A compressor may include first and second scrolls, an axial biasing chamber, and a control valve. The second scroll includes an outer port and an inner port. The outer and inner ports may be open to respective intermediate-pressure compression pockets. The control valve may be in fluid communication with the inner port, the outer port, and the axial biasing chamber. Movement of the control valve into the first position allows fluid communication between the inner port and the axial biasing chamber. Movement of the control valve into the second position allows fluid communication between the outer port and the axial biasing chamber.

Scroll compressor includes a shaft rotatably supported to a casing; an eccentric bush having a recess part into which one end portion of the shaft is inserted, an eccentric part eccentric to the shaft, and a balance weight disposed at the opposite side of the eccentric part with respect to the recess part; an orbiting scroll for performing the orbiting motion in interlock with the eccentric part; and a fixed scroll for forming a compression chamber together with the orbiting scroll. The casing has an orbiting groove in which the eccentric bush performs the orbiting motion, a buffer member is interposed between the orbiting groove and the balance weight. Rotation clearance is formed between the recess part and the shaft. The buffer member is compressed between the balance weight and the orbiting groove before the recess part and the shaft contact each other by the rotation clearance.

A scroll type positive displacement assembly includes a first scroll and a second scroll, where the second scroll is configured to orbit with respect to a center of the first scroll without rotating with respect to the first scroll. Together, the first scroll and the second scroll define a compression chamber between two seal points where the first scroll and the second scroll contact one another as the second scroll orbits with respect to the first scroll during a compression cycle, and the two seal points come together proximate to a discharge port between the first scroll and the second scroll such that there is at least substantially no dead space between the first scroll and the second scroll at an end of the compression cycle. For example, the two seal points remain in sealing contact during at least one hundred and eighty (180) degrees of the compression cycle.

A scroll type positive displacement assembly includes a first scroll and a second scroll, where the second scroll is configured to orbit with respect to a center of the first scroll without rotating with respect to the first scroll. Together, the first scroll and the second scroll define a compression chamber between two seal points where the first scroll and the second scroll contact one another as the second scroll orbits with respect to the first scroll during a compression cycle, and the two seal points come together proximate to a discharge port between the first scroll and the second scroll such that there is at least substantially no dead space between the first scroll and the second scroll at an end of the compression cycle. For example, the two seal points remain in sealing contact during at least one hundred and eighty (180) degrees of the compression cycle.

The scroll compressor includes scroll members that include a compression chamber to compress working fluid, a housing that houses the scroll members, a second driving-side shaft portion that discharges the compressed working fluid from the compression chamber and is rotated around an axis with respect to the housing, a bearing that rotatably supports the housing with respect to the second driving-side shaft portion , and a seal member between the second driving-side shaft portion and the housing . A lubricant is provided between the bearing and the seal member.

A screw compressor for a utility vehicle has a rotor housing, in which screw rotors of the screw compressor are arranged, a housing cover, and an air outlet pipe arranged on an output side of the housing cover and having a riser. The air outlet pipe has at least one oil separator.

A scroll type positive displacement assembly includes a first scroll and a second scroll, where the second scroll is configured to orbit with respect to a center of the first scroll without rotating with respect to the first scroll. Together, the first scroll and the second scroll define a compression chamber between two seal points where the first scroll and the second scroll contact one another as the second scroll orbits with respect to the first scroll during a compression cycle, and the two seal points come together proximate to a discharge port between the first scroll and the second scroll such that there is at least substantially no dead space between the first scroll and the second scroll at an end of the compression cycle. For example, the two seal points remain in sealing contact during at least one hundred and eighty (180) degrees of the compression cycle.

A scroll type positive displacement assembly includes a first scroll and a second scroll, where the second scroll is configured to orbit with respect to a center of the first scroll without rotating with respect to the first scroll. Together, the first scroll and the second scroll define a compression chamber between two seal points where the first scroll and the second scroll contact one another as the second scroll orbits with respect to the first scroll during a compression cycle, and the two seal points come together proximate to a discharge port between the first scroll and the second scroll such that there is at least substantially no dead space between the first scroll and the second scroll at an end of the compression cycle. For example, the two seal points remain in sealing contact during at least one hundred and eighty (180) degrees of the compression cycle.

A pump device includes: a variable capacity-type pump unit configured to include an inner rotor having a plurality of external teeth , an outer rotor having a plurality of internal teeth meshing with a portion of the plurality of external teeth of the inner rotor, a housing, a suction port and a discharge port, an adjustment member adjusting a discharge pressure of a fluid, a biasing mechanism biasing the adjustment member, a control flow passage causing a fluid pressure from the discharge port to be applied to the adjustment member, a solenoid valve adjusting the fluid pressure applied to the adjustment member, a bypass flow passage, and a relief valve; a rotation speed sensor measuring a rotation speed of a drive source; and a control unit controlling the solenoid valve.

A pump device includes: a variable capacity-type pump unit configured to include an inner rotor having a plurality of external teeth , an outer rotor having a plurality of internal teeth meshing with a portion of the plurality of external teeth of the inner rotor, a housing, a suction port and a discharge port, an adjustment member adjusting a discharge pressure of a fluid, a biasing mechanism biasing the adjustment member, a control flow passage causing a fluid pressure from the discharge port to be applied to the adjustment member, a solenoid valve adjusting the fluid pressure applied to the adjustment member, a bypass flow passage, and a relief valve; a rotation speed sensor measuring a rotation speed of a drive source; and a control unit controlling the solenoid valve.