Efficiency spur gear set housing
AssigneeCaterpillar Inc.
InventorsBenjamin T. Nelson, Andrew J. Krajnik, John J. Krone
Life of this patent
Estimating the term…
Abstract
A hydraulic pump housing comprises passages formed in an inner wall separating the gear cavity and the pump cavity to allow for the movement of fluid into and out of the gear cavity, thereby alleviating some of the power loss caused by churning lubricating oil. The hydraulic pump may comprise spaces integrally formed in axially opposing surfaces of the gear cavity walls adjacent the area where the gears mesh to enable the churning oil to expand and flow around the gears.
Claims25
A housing for a spur gear set, the housing comprising a first member and a second member affixed together to define a gear cavity within which are located a drive gear and a driven gear submerged in fluid, the gear cavity having an area where the gears mesh, the first member comprising an inner wall forming a substantially planar rear inner surface of the gear cavity, the second member forming a substantially planar front inner surface of the gear cavity, the housing further comprising:
- a first expansion integrally formed in the rear inner surface of the inner wall adjacent to the area where the gears mesh, the first expansion being a space through which the fluid flows around the gears from one side of the area where the gears mesh to the other side of the area where the gears mesh;
- a second expansion integrally formed in the front inner surface of the second member adjacent to the area where the gears mesh, the second expansion being a space through which the fluid flows around the gears from one side of the area where the gears mesh to the other side of the area where the gears mesh;
- wherein the first expansion is defined by a first outwardly sloping wall located adjacent an area of highest oil pressure within the gear cavity and a second outwardly sloping wall located adjacent an area of lowest oil pressure within the gear cavity;
- and
- wherein the second expansion is defined by a first outwardly sloping wall located adjacent an area of highest oil pressure within the gear cavity and a second outwardly sloping wall located adjacent an area of lowest oil pressure within the gear cavity.
A housing for a spur gear set, the housing comprising a first member and a second member affixed together to define a gear cavity within which are located a drive gear and a driven gear submerged in fluid, the gear cavity having an area where the gears mesh, the first member comprising an inner wall forming a substantially planar rear inner surface of the gear cavity, the second member forming a substantially planar front inner surface of the gear cavity, the housing further comprising:
- a first expansion integrally formed in the rear inner surface of the inner wall adjacent to the area where the gears mesh, the first expansion being a space through which the fluid flows around the gears from one side of the area where the gears mesh to the other side of the area where the gears mesh;
- a second expansion integrally formed in the front inner surface of the second member adjacent to the area where the gears mesh, the second expansion being a space through which the fluid flows around the gears from one side of the area where the gears mesh to the other side of the area where the gears mesh;
- wherein the first expansion comprises a first concave area formed in the inner wall, the first concave area being elongated in a direction defined by a line passing through an area of greatest gear engagement;
- and
- wherein the second expansion comprises a second concave area formed in the front inner surface, the second concave area being elongated in a direction defined by a line passing through an area of greatest gear engagement.
A housing for a spur gear set, the housing comprising a first member and a second member affixed together to define a gear cavity within which are located a drive gear and a driven gear submerged in fluid, the gear cavity having an area where the gears mesh, the first member comprising an inner wall forming a substantially planar rear inner surface of the gear cavity, the second member forming a substantially planar front inner surface of the gear cavity, the housing further comprising:
- a first expansion integrally formed in the rear inner surface of the inner wall adjacent to the area where the gears mesh, the first expansion being a space through which the fluid flows around the gears from one side of the area where the gears mesh to the other side of the area where the gears mesh;
- a second expansion integrally formed in the front inner surface of the second member adjacent to the area where the gears mesh, the second expansion being a space through which the fluid flows around the gears from one side of the area where the gears mesh to the other side of the area where the gears mesh;
- one or more passages formed in the inner wall to allow movement of the fluid into and out of the gear cavity;
- wherein the first member further comprises a perimeter wall forming a top inner surface, a bottom inner surface and side inner surfaces of the gear cavity, and wherein the one or more passages comprises two arcuate shaped side passages located near the side inner surfaces of the perimeter wall, each side passage forming an arc of less than ninety degrees;
- wherein the side passages are equidistant from the top inner surface and the bottom inner surface of the perimeter wall;
- and
- wherein the first member comprises integrally formed top and bottom gear shrouds, the top gear shroud extending downward from the top inner surface of the perimeter wall and having downwardly converging curved sides that meet along a substantially linear apex located equidistant the gears, the bottom gear shroud extending upward from the bottom inner surface of the perimeter wall and having upwardly converging curved sides that meet along a substantially linear apex located equidistant the gears.
Dependencies are inferred from the claim text.