Design of Hobbing Cutter for Variable-Pitch Screw Rotor

Innovatively extended a single-degree-of-freedom hobbing algorithm and proposed a low cost processing method for variable-pitch screw rotor of twin screw compressor and expander. Firstly, summarized the design method of hobbing cutter for constant-pitch screw rotor and derived the three-degree-of-freedom hobbing algorithm. Secondly, extended the algorithm to the design method of variable-pitch hob which can process the variable-pitch screw rotor. Finally, a design example which pitch has changed by a factor of 1.7 is given to verify the algorithm.