A flexible gear concentricity calibration jig for harmonic reducer assembly

Abstract

A kind of flexible wheel concentricity calibration fixture for harmonic reducer assembly, the calibration fixture includes: base flange, fixed ring, fixedly connected to the base flange, first inclined surface is provided on the fixed ring;Concentric deformation block, abuts the fixed ring, the concentric deformation block includes second inclined surface, also includes the third inclined surface of abutting the first inclined surface, and the deformation reserved groove integrally formed on the third inclined surface;Rigid wheel, fixedly connected to the base flange;Cross bearing, located at the side of the rigid wheel away from the base flange;Flexible wheel, with the rigid wheel engages, and abuts the concentric deformation block, and located at the side of the cross bearing away from the rigid wheel, the flexible wheel includes the positioning ring with fourth inclined surface, the positioning ring is located at the side of the flexible wheel away from the cross bearing, and with the flexible wheel clamping.

Description

Technical Field

[0001] This utility model relates to the field of harmonic reducers, and in particular to a flexible gear concentricity calibration fixture for assembling harmonic reducers. Background Technology

[0002] Harmonic reducers are precision transmission devices that transmit power based on the principle of elastic deformation. Their core consists of three main components: a wave generator, a flexible wheel, and a rigid wheel. With their superior characteristics such as high reduction ratio, high torque density, high precision, and zero backlash, harmonic reducers are widely used in high-precision servo transmission fields such as industrial robots, aerospace, and precision machine tools. Among them, the cap-type harmonic reducer is the preferred solution in many scenarios due to its compact structure and ease of integration with motors.

[0003] In the assembly process of a cap-type harmonic reducer, ensuring high concentricity between the flexure and the crossed roller bearing is crucial for guaranteeing the product's transmission accuracy, operational stability, and service life. Currently, the assembly fixtures commonly used in the industry are mostly rigid press-fit structures. Traditional fixtures press the crossed bearing into the flexure through simple mechanical fitting. Due to the existence of part machining tolerances and assembly clearances, micron-level concentricity deviations are easily generated after press-fitting. To solve this problem, operators have to perform tedious secondary measurements and manual calibration using dial indicators after press-fitting. This process not only severely restricts assembly efficiency and is difficult to adapt to the needs of automation and mass production, but more importantly, its calibration accuracy is highly dependent on the operator's personal experience, making it difficult to guarantee product quality consistency. In addition, existing rigid structures lack effective stress compensation mechanisms. During the press-fitting process, if there is slight misalignment, the resulting assembly stress cannot be effectively released or evenly distributed, leading to stress concentration. This excessive local stress may damage the thin-walled elastic structure of the flexure or the precision raceway of the crossed bearing, posing a hidden danger to the long-term reliable operation of the reducer.

[0004] Therefore, there is a need for a flexure concentricity calibration fixture for harmonic reducer assembly that can improve the concentricity of the flexure and the cross bearing and avoid stress concentration during press-fitting. Utility Model Content

[0005] The purpose of this invention is to provide a flexure concentricity calibration fixture for harmonic reducer assembly that can improve the concentricity of the flexure and the cross bearing and avoid stress concentration during press-fitting.

[0006] According to one aspect of this application, a flexspline concentricity calibration fixture for assembling a harmonic reducer is provided, the calibration fixture comprising: Base flange, A retaining ring is fixedly connected to the base flange, and the retaining ring is provided with a first inclined surface; A concentric deformation block abuts against the fixed ring. The concentric deformation block includes a second inclined surface, a third inclined surface abutting against the first inclined surface, and a deformation reserved groove integrally formed on the third inclined surface. The rigid wheel abuts against the base flange at one end; A cross bearing is located on the side of the rigid wheel opposite to the base flange; The flexible wheel meshes with the rigid wheel and abuts against the concentric deformable block, and is located on the side of the cross bearing away from the rigid wheel. The flexible wheel includes a positioning ring with a fourth inclined surface, which is located on the side of the flexible wheel away from the cross bearing and is engaged with the flexible wheel. The calibration fixture further includes an upper pressure cap with a fifth inclined surface. The upper pressure cap is inserted sequentially into the concentric deformation block and the positioning ring along a first direction from a position on the side of the concentric deformation block away from the fixed ring. The fifth inclined surface contacts the second and fourth inclined surfaces in sequence. Tightening the screw continuously applies pressure to the flexible wheel along the first direction with the upper pressure cap. The fourth inclined surface decomposes the pressure in the first direction and drives the positioning ring to expand elastically in the radial direction to calibrate the concentricity of the flexible wheel. The concentric deformation block moves towards the fixed ring under the pressure in the first direction. The first inclined surface decomposes the pressure in the first direction applied by the third inclined surface and squeezes the concentric deformation block. The deformation groove of the third inclined surface undergoes elastic deformation and clamps the cross bearing to center the cross bearing radially.

