CN-121988988-A - Precise manufacturing method for integrated structure of harmonic reducer

CN121988988ACN 121988988 ACN121988988 ACN 121988988ACN-121988988-A

Abstract

The invention discloses a precise manufacturing method of an integrated structure of a harmonic reducer, in particular to the technical field of manufacturing of the harmonic reducer, comprising the following steps of S1, process decision and optimization; S2, preparing a flexible gear ring gradient material, S3, establishing a reference, S4, carrying out cooperative grinding on a rigid gear, S5, carrying out cooperative processing on a wave generator, S6, integrating an assembly and carrying out in-situ fine adjustment, S7, carrying out pre-tightening solidification and healthy fingerprint implantation, and S8, carrying out initial health information acquisition and association. According to the invention, through the reverse optimization of the digital twin model and the collaborative investigation based on a unified reference, random errors caused by tolerance accumulation of parts are fundamentally eliminated, so that key performance indexes of the product reach the top level on the absolute value, high consistency is realized in batches, the contradiction between tooth wear resistance and root fatigue resistance is broken through from the material level, fatigue crack initiation can be obviously delayed, and the service life of the whole machine is stably broken through and surpassed that of imported peer products.

Inventors

SUN CHENGQUN
ZHONG XIUJUAN
JIANG LIHUI

Assignees

鸣志电器(常州)有限公司

Dates

Publication Date: 20260508
Application Date: 20260204

Claims (10)

1. The precise manufacturing method of the integrated structure of the harmonic reducer is characterized by comprising the following steps of: S1, process decision and optimization are carried out according to performance indexes of target products, reverse optimization is carried out based on a pre-established digital twin model, and a customized current manufacturing process parameter set is generated; S2, preparing a flexible gear ring gradient material, namely cladding metal powder with different components layer by layer along the tooth height direction in a gear ring area of a flexible gear blank by adopting a laser metal deposition technology to form a gradient material layer with gradually changed tooth top to tooth root performance; S3, establishing a reference, namely precisely machining an integrated reference ring belt on the end face of the non-working end of the flexible gear, wherein the end face is prepared by the gradient material; S4, carrying out cooperative grinding on the rigid gear, namely positioning and clamping by using an integrated reference ring belt of the flexible gear, firstly measuring the actual shape of an outer gear ring of the flexible gear in place and generating an error model, and then carrying out paired grinding on the inner tooth surface of a blank of the rigid gear according to the error model; S5, the wave generator is cooperatively processed, namely the flexible gear and the rigid gear processed in the S4 are initially assembled into a semi-integrated assembly, the semi-integrated assembly is positioned by the integrated reference endless belt, the simulation wave generator is inserted, the simulation torque is applied, the tooth surface contact state is measured, and the optimal actual profile of the cam of the wave generator is calculated and processed according to the semi-integrated assembly; s6, integrating the assembly and fine-tuning in situ, namely loading the wave generator processed in the S5 into the semi-integrated assembly, performing simulated operation on a machine tool, measuring return stroke errors and torsional rigidity, and performing selective fine-grinding compensation on the inner tooth surface of the rigid gear or the outer tooth surface of the flexible gear according to a measuring result if the return stroke errors and torsional rigidity do not reach the target; S7, pre-tightening solidification and healthy fingerprint implantation, namely applying axial pre-tightening force to the integrated structure in the state that the S6 reaches the performance target, and synchronously solidifying the relative positions of the wave generator component, the flexible wheel and the bearing by adopting laser scanning welding; And S8, initial health information acquisition and association are carried out, namely pulse excitation is carried out on the solidified integrated structure, the vibration spectrum of the integrated structure is acquired as initial health fingerprint data of the component, and the data are associated to a product identifier.
2. The method for precisely manufacturing an integrated structure of a harmonic reducer according to claim 1, wherein in S1, the digital twin model is a machine learning model which is trained based on historical manufacturing data and can map a relation between a technological parameter and final service performance of a product, and the performance index at least comprises two or more of return stroke error, torsional rigidity, life expectancy and noise level.
3. The method for precisely manufacturing the integrated structure of the harmonic reducer according to claim 1, wherein in the step S2, the gradient material layer is configured such that a first alloy material with high hardness and high wear resistance is clad in a tooth top region, a second alloy material with high toughness and fatigue resistance is clad in a tooth root region, and a transitional mixed layer of the first alloy material and the second alloy material is arranged in a middle region.
4. The method for precisely manufacturing the integrated structure of the harmonic reducer according to claim 1, wherein in S4 and/or S6, the in-situ measurement is performed by a measuring probe coaxial with a main shaft of a machine tool, and the matched grinding or the selective in-situ lapping is performed by the same machine tool.
5. The method for precisely manufacturing an integrated structure of a harmonic reducer according to claim 1, wherein in S5, the cam profile of the analog wave generator can be adjusted in a micro-continuous or discrete manner, and the tooth surface contact state is measured by a plurality of film pressure sensors or gap sensors distributed on the outer ring of the rigid wheel.
6. The method for precisely manufacturing the integrated structure of the harmonic reducer according to claim 1, wherein in the step S6, the selective in-situ lapping is specifically performed by performing magneto-rheological fluid flexible polishing on a high stress area of a tooth surface in the rigid gear when the tooth surface contact stress is judged to be uneven, and performing nanoscale laser ablation shaping on an outer tooth surface of the flexible gear when the return error is excessive due to insufficient deformation of the flexible gear.
7. The method for precisely manufacturing the integrated structure of the harmonic reducer according to claim 1, wherein in the step S3, a shape memory alloy ring is coaxially embedded in a region of the flexible gear cylinder close to the gear ring when the integrated reference annular belt is processed, and in the step S6, if the roundness of the flexible gear ring is found to be out of tolerance by in-situ measurement, controllable micro-current is applied to a corresponding region of the shape memory alloy ring to enable the shape memory alloy ring to generate preset deformation, so that the gear ring is pushed to generate elastic deformation to compensate roundness errors.
8. The method for precisely manufacturing the integrated structure of the harmonic reducer according to claim 6, wherein the grinding tool used for flexibly polishing the magnetorheological fluid is an elastic matrix, the working surface of the grinding tool is provided with a plurality of microcavities filled with the magnetorheological fluid and abrasive particles, and the rigidity and the shape of the working surface of the grinding tool are dynamically adjusted by changing the intensity and the distribution of a gradient magnetic field applied near the grinding tool in the polishing process so as to adapt to the curvature of a tooth surface and carry out intensified polishing on a high-contact stress area.
9. The method for precisely manufacturing the integrated structure of the harmonic reducer according to claim 1, wherein in the step S2, after the laser metal deposition is completed, the flexible gear blank is slowly cooled to a preset temperature range in a controlled heat preservation environment, then reference establishment processing of the step S3 is directly performed, and stress release and stabilization processing is performed by using material residual temperature.
10. The method for precisely manufacturing the integrated structure of the harmonic reducer according to claim 1, wherein in the step S8, the product identifier is a two-dimensional code marked on the non-working surface of the integrated structure by laser, the initial health fingerprint data is stored in an encrypted form in a cloud server, and the two-dimensional code comprises a unique link or an identification code for accessing the cloud data.

