A hydraulic rotary machine configured to reduce sliding resistance of a reciprocating piston and to suppress a reduction in volumetric efficiency corresponding to an amount of leakage of hydraulic oil. A piston pump includes a rotor shaft, a cylinder block, a piston head, a piston rod, a retainer, a swash plate, and a tilt regulation mechanism. When the tilt regulation mechanism rocks the swash plate, the amount of discharge from the piston pump is variably changed. The retainer which rotates with both the piston head and the piston rod is supported by a retainer bush provided to the rotor shaft. The retainer sphere section of the retainer and the retainer bush sphere section of the retainer bush have spherical shapes having the same curvature. During the regulation of tilt, the retainer rocks while the retainer bush sphere section is in sliding contact with the retainer bush.

A hydraulic machine comprising: an outer casing comprising a first front plate and a second front plate, a shaft rotatable about a main axis, a first rotor comprising a first rotor body rotatable with said shaft around said main axis, and a plurality of first pistons with respective spherical ring heads fixed to said first rotor body, a second rotor comprising a second rotor body and a plurality of second pistons with respective spherical ring heads, wherein the second rotor is rotatable about a secondary axis, inclined with respect to said main axis, a plurality of sleeves that are separate and independent from each other, each having a cylinder open at opposite ends and engaged on opposite sides by a first piston and by a second piston.

A flow divider assembly for use with a hydraulic pump provides flow to separate drive motors for use in a vehicle or other application. A pair of flow divider motors may be mounted on a block and have a common axis of rotation. The ratio between the two may be controlled by adjustment of the angles of the respective thrust bearings of the flow divider motors. A valve may connect the outlet of one of the flow divider motors or the outlet of the other flow divider motor. passage to the second outlet passage. Additional bypass valves may be provided to permit direct connection between the hydraulic pump and the separate drive motors.

A port plate for use in an integrated drive generator has a body defining a semi-cylindrical charge port communicating with two circumferentially smaller charge port portions. A diametrically opposed working pressure port has three smaller working pressure ports. A center plane is defined extending through a center axis of a bore within the body and equidistance between circumferential ends of the charge port and the working fluid port. A first angle is defined between the plane and a circumferential end of the smaller charge port. The first angle is between 15 and 25 degrees. An integrated drive generator and a method are also disclosed.

A hydraulic device comprises a housing, a shaft rotatable about a first axis of rotation and a flange. A plurality of cylindrical sleeves cooperate with a plurality of pistons on the flange to form compression chambers, wherein the cylindrical sleeves are rotatable about a second axis of rotation which intersects the first axis of rotation by an acute angle such that upon rotating the shaft the volumes of the compression chambers change. A barrel plate is rotatable about the second axis has a first side for supporting the cylindrical sleeves. An opposite second side is supported by a supporting surface of a plate-shaped face element which is fixed to the housing. The supporting surface lies in a first plane. The face element has a back side that lies in a second plane, which forms an angle with the first plane that is smaller than said acute angle.

An opposed swash plate type fluid pressure rotating machine in which a first piston and a second piston projecting from opposite ends of a cylinder block reciprocate in a cylinder, respectively following a first swash plate and a second swash plate includes a center spring for biasing the cylinder block toward the second swash plate. A housing hole (biasing force receiving part) for receiving a biasing force of the center spring is formed on one end part of the cylinder block. The tip of a second neck (reaction force receiving part) for receiving a reaction force from the second swash plate is formed on the other end part of the cylinder block. The cylinder block is biased only toward the second swash plate by the center spring.

A hydrostatic axial piston machine includes a control disk that has a permanent relief field and at least one hydrostatic auxiliary relief field.

A hydraulic machine comprising: an outer casing comprising a first front plate and a second front plate, a shaft rotatable about a main axis, a first rotor comprising a first rotor body rotatable with said shaft around said main axis, and a plurality of first pistons with respective spherical ring heads fixed to said first rotor body, a second rotor comprising a second rotor body and a plurality of second pistons with respective spherical ring heads, wherein the second rotor is rotatable about a secondary axis, inclined with respect to said main axis, a plurality of sleeves that are separate and independent from each other, each having a cylinder open at opposite ends and engaged on opposite sides by a first piston and by a second piston.

A hydraulic device comprises a housing and a shaft with a flange extending perpendicularly to a first axis of rotation. A plurality of pistons are fixed to the flange and move each in a sleeve supported by and rotatable with a barrel plate. The barrel plate is provided with a plurality of actuators for exerting counter forces (Fa) on the respective sleeves in a direction and at a location such that at least when one of the pistons is at bottom dead center under operating conditions the counter force on the cooperating sleeve acts along a line at a distance from the center point of the piston head and causes a counter torque about the center point of the piston head against the tilting torque, wherein the actuators are controlled such that the counter forces increase with increasing rotational speed of the barrel plate about the second axis of rotation.

A device, system, and process for turning hydraulic pressure into rotational force and for turning rotational motion into hydraulic pressure. An example of the device/system for performing the process comprises actuators, rotationally positioned between two thrust plates that are fixed in a housing at an angle to a rotational axis and in parallel to each other.