Rotary pump with improved seal

摘要

A rotary pump with an improved seal on a control pressure chamber, including: a housing having a delivery chamber; a feed wheel rotatable in the delivery chamber; an actuating member surrounding the feed wheel forming delivery cells and moveable in the housing relative to the feed wheel. The control pressure chamber is delineated by the actuating member together with axially facing axial co-operating surfaces, forming an axial sealing gap and a radial sealing gap. A control fluid can be introduced into the control pressure chamber for applying pressure to the actuating member to exert an actuating force in the actuating direction; a restoring device for generating a restoring force; and a sealing element arranged on the actuating member or the circumferential co-operating surface. To compensate for a change in gap width of one of the axial sealing gaps, a base leakage cross-section is provided on the sealing element.

主权项

1. A rotary pump with an improved seal on a control pressure chamber, comprising:
a housing comprising an inlet and an outlet for a fluid, and a delivery chamber which connects the inlet and the outlet; a feed wheel which can be rotated about a rotational axis in the delivery chamber; an actuating member which surrounds the feed wheel at the circumference and forms delivery cells with the feed wheel and can be moved back and forth in the housing relative to the feed wheel, in an actuating direction and an actuating counter direction, in order to adjust the specific delivery volume of the rotary pump, wherein the control pressure chamber is delineated by the actuating member and axially facing axial co-operating surfaces together, respectively forming an axial sealing gap, and by the actuating member in sliding contact with a circumferential co-operating surface which faces the outer circumference of the actuating member, forming a radial sealing gap, and wherein a control fluid can be introduced into the control pressure chamber for applying pressure to the actuating member, in order to exert an actuating force on the actuating member in the actuating direction; a restoring device for generating a restoring force which acts on the actuating member in the actuating counter direction; and a sealing element which is arranged on the actuating member or the circumferential co-operating surface and situated in the sliding contact, wherein in order to compensate for a change in the gap width of one of the axial sealing gaps, a base leakage cross-section is provided on the sealing element, through which control fluid can flow off from the control pressure chamber to a low-pressure side of the pump.