[0007] More preferably, the upper cover is further provided with a first reserved hole, a first fastening hole and a second fastening hole that penetrate the upper cover along the first direction; When viewed along the first direction, the first reserved hole and the first fastening hole are located at the edge of the upper cover, and the second fastening hole is located at the center of the upper cover.

[0008] More preferably, the base flange is provided with a second reserved hole that penetrates the base flange along the first direction.

[0009] More preferably, a plurality of flexible wheel holes are integrally formed on the flexible wheel and penetrate the flexible wheel along the first direction; The cross bearing has a plurality of limiting holes integrally formed therethrough along the first direction; The bolt passes sequentially through the first reserved hole, the limiting hole, and the flexible wheel hole along the first direction, and the upper pressure cover, the cross bearing, and the flexible wheel are fixedly connected.

[0010] More preferably, a plurality of positioning holes are integrally formed on the concentric deformable block, extending through the concentric deformable block along the first direction.

[0011] More preferably, the bolt passes sequentially through the first fastening hole and the positioning hole along the first direction, and the upper pressure cover is fixedly connected to the concentric variable block.

[0012] More preferably, the calibration fixture further includes a fixing block, which is fixedly connected between the base flange and the upper pressure cover, and has a fixing hole extending through the first direction.

[0013] More preferably, the calibration fixture further includes: The locking screw passes through the second fastening hole, the fixing hole, and the second reserved hole in sequence; When the locking screw is tightened, the fifth inclined surface of the upper pressure cover abuts against and presses against the fourth inclined surface of the positioning ring, and applies pressure to the positioning ring.

[0014] More preferably, the cross bearing includes: The roller abuts between the crossed bearing and the flexible wheel; The oil seal skeleton is integrally formed on the cross bearing and is located on the side of the cross bearing near the base flange.

[0015] More preferably, the cross bearing further includes: The bearing inner ring is integrally formed on the outer surface of the cross bearing and is located between the roller and the oil seal skeleton; The bearing outer ring is integrally formed on the outer surface of the oil seal skeleton.

[0016] This utility model has the following beneficial effects: By engaging the fifth inclined surface of the upper pressure cap with the fourth inclined surface of the positioning ring, the clamping force in the first direction is partially decomposed into a radial expansion force on the directional ring. This drives the positioning ring to expand elastically in the radial direction, supporting the flexible wheel and thus achieving automatic centering of the flexible wheel, improving its concentricity. Similarly, by engaging the first inclined surface of the fixed ring with the third inclined surface of the concentric deformation block, the clamping force in the first direction is partially decomposed into a radial expansion force on the concentric deformation block. This drives the positioning ring to contract elastically in the radial direction, clamping the cross bearing and thus achieving automatic centering of the cross bearing. Furthermore, by setting deformation pre-reserved grooves on the concentric deformation block, it can undergo elastic deformation around the cross bearing under axial pressure and contract radially to uniformly clamp the cross bearing, avoiding stress concentration and component damage during rigid press-fitting. Attached Figure Description

[0017] 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a three-dimensional structural diagram of the calibration fixture described in one embodiment of this application; Figure 2 This is an exploded view of the calibration fixture described in one embodiment of this application; Figure 3 for Figure 1 A cross-sectional view AA of the calibration fixture after disassembly and cut along the cutting line AA; Figure 4 for Figure 3 Enlarged view of point A in the middle; Explanation of reference numerals: 100, Calibration fixture; 10, Base flange; 11, Second reserved hole; 20, Fixing ring; 21, First inclined surface; 30, Concentric deformation block; 31, Second inclined surface; 32, Third inclined surface; 33, Deformation reserved groove; 34, Positioning hole; 40, Rigid wheel; 50, Cross bearing; 51, Limiting hole; 52, Roller; 53, Oil seal skeleton; 54, Bearing inner ring; 55, Bearing outer ring; 60, Flexible wheel; 61, Positioning ring; 61A, Fourth inclined surface; 62, Flexible wheel hole; 70, Upper pressure cover; 71, Fifth inclined surface; 72, First reserved hole; 73, First fastening hole; 74, Second fastening hole; 80, Fixing block; 81, Fixing hole; 90, Locking screw; F1, First direction. Detailed Implementation

