A port plate assembly of a hydraulic unit includes a port plate and a journal bearing. The port plate includes a fixed-speed interface side having a fixed-speed interface surface, and a variable-speed interface side having a variable-speed interface surface. A plurality of kidney-shaped apertures is defined at a kidney pitch diameter about a central bore of the port plate between the fixed-speed interface surface and the variable-speed interface surface. The port plate also includes control cylinder interface formed at a control cylinder radial offset from a central axis of the central bore, where a ratio of the control cylinder radial offset to the kidney pitch diameter is between 1.629 and 1.639. The journal bearing is installed in the central bore of the port plate, where the journal bearing provides an interface for a fixed-speed shaft and a variable-speed shaft of the hydraulic unit.

A port plate assembly of a hydraulic unit includes a port plate and a journal bearing. The port plate includes a fixed-speed interface side having a fixed-speed interface surface, and a variable-speed interface side having a variable-speed interface surface. A plurality of kidney-shaped apertures is defined at a kidney pitch diameter about a central bore of the port plate between the fixed-speed interface surface and the variable-speed interface surface. The port plate also includes control cylinder interface formed at a control cylinder radial offset from a central axis of the central bore, where a ratio of the control cylinder radial offset to the kidney pitch diameter is between 1.629 and 1.639. The journal bearing is installed in the central bore of the port plate, where the journal bearing provides an interface for a fixed-speed shaft and a variable-speed shaft of the hydraulic unit.

A fluid-powered rotary actuator having a body with a shaft disposed therein and having a linear-to-rotary force-converting member mounted for longitudinal movement within said body in response to the selective application of pressurized fluid thereto. The actuator uses a torque member having a flange portion attached to the body or an external structure and a grooved central portion. A piston sleeve has outward grooves meshing with inward grooves on the shaft and inward grooves for meshing with outward grooves on the torque member central portion. The body sidewall is not used as a torque transmission surface during fluid-powered operation of the actuator.

A valve for controlling the flow of hydraulic fluid to a hydraulic motor. The valve includes a sleeve and a spool. The sleeve includes a first fluid flow port for receiving hydraulic fluid from the supply line; a second fluid flow port for supplying hydraulic fluid to a second valve; a third fluid flow port for receiving hydraulic fluid from a first control line; a fourth fluid flow port for receiving hydraulic fluid from a second control line; and a fifth fluid flow port in fluid communication with the return line. The valve is arranged to be actuated to move the spool between a first position and a second position. When the spool is in the second position, the fifth fluid flow port is in fluid communication with the second, third and fourth fluid flow ports and the first fluid flow port is closed by the spool.

A housing of an axial piston device is provided with a drain port for discharging the retained oil to the outside and a supply oil passage for guiding lubricating oil, which has been supplied from an oil source, toward a first hydraulic axial piston member. The drain port is arranged so as to bring about such a retained-oil level that a second hydraulic axial piston member, which is disposed below the first hydraulic axial piston member, is partially or entirely immersed in the retained oil while the first hydraulic axial piston member is not immersed in the retained oil.

A hydrostatic axial piston machine has a drive shaft penetrating a housing on either side. In this case, the mechanically weaker of the two shaft ends is strengthened by an undercut being eliminated, said undercut defining the minimum diameter of the shaft end and thus of the entire drive shaft. Instead, the strength of the relevant shaft end is increased by a displacement of a circular bearing surface for a rolling bearing radially outwardly and away from the rolling bearing. In this case, the circular bearing surface is displaced below a compression spring which clamps the cylinder drum against a distributor plate. The resulting spacing between the circular bearing surface and the rolling bearing remaining in place is bridged by a sleeve or by a ring. A concave rounded shaft shoulder is simply formed below the sleeve and/or the ring.

External combustion engine which comprises a first cylinder and a second cylinder, in which a first piston and a second piston are able to slide respectively. The first and second cylinder are fluidically connected with respect to each other for the passage of a heat-carrying fluid suitable to determine the cyclical movement of the first piston and the second piston. The external combustion engine also comprises a drive shaft rotating around an axis of rotation, and with which crank means are solidly associated, provided with at least a first pin and a second pin having pivoting axes parallel to each other, and also disposed distanced radially from the axis of rotation. The external combustion engine also comprises first and second kinematic connection means suitable to connect respectively the first pin and the second pin to the first piston and respectively to the second piston. The first pin and the second pin are disposed with the respective pivoting axes angularly offset so as to be angled by a desired angular amplitude equal to a first acute angle with respect to the axis of rotation.

A reciprocating internal combustion engine is disclosed having co-axially aligned cylinder blocks within a housing, each cylinder block having a piston structure comprising a piston head and a connecting rod. The piston heads are adapted to reciprocate within their respective cylinder blocks. The connecting rods are connected to opposite ends of a central yoke structure, pivotally, with the ability to angularly deviate from a longitudinal axis during a cycle of motion. The central yoke structure consists of a roller gear disposed within a void of the central yoke structure, and the linear motion of the piston structure is translated into the rotary motion of the roller gear.

A composition for sliding member includes a binder resin, a solid lubricant, and an epoxy modified silicone oil having an epoxy group at both ends or at one end thereof. A weight ratio of the binder resin and the epoxy modified silicone oil is 97:3 to 75:25.

A rotational combustion engine that generates force from the reciprocal motion and centripetal motion of one or more pistons that is then converted into rotational motion of a first cam and second cam wherein the cams are separated by a 2-3 degree horizontal offset and an angle of 60 degrees as well as camshaft assembly and driving shaft to provide power to an entity such as an automobile.