What precision machining challenges does five axis CNC solve for the joint shell processing of humanoid robots?

The humanoid robot integrates motors, reducers, encoders, torque sensors inside each joint, the entire set of electromechanical units relies on joint shells to carry protect. The machining accuracy structural rigidity of the shell directly determine the overall motion stability load capacity of the robot. the shoulder elbow joints to the wrist hip joints, there are differences in the mechanical loads internal assembly spaces borne by different joint shells, which belong to typical high difficulty thin-walled complex structural components. Shenzhen Huiwen Intelligent Manufacturing focuses on five axis CNC machining provides one-stop manufacturing services for precision parts such as joint shells, structural brackets, connecting flanges for humanoid robot collaborative robot manufacturers.

1、 Practical difficulties in the processing of joint shells for humanoid robots

Typical robot joint structural components include motor housing, reducer mounting seat, encoder cover plate, cross roller bearing seat, connecting flange, other parts. The common features of these parts are: thin wall thickness to control weight, strict form position tolerances to ensure assembly coaxiality, multiple installation surfaces complex spatial angles, materials typically made of aluminum titanium alloys to balance strength lightweight. Taking the elbow joint shell of a humanoid robot as an example, its interior needs to accommodate the frameless torque motor stator, harmonic reducer, cross roller bearings, dual encoder simultaneously. There are strict requirements for coaxiality perpendicularity between the installation stops of each component, usually within 0.01mm.

The outer wall of the shell also needs to be designed with features such as cable trays, sensor installation positions, heat dissipation ribs, which makes it difficult to complete traditional three-axis machining in one go requires the use of five axis CNC machining centers to achieve multi-faceted composite machining. Meanwhile, thin-walled structures are prone to vibration during the cutting process. How to optimize tool paths cutting parameters to achieve good surface quality dimensional stability is the core process challenge in precision parts machining.

2、 Five axis CNC machining solves the complex machining problem of thin-walled joint shells

The five axis linkage machining center is the core equipment for precision machining of robot joint structural components. Through the coordinated motion of the three linear axes X, Y, Z the two rotational axes A C, a five axis machine tool can complete all machining tasks such as milling, drilling, tapping, boring of the five surfaces of the part in one clamping. This is particularly important for parts with multi spatial angle features such as joint shells - one clamping means eliminating the reference error caused by multiple flips, the positional accuracy between each installation stop is directly guaranteed by the machine tool accuracy.

In response to the pain points of deformation of thin-walled shells, Huiwen Zhizao relies on the German imported Demage five axis linkage machining center, combined with a complete matrix of precision three-axis, four axis, five axis equipment, turning milling composite, CNC lathe other processing equipment, to precipitate a mature process solution: firstly, using customized hydraulic fixtures vacuum suction cups to achieve low stress clamping of thin-walled shells, avoiding clamping deformation; Secondly, a three-stage cutting strategy of rough machining, semi precision machining, precision machining is adopted. After rough machining, the internal stress of the material is released, a uniform margin is reserved for semi precision machining. For precision machining, a high-speed small cutting depth method is used to obtain good surface quality; Finally, precision boring is performed on the key mating surfaces, with an aperture accuracy of up to H6 level a surface roughness of Ra0.8 less. In terms of materials, the most commonly used joint structural components for robots are 7075-T6 aluminum alloy, which has high strength, light weight, good cutting performance; For high load joints scenarios with corrosion resistance requirements, TC4 titanium alloy 304 stainless steel should be selected.

3、 Surface treatment assembly accuracy guarantee

The surface treatment of joint shells only affects appearance, but also affects corrosion resistance assembly reliability. Huiwen Zhizao provides a complete set of surface treatment processes: hard anodizing can increase the surface hardness of aluminum alloys to HV300 above, significantly enhancing wear resistance; Ordinary anodizing can achieve multiple colors such as black, silver, deep space gray, meeting the requirements of overall appearance consistency; Conductive oxidation is suitable for installation surfaces that require electromagnetic shielding. For titanium alloy parts, micro arc oxidation treatment can be provided to improve surface hardness corrosion resistance. The guarantee of assembly accuracy begins with the precision reservation in the processing stage. Huiwen Zhizao adopts transitional fit tolerance design for the bearing position motor stator position in the joint shell processing, uses end face runout control for the reducer installation surface to ensure that customers can achieve precise fit without additional repairs during assembly.

4、 Full cycle service prototype iteration to mass production delivery

The humanoid robot industry is in a period of rapid iteration, with frequent changes in joint shell design. Huiwen Zhizao provides flexible fast sampling services for customers in the R&D stage: single to small batch orders can be delivered within 7 to 15 working days, supporting rapid iteration modification of design drawings. After entering the mass production stage, the single piece processing time is compressed through process solidification, fixture standardization, production line special machine configuration, achieving cost controllable large-scale delivery. In terms of quality control, Huiwen Zhizao performs first piece Zeiss three-dimensional full-size inspection on each batch of joint structural components, random inspection of key dimensional processes, full inspection of finished product appearance thread connection stop specifications. All inspection data is traceable meets the supply chain quality audit requirements of robot manufacturers. 

As a service provider specializing in precision robot parts processing in Shenzhen, Huiwen Zhizao has passed ISO9001 IATF16949 quality management system certifications, is a national high-tech enterprise specialized new enterprise. Our business covers humanoid robots, mechanical dogs, flexible robotic arms, bionic robots, medical robot components, can undertake full chain OEM single piece sampling to medium to large-scale production; At present, we have served numerous listed companies, industry leaders, research institutions such as Lenovo, Xinsong, Xiaomi Ecological Chain, Beijing Institute of Technology, our product quality has been verified through practical projects. The company has a production plant of 20000 square meters, more than 370 processing equipment, multiple five axis machining centers. If you have machining needs for joint shells, structural brackets, connecting flanges other parts, please provide drawings technical requirements to customize professional manufacturing solutions for you.