[0019] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0020] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] Please refer to Figure 1 - Figure 4 One embodiment of this application provides a concentricity calibration fixture 100 for assembling a harmonic reducer flexure 60. The calibration fixture 100 includes: a base flange 10, a fixing ring 20, a concentric deformation block 30, a rigid wheel 40, a cross bearing 50, and a flexure 60.

[0023] The fixing ring 20 is fixedly connected to the base flange 10, and the fixing ring 20 is provided with a first inclined surface 21. The concentric deformation block 30 abuts against the fixing ring 20. The concentric deformation block 30 includes a second inclined surface 31, a third inclined surface 32 abutting against the first inclined surface 21, and a deformation reserved groove 33 integrally formed on the third inclined surface 32. The end face of the rigid wheel 40 contacts the internal groove of the base flange 10. The cross bearing 50 is located on the side of the rigid wheel 40 away from the base flange 10. The flexible wheel 60 meshes with the rigid wheel 40 and abuts against the concentric deformation block 30, and is located on the side of the cross bearing 50 away from the rigid wheel 40. The flexible wheel 60 includes a positioning ring 61 provided with a fourth inclined surface 61A. The positioning ring 61 is located on the side of the flexible wheel 60 away from the cross bearing 50 and engages with the flexible wheel 60. The calibration fixture 100 further includes an upper pressure cap 70 with a fifth inclined surface 71. The upper pressure cap 70 is inserted sequentially into the concentric deformation block 30 and the positioning ring 61 along the first direction F1 from the position of the concentric deformation block 30 away from the fixed ring 20. The fifth inclined surface 71 contacts the second inclined surface 31 and the fourth inclined surface 61A in sequence. Tightening the screw continuously applies pressure to the flexible wheel 60 along the first direction F1 with the upper pressure cap 70. The fourth inclined surface 61A decomposes the pressure of the first direction F1 and drives the positioning ring 61 to expand elastically in the radial direction to calibrate the concentricity of the flexible wheel 60. The concentric deformation block 30 moves towards the fixed ring 20 under the pressure of the first direction F1. The first inclined surface 21 decomposes the pressure of the first direction F1 applied by the third inclined surface 32 and squeezes the concentric deformation block 30. The deformation reserved groove 33 of the third inclined surface 32 undergoes elastic deformation and clamps the cross bearing 50 to center the cross bearing 50 in the radial direction.

