigid wheel 2 coincides, and the flexure 6 and rigid wheel 2 can mesh normally when the motor rotates.

[0045] like Figure 2 The diagram shows the structure of the flexible gear 6 and rigid gear 2 in a harmonic reducer when there is a coaxiality error. In this case, the axis lines of the flexible gear 6 and rigid gear 2 are not completely coincident. If the meshing surface of the rigid gear and the flexible gear is a plane, when there is a coaxiality deviation between the flexible gear and the rigid gear, there will be a large interference between the rigid gear and the flexible gear during the meshing process, resulting in poor meshing between the teeth of the flexible gear 6. Poor meshing will aggravate tooth wear and generate abnormal noise and other performance problems.

[0046] To address the aforementioned issues, this application provides a gear meshing structure comprising a flexible gear 6 and a rigid gear 2. A rigid gear is disposed on the inner sidewall of the rigid gear 2, and a flexible gear is disposed on the outer sidewall of the flexible gear 6. The rigid gear and the flexible gear mesh. Simultaneously, an arc-shaped protrusion 61 is provided at the meshing portion of the teeth in the flexible gear, and the arc-shaped protrusion 61 is distributed along the axial direction of the flexible gear. An arc-shaped recess 21 is provided at the meshing portion of the tooth groove in the rigid gear, and the arc-shaped recess 21 is adapted to the arc-shaped protrusion 61.

[0047] Specifically, in this application, the flexible gear has teeth, and the rigid gear has grooves. The teeth of the flexible gear and the grooves of the rigid gear mesh to form a complete meshing structure. The meshing part of the teeth is provided with an arc-shaped protrusion 61. The arc-shaped protrusion 61 is distributed along the axis of the flexible gear. That is, in the axis of the flexible gear, the two ends of the arc-shaped protrusion 61 are flush with the two ends of the teeth, and the middle part of the arc-shaped protrusion 61 protrudes in a direction away from the axis of the flexible gear. At the same time, the meshing part of the tooth groove of the rigid gear is provided with an arc-shaped recess 21 that matches the arc-shaped protrusion 61.

[0048] In this application, the flexible gear with arc-shaped protrusion 61 and the rigid gear with arc-shaped recess 21 still maintain a meshing structure. However, the meshing surface changes from planar meshing to arc-shaped meshing. Arc-shaped meshing can ensure that even if there is a coaxiality error between the flexible gear and the rigid gear, the flexible gear and the rigid gear can still mesh. This avoids the situation in the prior art where planar meshing can only maintain a meshing state in a single plane. Once there is a coaxiality error, there will be a situation of poor meshing.

[0049] In this application, the arc surface meshing can accommodate a certain range of coaxiality errors. It is only necessary to ensure that the arc-shaped protrusion 61 and the arc-shaped recess 21 can contact each other within the arc surface. The gear meshing structure in this application can accommodate a certain range of coaxiality errors, reduce wear and noise caused by coaxiality errors, and improve service life.

[0050] Meanwhile, the arc-surface meshing in this application can also reduce the reliance on complex assembly fixtures, eliminating the need for repeated adjustments and measurements during the installation of the gear meshing structure, simplifying the assembly fixtures and assembly steps, reducing the requirements for the coaxiality of the flexible wheel 6 and the rigid wheel 2, and thus improving the assembly efficiency of the gear meshing structure.

[0051] Example 2

[0052] This application provides a gear meshing structure, including a flexible gear 6 and a rigid gear 2. The inner sidewall of the rigid gear 2 is provided with a rigid gear, and the outer sidewall of the flexible gear 6 is provided with a flexible gear. The rigid gear and the flexible gear mesh. The meshing part of the flexible gear's teeth is provided with an arc-shaped protrusion 61, which is distributed along the axis of the flexible gear. The meshing part of the rigid gear's tooth groove is provided with an arc-shaped recess 21, which is adapted to the arc-shaped protrusion 61.

