The invention relates to a valve assembly (50) of a radial piston hydraulic apparatus (1). Said apparatus includes a cylinder block (4) insertable onto a shaft (2) by translation. Said assembly (50) includes: a valve (51) in contact with said cylinder block (4); a valve train cover (52); and a first (541) and second (542) chamber that are defined, respectively, by a first (511, 521) and second (512, 522) space that are located at the interface between said valve (51) and said valve train cover (52), and are intended for the pressurized fluids that enable the conversion of pressure and/or mechanical stress. Said assembly (50) includes an additional section (54) defined by a third space (541, 542) located at the interface between said valve (51) and said valve train cover (52). Said section (54) is intended for receiving a pressurized fluid such as to enable the cylinder block (4) to be inserted onto the shaft (2).

A motor (10) to be driven by a pressurized fluid includes a manifold (16) with an arcuate surface (20) defining a valve opening (22) surrounded by a sealing surface. A cylinder (26) has an aperture (30) cooperating with the arcuate surface (20). The cylinder (26) is pivotally mounted so as to be pivotable between a neutral state in which the aperture faces the sealing surface, an inlet state in which the aperture (30) is in fluid connection with the valve opening (22), and an exhaust in which the aperture (30) is in fluid connection with a drainage volume. A piston (34), deployed in the cylinder (26), is driven to extend by pressure within the cylinder. The piston is linked to a crank (36) so that rotation of a crankshaft (38) causes a cyclic motion of the piston (34) and cylinder (26) from the inlet state for an extension power stroke of the piston (34), through the neutral state and to the exhaust state for a return motion of the piston (34). The pivot axis of the cylinder, preferably implemented using a pivot axle (32), is located between the crankshaft axis and the arcuate surface (20).

A hydraulic piston pump motor in which water is used as a working fluid includes an axial directional passage opened on an end surface of one end of a shaft that couples to a cylinder block and drilled open along a shaft center of the shaft; a first radial directional passage drilled open along a radial direction of the shaft from the axial directional passage and configured to guide working fluid into a casing; a second radial directional passage drilled open from the axial directional passage along the radial direction of the shaft at a position closer to the one end of the shaft than the first radial directional passage; and an introduction passage communicating a passage, through which the higher pressure working fluid flows, among the supply passage and the discharge passage with the axial directional passage.

A hydraulic piston pump motor in which water is used as a working fluid includes an axial directional passage opened on an end surface of one end of a shaft that couples to a cylinder block and drilled open along a shaft center of the shaft; a first radial directional passage drilled open along a radial direction of the shaft from the axial directional passage and configured to guide working fluid into a casing; a second radial directional passage drilled open from the axial directional passage along the radial direction of the shaft at a position closer to the one end of the shaft than the first radial directional passage; and an introduction passage communicating a passage, through which the higher pressure working fluid flows, among the supply passage and the discharge passage with the axial directional passage.

A hydraulic rotary machine includes a plurality of pistons, a cylinder block accommodating the pistons, a shaft penetrating through the cylinder block, a swash plate making the pistons reciprocate to expand and contract a capacity chamber of the cylinder, a casing accommodating the cylinder block, a front cover closing an opened end of the casing, an extending portion formed in the front cover and extending along the shaft towards the cylinder block, and a first slide bearing provided between the extending portion and the cylinder block. The first slide bearing is fixed to the extending portion or the cylinder block by a pin member.

A hydraulic rotary machine includes a plurality of pistons, a cylinder block accommodating the pistons, a shaft penetrating through the cylinder block, a swash plate making the pistons reciprocate to expand and contract a capacity chamber of the cylinder, a casing accommodating the cylinder block, a front cover closing an opened end of the casing, an extending portion formed in the front cover and extending along the shaft towards the cylinder block, and a first slide bearing provided between the extending portion and the cylinder block. The first slide bearing is fixed to the extending portion or the cylinder block by a pin member.

The invention relates to a valve assembly (50) of a radial piston hydraulic apparatus (1). Said apparatus includes a cylinder block (4) insertable onto a shaft (2) by translation. Said assembly (50) includes: a valve (51) in contact with said cylinder block (4); a valve train cover (52); and a first (541) and second (542) chamber that are defined, respectively, by a first (511, 521) and second (512, 522) space that are located at the interface between said valve (51) and said valve train cover (52), and are intended for the pressurized fluids that enable the conversion of pressure and/or mechanical stress. Said assembly (50) includes an additional section (54) defined by a third space (541, 542) located at the interface between said valve (51) and said valve train cover (52). Said section (54) is intended for receiving a pressurized fluid such as to enable the cylinder block (4) to be inserted onto the shaft (2).

Noise from an axial piston device for use as, for example, a hydraulic pump or a hydraulic motor of a continuously variable hydrostatic transmission is suppressed. A port block includes a supply and discharge port surface section with which a cylinder block is configured to come into contact while rotating, a first port and a second port. In at least one of a first dead center portion and a second dead center portion, the supply and discharge port surface section has a recess extending from one of the first port and the second port that is located on a downstream side in a rotation direction of the cylinder block, toward an upstream side in the rotation direction of the cylinder block.