Strictly-sealed screw rotor profile of dry-type screw vacuum pump

Abstract

The invention discloses a strictly-sealed screw rotor profile of a dry-type screw vacuum pump, which belongs to the technical field of dry-type screw vacuum pumps. The rotor profile disclosed by the invention comprises six sections of curves, namely an involute ab, a transition curve bc, a tooth crest arc cd, a prolate cycloid de, a tooth root arc ef and a transition curve fa. The transition curve bc and the transition curve fa are designed to be with conjugate of arcs and cycloids or conjugate of cycloids and arcs. The two transition curves are respectively added between the tooth crest arc cd and the involute ab and between the tooth root arc ef and the involute ab to form smooth connection, so that leakage areas are avoided and strict sealing is formed. The changes of end faces generated from the smooth connection promote the improvement of dynamic properties. Meanwhile, the transition curves enable the tooth root of a rotor to be smoothly connected with a tooth profile part, so that only one cutter is needed to process the tooth root and the tooth profile and the manufacturing cost is effectively lowered. The dry-type screw vacuum pump with the profile disclosed by the invention can be widely applied to the fields of electrons, semiconductors, chemical industry, food, aerospace and the like.

Description

Technical field: [0001] The invention relates to a dry screw vacuum pump, in particular to a screw rotor profile of a dry screw vacuum pump suitable for paired strict sealing. Background technique: [0002] The dry screw vacuum pump is a positive displacement pump, relying on the airtight volume formed by the two screw rotors in the pump and the inner cavity of the pump body to transport gas and form a vacuum at the pump inlet. The key technology of the dry screw vacuum pump is a pair of intermeshing helical rotors. The key to the intermeshing rotors is the end surface profile of the rotor. The quality of the end surface profile will directly affect the performance of the screw vacuum pump, such as sealing and efficiency. , Area utilization coefficient, etc., at the same time determine the processing and manufacturing cost of the pump. Almost all the invention patents for profiled lines with better rotor performance of screw vacuum pumps are applied abroad or in Taiwan, and...

AI Technical Summary

Problems solved by technology

For example, the invention patent 201010605321.6 published in China is a pair of self-conjugate rotor profiles, but the designed helix and large arc, the helix envelope and the small arc are not smooth transitions, especially this The position of the intersection of the two curves is not completely conjugated, there is a relatively obvious leakage area, and the manufacture of the transition area is time-consuming

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