A three-screw screw with circular arc correction tooth shape

Abstract

The invention discloses a triple screw for correcting tooth profiles through arcs. The triple screw comprises two double-end driven screw bodies and a double-end driving screw body. The driving screw body is located in the middle, and the driven screw bodies are symmetrically arranged along the circumference of the driving screw body. Each tooth profile of each driven screw body is composed of the transition arc, a long-amplitude epicycloid, a tooth root circle and a tooth crest circle. Each tooth profile of the driving screw body is composed of an arc envelope line, a tooth crest circle and a tooth root circle. The design range of the radius of the transition arc in each tooth profile of each driven screw body is ro / dj, and the value ranges from 0.015 to 0.025. According to the triple screw for correcting the tooth profiles through the arcs, smoothness is achieved in the engagement process, wear resistance of the driven screw bodies is remarkably improved, the work life of a screw pair is prolonged by about 30% to 40%, and the stable volume efficiency is kept. In addition, when a disc milling cutter or a grinding wheel machines the driving screw body, the service life of the cutter is prolonged by about 50%, and the machining difficulty is reduced.

Description

technical field [0001] The invention belongs to the technical field of screw pumps, and relates to a modification of the tooth profile of a three-screw, more specifically, it relates to a three-screw which adopts an arc to modify the tooth profile. Background technique [0002] In the common three-screw pumps currently on the market, the tooth shape of the driven screw end surface includes dedendum circle, long epicycloid, radial straight line and addendum circle, and the tooth shape of the active screw end surface includes dedendum circle, epicycloid, short Epicycloids and addendum circles. Because there is a sharp angle at the junction of the radial straight line and the addendum circle in the tooth profile of the driven screw, during operation, the driven screw is more likely to wear when it rotates, which increases the leakage of the screw pump during the working process , the volumetric efficiency drops. On the other hand, when using a disc milling cutter or grinding ...

AI Technical Summary

Problems solved by technology

Because there is a sharp angle at the junction of the radial straight line and the addendum circle in the tooth profile of the driven screw, during operation, the driven screw is more likely to wear when it rotates, which increases the leakage of the screw pump during the working process , volumetric efficiency drops

On the other hand, when using a disc milling cutter or grinding wheel to process a screw, not only there are sharp corners in the outline of the milling cutter or grinding wheel, which is easy to wear and shorten the tool life, but also the installation angle of the tool is strictly limited, making the machining difficult increase

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