[0053] like Figure 5 As shown, the flexible gear in this application has teeth, and the rigid gear has grooves. The teeth of the flexible gear and the grooves of the rigid gear mesh to form a complete meshing structure. The meshing part of the teeth is provided with an arc-shaped protrusion 61. The arc-shaped protrusion 61 is distributed along the axis of the flexible gear. That is, in the axis of the flexible gear, the two ends of the arc-shaped protrusion 61 are flush with the two ends of the teeth, and the middle part of the arc-shaped protrusion 61 protrudes in a direction away from the axis of the flexible gear. At the same time, the meshing part of the tooth groove of the rigid gear is provided with an arc-shaped recess 21 that matches the arc-shaped protrusion 61.

[0054] When the size of the arc-shaped protrusion 61 is large, the arc-shaped meshing surface becomes larger, which is beneficial for compatibility under coaxiality errors, but also increases the difficulty of machining and installation. When the size of the arc-shaped protrusion 61 is small, the arc-shaped meshing surface becomes smaller, which is beneficial for machining flexible and rigid gears, but is detrimental to the degree of compatibility with coaxiality errors. Therefore, in actual operation, in order to balance the compatibility with coaxiality errors and the difficulty of machining and installation, the degree of protrusion of the arc-shaped protrusion 61 needs to be limited to a certain range. Since the arc-shaped recess 21 is adapted to the arc-shaped protrusion 61, the degree of recess in the graphic recess and the degree of protrusion of the arc-shaped protrusion 61 only need to be meshed and matched.

[0055] Furthermore, in the direction of the axis of the flexible gear, the dimension of the arc-shaped protrusion 61 is x2; in the direction parallel to the diameter of the flexible gear, the maximum dimension of the arc-shaped protrusion 61 is y2; x2 and y2 satisfy the following relationship:

[0056] 0.05x² ≥ y² > 0.01x².

[0057] In the direction of the axis of the flexible gear, such as Figure 5 As shown, the arc-shaped protrusion 61 has a vertical dimension of x2, and its dimension along the axial direction is equal to the tooth width of the flexible gear. The tooth width of the flexible gear refers to... Figure 5 The vertical dimension of the flexible gear. When the axis of the flexible gear extends vertically, the height of the flexible gear is equal to the height of the arc-shaped protrusion 61, which is x2. That is, in this application, the arc-shaped protrusion 61 is a progressive protrusion structure. The two ends of the arc-shaped protrusion 61 are flush with the meshing part of the gear teeth in the flexible gear, and the middle of the arc-shaped protrusion 61 protrudes in a direction away from the center of the flexible gear.

[0058] To ensure the symmetry of the arc-shaped meshing surface, the arc-shaped protrusion 61 can be set as a symmetrical shape, with the center of symmetry being the center position of the gear tooth.

[0059] In the diametrical direction parallel to the flexible gear, the maximum dimension of the arc-shaped protrusion 61 is y2. Since the arc-shaped protrusion 61 gradually rises from the top to the bottom of the tooth in the flexible gear and then gradually returns to the tooth position, the dimension of the arc-shaped protrusion 61 first increases and then decreases from top to bottom in the diametrical direction parallel to the flexible gear. In this application, y2 refers to the maximum dimension of the arc-shaped protrusion 61 in the diametrical direction parallel to the flexible gear. As described above, when the arc-shaped protrusion 61 is a symmetrical shape, and the center of symmetry is located at the center of the tooth, the maximum dimension of the arc-shaped protrusion 61 in the diametrical direction parallel to the flexible gear is the dimension of the arc-shaped protrusion 61 at its center position.

[0060] This application sets 0.05x2≥y2>0.01x2. When the height of the teeth in the flexible gear is determined, that is, the value of x2 is determined, the maximum protrusion amplitude of the arc-shaped protrusion 61 at the meshing part of the teeth can be calculated according to the above formula. At the same time, the total length of the arc-shaped protrusion 61 in the vertical direction is equal to the tooth width of the flexible gear. That is, the height and maximum width of the arc-shaped protrusion 61, as well as the position of the maximum width, are all determined. At this time, the flexible gear can be machined according to the determined parameters.

