An axial piston pump controller for an axial piston pump having a fixed valve plate and a variable displacement is provided. The axial piston pump controller is configured to determine a displacement of the axial piston pump, and to calculate a pump displacement control current to be supplied to the axial piston pump to control the displacement of the axial piston pump. Calculating the pump displacement control current comprises calculating a nominal value for the pump displacement control current based on a rotational speed of the axial piston pump, calculating a pump stiffness adjustment factor based on a pump stiffness control map having as inputs: an output pressure of the axial piston pump; and the estimated pump displacement, and calculating the pump displacement control current to be supplied to the axial piston pump based on the nominal value and the pump stiffness adjustment factor. The controller is further configured to output an instruction to output the calculated pump displacement control current to the axial piston pump in order to control the displacement of the axial piston pump.

An axial piston pump controller for an axial piston pump having a fixed valve plate and a variable displacement is provided. The axial piston pump controller is configured to determine a displacement of the axial piston pump, and to calculate a pump displacement control current to be supplied to the axial piston pump to control the displacement of the axial piston pump. Calculating the pump displacement control current comprises calculating a nominal value for the pump displacement control current based on a rotational speed of the axial piston pump, calculating a pump stiffness adjustment factor based on a pump stiffness control map having as inputs: an output pressure of the axial piston pump; and the estimated pump displacement, and calculating the pump displacement control current to be supplied to the axial piston pump based on the nominal value and the pump stiffness adjustment factor. The controller is further configured to output an instruction to output the calculated pump displacement control current to the axial piston pump in order to control the displacement of the axial piston pump.

The present invention concerns an axial piston pump (1, 1′, 1″,1′″) for the pumping of a liquid comprising: a head (20) in which there is at least partially made a plurality of cylinders (25) in a number greater than three, with central axes parallel between them, a plurality of pistons (75) each of which slide in a respective cylinder (25) of the plurality of cylinders (25) for the pumping of the liquid, and a suction channel of the liquid to pump, which is equipped with a primary duct (140) and a plurality of branch ducts (145, 145′,145″), each of said branch ducts (145, 145′,145″) being adapted to place the primary duct (140) in fluid communication with a respective cylinder (25) of the plurality of cylinders (25), in which the primary duct (140) is positioned between the central axes of the cylinders (25).

The present invention concerns an axial piston pump (1, 1′, 1″,1′″) for the pumping of a liquid comprising: a head (20) in which there is at least partially made a plurality of cylinders (25) in a number greater than three, with central axes parallel between them, a plurality of pistons (75) each of which slide in a respective cylinder (25) of the plurality of cylinders (25) for the pumping of the liquid, and a suction channel of the liquid to pump, which is equipped with a primary duct (140) and a plurality of branch ducts (145, 145′,145″), each of said branch ducts (145, 145′,145″) being adapted to place the primary duct (140) in fluid communication with a respective cylinder (25) of the plurality of cylinders (25), in which the primary duct (140) is positioned between the central axes of the cylinders (25).

Various surface cam planetary mechanisms are described that convert rotational motion to linear reciprocating motion. Also described are assemblies using such mechanisms such as pump drives. A surface cam component used in the mechanisms includes a cam race that exhibits an undulating surface.

The present invention relates to a hydraulic pump system including a variable displacement pump that generates an outlet pressure. The hydraulic pump system also includes a control system that decreases a displacement volume of the variable displacement pump in response to an increase in the outlet pressure and increases a displacement volume of the variable displacement pump in response to a decrease in the outlet pressure.

The present invention relates to a hydraulic pump system including a variable displacement pump that generates an outlet pressure. The hydraulic pump system also includes a control system that decreases a displacement volume of the variable displacement pump in response to an increase in the outlet pressure and increases a displacement volume of the variable displacement pump in response to a decrease in the outlet pressure.

Disclosed herein is an electric power and thermal management system in which, when a shaft is rotated due to an operation of a power part, generation of electric power and a circulation of a fluid are performed together so that the generation of the electric power and a circulation structure of oil are integrated, and thus a layout can be reduced, and a structure can be simplified. In addition, in a state in which the generation of the electric power and the circulation structure of the oil are integrated, a circulation amount of the oil is adjusted according to an angle of an inclined plate constituting a pumping mechanism so that an oversupply of the oil to parts through which the oil is circulated can be prevented.

Disclosed herein is an electric power and thermal management system in which, when a shaft is rotated due to an operation of a power part, generation of electric power and a circulation of a fluid are performed together so that the generation of the electric power and a circulation structure of oil are integrated, and thus a layout can be reduced, and a structure can be simplified. In addition, in a state in which the generation of the electric power and the circulation structure of the oil are integrated, a circulation amount of the oil is adjusted according to an angle of an inclined plate constituting a pumping mechanism so that an oversupply of the oil to parts through which the oil is circulated can be prevented.

A metering pump system includes a variable displacement pump having an inlet and an outlet, a flow sensing valve fluidically connected to the outlet of the variable displacement pump, and an actuator mechanically coupled to a displacement mechanism of the variable displacement pump. The metering pump system also includes an electronic engine controller in communication with the flow sensing valve. An electrohydraulic servo valve is electrically connected to the electronic engine controller and hydraulically connected to the actuator. The electrohydraulic servo valve is configured to hydraulically drive the actuator to move the displacement mechanism to change displacement of the variable displacement pump.