A rotary pump includes: a pump rotor having a flat rotor side surface facing in an axial direction; a housing body having an opening in the axial direction and a flat flange surface formed around the opening, the housing body rotatably housing the pump rotor in the opening such that the rotor side surface is flush with the flange surface; and a cover member having a flat mating surface that is fixed while being pressed against the flange surface by fastening of a bolt, and a flat sliding/guiding surface that slides and guides the rotor side surface. The cover member is formed of a crosslinked fluororesin and a metal body. The metal body is provided with the mating surface, and a recess obtained by recessing an area corresponding to the sliding/guiding surface, in the axial direction with respect to the mating surface.

A board surface of a control board is disposed on an outward side of a motor in a radial direction in a posture along an axial direction. A rotation angle sensor is disposed on a rear side of a control board in the axial direction. A power supply input portion on the control board is disposed in an end portion on the rear side in the axial direction. A main body of a motor includes the control board and a wiring assembly electrically connecting a connector and the rotation angle sensor to each other. The wiring assembly includes a power supply input wiring, a sensor wiring, and a wiring holder holding the power supply input wiring and the sensor wiring.

A displacement device including an inner rotor and an outer rotor with meshing projections. Points on each rotor trace a hypotrochoidal path relative to the other. The tips of the outer rotor projections may contact the inner rotor at Top Dead Center (TDC) and Bottom Dead Center (BDC) to form higher and lower pressure regions. Various elements may shape other elements to form seals.

A crosslinked fluororesin-coated rotor manufacturing method is a method for manufacturing an annular outer rotor of an internal gear pump including the outer rotor, and an inner rotor, a side surfaces of the outer rotor being coated with a crosslinked fluororesin, an inner peripheral surface of the outer rotor not being coated with the crosslinked fluororesin, the method including: using an outer masking jig for covering the inner peripheral surface in a state where the side surfaces of the outer rotor are exposed; coating the outer rotor with an uncrosslinked fluororesin in a state where the outer masking jig is mounted to the outer rotor; and then irradiating the fluororesin with radiation in a state where the outer masking jig is removed from the outer rotor, to crosslink the fluororesin.

A crosslinked fluororesin-coated pump rotor manufacturing method is a method for manufacturing a pump rotor having flat rotor side surfaces and provided with a coating layer of a crosslinked fluororesin on each rotor side surface, the method including: screen-printing a dispersion liquid obtained by dispersing particles of a fluororesin in a solvent, on the rotor side surface by using a screen plate having an opening having a shape in which the opening does not protrude from an outer peripheral edge of the rotor side surface; then heating the pump rotor to a temperature equal to or higher than a melting point of the fluororesin to bake the fluororesin on the rotor side surface; and then irradiating the fluororesin with radiation to crosslink the fluororesin.

A rotary piston and cylinder device comprising a rotor (2), comprising a rotor surface (2a), a stator (4), a rotatable shutter (3), a piston (5) which extends from the rotor surface, the rotor surface and the stator together defining an annular chamber, and the piston arranged to rotate, through the annular chamber, and the rotor surface being orientated at an incline to a plane (P-P) substantially perpendicular to the axis of rotation (A-A) of the rotor and the rotor surface faces generally away from, or outwardly of, the axis of rotation of the rotor.

A progressing cavity device operates as a motor to impart torque to a bit. A stator of the device defines an internal profile having uphole stages with a first dimension being less than a second dimension of downhole stage. A rotor has an external profile with a constant outer dimension along its length. Disposed in the stator, the rotor defines cavities with the stator and is rotatable with pumped fluid progressing in the cavities from the uphole to downhole to transfer torque to the drive toward the downhole end. Although the rotor is subjected at the downhole end to a reactive torque from the bit, the interference fit of the rotor's constant dimension with the stator's downhole stages is less than with the uphole stages, which can mitigate issues with heat buildup in the downhole stages. The device can also operates as a progressing cavity pump.

A screw compressor includes a housing, a first rotor rotatable about a first axis relative to the housing, and a second rotor rotatable about a second axis relative to the housing. The second rotor is enmeshed with the first rotor. A motor is embedded within the first rotor such that the motor is coaxial with the first axis.

A scroll compressor (1) including an enclosure (2); a compression section (6) arranged within the enclosure (2), the compression section (6) has a fixed scroll element (7) having a first baseplate (11) and a first wrap portion (12) extending from the first baseplate (11), and an orbiting scroll element (8) having a second baseplate (13) and a second wrap portion (14) extending from the second baseplate (13), the fixed and orbiting scroll elements (7, 8) being intermeshed to form compression chambers (15); and a driving section (16) coupled with the orbiting scroll element (8) for moving the orbiting scroll element (8) in an orbiting motion during operation of the scroll compressor (1). At least one of the fixed and orbiting scroll elements (7, 8) is made of solid solution strengthened ferritic ductile iron.

The present disclosure relates to a compressor including a branch part for reducing vibration and noise caused by a refrigerant flowing inside a muffler by expanding an enclosed space formed by a compression part and the muffler in the direction of a rotation axis.