A new toothed screw profile

Abstract

The invention discloses a novel tooth-shaped screw type wire, which belongs to the technical field of dry type screw vacuum pumps. The screw type wire disclosed by the invention comprises 5 curve segments, including a dedendum arc ab, a deformed involute bc, an envelop curve cd of a deformed involute b'c', an addendum arc de and a long cycloid ea, wherein the dedendum arc ab and the deformed involute bc are in smooth transition, and the envelop curve cd and the addendum arc are in smooth transition. According to the screw type wire disclosed by the invention, the deformed involutes and the envelop curve are taken as transition curves between the dedendum arc and the addendum arc, so that the dedendum arc and the addendum arc are in smooth connection with the transition curves to prevent a leakage zone and a stagnation zone and to form tight sealing, and the change of a formed end face prompts the improvement of dynamic performance; and simultaneously, the dedendum and the tooth profile part of a rotor are in smooth connection by virtue of the transition curves, and thus manufacturing costs are effectively reduced. The dry type screw vacuum pump provided by the invention can be widely applied to the fields of electronics, semiconductors, chemical industry, food, aerospace and the like.

Description

technical field [0001] The invention relates to a dry-type screw vacuum pump, in particular to a screw profile suitable for paired dry-type screw vacuum pumps. Background technique [0002] The dry screw vacuum pump is a positive displacement pump, relying on the airtight volume formed by the two screws in the pump and the inner cavity of the pump 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 screw rotors. The key to the intermeshing rotors is the end surface profile of the screw. 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 of the invention patents for the better screw performance of screw vacuum pumps are applied abroad or in Taiwan, and there are relatively few domestic applicat...

AI Technical Summary

Problems solved by technology

The same problem exists in the invention patent 201010605321.6 published in China. This patent describes a pair of self-conjugated screw profiles, but its designed exponential helix and addendum arc, exponential helix envelope and dedendum The arc does not explain the transition form, and it is obvious that the intersection of these two curves is not completely conjugated, and there are also obvious leakage areas and stagnation areas.

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