Variable sealed hydraulic pump or motor

Claim 2

In a hydraulic device comprised of a housing having a cavity therein having spaced opposing end walls, shaft means extending into said cavity through one of said end walls and rotatably supported in said housing, a plurality of displacement members in said cavity and rotatable with said shaft means and cooperating to define a plurality of axially open ended chambers which progressively increase and decrease in volume as said shaft means rotates to respectively take in and discharge hydraulic fluid, inlet and outlet ports in said housing and arranged to communicate with said increasing and decreasing volume chambers, the improvement comprising: a sealing plate in the form of a washer disposed between at least one axial end of said members and one of said end walls and having an opening through which said shaft means extend; the total axial width of said displacement members and said plate being slightly less than the spacing between said end walls to provide a running clearance; one side of said plate being normally in engagement with the adjacent end wall of the cavity in said housing, and the other side of said plate being normally spaced from said one axial end face by said running clearance; means rigidly securing the outer periphery of said plate to aid housing; means responsive to operating conditions of said device biasing the inner periphery of said plate toward said displacement members.

Claim 3

The improved device of claim 1 and including a plate at both axial ends of said displacement members.

Claim 4

The improved device of claim 1 and further including pressure groove means in said housing communicating the pressure of the device to the side of the plate normally in engagement with the adjacent side wall of the cavity whereby the fluid pressure acts against said plate to displace it toward said displacement members.

Claim 5

The improved device of claim 1 and including means responsive to the temperature of the hydraulic fluid for deforming said inner periphery of said plate into engagement with said axial end face.

Claim 6

The improved device of claim 1 and including means responsive to the temperature and means responsive to the pressure of the device for deforming said inner periphery of said plate into sealing engagement with said axial end face.

Claim 7

The improved device of claim 1 wherein said plate is of a bi-metallic construction.

Claim 8

The improved device of claim 6 wherein the metal of the plate on the side spaced from said one axial end face hAs a greater coefficient of thermal expansion than the metal comprising the plate''s other side.

Claim 9

The improved device of claim 1 wherein said displacement members comprise: an externally toothed gear supported on said shaft for rotation therewith, an internally toothed ring gear surrounding said externally toothed gear and having teeth in sliding sealing engagement therewith, said teeth defining said open ended chambers, said plate means having a port therethrough located adjacent the open meshed position of said chambers and adapted to communicate the side of said plate, adjacent said housing with said open meshed chamber.

Claim 10

The improved device of claim 16 wherein said port is positioned radially less than the root diameter of said internally toothed ring gear but greater than the diameter of the tips of the teeth. 10, The improvement of claim 9 wherein the end wall of said housing at open mesh has a recess communicating with said port and extending radially inwardly short of said shaft opening and between but spaced from the circumferential ends of the inlet and outlet manifolds.

Claim 11

In a hydraulic device comprised of a housing having a cavity therein having spaced opposing end walls, shaft means extending into said cavity through one of said end walls and rotatably supported in said housing, a plurality of displacement members in said cavity and rotatable with said shaft means and cooperating to define a plurality of axially open ended chambers which progressively increase and decrease in volume as said shaft means rotates to take in and discharge hydraulic fluid, inlet and outlet ports in said housing and arranged to communicate with said increasing and decreasing volume chambers, the improvement comprising: a sealing plate normally in the form of a dished washer disposed between at least one axial end of said members and one of said end walls and having an opening through which said shaft means extend; the total axial width of said displacement members and said plate being slightly less than the spacing between said end walls to provide a running clearance; means rigidly securing the outer periphery of said plate to said housing, and biasing the inner periphery of said plate toward said one end wall by compressing said plate between an end wall and said securing means; means responsive to operating conditions of said device for overcoming the bias of the plate and urging the inner periphery of said plate toward said displacement members thereby reducing said running clearance.

Claim 12

In a hydraulic device comprised of a housing having a cavity therein having spaced opposing end walls, shaft means extending into said cavity through one of said end walls and rotatably supported in said housing, a plurality of displacement members in said cavity and rotatable with said shaft means and cooperating to define a plurality of axially open ended chambers which progressively increase and decrease in volume as said shaft means rotates to take in and discharge hydraulic fluid, inlet and outlet ports in said housing and arranged to communicate with said increasing and decreasing volume chambers, the improvement comprising: a sealing plate normally in the form of a dished washer disposed between at least one axial end of said members and one of said end walls and having an opening through which said shaft means extend; the total axial width of said displacement members and said plate being slightly less than the spacing between said end walls to provide a running clearance; means rigidly securing the outer periphery of said plate to said housing, and biasing the inner periphery of said plate toward said one end wall by compressing said plate between an end wall and said securing means; means responsive to operating conditions of said device for overcoming the bias of the plate and urging the inner periphery of said plate toward said displacement members thereby reducing said running clearance.

Claim 13

The improved device of claim 11, wherein means communicate the high pressure between said plate and end wall whereby said operating conditions include the hydraulic pressure of the device.

Claim 14

The improved device of claim 11 wherein said plate is bimetallic whereby said operating conditions include the temperature of the device.

Claim 15

The improved device of claim 13 wherein means communicate the high pressure between said plate and end wall whereby said operating conditions additionally include the hydraulic pressure of the device.