A scroll compressor is provided. The scroll compressor may include a casing, a discharge cover to partition an inside of the casing into suction and discharge spaces, a first scroll, a second scroll that defines compression chambers together with the first scroll and includes an intermediate pressure discharge hole that communicates with a compression chamber having an intermediate pressure of the compression chambers, a back pressure plate that defines a back pressure chamber that accommodates a refrigerant discharged from the intermediate pressure discharge hole, a floating plate that defines the back pressure chamber together with the back pressure plate, and a gasket disposed between the back pressure plate and the second scroll and having an intermediate pressure communication hole that allows the intermediate pressure discharge hole to communicate with the intermediate pressure suction hole. The gasket may block communication between the back pressure chamber and the suction and discharge spaces.

A pump body assembly and a compressor are provided. The pump body includes: a spindle, wherein the spindle has a sliding vane chute, a back pressure oil cavity being at least a part of an oil passage is located at a tail end of the sliding vane chute, an oil outlet of the back pressure oil cavity is located at the top of the back pressure oil cavity, and a position of the oil inlet of the back pressure oil cavity is lower than that of an oil outlet of the back pressure oil cavity such that a lubrication medium enters the back pressure oil cavity through the oil inlet of the back pressure oil cavity and fills up the back pressure oil cavity and flows out from the top of the back pressure oil cavity.

An eccentric screw pump for pumping fluids or flowing conveying media from a suction side to a pressure side, which includes a rotor and a stator, the stator being flexible and is connected to the pump housing on one side, in particular on the suction side. The rotor is connected to the drive shaft by means of an articulation. When the eccentric screw pump is in the idle state, there is no sealing contact at least in areas between the rotor and the stator in the sealing areas. When the eccentric screw pump is in the operating state, the stator is surrounded, at least in sections and/or, essentially, on the periphery by the conveying medium. The rotor and the stator are brought into contact with each other in the operating state along the sealing area.

Provided is a tip seal that makes it possible to improve the durability of a tip seal installed on the tooth tip of a wall even when a continuously inclined section is provided to the wall. The tip seal is provided with: a tip seal inclined section (7A) installed in a groove section of a wall in which the height changes continuously in a spiral direction; and a tip seal flat section (7B) that is installed in a groove section of the wall in which the height is fixed in the spiral direction and that is adjacent to the tip seal inclined section (7A). A recess (8) is formed at a position away from the adjacent area between the tip seal inclined section (7A) and the tip seal flat section (7B).

A rotor pair for a compressor block of a screw machine includes a secondary rotor that rotates about a first axis and a main rotor that rotates about a second axis. The number of teeth of the main rotor is 3 and the number of teeth of the secondary rotor is 4. The relative profile depth of the secondary rotor is at least 0.5 rk1 is an addendum circle radius drawn around the outer circumference of the secondary rotor and rf1 is a dedendum circle radius starting at the profile base of the secondary rotor. The ratio of the axis distance of the first axis from the second axis and the addendum circle radius rk1 is at least 1.636.

An air heating apparatus may comprise a housing with a path through an interior of the housing between openings in the housing. An isolating wall may divide the interior into primary and secondary chambers, and may have a transfer opening through which the path extends from the primary to secondary chambers. An air heating assembly may comprise an engine in the primary chamber, a heat generator in the primary chamber and connected to the engine, and a main heat exchanger in the secondary chamber and in fluid communication with the heat generator to transfer heat generated by the heat generator to air flowing along the path. The apparatus may include an air movement assembly configured to move air along the path and comprises a primary fan between the primary and secondary chambers to move air from the primary chamber to the secondary chamber.

A uniaxial eccentric screw pump for rotating a rotor about its axis and revolving the rotor without involving complicated operations and control is provided. The uniaxial eccentric screw pump includes a rotor drive mechanism capable of revolving a rotor while rotating the rotor about its axis. The rotor drive mechanism includes a rotation power transmission member rotatable about a predetermined center axis, and a revolution track formation member capable of revolving a proximal shaft portion of the rotor while allowing rotation of the proximal shaft portion about its axis. The rotor drive mechanism distributes power output from the same motor in parallel and transmit the power to the rotation power transmission member and the revolution track formation member, enabling the rotation power transmission member and the revolution track formation member to rotate about their axes while being synchronized mechanically, and enabling the rotor to revolve while rotating about its axis.

An oil lubrication system for a multi-stage compressor separates oil from a refrigerant at an intermediate pressure following the first stage of compression and then routes the separated oil at the intermediate pressure to the compressor suction cavity bearings at the intermediate pressure, thus avoiding further compression of oil in subsequent stages of compression. The efficiency of the multi-stage compressor can be increased by not raising the pressure of the oil through the subsequent stages of compression.

A rotary engine includes a housing having a working cavity, a shaft, the shaft having an eccentric portion, a rotor having a first axial face, and a second axial face opposite the first axial face, the rotor disposed on the eccentric portion and within the working cavity, the rotor comprising a first cam on the first axial face, the first came having an eccentricity corresponding to the eccentricity of the eccentric portion of the shaft, and a cover integral with, or fixedly attached to, the housing, the cover comprising a plurality or rollers, each roller engaged with the cam, wherein the cam guides the rotation of the rotor as the rotor rotates within the working cavity and orbits around the shaft.

Provided is an internal gear pump requiring fewer machining steps, allowing inexpensive manufacture, and offering high safety from the standpoint of function. The internal gear pump 1 comprises: a trochoid 4 in which an inner rotor 3 having a plurality of outer teeth is eccentrically and rotatably accommodated in an outer rotor 2 having a plurality of inner teeth, the outer teeth meshing with the inner teeth, and in which a suction-side chamber for suctioning liquid and a discharge-side chamber for discharging liquid that has been suctioned into the suction-side chamber are formed in between the inner teeth and outer teeth; a casing 5 in which is formed a recess 5a for accommodating the trochoid 4; and a cover 6 for closing off the recess 5a of the casing 5. At least some of the casing 5 is a body injection-molded from a resin composition. The invention also comprises a groove 5d in a portion of the recess 5a of the casing 5 in which the outer periphery is sealed, with a sealing ring 13 installed therein, and bushings 7 made from sintered metal that are provided integrally during injection molding in bolt fixing hole portions.