[0024] The base flange 10 forms the bottom foundation of the calibration fixture 100, with its top surface serving as a reference surface for contact with the bottom of the rigid wheel 40. A retaining ring 20 is fixed above the base flange 10 by bottom screws. This retaining ring 20 has a specific inner inclined surface, which is the first inclined surface 21. A concentric deformation block 30 is fitted inside the retaining ring 20. Its outer side has an outer inclined surface matching the first inclined surface 21 of the retaining ring 20, and a third inclined surface 32, which abut against each other. The upper part of the inner ring of the concentric deformation block 30 is designed with a conical surface, namely the second inclined surface 31, on which a deformation pre-reserved groove 33 is opened, giving it elastic deformation capability. A cross bearing 50 is placed above the rigid wheel 40, located on the side of the rigid wheel 40 away from the base flange 10. Its outer outer ring abuts against and tightly fits the inner structure of the concentric deformation block 30. The flexible wheel 60 meshes with the rigid wheel 40 and is located on the side of the crossed bearing 50 opposite to the rigid wheel 40, i.e., above the crossed bearing 50. The flexible wheel 60 is divided into upper and lower parts. The lower end face of the upper part contacts the upper surface of the crossed bearing 50, while the outer surface of the lower part contacts the rigid wheel 40. The upper end of the flexible wheel 60 has a positioning ring 61 for the flange of the flexible wheel 60. Its outer ring has a right-angled stepped structure for precise engagement with the thickened part of the flange end of the flexible wheel 60. Its inner ring is designed with a conical surface, i.e., the fourth inclined surface 61A. The upper pressure cover 70, as the core clamping component, has a central boss at its lower part. The outer side of the boss is a ring of inclined surfaces, i.e., the fifth inclined surface 71. During assembly, the upper pressure cover 70 is placed from above along the first axial downward direction F1, so that it is sequentially embedded into the internal space of the concentric variable block 30 and the positioning ring 61. At this point, the fifth inclined surface 71 of the upper pressure cover 70 contacts the second inclined surface 31 of the concentric deformation block 30 and the fourth inclined surface 61A of the positioning ring 61 in sequence. Tightening the bolts passing through the upper pressure cover 70 drives the upper pressure cover 70 to continuously move downwards along the first direction F1. During this process, the upper pressure cover 70 moves downwards, its inner bottom surface presses against the upper end face of the positioning ring 61, and simultaneously its fifth inclined surface 71 wedges into the fourth inclined surface 61A of the positioning ring 61. Through this inclined surface engagement, the axial clamping force is decomposed, generating a radially outward expansion force. This force drives the positioning ring 61 to produce a slight radial elastic expansion. Since its outer ring right-angle step has engaged the flexible wheel 60, this expansion force effectively positions the flange of the flexible wheel 60 radially, ensuring the final concentricity of the flexible wheel 60 using the high roundness reference of the flexible wheel 60 flange itself. This achieves automatic centering of the flexible wheel 60, replacing manual dial indicator calibration and improving calibration accuracy and assembly efficiency. When the upper pressure cap 70 moves downward, its fifth inclined surface 71 also drives the concentric variable block 30 to move downward together. The third inclined surface 32 of the concentric variable block 30 then slides along the first inclined surface 21 of the fixed ring 20. Through the cooperation of the first inclined surface 21 of the fixed ring 20 and the third inclined surface 32 of the concentric variable block 30, the axial force is decomposed into a compressive force that drives the concentric variable block 30 to contract radially.The force acts on the concentric deformation block 30, causing its structure to undergo the expected elastic deformation along the deformation groove 33, resulting in overall contraction towards the center. The use of the deformation groove 33 on the concentric deformation block 30 ensures that the contraction is elastic and uniform. The inner side of the concentric deformation block 30 then precisely and uniformly presses against the outer ring of the cross bearing 50, achieving centering. Elastic deformation avoids stress concentration during rigid pressing, effectively preventing damage to the thin wall of the flexible wheel 60 or the precision raceway of the bearing, thus improving product reliability. The core advantage of this calibration fixture 100 is that it can simultaneously drive the radial expansion of the positioning ring 61 and the radial contraction of the concentric deformation block 30 with a single locking operation. This forces the center of the flexible wheel 60 and the center of the outer ring of the cross bearing 50 to be coaxial, achieving efficient and high-precision concentricity calibration.

[0025] More preferably, the upper pressure cover 70 is further provided with a first reserved hole 72, a first fastening hole 73, and a second fastening hole 74 penetrating the upper pressure cover 70 along the first direction F1. When viewed along the first direction F1, the first reserved hole 72 and the first fastening hole 73 are located at the edge of the upper pressure cover 70, and the second fastening hole 74 is located at the center of the upper pressure cover 70.

[0026] The upper pressure cover 70, as the core clamping component, has multiple threaded holes extending along the first direction F1 (i.e., axial direction). The first reserved hole 72 is for the locking screw 90, intended for final equipment assembly, specifically for installing bolts to ultimately fix the flexible wheel 60 to its output flange. The first fastening hole 73 is a threaded hole for the concentric variable block 30. Outside of the main locking process, it can be used independently for pre-tightening or auxiliary fixing of the concentric variable block 30. The second fastening hole 74 is a central hole; in the main locking principle, tightening the bolt passing through this hole connects the upper pressure cover 70, the fixing block 80, and the base flange 10, thereby generating the locking force for the entire calibration fixture 100. Viewed from above the upper pressure cover 70 along the first direction F1, the first reserved hole 72 and the first fastening hole 73 are located in the edge area of ​​the upper pressure cover 70, evenly distributed circumferentially. The second fastening hole 74 is located in the central area of ​​the upper pressure cover 70.

[0027] More preferably, the base flange 10 is provided with a second reserved hole 11 that penetrates the base flange 10 along the first direction F1.

