Simulation of the surface profile of the groove bottom enveloped by milling cutters in single screw compressors

In machining of a single screw compressor, the milling technique of screw rotor grooves with cylindrical milling cutters has far higher machining efficiency than turning. But, the screw groove bottom surface produced by the flat end of milling cutters will fail to mesh with the flat tooth tip hermetically, and thus give rise to compressed gas leakage. This paper carries out a mathematic simulation of the screw groove bottom surface profiles. The research brings screw groove bottom profiles machined by different cylindrical milling cutters to light, and provides some references for designing the column envelope meshing pairs in single screw compressors.

Research highlights► Cylindrical milling of the screw groove of a single screw compressor will produce an uneven groove bottom surface. ► When the flat tooth tip meshes with the groove bottom, clearance exists between them and allows gas leakage. ► Chip gullet at the center of the cutter end will leave too much material on the groove bottom at some position, where the newly produced groove bottom will interfere with the flat tooth tip.