[0061] The arc-shaped protrusion 61 in this application has a protrusion amplitude that is related to its height and satisfies the above formula. This ensures that the formed arc-shaped meshing surface can be compatible with a large range of coaxiality errors. It also reduces the machining and installation difficulty of the teeth in the flexible gear, ensuring that even when the axes of the rigid gear 2 and the flexible gear 6 intersect, the teeth can still maintain good meshing, reduce tooth wear, and reduce abnormal noise caused by poor meshing.

[0062] Furthermore, such as Figure 6 and Figure 7 As shown, the dimension of the arc-shaped recess 21 is x1 in the direction of the axis of the rigid gear; the maximum dimension of the arc-shaped recess 21 is y1 in the direction parallel to the diameter of the rigid gear; x1 and y1 satisfy the following relationship:

[0063] 0.05x1≥y1>0.042x1.

[0064] In the direction of the rigid gear's axis, the size of the arc-shaped recess 21 is x1, and the size of the arc-shaped recess 21 in the direction of the axis is equal to the size of the rigid gear. When the axis of the rigid gear extends vertically, the height of the rigid gear is equal to the height of the arc-shaped recess 21, which is x1. That is to say, in this application, the arc-shaped recess 21 is a progressively raised structure, with both ends of the arc-shaped recess 21 flush with the meshing part of the tooth groove in the rigid gear, and the middle of the arc-shaped recess 21 recessed in a direction away from the center of the rigid gear.

[0065] To ensure the symmetry of the arc-shaped meshing surface, the arc-shaped recess 21 can be set as a symmetrical shape, with the center of symmetry being the center of the tooth groove.

[0066] In the diametrical direction parallel to the rigid gear, the maximum dimension of the arc-shaped recess 21 is y1. Since the arc-shaped recess 21 gradually bulges from the top to the bottom of the tooth groove in the rigid gear and then gradually returns to the tooth groove position, the dimension of the arc-shaped recess 21 first increases and then decreases from top to bottom in the diametrical direction parallel to the rigid gear. In this application, y1 refers to the maximum dimension of the arc-shaped recess 21 in the diametrical direction parallel to the rigid gear. As described above, when the arc-shaped recess 21 is a symmetrical shape, and the center of symmetry is located at the center of the tooth groove, the maximum dimension of the arc-shaped recess 21 in the diametrical direction parallel to the rigid gear is the dimension of the arc-shaped recess 21 at its center position.

[0067] This application sets 0.05x1≥y1>0.042x1. When the height of the tooth groove in the rigid gear is determined, that is, the value of x2 is determined, the maximum protrusion of the arc-shaped recess 21 at the tooth groove meshing part can be calculated according to the above formula. At the same time, the height of the arc-shaped recess 21 is equal to the height of the tooth groove in the rigid gear. That is, the height and maximum width of the arc-shaped recess 21, as well as the position of the maximum width, are all determined. At this time, the rigid gear can be machined according to the determined parameters.

[0068] In this application, the convexity of the arc-shaped recess 21 is related to its height and satisfies the above formula. This ensures that the formed arc-shaped meshing surface can accommodate a large range of coaxiality errors, and also reduces the machining and installation difficulty of the tooth groove in the rigid gear. It ensures that even when the axes of the rigid gear 2 and the flexible gear 6 intersect, the teeth can still maintain good meshing, reduce tooth wear, and reduce abnormal noise caused by poor meshing.

[0069] Furthermore, in this application, y1 and y2 also need to satisfy the following relationship:

[0070] 1.18y2≥y1>y2.

[0071] In other words, the maximum concave size y1 of the arc-shaped recess 21 in the direction parallel to the diameter of the rigid gear is greater than the maximum protrusion size y2 of the arc-shaped protrusion 61 in the direction parallel to the diameter of the flexible gear, while being less than or equal to 1.18 times the maximum protrusion size y2 of the arc-shaped protrusion 61 in the direction parallel to the diameter of the flexible gear.