[0028] The base flange 10 serves as the bottom foundation and positioning reference for the entire calibration fixture 100, and its body is integrally formed with several axially penetrating holes. The second reserved hole 11 is positioned corresponding to the second fastening hole 74 on the upper cover 70 and is located at the center of the base flange 10. It is used for the center bolt of the upper cover 70 to pass through, thereby applying pressure to the components below the upper cover 70 and providing an anchor point for the locking operation of the upper cover 70.

[0029] More preferably, the flexible wheel 60 is integrally formed with a plurality of flexible wheel holes 62 extending through the flexible wheel 60 along the first direction F1. The cross bearing 50 is integrally formed with a plurality of limiting holes 51 extending through the cross bearing 50 along the first direction F1.

[0030] The flexible wheel 60, as a key thin-walled elastic component being assembled, has a plurality of axially penetrating flexible wheel holes 62 integrally formed on its end flange for bolts to ultimately secure the flexible wheel 60 to its output flange. The cross bearing 50 has a plurality of limiting holes 51 integrally formed along the first direction F1. These holes allow bolts to pass through.

[0031] More preferably, the bolt passes sequentially through the first reserved hole 72, the limiting hole 51 and the flexible wheel hole 62 along the first direction F1, and the upper pressure cover 70, the cross bearing 50 and the flexible wheel 60 are fixedly connected.

[0032] During the calibration process, once the calibration fixture 100 has completed the concentricity calibration of the flexible wheel 60 and the cross bearing 50 and is in a locked state, the bolt can pass sequentially from top to bottom along the first direction F1 through the corresponding first reserved hole 72 and the limiting hole 51 on the upper pressure cover 70, and finally screw into the flexible wheel hole 62. This connection path fixes the upper pressure cover 70, the cross bearing 50, and the flexible wheel 60 together in this calibrated concentric position.

[0033] More preferably, a plurality of positioning holes 34 are integrally formed on the concentric variable block 30, extending through the concentric variable block 30 along the first direction.

[0034] The concentric variable block 30 has a plurality of positioning holes 34 integrally formed therethrough along its axial direction. These holes are axially aligned with the first fastening hole 73 of the upper pressure plate 70. The positioning holes 34 are used for connecting bolts to pass through.

[0035] More preferably, the bolt passes through the first fastening hole 73 and the positioning hole 34 in sequence along the first direction F1, and the upper pressure cover 70 is fixedly connected to the concentric variable block 30.

[0036] During assembly, the bolts can pass sequentially through the first fastening hole 73 on the upper cover 70 and the positioning holes 34 on the concentric variable block 30 along the first direction F1, thereby fixing or pre-positioning the two, and achieving auxiliary fixing of the concentric variable block 30 in addition to the main locking operation achieved through the second fastening hole 74.

[0037] More preferably, the calibration fixture 100 further includes a fixing block 80, which is fixedly connected between the base flange 10 and the upper pressure cover 70, and is provided with a fixing hole 81 extending through the first direction F1.

[0038] The fixing block 80 is an independent component, fixedly connected between the base flange 10 and the upper pressure cover 70. The fixing block 80 is securely fixed to the base flange 10 by bolts passing through its body and the second pre-drilled hole 11 in the base flange 10. This makes it an integral part of the structure of the base flange 10. The fixing block 80 has a threaded hole 81 extending axially through it for engaging with the locking screw 90 used in the main locking operation.

[0039] More preferably, the calibration fixture 100 further includes a locking screw 90.

[0040] The locking screw 90 passes through the second fastening hole 74, the fixing hole 81, and the second reserved hole 11 in sequence. When the locking screw 90 is tightened, the fifth inclined surface 71 of the upper pressure cover 70 abuts against and presses against the fourth inclined surface 61A of the positioning ring 61, and applies pressure to the positioning ring 61.

[0041] The locking screw 90 is a bolt that passes through the second fastening hole 74 of the upper cover 70, and it is the core component for achieving a single locking operation. The installation path of the locking screw 90 is precisely defined; it passes sequentially through the second fastening hole 74, the fixing hole 81, and the second reserved hole 11. In actual assembly, the locking screw 90 completes the connection after being screwed into the base flange 10, and is finally anchored to the base flange 10. By tightening the locking screw 90, the upper cover 70 is pulled towards the fixing block 80, thereby generating an axial clamping force.

[0042] More preferably, the cross bearing 50 includes: rollers 52 and oil seal skeleton 53.

[0043] The roller 52 abuts between the cross bearing 50 and the flexible wheel 60. The oil seal skeleton 53 is integrally formed on the cross bearing 50 and is located on the side of the cross bearing 50 near the base flange 10.

