US 2017/0314553 A1 · POSITIVE DISPLACEMENT PUMP INCLUDING AN UNLOADING DEVICE

Abstract

A transfer pump configured to move a hydraulic fluid in a hydraulic fluid management system of a hydraulic system of a vehicle including a transmission. In one embodiment, the transfer pump moves the fluid from a differential case to a hydraulic reservoir coupled to the transmission. The transfer pump is a positive displacement pump including an unloading device, such as a sealing plate, that is resiliently biased against the pump during a normal operation but is moved away from the pump upon the application of a pilot pressure. The result is an open chamber for the pump gears to turn without developing pressure, to thereby reduce parasitic losses.

Claims20

Dependent claims

A fluid transfer pump comprising:

a housing defining a first cavity and a passage operatively coupled to a second cavity, the passage configured to provide fluid transfer into the second cavity, wherein the housing further includes an interior wall disposed in the housing and a fixed side wall disposed at an end of the housing;
a movable member movably disposed within the housing;
and
a bias element disposed between the wall and the movable member, wherein a fluid applied to the passage into the second cavity changes the bias force of the bias element and the location of the movable member with respect to the interior wall to change a volume of the first cavity.

1 more element

Dependencies are inferred from the claim text.

Positive displacement pump including an unloading device

Life of this patent

Positive displacement pump including an unloading device

Life of this patent

Abstract

Claims20