A radial piston hydraulic device distributed by pilot operated check valves includes a housing, a plurality of piston assemblies, a main shaft, the rotating shaft, first pilot operated check valves having a same number with the plurality of piston assemblies and one-to-one corresponding to the plurality of piston assemblies, and second pilot operated check valves having a same number with the plurality of piston assemblies and one-to-one corresponding to the plurality of piston assemblies. The housing includes a plurality of piston chambers, a rotating shaft chamber, a high-pressure oil passage, and a low-pressure oil passage. Each of the plurality of piston assemblies is slidable up and down in a corresponding piston chamber of the plurality of piston chambers. The main shaft is rotatably connected to the housing and is connected to the plurality of piston assemblies in a transmission way.

A pump for exerting a compression action on a fluid, includes a casing for rotatably supporting a shaft having an axis; and an actuating device for actuating the fluid, including a reciprocating device movable in an axial direction. A connection device includes a driving device having a circumferential surface eccentrically extending from the axis and which is rotatable together with the shaft. A device for transmitting a driving motion of the eccentric surface to the actuation device includes a body suitable to convert the rotary motion of the eccentric driving surface into said reciprocating axial motion for the actuating device. A motor includes a drive shaft rotated by a fluid device. The fluid device including reciprocatingly movable thrust devices and a transformation device for transforming movement of the thrust devices, into a rotary motion of the drive shaft.

A pump body of a high-pressure pump includes a pressure chamber formed in a deep portion of a cylinder. The pump body closes the pressure chamber on a side opposite to a plunger. The plunger reciprocates within the cylinder to vary a volume of the pressure chamber. The large-diameter portion provided at an end of the plunger on a side protruding to the pressure chamber has an outside diameter larger than an inside diameter of the cylinder and smaller than an inside diameter of the pressure chamber. In this case, the large-diameter portion is engaged with a step portion between the cylinder and the pressure chamber in a state before attachment of the high-pressure pump to an internal combustion engine. Accordingly, separation of the plunger from the cylinder is avoidable.

An air compressor pump is provided, including a crankcase with an opening and a crankshaft extending out of the opening; a cover disposed over the opening in the crankcase; and a condensing chamber formed between the crankcase and the cover.

A high-pressure fuel pump includes a pump housing which defines a pumping chamber, a fuel inlet which allows low-pressure fuel into the pumping chamber, a fuel outlet which allows high-pressure fuel out of the pumping chamber, and a plunger bore which extends along an axis and opens into the pumping chamber. The high-pressure fuel pump also includes a pumping plunger which reciprocates within the plunger bore along the axis such that reciprocation of the pumping plunger within the plunger bore increase and decreases a volume of the pumping chamber. The pumping plunger includes a sealing ring groove which is concentric with the plunger bore, the sealing ring groove including a sealing ring therein which engages the plunger bore in an interference fit. A diametric clearance greater than 12 microns is provided between the pumping plunger and the plunger bore.

A lubrication system for a frac pump includes a lubrication system housing, a lubricant tank held by the lubrication system housing, a heating device held by the lubrication system housing, a cooling device held by the lubrication system housing, and a filtration device held by the lubrication system housing. The lubrication system housing is configured to be at least one of mounted to a frac pump housing of the frac pump or held within the frac pump housing.

A multi-piece fluid end that can be produced with fewer raw materials and at a lower cost. In one embodiment, a fluid end is formed from a first body attached to a separate second body. Their respective external surfaces may be engaged flushly, partially, or via one or more spacer elements. In some embodiments, the body pieces are flangeless to reduce stress on the fluid end. The second body may have a plurality of bores that are alignable with a plurality of corresponding bores formed in the first body. The second body may be connected to a power end using a plurality of stay rods. In other implementations, more than two body pieces may be utilized.

A multi-piece fluid end that can be produced with fewer raw materials and at a lower cost. In one embodiment, a fluid end is formed from a first body attached to a separate second body. Their respective external surfaces may be engaged flushly, partially, or via one or more spacer elements. In some embodiments, the body pieces are flangeless to reduce stress on the fluid end. The second body may have a plurality of bores that are alignable with a plurality of corresponding bores formed in the first body. The second body may be connected to a power end using a plurality of stay rods. In other implementations, more than two body pieces may be utilized.

A high-pressure fuel pump includes a pump housing, a pump piston accommodated in a receiving opening of the pump housing, a high-pressure seal which surrounds the pump piston in a sealing manner and which seals off a high-pressure region from a low-pressure region, and a guide device which comprises at least two guide portions that are axially spaced apart from one another and guide the pump piston with a sliding fit. The at least two guide portions are arranged in the receiving opening of the pump housing. A first guide portion is arranged, as seen in an axial direction, on a side of the high-pressure seal facing toward the delivery space. And a second guide portion is arranged, as seen in the axial direction, on a side of the high-pressure seal facing away from the delivery space.

A clamp comprising a first contact surface perpendicular to a central axis of the clamp and a second contact surface tapered relative to a central axis of the clamp, whereby the clamp allows for concentric or non-concentric mating between a first component and a second component such that, when rigidly held together by the clamp such that the first contact surface of the clamp contacts a portion of the first component and the second contact surface of the clamp contacts a portion of the second component, a central axis of the first component is parallel to or coincident with a central axis of the second component.