[0044] The crossed bearing 50 contains rollers 52 and a skeleton oil seal. Rollers 52 are the core transmission element of the bearing, located inside the crossed bearing 50, directly abutting against the raceway between the inner and outer rings. In the assembly of the calibration fixture 100, the crossed bearing 50 acts as a frame, mounting the rigid wheel and flexure wheel on its inner and outer rings respectively. Therefore, the rollers 52 of the crossed bearing 50 functionally form the force transmission interface between the crossed bearing 50 and the lower rigid wheel 40 and the upper flexure wheel 60. The skeleton oil seal is the sealing element of the bearing, fixed to the end structure of the crossed bearing 50 by an interference fit. Specifically, the skeleton oil seal is located on the side of the crossed bearing 50 near the base flange 10, i.e., the lower end face during installation. The presence of rollers 52 enables the crossed bearing 50 to achieve high-precision, low-friction rotational motion. During calibration, the roller 52 and its inner and outer rings form a unified whole, providing a highly rounded and rigid reference ring for the radial clamping of the concentric deformation block 30. This is the physical basis for achieving high-precision centering. The main function of the skeleton oil seal is to prevent lubricant leakage and impurity intrusion, ensuring a long bearing life. In the calibration fixture 100, its structure also constitutes a positioning feature of the bearing end face. Placing it on the side near the base flange 10 helps to initially define the bearing's installation direction in the axial direction and form a stable fit with other positioning surfaces of the fixture.

[0045] More preferably, the cross bearing 50 further includes an inner bearing ring 54 and an outer bearing ring 55.

[0046] The inner bearing ring 54 is integrally formed on the outer surface of the crossed bearing 50 and is located between the roller 52 and the oil seal skeleton 53. The outer bearing ring 55 is integrally formed on the outer surface of the oil seal skeleton 53.

[0047] The cross bearing 50 further comprises an inner ring 54 and an outer ring 55 of the cross roller bearing 52. The inner ring 54 is integrally formed on the inner surface of the cross bearing 50 structure. In the assembled state, it is located between the rollers 52 and the internal space of the bearing, and is the surface that will directly mate with the wave generator or output shaft. The outer ring 55 is integrally formed on the outer surface of the cross bearing 50 structure. In the assembled state, it is located outside the rollers 52 and the skeleton oil seal, and is the surface that directly contacts and is radially clamped by the inner structure of the concentric deformation block 30 of the calibration fixture 100. The outer ring 55 is the most critical component of this fixture. The core working principle of the fixture is that after the concentric deformation block 30 radially contracts, it precisely and uniformly presses and clamps the outer ring 55. Therefore, a perfectly round, surface-hardened outer ring 55 is the direct working surface and accuracy guarantee for the fixture to effectively and accurately perform centering operations. The inner ring 54 and outer ring 55 of the bearing together form the precision raceway of the roller 52. Their high-precision relative motion is fundamental to realizing the transmission function of the harmonic reducer. In the fixture, the strong centering of the outer ring indirectly ensures the coaxiality between the inner ring and the flexure 60, thereby ensuring the initial assembly accuracy of the entire transmission chain and laying a solid foundation for the high-performance operation of the final product.

[0048] By engaging the fifth inclined surface 71 of the upper pressure cap 70 with the fourth inclined surface 61A of the positioning ring 61, the clamping force in the first direction F1 is partially decomposed into a radial expansion force on the directional ring. This drives the positioning ring 61 to expand elastically in the radial direction, supporting the flexible wheel 60 and thus achieving automatic centering of the flexible wheel 60, improving its concentricity. Similarly, by engaging the first inclined surface 21 of the fixing ring 20 with the third inclined surface 32 of the concentric deformation block 30, the clamping force in the first direction F1 is partially decomposed into a radial expansion force on the concentric deformation block 30. This drives the positioning ring 61 to contract elastically in the radial direction, clamping the cross bearing 50 and thus achieving automatic centering of the cross bearing 50. Furthermore, by setting a deformation pre-reserved groove 33 on the concentric deformation block 30, it can undergo elastic deformation around the cross bearing 50 under axial pressure and contract radially, uniformly clamping the cross bearing 50 and avoiding stress concentration and component damage during rigid press-fitting.

