Abstract: An integrated electro-hydraulic unit including an electric machine, a hydraulic machine, and a shared casing. The electric machine includes a winding and a stator. The hydraulic machine includes a shaft, a cylinder block, a plurality of pistons, and a valve plate. The shared casing includes a cooling channel located between the electric machine and the hydraulic machine. By action of the pistons, a first port on the valve plate receives working fluid pulled into the cylinder block and a second port on the valve plate receives working fluid pushed out. By action of the pistons, a third port on the valve plate is configured to receive a cooling flow of the working fluid. The cooling flow through the third port is separate from the first port and the second port, such that volumetric efficiency measured between the first port and the second port is not affected by the cooling flow.

Abstract: A piston and cylinder assembly of an axial piston machine is disclosed which includes a cylinder having a uniform internal diameter, a cylindrical bushing press-fit against the inner surface of the cylinder and extending at least partially therein, the bushing comprising at least one circumferential groove formed on an outer surface of the bushing against the inner surface of the cylinder, a piston reciprocably disposed within the cylindrical bushing, generating a piston-bushing-interface, the piston and the bushing defining a diametrical clearance therebetween, the diametrical clearance defining a lubrication gap and a fluid-dynamic seal between the piston and the cylindrical bushing.

Abstract: A piston and cylinder assembly of an axial piston machine is disclosed which includes a cylinder having a uniform internal diameter, a cylindrical bushing press-fit against the inner surface of the cylinder and extending at least partially therein, the bushing comprising at least one circumferential groove formed on an outer surface of the bushing against the inner surface of the cylinder, a piston reciprocably disposed within the cylindrical bushing, generating a piston-bushing-interface, the piston and the bushing defining a diametrical clearance therebetween, the diametrical clearance defining a lubrication gap and a fluid-dynamic seal between the piston and the cylindrical bushing.