US 9,657,726 B1Granted

Hydraulic running surface

AssigneeHydro-Gear Limited Partnership

InventorNathan W. Bonny

Life of this patent

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Abstract

A mounting member for a hydraulic pump or other rotating kit for a hydraulic drive device includes a running surface having a pair of arcuate kidney ports formed thereon. The running surface also includes a plurality of pressure gradient grooves formed on the running surface, each pressure gradient groove having a proximal end adjacent to a respective one of the ends of one of the kidney ports and a distal end. The distal end of one of the pressure gradient grooves associated with one kidney port may overlap the distal end of a pressure gradient groove associated with the other kidney port. The distal end of at least one of the pressure gradient grooves is located outside the circumference of a pitch circle that passes through the center of each of the kidney ports. The distal end of at least one of the other pressure gradient grooves is located inside the circumference of the pitch circle.

Claims20

Dependent claims

A running surface for connecting a rotatable pump cylinder block to a hydraulic circuit, the running surface comprising:

a first kidney port having a first leading end and a first trailing end, and a second kidney port having a second leading end and a second trailing end, the first and second kidney ports each having a generally arcuate shape and a center, and defining a pitch circle passing generally through the center of the first kidney port and the center of the second kidney port;
a first pressure gradient groove connected to the first kidney port and having a first proximal end connected to the first leading end, and a first distal end;
a second pressure gradient groove connected to the first kidney port and having a second proximal end connected to the first trailing end, and a second distal end;
a third pressure gradient groove connected to the second kidney port and having a third proximal end connected to the second leading end, and a third distal end;
a fourth pressure gradient groove connected to the second kidney port and having a fourth proximal end connected to the second trailing end, and a fourth distal end;
wherein the second distal end and the fourth distal end are disposed outside the pitch circle and the first distal end and the third distal end are disposed inside the pitch circle.

3 more elements

A drive device, comprising:

a rotating pump cylinder block disposed on a mounting member in a housing;
and
a running surface located on the mounting member, the running surface comprising:
a first kidney port formed on one side of a centerline and having a generally arcuate shape;
a second kidney port formed on an opposite side of the centerline and being symmetric with the first kidney port, wherein a circle passing through the first kidney port and the second kidney port defines a pitch circle having a defined circumference;
a first pair of pressure gradient grooves formed on the running surface and connected to the first kidney port, each one of the first pair of pressure gradient grooves having a first proximal end and a first distal end, wherein each first proximal end is connected to a respective opposite end of the first kidney port;
and
a second pair of pressure gradient grooves formed on the running surface and connected to the second kidney port, each one of the second pair of pressure gradient grooves having a second proximal end and a second distal end, wherein each second proximal end is connected to a respective opposite end of the second kidney port,
wherein the first distal end of one of the first pair of pressure gradient groove overlaps the second distal end of one of the second pair of pressure gradient grooves along a first arc of the pitch circle.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/248,570Filed 9 Apr 2014 · us provisional application
Priority: 19 Apr 2013
Granted: 23 May 2017
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

F04B 1/2021
Details or component parts: characterised by the contact area between cylinder barrel and valve plate
F04B 1/2078
Details or component parts: swash plates
F04B 27/0804
Having cylinders coaxial with, or parallel or inclined to, main shaft axis: having rotary cylinder block
F04B 27/0826
Component parts, details, e.g. valves, sealings, lubrication: particularities in the contacting area between cylinder barrel and valve plate