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US 10,309,396 B2Granted
Positive displacement pump including an unloading device
AssigneeDeere & Company
InventorsRobert C. Emmert, Thomas W. Butts
Life of this patent
Estimating the term…
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.
Claims10
A fluid transfer pump comprising:
- a housing defining a cavity and a passage having an inlet disposed at an external portion of the housing;
- a movable member disposed within the cavity, the movable member defining a first chamber, wherein the volume of the first chamber is adjustable with movement of the movable member;
- a gear set disposed at the first chamber, wherein the first chamber is configured to hold a fluid;
- and
- a bias element disposed at the movable member, wherein the bias element is configured to adjust the location of the movable member to a first position defining a first volume of the first chamber and to a second position defining a second volume of the first chamber;
- wherein the movable member partially defines a second chamber in which a volume of the second chamber is adjustable with movement of the movable member, and the passage is configured to direct a pilot fluid from the inlet to the second chamber to adjust a size of the second chamber from a first size to a second size;
- further wherein, a first fluid pressure in the first chamber is greater than a second fluid pressure in the first chamber and the second fluid pressure is insufficient to provide a working pressure.
4 more elements
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;
- a bias element disposed between the fixed side 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;
- a gear disposed at the first cavity, wherein the volume of the first cavity is configured to provide a fluid pressure within the first cavity to enable the fluid transfer pump to transfer fluid at a working pressure;
- a spindle coupled to the gear, wherein the gear partially defines the interior wall;
- and
- a fixed second sidewall, a second sidewall bearing located at the fixed second sidewall, and movable member bearing located at the movable member;
- wherein the movable member defines with the housing the first cavity and the second cavity, wherein an increase in volume of the second cavity increases the volume of the first cavity;
- further wherein, the spindle extends from the second sidewall bearing to the movable member bearing.
6 more elements
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 a fixed side wall disposed at an end of the housing;
- a movable member movably disposed within the housing;
- a bias element disposed between the fixed side wall and the movable member, wherein a fluid applied to the passage into the second cavity changes the location of the movable member with respect to the fixed side wall to change a volume of the first cavity;
- a gear disposed at the first cavity and coupled to a spindle;
- and
- a fixed second sidewall, a second sidewall bearing located at the fixed second sidewall, and movable member bearing located at the movable member;
- wherein the movable member defines with the housing the first cavity and the second cavity, wherein an increase in volume of the second cavity increases the volume of the first cavity;
- further wherein, the spindle extends from the second sidewall bearing to the movable member bearing.
5 more elements
Dependencies are inferred from the claim text.