COMPUTER AIDED GEOMETRICAL ANALYSIS OF THE GEOMETRICAL CHARACTERISTICS OF A HELICAL SCREW COMPRESSOR

摘要

In this paper a universal program developed by the authors is introduced, which is used to calculate all the useful geometrical relationships and parameters of a helical screw compressor, the rotor end profile of which may be of any practical shape. The geometrical relationships include those which are required in a thermodynamic model for simulating the working processes of the compressor, such as, the cross-sectional area bounded by the two rotors, and the housing bores, the cavity volume, the axial and radial discharge port areas, the contact line length, the blow hole areas along the two cusps of the housing bores, the tip to bore sealing line lengths and the leakage path widths on the rotor end faces at suction and discharge end, all of which are expressed in terms of the rotational angle of the male rotor. The geometrical parameters include those which are required both in the thermodynamic model and for the design of the compressor, such as, the overlap conftant, the full thread cross-sectional area, the theoretical and real cavity volumes, the suction-stop angle and discharge port opening angles, and the suction and discharge pocket volumes, etc. The definitions of these geometrical relationships and parameters and the mathematical procedures for their calculations are presented.