[0072] This application limits the dimensions of the arc-shaped protrusion 61 and the arc-shaped recess 21, thereby increasing the tolerance of the rigid gear located outside the flexible gear to the teeth of the flexible gear. This ensures that even with large coaxiality errors, meshing between the teeth of the flexible gear and the tooth grooves of the rigid gear can still be achieved. Simultaneously, it ensures the installation stability of the flexible and rigid gears, guaranteeing stable operation after assembly and preventing operational instability caused by significant dimensional differences between the arc-shaped protrusion and the arc-shaped recess 21.

[0073] In the prior art, the tooth meshing part of the flexible gear and the tooth groove meshing part of the rigid gear are planar structures in the axial direction. In this application, an arc-shaped protrusion 61 is provided in the tooth meshing part of the flexible gear. The arc-shaped protrusion 61 is distributed along the axial direction of the flexible gear. An arc-shaped recess 21 is provided in the tooth groove meshing part of the rigid gear. The arc-shaped recess 21 is adapted to the arc-shaped protrusion 61, so that the tooth meshing part of the flexible gear and the tooth groove meshing part of the rigid gear have an arc-shaped meshing surface in the axial direction. Even if there is an axial deviation between the flexible gear and the rigid gear, as long as the deviation is within the arc range of the arc-shaped meshing surface, the meshing of the teeth in the flexible gear and the tooth groove in the rigid gear can be achieved.

[0074] In this application, the arc surface meshing can accommodate a certain range of coaxiality errors. It is only necessary to ensure that the arc-shaped protrusion 61 and the arc-shaped recess 21 can contact each other within the arc surface. The gear meshing structure in this application can accommodate a certain range of coaxiality errors, reduce wear and noise caused by coaxiality errors, improve service life, and reduce the requirements for the coaxiality of the flexible gear 6 and the rigid gear 2 assembly.

[0075] Example 3

[0076] This application provides a gear meshing structure, including a flexible gear 6 and a rigid gear 2. The inner sidewall of the rigid gear 2 is provided with a rigid gear, and the outer sidewall of the flexible gear 6 is provided with a flexible gear. The rigid gear and the flexible gear mesh. The meshing part of the flexible gear's teeth is provided with an arc-shaped protrusion 61, which is distributed along the axis of the flexible gear. The meshing part of the rigid gear's tooth groove is provided with an arc-shaped recess 21, which is adapted to the arc-shaped protrusion 61.

[0077] In this application, the flexible gear has teeth, and the rigid gear has grooves. The teeth of the flexible gear and the grooves of the rigid gear mesh to form a complete meshing structure. The meshing part of the teeth is provided with an arc-shaped protrusion 61. The arc-shaped protrusion 61 is distributed along the axis of the flexible gear. That is, in the axis of the flexible gear, the two ends of the arc-shaped protrusion 61 are flush with the two ends of the teeth, and the middle part of the arc-shaped protrusion 61 protrudes in a direction away from the axis of the flexible gear. If the arc-shaped protrusion 61 in this application is not present, the meshing part of the teeth in the flexible gear is planar.

[0078] like Figure 5As shown, to ensure the symmetry of the arc-shaped meshing surface, the arc-shaped protrusion 61 can be designed as a symmetrical shape, with the center of symmetry at the center of the tooth. That is, the arc-shaped protrusion 61 gradually rises from the top to the bottom of the tooth in the flexible gear and then gradually returns to the tooth position. Therefore, in the direction parallel to the diameter of the flexible gear, the size of the arc-shaped protrusion 61 first increases and then decreases from top to bottom. The arc-shaped protrusion 61 can be understood as part of a spherical structure. Since the number of arc-shaped protrusions 61 corresponds one-to-one with the number of teeth in the flexible gear, the arc-shaped protrusions 61 at the meshing parts of each tooth in the flexible gear are located inside the same spherical structure. In other words, the arc-shaped protrusions 61 of each tooth in the flexible gear form a spherical structure. Here, "forming a spherical structure" refers to forming a part of the spherical structure, not the entire spherical structure.

