Hydraulic pumps with double axial pistons

Claim 2

A double hydraulic pump comprising a casing, first and second barrel means mounted in side by side parallel relation for rotation about their respective axes within said casing, at least one reciprocal piston means mounted within each of said barrels, a common swash plate pivotally mounted within said casing and having a flat surface disposed in contact with said piston means, first and second shaft means drivingly connected to said first and second barrel means respectively, a pair of gears mounted on said first and second shaft means respectively, disposed in meshing engagement with each other and coacting with said casing to provide a feed pump for said double hydraulic pump, one of said shaft means extending outside said casing for connection to a suitable power source, spring biased push rod means disposed intermediate said first and second barrel means and bearing against said swash plate, and flange means mounted on said swash plate adjacent each of said barrel means, said push rod having two parallel flat surfaces on opposite sides thereof disposed intermediate said flange means.

Claim 3

A double hydraulic pump comprising a casing, first and second barrel means mounted in side by side parallel relation for rotation about their respective axes within said casing, at least one reciprocal piston mEans mounted within each of said barrels, a common swash plate pivotally mounted within said casing and having a flat surface disposed in contact with said piston means, first and second shaft means drivingly connected to said first and second barrel means respectively, a pair of gears mounted on said first and second shaft means respectively, disposed in meshing engagement with each other and coacting with said casing to provide a feed pump for said double hydraulic pump, one of said shaft means extending outside said casing for connection to a suitable power source, and cradle means fixed to said casing and having a concave cylindrical portion formed therein, said swash plate having a convex cylindrical portion adapted to be received in the concave cylindrical portion of said cradle, said swash plate having grooves therein disposed transversely to the pivotal axis of said swash plate for simultaneously uncovering fixed ports formed in the concave cylindrical surface of said cradle, said ports connecting inlet and outlet channels of said feed pump.

Claim 4

A double hydraulic pump comprising a casing, first and second barrel means mounted in side by side parallel relation for rotation about their respective axes within said casing, at least one reciprocal piston mEans mounted within each of said barrels, a common swash plate pivotally mounted within said casing and having a flat surface disposed in contact with said piston means, first and second shaft means drivingly connected to said first and second barrel means respectively, a pair of gears mounted on said first and second shaft means respectively, disposed in meshing engagement with each other and coacting with said casing to provide a feed pump for said double hydraulic pump, one of said shaft means extending outside said casing for connection to a suitable power source, and cradle means fixed to said casing and having a concave cylindrical portion formed therein, said swash plate having a convex cylindrical portion adapted to be received in the concave cylindrical portion of said cradle, said swash plate having grooves therein disposed transversely to the pivotal axis of said swash plate for simultaneously uncovering fixed ports formed in the concave cylindrical surface of said cradle, said ports connecting inlet and outlet channels of said feed pump.

Claim 5

A double hydraulic pump as set forth in claim 2 further comprising chamber means located in the convex cylindrical surface portion of said swash plate and means for transmitting fluid under pressure from the output of said double pump to said chambers.

Claim 6

A double hydraulic pump comprising a casing, first and second barrel means mounted in side by side parallel relation for rotation about their respective axes within said casing, at least one reciprocal piston means mounted within each of said barrels, a common swash plate pivotally mounted within said casing and having a flat surface disposed in contact with said piston means, first and second shaft means drivingly connected to said first and second barrel means respectively, a pair of gears mounted on said first and second shaft means respectively, disposed in meshing engagement with each other and coacting with said casing to provide a feed pump for said double hydraulic pump, one of said shaft means extending outside said casing for connection to a suitable power source, and power regulating means disposed in said casing intermediate said first and second barrel means, said power regulating means comprising spring means operably bearing against said swash plate on one side of the pivot axis thereof and hydraulic jack means operatively bearing on said swash plate on the opposite side of said pivot axis.

Claim 7

A double hydraulic pump comprising a casing, first and second barrel means mounted in side by side parallel relation for rotation about their respective axes within said casing, at least one reciprocal piston means mounted within each of said barrels, a common swash plate pivotally mounted within said casing and having a flat surface disposed in contact with said piston means, first and second shaft means drivingly connected to said first and second barrel means respectively, a pair of gears mounted on said first and second shaft means respectively, disposed in meshing engagement with each other and coacting with said casing to provide a feed pump for said double hydraulic pump, one of said shaft means extending outside said casing for connection to a suitable power source, and power regulating means disposed in said casing intermediate said first and second barrel means, said power regulating means comprising spring means operably bearing against said swash plate on one side of the pivot axis thereof and hydraulic jack means operatively bearing on said swash plate on the opposite side of said pivot axis.

Claim 8

A double hydraulic pump as set forth in claim 4 further comprising fluid passage means operatively connecting the output of each of said double hydraulic pumps to said hydraulic jack means.