A bearing device includes a piston arranged in a cylinder of a rotor, and a half bearing mounted on the piston to support a roller. The piston includes a recessed holding surface, and holding side surfaces on both axial sides thereof. Each holding side surface includes a ridge portion having an arc-shaped or elliptic-arc-shaped profile protruding toward a radially inner side of the piston. The half bearing includes a partially cylindrical portion, and protruding portions protruding from axial end faces thereof. Each protruding portion has a protruding portion end face which includes a central recessed surface, and two support recessed surfaces located on both circumferential sides thereof, that have an arc shape or an elliptic arc shape to correspond to the profile of the ridge portion, so that only the two support recessed surfaces are in contact with the ridge portion.

A hydraulic control circuit for a hydraulic motor operable at least at two displacements, having a proportional speed control valve with a control valve spool continuously moveable by means of a force generated by a pilot pressure being controlled by a continuously, electrically adjustable pilot valve having an electrical actuator, wherein the control valve spool is moveable between a full-torque end position, a reduced-torque end position, and at least one intermediate position. A time related control current function is provided for controlling the current applied to the electrical actuator for controlling the pilot pressure including a pre-current portion with a constant non-zero current and a current ramp portion during which the current is raised or lowered continuously from a ramp starting current level to an intermediate current level. The current is changed abruptly to a switching current level at the end of the current ramp portion for allowing the movement of the speed control valve spool from one of the two end positions via the at least one intermediate switching position into the other end position.

The object of the present invention is to provide a fluid rotary machine in which dead spaces can be reduced as much as possible even if the machine is enlarged by arranging rotary valves directly behind cylinder chambers. The fluid rotary machine in which first and second double-headed pistons (7, 8) intersecting within a case body (1, 2) move linearly back and forth within cylinders (16) due to the hypocycloid principle along with rotation of shafts (4a, 4b) and in which intake and exhaust cycles are repeated in chambers (22), wherein cylinder heads (17) for closing the cylinder chambers (22) are each provided with rotary valves (19) which are rotated by drive transmission from the shafts (4a, 4b) and which are provided with intake holes and discharge holes (19b) alternately communicated with the cylinder chambers (22) via communication channels (20a, 20b), and the rotary valves (19) intersect longitudinal axis of the opposing pistons (7, 8) and are capable of rotating parallel with output axil lines.

The object of the present invention is to provide a fluid rotary machine in which dead spaces can be reduced as much as possible even if the machine is enlarged by arranging rotary valves directly behind cylinder chambers. The fluid rotary machine in which first and second double-headed pistons (7, 8) intersecting within a case body (1, 2) move linearly back and forth within cylinders (16) due to the hypocycloid principle along with rotation of shafts (4a, 4b) and in which intake and exhaust cycles are repeated in chambers (22), wherein cylinder heads (17) for closing the cylinder chambers (22) are each provided with rotary valves (19) which are rotated by drive transmission from the shafts (4a, 4b) and which are provided with intake holes and discharge holes (19b) alternately communicated with the cylinder chambers (22) via communication channels (20a, 20b), and the rotary valves (19) intersect longitudinal axis of the opposing pistons (7, 8) and are capable of rotating parallel with output axil lines.

A hydraulic motor includes a motor mechanism that rotates by hydraulic liquid that is supplied/discharged from a hydraulic liquid pressure source through one of a first motor passage and a second motor passage. The hydraulic motor comprises a casing that defines a casing chamber which accommodates the motor mechanism, and a flushing passage that is in communication with the casing chamber and extracts a portion of the hydraulic liquid from a low pressure side among the first motor passage and the second motor passage and leads it to the casing chamber.

A bearing device includes a piston arranged in a cylinder of a rotor, and a half bearing mounted on the piston to support a roller. The piston includes a recessed holding surface, and holding side surfaces on both axial sides thereof. Each holding side surface includes a ridge portion having an arc-shaped or elliptic-arc-shaped profile protruding toward a radially inner side of the piston. The half bearing includes a partially cylindrical portion, and protruding portions at a circumferential center thereof. Each protruding portion has a protruding portion end face which includes a central recessed surface, and two support recessed surfaces located on both circumferential sides thereof, that have an arc shape or an elliptic arc shape to correspond to the profile of the ridge portion, so that only the two support recessed surfaces are in contact with the ridge portion.

A rotating machine is disclosed and includes a stator defining a circumference, a plurality of first magnet arrays, a rotor, and a first piston. The first magnet arrays are comprised of a plurality of discrete magnets arranged around the circumference of the stator in a first magnetic pattern. The rotor is rotatable about an axis of rotation and defines a main body. The main body defines a first passageway. The first piston includes a plurality of first magnetic elements and is actuated within the first passageway of the rotor. The plurality of discrete magnets are arranged in the first magnetic pattern and are positioned to interact with the magnetic elements of the first piston to create a first magnetic force as the rotor rotates about the axis of rotation. The first magnetic force represents a first amount of force required to actuate the first piston.

A radial piston machine includes at least one piston unit with a piston and at least one rolling element rotatably mounted in a rolling element receptable of the piston. The piston of the piston unit is polished.

A hydrostatic radial piston machine is useable inversely. The hydrostatic radial piston machine has a distributor in which a flushing valve, a pressure-maintaining valve connected downstream of the flushing valve, and two nonreturn valves are arranged.

A hydraulic machine includes radial cylinders including, oscillating radial cylinders arranged in a crown or star of cylinder-piston units, the pistons of the groups are made slidable on a crankshaft or with a cam, or on interposed members concentric to it, and realizing the reciprocating motion in the oscillating cylinders. The oscillating cylinders are placed in contact with a surface of distribution concentric or corresponding to the surface of oscillation of the respective cylinder on which a distributor body is placed separate from the machine body and housed in a seat in the body, or part fixed to the body, of the hydraulic machine, and each distributor body is mobile in its seat under the action of the pressure of liquid in connection on the back surface of the distributor body against the surface of distribution of the oscillating radial cylinder subject to the distribution.