[0079] like Figure 6 and Figure 7 As shown, the meshing part of the tooth groove in the rigid gear is provided with an arc-shaped recess 21. The arc-shaped recess 21 is distributed along the axis of the rigid gear. That is, in the axis of the rigid gear, the two ends of the arc-shaped recess 21 are flush with the two ends of the tooth groove, and the middle part of the arc-shaped recess 21 is recessed in a direction away from the axis of the rigid gear. If there is no arc-shaped recess 21 as in this application, the meshing part of the tooth groove in the rigid gear is planar.

[0080] To ensure the symmetry of the arc-shaped meshing surface, the arc-shaped recess 21 can be designed as a symmetrical shape, with the center of symmetry at the center of the tooth groove. That is, the arc-shaped recess 21 gradually bulges from the top to the bottom of the tooth groove in the rigid gear and then gradually returns to the tooth groove position. Therefore, in the direction parallel to the diameter of the rigid gear, the size of the arc-shaped recess 21 first increases and then decreases from top to bottom. The arc-shaped recess 21 can be understood as part of a spherical structure. Since the number of arc-shaped recesses 21 corresponds one-to-one with the number of tooth grooves in the rigid gear, the arc-shaped recesses 21 at each meshing part of the rigid gear are located within the same spherical structure. In other words, the arc-shaped recesses 21 of each tooth groove in the rigid gear form a spherical structure. Here, "forming a spherical structure" refers to forming a part of a spherical structure, not the entire spherical structure.

[0081] This application incorporates the arc-shaped protrusion 61 and arc-shaped recess 21 as part of a spherical structure. This increases the tolerance of the rigid gear located outside the flexible gear to the teeth in the flexible gear, ensuring that meshing between the teeth in the flexible gear and the tooth grooves in the rigid gear can still be achieved even with large coaxiality errors. Simultaneously, it ensures the installation stability of both the flexible and rigid gears, guaranteeing stable operation after assembly and preventing operational instability caused by significant dimensional differences between the arc-shaped protrusion and recess 21.

[0082] Furthermore, in the direction of the axis of the flexible gear, the dimension of the arc-shaped protrusion 61 is x2; in the direction parallel to the diameter of the flexible gear, the maximum dimension of the arc-shaped protrusion 61 is y2; x2 and y2 satisfy the following relationship:

[0083] 0.05x² ≥ y² > 0.01x².

[0084] In the direction of the axis of the rigid gear, the dimension of the arc-shaped recess 21 is x1; in the direction parallel to the diameter of the rigid gear, the maximum dimension of the arc-shaped recess 21 is y1; x1 and y1 satisfy the following relationship:

[0085] 0.05x1≥y1>0.042x1.

[0086] In this application, y1 and y2 also need to satisfy the following relationship:

[0087] 1.18y2≥y1>y2.

[0088] As a specific embodiment, this application can limit the dimension x1 of the arc-shaped recess 21 in the axial direction to be equal to the dimension of the rigid gear, specifically 13 mm. Since the arc-shaped recess 21 gradually bulges from the top to the bottom of the tooth groove in the rigid gear and then gradually returns to the tooth groove position, the dimension of the arc-shaped recess 21 first increases and then decreases from top to bottom in the diametrical direction parallel to the rigid gear. In this application, y1 refers to the maximum dimension of the arc-shaped recess 21 in the diametrical direction parallel to the rigid gear, specifically 0.64 mm.

[0089] This application can define the size of the arc-shaped protrusion 61 as x2. Simultaneously, the size of the arc-shaped protrusion 61 in the axial direction is equal to the tooth width of the flexible gear, specifically 11 mm. Since the arc-shaped protrusion 61 gradually rises from the top to the bottom of the teeth in the flexible gear and then gradually returns to the tooth position, the size of the arc-shaped protrusion 61 first increases and then decreases from top to bottom in the diametrical direction parallel to the flexible gear. In this application, y2 refers to the maximum size of the arc-shaped protrusion 61 in the diametrical direction parallel to the flexible gear, specifically 0.55 mm.

