Three-cavity sliding vane vacuum pump cylinder and type line design method thereof

Abstract

The invention discloses a three-cavity sliding vane vacuum pump cylinder and a type line design method thereof. A sine spiral line is adopted to form a cylinder type line; a first suction section curved line, a second suction section curved line and a third suction section curved line as well as a first discharge section curved line, a second discharge section curved line and a third discharge section curved line rotate around an original point at 120 degrees so as to be symmetrical, so that the formed curved lines are in completely smooth connection and second derivative continuity; the sizeof a central angle corresponding to the first suction section curved line is alpha, the size of a central angle corresponding to the first discharge section curved line is beta, alpha is smaller thanbeta, and alpha plus beta is equal to 120 degrees; and three same unsymmetrical working cavities are formed between the cylinder and a rotor, so that the displacement volume is reduced, and the interior volume specific ratio is effectively increased. According to the three-cavity sliding vane vacuum pump cylinder provided by the invention, on the premise of ensuring that the top ends of sliding vanes slide on an inner wall of the cylinder in a contacting way, rigid impulse and flexible impulse are avoided; and the interior volume specific ratio of a sliding vane vacuum pump can be increased through changing the sizes of the central angles corresponding to the curved lines, so that the slide vane vacuum pump has a higher limiting vacuum degree.

Description

technical field [0001] The invention relates to a sliding vane vacuum pump, in particular to a three-cavity sliding vane vacuum pump cylinder body and a design method thereof. Background technique [0002] The sliding vane vacuum pump is a volumetric fluid machine. When rotating, the top of the sliding vane is kept in contact with the inner wall of the cylinder by centrifugal force. The rotor drives the sliding vane to slide along the inner wall of the cylinder, forming a vacuum between the upper and lower end covers, sliding vanes, rotor and cylinder. The closed working chamber realizes the suction, compression and discharge of gas. It has the advantages of high pumping speed, small volume, and can pump a certain amount of condensable gas. It is widely used in machinery, electronics, chemical industry, automobile and other industries. Common vane vacuum pumps include single-chamber, double-chamber and triple-chamber vane vacuum pumps. In order to obtain better working perf...

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Problems solved by technology

Relevant studies have proposed multiple function curves, trigonometric function curves, and multi-segment combination curves, etc., but each working chamber of the corresponding cylinder has a symmetrical structure, and the exhaust volume is large, resulting in a small internal volume ratio and low compression efficiency.

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