An axial piston machine may include a rotor rotatably mounted in a housing. A plurality of cylinders may be arranged in a ring around the rotor. A plurality of pistons may each be arranged within each of the plurality of cylinders and may be constructed and arranged to selectively translate within the plurality of cylinders. A plurality of inlet openings may be defined in a cylinder head and at least one outlet opening may be defined in the housing. The plurality of cylinders may be in operative communication with the plurality of inlet openings and the at least one outlet opening. An inlet channel may be defined in the cylinder head and may extend to each of the plurality of inlet openings. An outlet channel may be defined in the housing and may be in operative communication with the at least one outlet opening. A bypass channel may be defined in the housing and may extend from the cylinder head into one of the outlet channel or a swashplate space. A bypass valve may be connected to the cylinder head or may be integrated with the cylinder head. The bypass valve may be constructed and arranged to selectively apportion a working medium to the inlet channel and the bypass channel based on a switching position of the bypass valve.

A hydraulic pump assembly comprises a rotatable piston drum (20) with at least one centrifugal lever (23) pivotally attached thereto for radial movements between radial flanges (20) under the action of centrifugal force at rotation of the piston drum. The centrifugal lever (23) is arranged to control the position of a valve member, preferably a ball (22), at the opening end of a bore (21) in the piston drum (20). There is a defined friction surface (28; 32) between the lever (23) and one of the radial flanges (20), and there are spring means (29-31; 25, 33) for resiliently biasing the lever against said one of the flanges.

An axial piston machine may include a rotor rotatably mounted in a housing. A plurality of cylinders may be arranged in a ring around the rotor. A plurality of pistons may each be arranged within each of the plurality of cylinders and may be constructed and arranged to selectively translate within the plurality of cylinders. A plurality of inlet openings may be defined in a cylinder head and at least one outlet opening may be defined in the housing. The plurality of cylinders may be in operative communication with the plurality of inlet openings and the at least one outlet opening. An inlet channel may be defined in the cylinder head and may extend to each of the plurality of inlet openings. An outlet channel may be defined in the housing and may be in operative communication with the at least one outlet opening. A bypass channel may be defined in the housing and may extend from the cylinder head into one of the outlet channel or a swashplate space. A bypass valve may be connected to the cylinder head or may be integrated with the cylinder head. The bypass valve may be constructed and arranged to selectively apportion a working medium to the inlet channel and the bypass channel based on a switching position of the bypass valve.

A hydraulic actuation unit for controlling the starting and stopping of hydraulic motors includes a first main circuit and a second main circuit, a first recirculation circuit and a second recirculation circuit, a counterbalancing valve, which includes a shuttle, and a first discharge channel and a second discharge channel. The shuttle includes a first check valve and a second check valve. The first check valve includes at least one first flow control element that can move from an open position to a closure position. The second check valve includes at least one second flow control element that can move from an open position to a closure position. The first and second check valves respectively are provided with first damping means and second damping means in order to slow down the passage movement respectively of the first flow control element and of the second flow control element.