A method for manufacturing an at least sectionally spherical-cap-shaped recess on a drive shaft for a hydrostatic axial piston machine includes whirling of the recess and heat treatment of the recess to form a wear layer. A drive shaft for a hydrostatic axial piston machine includes at least one recess manufactured according to the method. A hydrostatic axial piston machine includes a drive shaft with at least one recess manufactured according to the method.

A pump system includes a pressure compensator and a speed compensator for controlling the displacement of a variable displacement pump having an inlet and an outlet. The variable displacement pump is driven by a drive shaft powered by an electric motor. The pressure compensator adjusts the displacement of the variable displacement pump based on a pump pressure at the pump outlet. The speed compensator adjusts a maximum magnitude of the displacement of the variable displacement pump based on a speed of the electric motor.

A hydraulic piston pump includes a reciprocal piston disposed in a blind housing bore of a piston housing to generate a pumping action. To accommodate the piston, a piston cartridge is installed in each of the housing bores. The piston cartridge includes a piston sleeve having an inner sleeve periphery, a first outer sleeve periphery, and a second outer sleeve periphery. The inner sleeve periphery is configured to establish sliding contact with the piston. The first outer sleeve periphery has a first outer sleeve diameter that is larger than a second outer sleeve diameter of the second outer sleeve periphery. To seal against the blind housing bore, a liner cap having a cylindrical liner wall and an axial liner cover is disposed over the first outer sleeve periphery. The axial liner cover abuts a housing bore ceiling of the blind housing bore and can receive hydraulic fluid there through.

An axial reciprocation device having a main piston and an anchor piston coupled to one another via a swivel joint interconnecting 20 a pair of connecting rods, the main piston positioned in a main cylinder bore and the anchor piston positioned in an anchor piston bore of a housing, such that the main piston is configured for axial reciprocation in the main cylinder bore; wherein variable positioning of the anchor piston along the anchor piston bore results in variable displacement of the main piston of hydraulic fluid with respect to an inlet/outlet port of the housing.

A rotatable piston assembly for a reciprocating piston type hydraulic machine includes a rotatable piston configured for a controlled rotation and configured to reciprocate within a cylinder bore of the reciprocating piston type hydraulic machine.

A rotatable piston assembly for a reciprocating piston type hydraulic machine includes a rotatable piston configured for a controlled rotation and configured to reciprocate within a cylinder bore of the reciprocating piston type hydraulic machine.

A portable suction system including a pump device and a removable bag device. The pump device includes a housing defining a recess; a motor assembly positioned within the housing; a first rod at least partially extending from the housing into the recess; and a second rod at least partially extending from the housing into the recess. The first rod and the second rod are driven in response to energization of the motor assembly. The bag device is at least partially positioned within the recess, and the bag device includes: a bag; a vacuum connector; a first piston coupled to the first rod; and a second piston coupled to the second rod.

A balanced pump-axial piston pump for a hydraulic tool is provided. The balanced pump-axial piston pump includes a camshaft, cam followers, a lift block, a spring, a pump piston, a piston chamber, and a manifold. Rotation of the camshaft drives radial movement of the cam followers at the same time. The radial movement of the cam followers make the lift block move linearly along the axis of the hydraulic tool. The spring pushes the piston against the lift block so that the piston is kept in contact with the lift block. The linear movement of the lift block moves the piston linearly in the piston chamber, thereby pumping oil and providing hydraulic power.

A method to dislodge debris from a pump system in which the pump system includes a down-hole pump coupled by a rod string to an above-ground pump actuator, which is coupled to a controller configured to operate the pump system. The method also includes determining that the pump system should begin operating in a pump clean mode, and implementing the pump clean mode configured in the controller. The method also includes impressing a preset vibration frequency during a portion of a pump stroke of at least one pump cycle. Further, the method calls for determining that the pump clean mode is complete, and returning the pump system to a normal operation mode.

An electro-hydraulic apparatus comprising a base structure; an electric machine comprising a stator fixed to the base structure and a rotor rotatable about a rotation axis, the rotor being positioned radially inside of the stator with respect to the rotation axis; and a hydraulic machine comprising a revolver fixed to the rotor and including a plurality of cylinders, at least one piston plate, and a plurality of pistons fixed to the at least one piston plate, each piston being arranged to reciprocate inside one of the cylinders during rotation of the revolver to perform suction strokes and discharge strokes. A vehicle comprising an electro-hydraulic apparatus is also provided.