A brake device that puts a brake on a hydraulic motor includes a disc plate configured to rotate with a cylinder block, a brake piston supported by a first case, and brake springs compressed and placed between the brake piston and a second case. The second case has a dent shaped or projection shaped holding portion into which one ends of the brake springs are inserted, and the brake springs are held by the holding portion even in a state where the other ends are away from the brake piston.

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 sliding end part of a shoe has an annular seal part located to surround one opening of a lubricant supply hole and sliding on a slide-receiving surface. The sliding end part has a first pad part that has a height from a reference surface lower than the seal part, that is located on the same circumference to partially surround the opening, and that faces the seal part in a radial direction via an annular groove present on an inner side in the radial direction of the seal part. The sliding end part has a second pad part that has a height from the reference surface lower than the seal part, that is located on the same circumference to partially surround the opening, and that faces the seal part in the radial direction via an annular groove present on an outer side in the radial direction of the seal part.

A hydrostatic axial piston pump of swashplate construction, which is also configured to be operated as a motor, has a stationary control plate against which a rotating cylinder drum is tensioned. During operation, a tilting tendency of the cylinder drum arises in the direction of that quadrant of the control plate which is operatively connected to the first part of the displacement stroke of the pistons. The control plate has a supporting device configured for the cylinder drum. The supporting device is arranged adjacent to an outer edge of the control plate in the first quadrant thereof. The supporting device is configured to be formed by a hydrostatically relieved additional field.

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 swash plate type liquid-pressure rotating device includes a movement restricting mechanism configured to restrict a movement of a spherical bushing relative to a rotating shaft toward a first side in an axial direction. The movement restricting mechanism is a restricting member such that a portion of the spherical bushing which portion is located at the first side in the axial direction contacts the restricting member. The swash plate type liquid-pressure rotating device further includes: a stopper attached to the rotating shaft; and a gap adjusting member. The gap adjusting member is inserted into a gap G3 formed between the stopper and the bearing when the spherical bushing, the retainer plate, the shoe, and the swash plate tightly contact one another in the axial direction. The gap adjusting member restricts a movement of the rotating shaft relative to the casing toward the first side in the axial direction.

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.

A hydraulic piston motor/pump includes a first rotor including a first cylinder, a second rotor opposing the first rotor and including a second cylinder that opposes the first cylinder, a first swashplate including a first angled face adjacent the first rotor, a second swashplate adjacent the second rotor and opposing the first swashplate. The hydraulic piston motor/pump further includes a first shoe cage including a first piston opening, a second shoe cage including a second piston opening, a piston configured to travel into and out of the first cylinder and the second cylinder, a piston shoe configured to engage the piston, the first shoe cage, and the second shoe cage, and a shaft engaging the first shoe cage and the second shoe cage. The shaft configured to rotate in response to a rotation of the first shoe cage and the second shoe cage.