Systems, methods and devices are described providing a selective hydraulic or electrically powered prime mover that is a bi-directional power unit system, including movement within a device used to compress and/or expand a fluid and provide fluid movement. The use of a hydraulic power unit is involved and comprises at least a pump or other fluid moving device, a first set of selective control valves delivering pressurized fluid to the device(s), and a second set of selective control valves returning unpressurized fluid from the device(s), a reservoir comprising a compensator tank, a port for operation at ambient pressure, and a pressure measuring device measuring ambient pressure allowing for unbalanced flow to and from the device as well as thermal expansion or compression. The use of a multiport and in some cases a swashplate pump that incorporates the features and functions of several valves for the system is also described.

In an embodiment, a pump assembly may include a mounting structure and a pump mechanism and a starter motor coupled to the mounting structure. The pump mechanism may include an input shaft configured to be rotatably coupled with an output shaft of a prime mover engine. The starter motor may be coupled with the input shaft of the pump mechanism for rotatably driving the input shaft of the pump mechanism.

A compression part of a rotary compressor includes an intermediate partition plate that is arranged between an upper cylinder and a lower cylinder, an upper vane that sections an upper cylinder chamber formed within the upper cylinder into an upper suction chamber and an upper compression chamber, and a lower vane that sections a lower cylinder chamber formed within the lower cylinder into a lower suction chamber and a lower compression chamber. The intermediate partition plate is formed with an injection hole that injects a liquid refrigerant into the upper compression chamber and the lower compression chamber and an injection passage that supplies the liquid refrigerant to the injection hole. The injection passage is formed along a straight line that does not cross a rotary shaft insertion hole into which a rotary shaft is inserted.

A piston is provided with a piston body that includes an internal space and a leading end member that includes an insertion portion placed in the internal space and a protrusion protruding from a leading end surface of the piston body.

A piston is provided with a piston body that includes an internal space and a leading end member that includes an insertion portion placed in the internal space and a protrusion protruding from a leading end surface of the piston body.

There is provided a wobble plate piston water pump including: a pump body defining a plurality of channels; a rotatable wobble plate disposed in the pump body; a plurality of pistons each located in a respective one of the plurality of channels, the pistons being reciprocatable within the channel along a piston axis; a water passage defined by a water inlet and a water outlet; and a plurality of inlet check valves, each associated with one of the channels, and positioned between the water inlet and the associated channel, the inlet check valves reciprocate along an axis parallel to the piston axis to transition between closed states and open states.

There is provided a wobble plate piston water pump including: a pump body defining a plurality of channels; a rotatable wobble plate disposed in the pump body; a plurality of pistons each located in a respective one of the plurality of channels, the pistons being reciprocatable within the channel along a piston axis; a water passage defined by a water inlet and a water outlet; and a plurality of inlet check valves, each associated with one of the channels, and positioned between the water inlet and the associated channel, the inlet check valves reciprocate along an axis parallel to the piston axis to transition between closed states and open states.

There is provided a wobble plate piston water pump for use in a pressure washer and driven by a driving source, the water pump includes a pump body, a wobble plate, four or more pistons and a water passage defined by a water inlet and a water outlet. The driving source being electric powered and having a power consumption of less than or equal to a 15 ampere draw at 120 volts or 220 volts or the driving source being gas powered and having an engine displacement of less than or equal to 250 cubic centimetres.

There is provided a wobble plate piston water pump for use in a pressure washer and driven by a driving source, the water pump includes a pump body, a wobble plate, four or more pistons and a water passage defined by a water inlet and a water outlet. The driving source being electric powered and having a power consumption of less than or equal to a 15 ampere draw at 120 volts or 220 volts or the driving source being gas powered and having an engine displacement of less than or equal to 250 cubic centimetres.

A hydraulic pump or motor includes a mounting flange that is disposed at the first end of the housing. The mounting flange defines a pair of bolt receiving slots that are disposed along the X-axis on either side of the shaft. The pair of bolt receiving slots each define a radius center that are spaced away from each other a X dimension, and a pilot projection extends longitudinally away from the mounting flange, defining a pilot projection diameter. A ratio of the X dimension to the pilot projection diameter ranges from 1.1 to 1.5.