Provided is a hydraulic orbital machine and a method of adjusting a hydraulic orbital machine comprising a first and a second lobed disk which rotate eccentrically about a rotation axis and within respective rotors; the machine is characterized by the fact that it has adjustment means designed to mutually angularly offset the angles at which, when the machine is at a standstill, the chambers defined between the lobed disks and the stator have minimum volume.

A scroll compressor is disclosed, which may provide an oil supply path opened only in case of driving of a low pressure ratio to improve a differential pressure oil supply structure which may have a defect in oil supply in case of driving of the low pressure ratio.

Technologies are generally described for clearance adjustments in twin-screw pump assemblies. A twin-screw pump assembly may include a conically shaped portion of a drive shaft enveloped by a bushing. For clearance adjustment, both clamping nuts of the drive shaft, which provide pretention to the bushing and secure an axial position of a threaded screw to the drive shaft, may be removed on the flow side of the pump assembly and the bushing loosened to adjust the angularity between bushing and drive shaft. The bushing may then be pushed over the conically shaped portion and both clamping nuts re-assembled. In some examples, a clamping nut of the driven shaft may be designed and used as removal/loosening tool for the drive shaft bushing.

Systems and methods are provided for pumps that deliver optimized torque characteristics and volumetric efficiency. A system includes a housing defining a surface and a rotor defining a face. A face clearance is defined between the face and the surface. The face clearance is variable in magnitude and determinative of target performance characteristics of the pump system. The housing is made of a material selected to have a thermal expansion characteristic and the rotor is made of a second material selected to have another thermal expansion characteristic. The thermal expansion characteristics deliver the target performance characteristics of the pump system.

A compressor includes an orbiting scroll, a cooling pipe and a crankshaft, the cooling pipe includes an inlet pipe and an outlet pipe, an axial through hole is provided at a center of the orbiting scroll, a sealing portion of the orbiting scroll is provided with a sealing groove, a mounting hole is provided in the crankshaft, the cooling pipe passes through the crankshaft and enters from a tail portion of the crankshaft, through the mounting hole, the axial through hole and the sealing groove, and then returns back on the same way, and a part of the cooling pipe is arranged in the sealing portion of the orbiting scroll, the cooling pipe moves synchronously with the orbiting scroll and rotates with respect to the crankshaft.

Systems and methods are provided for pumps that deliver optimized torque characteristics and volumetric efficiency. A system includes a housing defining a surface and a rotor defining a face. A face clearance is defined between the face and the surface. The face clearance is variable in magnitude and determinative of target performance characteristics of the pump system. The housing is made of a material selected to have a thermal expansion characteristic and the rotor is made of a second material selected to have another thermal expansion characteristic. The thermal expansion characteristics deliver the target performance characteristics of the pump system.

A fluid delivery device has a primary pump and a main pump fluidically connected to the primary pump. The primary pump can be driven by a primary pump input shaft, the main pump can be driven by a main pump input shaft, and the primary pump input shaft and the main pump input shaft are mechanically coupled to a common drive shaft of the fluid delivery device. The primary pump is in the form of a non-compensated gear pump or a centrifugal pump and the main pump is in the form of a compensated internal gear pump.

A vane cell pump, including: a rotor and a plurality of vanes rotatable with the rotor, wherein the rotor includes a sub-vane chamber for each vane, and each vane forms a shifting wall of the sub-vane chamber assigned to it; first and second end-facing walls adjoining the rotor on end-facing sides and which, in order to control pressure to the sub-vane chamber, include sub-vane cavities which extend in the circumferential direction of the rotor and include control edges as viewed in the circumferential direction; wherein the control edge of the sub-vane cavity of the first end-facing wall, and the control edge of the sub-vane cavity of the second end-facing wall which is similar to it, are arranged angularly offset about the rotational axis as the apex with respect to each other.

A rotary compressor is provided that may include a roller slidingly coupled to an eccentric portion of a rotational shaft so as to be moved along an inner circumferential surface of a cylinder by the rotational shaft, and a vane slidingly coupled to the cylinder so as to divide the compression space into a plurality of compression chambers. An oil supply groove may be formed on an outer circumferential surface of the eccentric portion or an inner circumferential surface of the roller that faces the outer circumferential surface of the eccentric portion, and a depth of the oil supply groove may decrease as a distance in a circumferential direction from the second oil supply hole increases. Accordingly, an amount of oil supplied between the eccentric portion and the roller may be increased to thereby reduce friction loss.

A low pressure gear pump and wear plate is disclosed. The wear plate may comprise a sidewall, a drive portion, a driven portion, and a transition portion. The sidewall is free of a sealing member or a recess configured to receive the sealing member. The drive portion includes a drive inlet lip, a drive outlet lip, a drive recessed trough and a drive bore. The drive bore is configured to receive the drive shaft of the gear pump. The driven portion may that include a driven inlet lip, a driven outlet lip, a driven recessed trough, and a driven bore. The driven bore is configured to receive the driven shaft of the gear pump. The transition portion may include a transition aperture configured to receive a first fastener configured to mount the wear plate to the gear housing. The wear plate is made of bronze, aluminum or non-magnetic material.