[0049] The embodiments described above are merely examples of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A flexible gear concentricity calibration fixture for assembling harmonic reducers, characterized in that, The calibration fixture includes: Base flange, A retaining ring is fixedly connected to the base flange, and the retaining ring is provided with a first inclined surface; A concentric deformation block abuts against the fixed ring. The concentric deformation block includes a second inclined surface, a third inclined surface abutting against the first inclined surface, and a deformation reserved groove integrally formed on the third inclined surface. The rigid wheel abuts against the base flange at one end; A cross bearing is located on the side of the rigid wheel opposite to the base flange; The flexible wheel meshes with the rigid wheel and abuts against the concentric deformable block, and is located on the side of the cross bearing away from the rigid wheel. The flexible wheel includes a positioning ring with a fourth inclined surface, which is located on the side of the flexible wheel away from the cross bearing and is engaged with the flexible wheel. The calibration fixture further includes an upper pressure cap with a fifth inclined surface. The upper pressure cap is inserted sequentially into the concentric deformable block and the positioning ring along a first direction from a position on the side of the concentric deformable block away from the fixed ring. The fifth inclined surface contacts the second and fourth inclined surfaces in sequence. Tightening the screw continuously applies pressure to the flexible wheel along the first direction with the upper pressure cap. The fourth inclined surface decomposes the pressure in the first direction and drives the positioning ring to expand elastically in the radial direction to calibrate the concentricity of the flexible wheel. The concentric deformable block moves towards the fixed ring under the pressure in the first direction. The first inclined surface decomposes the pressure in the first direction applied by the third inclined surface and squeezes the concentric deformable block. The deformation groove of the third inclined surface undergoes elastic deformation and clamps the cross bearing to center the cross bearing radially.

2. The flexible gear concentricity calibration fixture for harmonic reducer assembly according to claim 1, characterized in that, The upper cover is also provided with a first reserved hole, a first fastening hole and a second fastening hole that penetrate the upper cover along the first direction; When viewed along the first direction, the first reserved hole and the first fastening hole are located at the edge of the upper cover, and the second fastening hole is located at the center of the upper cover.

3. The flexible gear concentricity calibration fixture for harmonic reducer assembly according to claim 2, characterized in that, The base flange is provided with a second reserved hole that penetrates the base flange along the first direction.

4. A flexible gear concentricity calibration fixture for harmonic reducer assembly according to claim 2, characterized in that, The flexible wheel has a plurality of flexible wheel holes integrally formed therethrough along the first direction; The cross bearing has a plurality of limiting holes integrally formed therethrough along the first direction; The bolt passes sequentially through the first reserved hole, the limiting hole, and the flexible wheel hole along the first direction, and the upper pressure cover, the cross bearing, and the flexible wheel are fixedly connected.

5. A flexible gear concentricity calibration fixture for harmonic reducer assembly according to claim 2, characterized in that, The concentric variable block has a plurality of positioning holes integrally formed therethrough along the first direction.

6. A flexible gear concentricity calibration fixture for harmonic reducer assembly according to claim 5, characterized in that, The bolt passes through the first fastening hole and the positioning hole in sequence along the first direction, and the upper pressure cover is fixedly connected to the concentric variable block.

7. A flexible gear concentricity calibration fixture for harmonic reducer assembly according to claim 3, characterized in that, The calibration fixture also includes a fixing block, which is fixedly connected between the base flange and the upper pressure cover, and has a fixing hole that extends through the first direction.

8. A flexible gear concentricity calibration fixture for harmonic reducer assembly according to claim 7, characterized in that, The calibration fixture also includes: The locking screw passes through the second fastening hole, the fixing hole, and the second reserved hole in sequence; When the locking screw is tightened, the fifth inclined surface of the upper pressure cover abuts against and presses against the fourth inclined surface of the positioning ring, and applies pressure to the positioning ring.

9. A flexible gear concentricity calibration fixture for harmonic reducer assembly according to claim 8, characterized in that, The crossed bearing includes: The roller abuts between the crossed bearing and the flexible wheel; The oil seal skeleton is integrally formed on the cross bearing and is located on the side of the cross bearing near the base flange.

10. A flexible gear concentricity calibration fixture for harmonic reducer assembly according to claim 9, characterized in that, The crossed bearing also includes: The bearing inner ring is integrally formed on the outer surface of the cross bearing and is located between the roller and the oil seal skeleton; The bearing outer ring is integrally formed on the outer surface of the oil seal skeleton.

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