[0090] Meanwhile, in the rigid gear, the arc-shaped recesses 21 at the meshing points of each tooth are located inside the same spherical structure. That is, the arc-shaped recesses 21 at each tooth groove of the rigid gear form a spherical structure with a radius of 32.5 mm. Similarly, in the flexible gear, the arc-shaped protrusions 61 at the meshing points of each tooth are located inside the same spherical structure. That is, the arc-shaped protrusions 61 at each tooth of the flexible gear form a spherical structure with a radius of 30 mm.

[0091] The specific dimensions described above satisfy all the relationships and can eliminate the poor meshing effect caused by coaxiality within 0.05mm. In this application, the arc surface meshing can accommodate a certain range of coaxiality errors, as long as it is ensured that the arc-shaped protrusion 61 and the arc-shaped recess 21 can contact each other within the arc surface; the gear meshing structure in this application can accommodate a certain range of coaxiality errors, reduce wear and noise caused by coaxiality errors, improve service life, and reduce the requirements for the coaxiality of the flexible gear 6 and the rigid gear 2 assembly.

[0092] Example 4

[0093] like Figures 1-4 As shown, the harmonic reducer provided in this application includes a rigid bearing 1, a flexible bearing 4, a cam 3, a flexible wheel 6, and a rigid wheel 2. The inner sidewall of the rigid wheel 2 is provided with a rigid gear, and the outer sidewall of the flexible wheel 6 is provided with a flexible gear. The rigid gear and the flexible gear mesh, and the number of rigid gears is greater than the number of flexible gears.

[0094] Meanwhile, a flexible gear is provided at the top of the flexible wheel 6, and a flange surface 62 is provided at the bottom of the flexible wheel 6. The cam 3 is located inside the flexible wheel 6, and a flexible bearing 4 is provided between the cam 3 and the flexible wheel 6. The rigid wheel 2 is fixedly connected to the rigid bearing 1 by screws 5, and the rigid bearing 1 is fixedly connected to the flange surface 62 of the flexible wheel 6 by screws 5.

[0095] A wave generator, consisting of a cam 3 and a flexible bearing 4, is placed in the hollow interior of the flexible wheel 6. The wave generator has an elliptical structure. The insertion of the elliptical wave generator deforms the flexible wheel 6. The teeth of the long axis of the flexible wheel 6 mesh with the rigid wheel 2, while the teeth of the short axis of the flexible wheel 6 disengage from the rigid wheel 2. The rigid wheel 2 is fixed, and rotating the wave generator causes the flexible wheel 6 to deform and continuously mesh with the teeth of the rigid wheel 2. Because the rigid wheel 2 typically has two more teeth than the flexible wheel 6, for every one clockwise rotation of the wave generator, the flexible wheel 6 moves two teeth counterclockwise.

[0096] Rigid gears and flexible gears are generally generated with tooth profiles along a straight trajectory, and during assembly, rigid gear 2 and flexible gear 6 are on the same shaft. However, in reality, due to factors such as machining errors and human assembly errors, the reducer as a whole will have a coaxiality error of 0-0.05mm. This error will affect the inter-tooth meshing and thus affect the performance and reliability of the reducer.

[0097] like Figure 5 As shown, in this application, the flexible gear has an arc-shaped protrusion 61 at the tooth meshing part, and the arc-shaped protrusion 61 is distributed along the axis of the flexible gear; the rigid gear has an arc-shaped recess 21 at the tooth meshing part, and the arc-shaped recess 21 is adapted to the arc-shaped protrusion 61.

[0098] Furthermore, in the direction of the axis of the flexible gear, the dimension of the arc-shaped protrusion 61 is x2; in the direction parallel to the diameter of the flexible gear, the maximum dimension of the arc-shaped protrusion 61 is y2; x2 and y2 satisfy the following relationship:

[0099] 0.05x² ≥ y² > 0.01x².

