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 compressor assembly becomes a compressor as a result of a terminal guard being attached. The compressor assembly includes a body, and a terminal guard mounting seat attached to an outer surface of the body. The terminal guard is attachable to the terminal guard mounting seat. A compressor includes the compressor assembly and the terminal guard. The compressor can be manufactured by attaching the terminal guard mounting seat to the outer surface, administering metal spraying to at least part of the outer surface after attaching the terminal guard mounting seat, and attaching the terminal guard to the terminal guard mounting seat after the administering metal spraying.

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 machine, for directing a quantity of fluid from an inlet to an outlet, comprises one or more elliptical or near-elliptical rotors having planetary rotation within a housing. The interior cavity of the housing comprises an inverse apex region that is in contact with the rotor during its rotation. In various embodiments the rotor and housing can be symmetric or asymmetric in cross-section. Features are described that can improve the operation of the machine for various end-use applications. Such features include cut-outs that are fluidly connected to the inlet or outlet ports of the machine, mechanisms for reducing variation in output flow rate from the rotary machine, linings for the interior cavity of the housing, pressure relief mechanisms, dynamic apex seals and other sealing mechanisms.

A screw compressor includes a male rotor and a female rotor enclosed in a casing inside which they counter-rotate, to drive the male rotor from a motor, a gas passes through an intake duct created between the two rotors, and the rotation closes this intake duct and the compressed gas is pushed towards a delivery. Each rotor includes a rotation shaft which rotates in the case due to special bearings which is surrounded by helical propellers which engage each other, the propellers being made to reduce progressively the space between rotors and casing, so that the gas sucked in by the suction duct compresses in the direction of the delivery. The helical propellers are made of a polymeric material.

Disclosed is a safety-reinforced water-ring vacuum pump including a built-in hogging flow path. The water-ring vacuum pump includes a first-stage body, a second-stage body, and an impeller. The first-stage body includes a gas inlet port through which gas is suctioned and a seal water supply port through which seal water is supplied. The second-stage body includes a mixed fluid outlet port through which a mixed fluid of the gas and the seal water is discharged. The impeller is rotated at high speed by an internal drive shaft penetrating the first-stage body and the second-stage body. The first-stage body has a fluid-mixing space provided therein, the fluid-mixing space having a mixed flow of the gas and the seal water therein. The second-stage body has a fluid guide space and an internal hogging flow path provided therein, the internal hogging flow path communicating with the fluid guide space.

Downhole tools for earth-boring applications may include a component of a steel material and including a bore. An inner surface defining the bore may be treated with a surface treatment. The surface treatment may include a nitrided region having nitrogen diffused into the steel material and a ceramic material adjacent to the nitrided region; the ceramic material defining the inner surface. Methods of making downhole tools for earth-boring applications may involve exposing a component of the downhole tool to an elevated temperature to heat the component in a nitrogen-rich environment. Nitrogen may be diffused into a steel material of the component and a nitrided region may be formed at one or more surfaces of the component. A ceramic material may be coated on the nitrided region of the component.

A rotary vane pump including a housing, and a motor. The motor includes a shaft which is coupled to a rotor. The rotor defines a plurality of slots. A plurality of free moving vanes are disposed within the slots. In one example, the rotor is formed from a first material and the plurality of vanes are formed from the first material and impregnated with a second material. The first material can be a carbon material. The second material can be a resin material, an antimony material, a copper material, or a silver material.

First closing plate and second closing plate close opening portions at both ends of cylindrical member in an axial direction. Base is housed in a space formed by cylindrical member, first closing plate, and second closing plate, and rotates around an axis in the same direction as the axial direction of cylindrical member. Resin layers are formed on thrust surfaces of base. Groove C is a plurality of concentric circular grooves or a spiral groove formed on each resin layer, and the center of circles of the circular grooves or the center of a spiral of the spiral groove is different from the rotation center of base.