Bauman Moscow State Technical University (Moscow, Russia):

A. A. Goncharov, Assistant, “Mechanical Engineering Technology” Dept., E-mail: al.goncharov@bmstu.ru

Modern designs of volumetric machines have parts containing complex-profile cycloidal screw surfaces as working bodies. The shaping of some types of this surfaces, such as the rotor surface of a conical singlescrew compressor, is possible only through the use of non-profiled tools and using specialized machining strategies. In view of the high prospects of using such structures in astronautics, robotics, medicine in the mining industry and metallurgy, there is an urgent problem of cycloidal helical surfaces accuracy during their processing on CNC machines. This work is devoted to the study of this problem. In the course of the study, a technological approach was chosen that provides control of the shape accuracy parameters when processing these surfaces, which consists in programmed feed control during processing. An analytical formalized algorithm for calculating the amount of feed change was integrated into an automated system for calculating the tool path, which made it possible to carry out experimental processing of a series of samples. The results of a metrological study of the accuracy of the shape of samples processed using a software-implemented technique for increasing the accuracy of the cross-section of cycloidal helical surfaces are presented. The efficiency of application of the proposed technique in the processing of miniature cycloidal helical surfaces is shown. Therefore, for the singlescrew micro-dispenser selected as a characteristic part of the rotor, it was possible to reduce the deviation from the circularity of the crosssectional profile of the cycloidal screw surface by more than three times. This demonstrates the possibility of increasing the accuracy of processing a complex-shaped surface by modifying the code of the control program without using additional equipment or more advance tools.

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