[0100] In the direction of the axis of the rigid gear, the dimension of the arc-shaped recess 21 is x1; in the direction parallel to the diameter of the rigid gear, the maximum dimension of the arc-shaped recess 21 is y1; x1 and y1 satisfy the following relationship:

[0101] 0.05x1≥y1>0.042x1.

[0102] In this application, y1 and y2 also need to satisfy the following relationship:

[0103] 1.18y2≥y1>y2.

[0104] In the direction of the axis of the flexible gear, such as Figure 5 As shown, the arc-shaped protrusion 61 has a vertical dimension of x2, and its dimension along the axis is equal to the tooth width of the flexible gear. When the axis of the flexible gear extends vertically, the height of the flexible gear is equal to the height of the arc-shaped protrusion 61, which is x2. In other words, the arc-shaped protrusion 61 in this application is a progressively raised structure; both ends of the arc-shaped protrusion 61 are flush with the meshing portion of the teeth in the flexible gear, and the middle of the arc-shaped protrusion 61 protrudes in a direction away from the center of the flexible gear.

[0105] In the direction parallel to the diameter of the flexible gear, the maximum dimension of the arc-shaped protrusion 61 is y2. Since the arc-shaped protrusion 61 gradually rises from the top to the bottom of the teeth in the flexible gear and then gradually returns to the tooth position, the dimension of the arc-shaped protrusion 61 first increases and then decreases from top to bottom in the direction parallel to the diameter of the flexible gear. In this application, y2 refers to the maximum dimension of the arc-shaped protrusion 61 in the direction parallel to the diameter of the flexible gear. The arc-shaped protrusion 61 can be understood as part of a spherical structure. Since the number of arc-shaped protrusions 61 corresponds one-to-one with the number of teeth in the flexible gear, the arc-shaped protrusions 61 at the meshing parts of each tooth in the flexible gear are located inside the same spherical structure. That is to say, the arc-shaped protrusions 61 of each tooth in the flexible gear form a spherical structure.

[0106] like Figure 6 and Figure 7As shown, the dimension of the arc-shaped recess 21 in the direction of the rigid gear's axis is x1, and the dimension of the arc-shaped recess 21 in the direction of the axis is equal to the dimension of the rigid gear. When the axis of the rigid gear extends vertically, the height of the rigid gear is equal to the height of the arc-shaped recess 21, which is x1. That is to say, in this application, the arc-shaped recess 21 is a progressively raised structure, with both ends of the arc-shaped recess 21 flush with the meshing part of the tooth groove in the rigid gear, and the middle of the arc-shaped recess 21 recessed in a direction away from the center of the rigid gear.

[0107] In the direction parallel to the diameter of the rigid gear, the maximum dimension of the arc-shaped recess 21 is y1. Since the arc-shaped recess 21 gradually bulges from the top to the bottom of the tooth groove in the rigid gear and then gradually returns to the tooth groove position, the dimension of the arc-shaped recess 21 first increases and then decreases from top to bottom in the direction parallel to the diameter of the rigid gear. In this application, y1 refers to the maximum dimension of the arc-shaped recess 21 in the direction parallel to the diameter of the rigid gear. The arc-shaped recess 21 can be understood as part of a spherical structure. Since the number of arc-shaped recesses 21 corresponds one-to-one with the number of tooth grooves in the rigid gear, the arc-shaped recesses 21 at the meshing parts of each tooth groove in the rigid gear are located inside the same spherical structure. That is to say, the arc-shaped recesses 21 of each tooth groove in the rigid gear form a spherical structure.

[0108] This application limits the dimensions of the arc-shaped protrusion 61 and the arc-shaped recess 21, thereby increasing the tolerance of the rigid gear located outside the flexible gear to the teeth of the flexible gear. This ensures that even with large coaxiality errors, meshing between the teeth of the flexible gear and the tooth grooves of the rigid gear can still be achieved. Simultaneously, it ensures the installation stability of the flexible and rigid gears, guaranteeing stable operation after assembly and preventing operational instability caused by significant dimensional differences between the arc-shaped protrusion and the arc-shaped recess 21.

