FIELD OF THE INVENTION

The present application relates to a vane pump, and particularly a vane pump with an improved seal assembly for sealing a control chamber.

BACKGROUND

FIG. 2shows a seal assembly100used in prior art vane pumps. The seal assembly has a bearing element102slidably engaged with the pump housing interior surface, and a base member104supporting it. The seal assembly100is mounted in a recess48formed on a part of the control slide18, which are discussed below.

The inventor have recognized that the prior seal assembly100has the disadvantage of the two parts102,104not being positionally located to one another. This allows the base member104to shift in the slide seal groove48and not be centered with the bearing element102. That causes uneven pressure on the bearing element102, and therefor uneven contact of the bearing element102on the inside surface of the pump housing.

SUMMARY OF THE INVENTION

The present application provides a vane pump comprising: a housing having an inlet and an outlet, and a control slide having a rotor receiving space communicated to the inlet and the outlet. The control slide is mounted in the housing for pivotal movement in opposing displacement increasing and displacement decreasing directions. A rotor comprises a plurality of vanes. The rotor is mounted to the housing and positioned within the rotor receiving space of the control slide. The rotor rotates in the rotor receiving space to draw lubricant under negative pressure into the rotor receiving space via the inlet and discharge the lubricant from the rotor receiving space via the outlet under positive pressure. Movement of the control slide in the displacement increasing direction increases eccentricity between the rotor and the control slide for increasing a pressure differential between the inlet and outlet, and movement of the control slide in the displacement decreasing direction decreases the eccentricity for decreasing the pressure differential. A resilient structure is positioned between the housing and the control slide to bias the control slide in the displacement increasing direction.

The control slide has one or more seals defining a control chamber between the control slide and the housing. The control chamber is communicated with a source of the pressurized lubricant to move the control slide in the displacement decreasing direction.

The one or more seals includes a seal assembly received in a recess formed in an outer surface of the control slide. The seal assembly has a base element received in the recess and a bearing element pivotally attached to the base element and bearing against an inner surface of the housing to provide sealing for the control chamber as the control slide moves in the displacement increasing and decreasing directions. One of the base element and the bearing element has a male pivotal connector and the other of the base element and the bearing element has a female pivotal connector. The male and the female pivotal connectors are coupled together.

Other aspects, features and advantages of the present application will become apparent from the following detailed description, the accompanying drawings, and the appended claims.

