Hydrostatic machines for use in transmission and transaxle product

A hydrostatic transmission located within a chamber defined by a surrounding housing structure and comprising a hydraulic pump fluidly coupled to an adjacent hydraulic motor;

• an input drive-shaft rotatably supported in said housing and drivingly connected to said hydraulic pump, said hydraulic pump including a first cylinder-barrel containing an array of radially arranged cylinders and a radial piston disposed in each of said radially arranged cylinders and where the stroking axes of the radial pistons all lie along a common plane arranged normal to the rotational axis of said first cylinder-barrel;
• said hydraulic motor having a second cylinder-barrel containing an array of axially arranged cylinders set equally spaced apart about a circle described by the stroking axes of axial pistons disposed in said axially arranged cylinders to lie radially within the radial outer dimension of said second cylinder-barrel such that the stroking axes of said axial pistons lie parallel to the rotational axis of said second cylinder-barrel;
• at least one outwardly extending output power transmission shaft rotatably supported in said housing and mechanically coupled to said hydraulic motor;
• wherein said plane containing the stroking axes of said radial pistons is disposed parallel to and offset from the rotational axis of said second cylinder-barrel.

A hydrostatic transmission located within a chamber defined by a surrounding housing structure and comprising a hydraulic pump and at least one hydraulic motor fluidly coupled together by a fluid coupling valve fixed to said housing;

• an input drive-shaft rotatably supported in said housing structure and drivingly connected to said hydraulic pump;
• and at least one output drive-shaft rotatably supported in said housing and mechanically coupled to said at least one hydraulic motor;
• said fluid coupling valve having a cylindrical support surface and at least one flat support surface and where at least two internal hydraulic fluid passages are provided within said fluid coupling valve, said passages terminating in at least four arcuate-slots of which a first pair of said arcuate-slots are provided on said cylindrical support surface and a second pair of said arcuate-slots are provided on said at least one flat support surface,
• said hydraulic pump having a first cylinder-barrel rotatably supported on said cylindrical support surface and containing an array of radially arranged cylinders and a radial piston disposed in each of said radially arranged cylinders and where the stroking axes of the radial pistons all lie along a common plane normal to the rotational axis of said first cylinder-barrel;
• said at least one hydraulic motor having a second cylinder-barrel operating against said at least one flat support surface and containing an array of axially arranged cylinders set equally spaced apart about a circle described by the stroking axes of axial pistons disposed in said axially arranged cylinders to lie radially within the radial outer dimension of said second cylinder-barrel such that the stroking axes of said axial pistons lie parallel to the rotational axis of said second cylinder-barrel;
• and where said radial cylinders successively communicate with said first pair of arcuate-slots during rotation of said first cylinder-barrel and said axial cylinders successively communicate with said second pair of arcuate-slots during rotation of said second cylinder-barrel for the transfer of power from said input-drive-shaft to said output drive-shaft or vice-versa;
• wherein said plane containing the stroking axes of said radial pistons is disposed parallel to and offset from the rotational axis of said second cylinder-barrel.

A hydrostatic transmission located within a chamber defined by a surrounding housing structure and comprising a hydraulic pump and a hydraulic motor fluidly coupled together by a fluid coupling valve;

• an input drive-shaft rotatably supported in said housing and drivingly connected to said hydraulic pump;
• at least one outwardly extending output power transmission shaft rotatably supported in said housing and mechanically coupled to said hydraulic motor;
• said hydraulic pump having a first cylinder-barrel containing an array of radially arranged cylinders and a radial piston disposed in each of said radially arranged cylinders and where the stroking axes of the radial pistons all lie along a common plane normal to the rotational axis of said first cylinder-barrel;
• said hydraulic motor having a second cylinder-barrel containing an array of axially arranged cylinders set equally spaced apart about a circle described by the stroking axes of axial pistons disposed in said axially arranged cylinders to lie radially within the radial outer dimension of said second cylinder-barrel such that the stroking axes of said axial pistons lie parallel to the rotational axis of said second cylinder-barrel;
• wherein said plane containing the stroking axes of said radial pistons is disposed parallel to and offset from the rotational axis of said second cylinder-barrel.