What are the difficulties in precision machining of harmonic reducers for humanoid robots? How to break the thin wall deformation of the flexible wheel?

In the joint transmission systems of humanoid robots, collaborative robots, high-end automation equipment, harmonic reducers have become the core components that determine the overall motion performance of the machine due to their irreplaceable advantages such as small size, large reduction ratio, high transmission accuracy, small backlash. A humanoid robot typically requires 14 to 30 harmonic reducers throughout its body, distributed in various joints such as shoulders, elbows, wrists, hips, knees, ankles, etc. With the continuous improvement of load levels increasingly stringent motion control requirements for humanoid robots, the manufacturing accuracy of harmonic reducers directly affects the repeatability, stability, service life of the entire machine. As a local enterprise deeply engaged in high-end precision machining in Shenzhen, Huiwen Zhizao provides a full chain manufacturing solution for key structural components of harmonic reducers, material selection, process development to finished product delivery, with five axis CNC machining as the core technology.

1、 Why is it difficult to manufacture harmonic reducers? Core structure analysis of fatal pain points in the industry

The harmonic reducer is mainly composed of three core components: flexible wheel, rigid wheel, wave generator. Among them, the flexible wheel is the component with the highest technical threshold in the entire reducer. It needs to work stably for a long time under periodic elastic deformation, has extremely high requirements for material fatigue strength, tooth profile accuracy, inner wall smoothness. For the rigid wheel, it is necessary to ensure the indexing accuracy hardness uniformity of the internal gear ring. The cam profile accuracy of the wave generator directly determines the meshing trajectory transmission smoothness of the flexible wheel.

In the actual machining process, the clamping deformation control of thin-walled structures with flexible wheels is a recognized difficulty in the industry. The cylindrical structure with a wall thickness usually only ranging 0.5mm to 2mm is prone to elastic deformation under cutting force, resulting in accumulated tooth pitch errors exceeding the tolerance. In addition, the flexible wheel will undergo irregular deformation after heat treatment. How to correct the deformation ensure the final roundness of the gear ring through precision machining is a systematic process issue that needs to be solved in precision parts processing. Shenzhen Huiwen Intelligent Manufacturing combines customized soft claw fixtures with low stress cutting technology to control the roundness error of the flexible wheel after processing within a strict range, ensuring that the backlash after assembly meets the design specifications.

2、 Key process points of CNC machining in the manufacturing of harmonic reducers

The machining of harmonic reducer components is a single process that can be completed, but a precision manufacturing process that involves multiple collaborative processes such as turning, milling, grinding, hobbing, gear hobbing. In the CNC machining process, the five axis linkage machining center can complete the composite machining of the flexible wheel flange end face, positioning stop, installation hole in one clamping, avoiding the accumulation of benchmark errors caused by multiple clamping. For the machining of the inner gear ring of the rigid wheel, a high-precision CNC gear hobbing forming grinding connection scheme is adopted. After heat treatment, the heat treatment deformation is corrected by grinding the teeth, the tooth profile error tooth orientation error are controlled within the design requirements.

The cam profile of the wave generator is precision CNC turned with contour grinding to ensure the lift accuracy surface roughness of the cam curve, reduce the wear rate of the flexible wheel during high-speed operation. Material selection is also an important step in precision machining of parts: the flexible wheel usually uses high-strength alloy structural steels such as 30CrMnSiA 40CrNiMoA, which are quenched tempered to obtain good comprehensive mechanical properties; Steel wheels often use 42CrMo carburizing quenching processes to improve the wear resistance of the tooth surface. During the incoming material stage, material spectral retesting hardness sampling are conducted to eliminate the impact of batch differences on the accuracy of the finished product the source. Relying on a hardware foundation of 20000 square meters of production plants over 370 precision machining equipment, Huiwen Zhizao has the ability to provide integrated services throughout the entire chain design, intelligent manufacturing to assembly. raw material inspection, multi process precision machining to finished product assembly, Huiwen Zhizao achieves independent controllable control of the entire process of harmonic reducer core components, ensuring consistency in batch product accuracy delivery stability.

3、 Precision testing quality control system

As a precision transmission component, the machining quality of harmonic reducers cannot rely solely on final inspection, but must be integrated throughout the entire process. Huiwen Zhizao has established a three-level quality control mechanism for the first Zeiss three coordinate inspection, process inspection, full-size re inspection of finished products. The flexible gear ring adopts a gear measurement center for full parameter measurement of tooth profile, tooth direction, tooth pitch; Use a dedicated gear measuring instrument to verify the meshing accuracy of the inner gear ring of the rigid wheel; The cam profile of the wave generator is jointly detected using a roundness meter a contour meter.

In the assembly verification stage, the transmission accuracy test bench is used to detect the backlash transmission error of the entire machine, ensuring that each batch of reducer housings structural components can meet the assembly requirements of the robot manufacturer. For application scenarios with special dust corrosion prevention requirements, surface treatment processes such as anodizing electroless nickel plating can also be provided to extend the service life of components under complex working conditions.

4、 Delivery advantages of Shenzhen Huiwen Intelligent Manufacturing

As a local precision machining enterprise in Shenzhen, Huiwen Zhizao's services cover high-end manufacturing fields such as humanoid robots, collaborative robots, semiconductor equipment, medical devices, etc. For the small-scale trial production needs of harmonic reducer customers, a fast sampling cycle of 7 to 15 days can be provided; For mass production orders, stable batch delivery capability is achieved through process standardization flexible production line configuration. a single prototype to large-scale production with an annual output of tens of thousands of pieces, consistent precision levels can be maintained. The company has passed ISO9001 IATF16949 quality management system certification, is a national high-tech enterprise specialized innovative enterprise. Currently, it has provided precision parts processing services to many technology innovation enterprises research institutions such as Huawei, Xinsong, Xiaomi Ecological Chain Enterprise, Beijing Institute of Technology, Chinese Academy of Sciences. If you are looking for a CNC machining supplier with precision machining capabilities for harmonic reducer structural components, please feel free to contact Shenzhen Huiwen Zhizao. We will provide customized process solutions quotation support based on your drawing requirements working conditions.