Description

Precise manufacturing method for integrated structure of harmonic reducer Technical Field The invention relates to the technical field of manufacturing of harmonic reducers, in particular to a precise manufacturing method of an integrated structure of a harmonic reducer. Background The harmonic reducer has become the core basic component of high-end equipment such as industrial robots, precision machine tools, aerospace servo systems and the like by virtue of excellent characteristics such as high transmission precision, large reduction ratio, compact structure, zero backlash and the like, and the performance of the harmonic reducer directly determines the positioning precision, motion stability and reliability of terminal equipment. However, the domestic high-end harmonic reducer has a remarkable gap from the international center product in the aspects of precision maintenance, service life, consistency and the like, and is seriously dependent on import. At present, the manufacturing of the domestic and foreign harmonic speed reducer generally adopts a traditional mode of 'independent part manufacturing and later-stage precise assembly', and the mode has the following inherent limitations: 1. The three core parts of the flexible wheel, the rigid wheel and the wave generator are independently processed according to the respective drawing tolerances, and then assembled through 'selective matching' or 'manual adjustment', the form and position tolerances and the heat treatment deformation of the parts are randomly overlapped in an assembly link, so that the final transmission precision (such as return error) is high in dispersity, the high precision requirement is difficult to stably reach, and the precision is seriously dependent on the experience of an assembler, so that large-scale and consistent production cannot be realized; 2. The failure mode of the flexible gear serving as a core piece working under periodical elastic deformation is mostly tooth surface abrasion and tooth root fatigue fracture, the prior art adopts homogeneous materials (such as 40Cr or martensitic stainless steel) and balances the hardness and the toughness through integral heat treatment, but the high wear resistance required by tooth tops and the high fatigue resistance required by tooth roots are mutually contradictory to the requirements on the material performance, so that the service life of the flexible gear is difficult to obtain a fundamental breakthrough; 3. In order to obtain ideal meshing state and pretightening force, an adjusting gasket, a measuring gap, a tightening bolt and a test are required to be repeatedly added in the assembly process, the process is long in time consumption and low in efficiency, the pretightening force is applied by empirical control, early failure of the flexible gear is easily caused when the pretightening force is too large, torsional rigidity and precision are affected when the pretightening force is too small, and accurate, rapid and repeatable locking of the optimal state is difficult to realize. Disclosure of Invention In order to overcome the defects in the prior art, the invention provides a precise manufacturing method of an integrated structure of a harmonic reducer. In order to achieve the purpose, the invention provides the following technical scheme that the precision manufacturing method of the integrated structure of the harmonic reducer comprises the following steps: S1, process decision and optimization are carried out according to performance indexes of target products, reverse optimization is carried out based on a pre-established digital twin model, and a customized current manufacturing process parameter set is generated; S2, preparing a flexible gear ring gradient material, namely cladding metal powder with different components layer by layer along the tooth height direction in a gear ring area of a flexible gear blank by adopting a laser metal deposition technology to form a gradient material layer with gradually changed tooth top to tooth root performance; S3, establishing a reference, namely precisely machining an integrated reference ring belt on the end face of the non-working end of the flexible gear, wherein the end face is prepared by the gradient material; S4, carrying out cooperative grinding on the rigid gear, namely positioning and clamping by using an integrated reference ring belt of the flexible gear, firstly measuring the actual shape of an outer gear ring of the flexible gear in place and generating an error model, and then carrying out paired grinding on the inner tooth surface of a blank of the rigid gear according to the error model; S5, the wave generator is cooperatively processed, namely the flexible gear and the rigid gear processed in the S4 are initially assembled into a semi-integrated assembly, the semi-integrated assembly is positioned by the integrated reference endless belt, the simulation wave generator is inserted, the simulation torque is