The impeller is the most important part on the rotor, and is generally composed of a wheel disc, a wheel cover and a blade. An integral impeller is an impeller in which the blades are fixed on the disc. When machining the impeller, in order for the impeller to meet the aerodynamic requirements, a large amount of material between the blades will be removed, and the blade structure will adopt a large twist angle and rounded roots.
This brings more difficulty to the impeller machining: the machining groove becomes smaller and narrower, the machining is extremely easy to deform, the machining groove is extremely deep, the tool is easily broken during machining, the overall impeller surface is a free-form surface, the blade is twisted seriously, and the machining is difficult. , it is difficult to maintain the consistency of the machined surface. The overall impeller requires high dynamic balance, and the impeller symmetry problem should be comprehensively considered during processing to minimize the errors caused by clamping and tool change.
To sum up, we use a vertical five-axis CNC machining center to process the integral impeller. Workpiece clamping should try to choose a fixture with small volume and light weight to reduce the impact of clamping on the workpiece.
Use solid carbide coated tools and add high-speed tool holders to extend the length of the tool. For products with complex profiles such as impellers, the three-coordinate measurement profile data is used, and the collected data is compared with the product modeling to determine the machining accuracy. Use special impeller processing programming software to process the integral impeller.
During five-axis machining, pay attention to the direction of the tool axis to avoid interference with the workpiece, and pay attention to the advance and retraction of the tool. When retracting the tool, it should exit the machining profile with the tool feed path to avoid interference.