[0109] In this application, the arc-shaped meshing can accommodate a certain range of coaxiality errors, as long as the arc-shaped protrusion 61 and the arc-shaped recess 21 can contact each other within the arc surface. This application uses a spherical tooth structure to solve the problem of inter-tooth meshing errors caused by coaxiality errors between the rigid wheel 2 and the flexible wheel 6 of the reducer, thereby improving inter-tooth meshing, reducing inter-tooth wear, reducing abnormal noise caused by poor meshing, and improving the performance and reliability of the harmonic reducer itself. Simultaneously, it can reduce the precision requirements of parts, reduce the use of complex assembly tooling, reduce processing costs, save assembly time, and thus improve assembly efficiency.

[0110] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this application. Any specific values ​​in all examples shown and discussed herein should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0111] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms 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 on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0112] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0113] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0114] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A gear meshing structure, comprising a flexible gear (6) and a rigid gear (2), wherein a rigid gear is disposed on the inner sidewall of the rigid gear (2), and a flexible gear is disposed on the outer sidewall of the flexible gear (6), wherein the rigid gear and the flexible gear mesh; characterized in that, The flexible gear has an arc-shaped protrusion (61) at the meshing part of the gear teeth, and the arc-shaped protrusion (61) is distributed along the axis of the flexible gear. The rigid gear has an arc-shaped recess (21) at the tooth meshing part, and the arc-shaped recess (21) is adapted to the arc-shaped protrusion (61); In the direction of the axis of the rigid gear, the size of the arc-shaped recess (21) is x1; in the direction parallel to the diameter of the rigid gear, the maximum size of the arc-shaped recess (21) is y1; the maximum size of the arc-shaped recess (21) is located at the center of the arc-shaped recess (21); x1 and y1 satisfy the following relationship: 0.05x1 ≥y1>0.042x1.

2. The gear meshing structure according to claim 1, characterized in that, In the direction of the axis of the flexible gear, the size of the arc-shaped protrusion (61) is x2; in the direction parallel to the diameter of the flexible gear, the maximum size of the arc-shaped protrusion (61) is y2; the maximum size of the arc-shaped protrusion (61) is located at the center of the arc-shaped protrusion (61); x² and y² satisfy the following relationship: 0.05x² ≥ y² > 0.01x².

3. The gear meshing structure according to claim 2, characterized in that, y1 and y2 satisfy the following relationship: 1.18y2 ≥y1>y2.

4. The gear meshing structure according to claim 3, characterized in that, x1 equals 13mm, x2 equals 11mm, y1 equals 0.64mm, and y2 equals 0.55mm.

5. The gear meshing structure according to claim 1, characterized in that, The arc-shaped protrusions (61) of each tooth in the flexible gear form a spherical structure, and the arc-shaped recesses (21) of each tooth groove in the rigid gear form a spherical structure.

6. A gear meshing structure according to claim 5, characterized in that, The spherical radius of the arc-shaped protrusion (61) is 30 mm, and the spherical radius of the arc-shaped depression (21) is 32.5 mm.

7. A harmonic reducer, characterized in that, Includes a gear meshing structure as described in any one of claims 1-6.

8. A harmonic reducer according to claim 7, characterized in that, The number of rigid gears is greater than the number of flexible gears.

9. A harmonic reducer according to claim 7, characterized in that, It also includes a rigid bearing (1), a flexible bearing (4) and a cam (3), the top of the flexible wheel (6) is provided with a flexible gear, and the bottom of the flexible wheel (6) is provided with a flange face (62); The cam (3) is located inside the flexible wheel (6), and a flexible bearing (4) is provided between the cam (3) and the flexible wheel (6). The rigid wheel (2) is fixedly connected to the rigid bearing (1), and the rigid bearing (1) is fixedly connected to the flange face (62) of the flexible wheel (6).

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