A positive displacement pump has a casing with a central body and two closing lids, the central body being provided with two cylindrical communicating chambers, one suction pipe and one discharge pipe, and two rotors revolvingly mounted in the chambers of the central body and supported by shafts revolvingly mounted in the closing lids. The two rotors include a male rotor having only protuberances, not cavities, and a female rotor having only cavities, not teeth or protuberances.

A housing for a rotary vane pump includes a suction flange and a discharge flange having a multi-angular cross-section with at least two sides extending parallel to each other, cooling ribs provided on an outer surface of the housing, with the number of cooling ribs in the region with a high internal pressure being greater than a number of cooling ribs in the region with a low internal pressure, inlet and outlet, with the inlet cross-section being greater than the outlet cross-section, and connection elements provided on the housing and each having two installation surfaces connected by a connection surface.

This electric horizontal scroll compressor (1) comprises an oil reservoir (13) in which lubricating oil that is separated from refrigerant passing through a compressing mechanism (20) is temporarily stored, and an oil return flow channel (15, 24) by which lubricating oil stored in the oil reservoir (13) is returned further upstream than the compressing mechanism (20). A main bearing (35) is fit into a holding face (14a) of an inner housing (14) by way of a clearance fit, and lubricating oil stored in the oil reservoir (13) is supplied to the region of the fit via the oil return flow channel (15, 24).

A screw compressor includes a screw rotor, a casing, and a delivery side shaft sealing unit. The delivery side shaft sealing unit includes an annular groove, a seal ring, and a shaft sealing fluid supply passage. Pressure of the fluid that is supplied to the one side, in the axial direction, of the seal ring via the shaft sealing fluid supply passage is set higher than pressure that acts on a first side surface, in an axial direction with respect to a first side wall surface of the annular groove, of the seal ring.

A disposable metering pump is made of plastic for products having solid fractions. The disposable metering pump has two rotors (10) which are coupled to each other by means of gears (11), can be driven in opposite directions, and are supported in a pump housing (5). Each rotor (10) has a rotor shaft, the rotor shaft ends (15) of which are supported in the walls of the pump housing (5). Each rotor (10) has two rotor blade walls (13), which are arranged diametrically opposite on the rotor shaft. One partially cylindrical rotor blade shoe (14) is formed at each of the peripheral ends of the rotor blade walls. The rotor blade shoes (14) lie against the cylindrical inner wall regions of the pump housing (5) in a sliding and sealing manner.

A vane pump includes: a casing forming a pump chamber therein; a rotor arranged inside the casing to rotate eccentrically with respect to the casing; and a plurality of vanes configured to rotate with the rotor and slide on an inner side surface of the casing. At least one of Formula (1): l≤(b/a)×k and Formula (2): l≤(c/a)×j is satisfied, where “a” represents a height of the pump chamber, “b” represents a height of the rotor, “c” represents a height of the vane in a rotation axis direction of the rotor, and where “l” represents a linear expansion coefficient of the casing in the rotation axis direction, “k” represents a linear expansion coefficient of the rotor in the rotation axis direction, and “j” represents a linear expansion coefficient of the vane in the rotation axis direction.

A variable displacement lubricant pump for providing a pressurized lubricant for an internal combustion engine includes a control ring configured to be shiftable, a pump rotor comprising a plurality of slidable vanes which are configured to rotate in the control ring, a hydraulic control chamber configured to directly actuate the control ring, a valve bore, and a temperature control valve configured to connect or disconnect the temperature control opening to an atmospheric pressure. The hydraulic control chamber comprises a side wall comprising a temperature control opening arranged therein. The temperature control valve comprises a switching strip which comprises a switching temperature. The switching strip is configured to be in an open position if a temperature is below the switching temperature, and to be in a closed position if the temperature is above the switching temperature so as to close the valve bore.

A rotary oscillating sub-assembly for positive displacement pumping of a fluid, said sub-assembly comprising: a hollow body defining a cavity having a wall with two ducts passing therethrough; a piston co-operating with said cavity to define a working chamber and including a channel that opens out longitudinally into said working chamber, said piston being movable angularly so as to put said working chamber into fluid-flow communication with one, then none, then the other of said ducts, and being movable in longitudinal translation to reciprocate so as to cause the volume of said working chamber to vary and successively suck in and then discharge said fluid, said piston carrying a sealing gasket that is formed of at least a sealing ring, a sealing half-ring, and at least one sealing strip that longitudinally connects said sealing ring to said sealing half-ring.

A rotary oscillating sub-assembly for positive displacement pumping of a fluid, said sub-assembly comprising: a hollow body defining a cavity having a wall with two ducts passing therethrough; a piston co-operating with said cavity to define a working chamber and including a channel that opens out longitudinally into said working chamber, said piston being movable angularly so as to put said working chamber into fluid-flow communication with one, then none, then the other of said ducts, and being movable in longitudinal translation to reciprocate so as to cause the volume of said working chamber to vary and successively suck in and then discharge said fluid, said piston carrying a sealing gasket that is formed of at least a sealing ring, a sealing half-ring, and at least one sealing strip that longitudinally connects said sealing ring to said sealing half-ring.

A scroll type fluid machine (1) including a rotation stopping mechanism (36) for stopping rotation of a movable scroll without hindering revolving motion of the movable scroll (16) relative to a fixed scroll (14) fixed to a casing (4), the rotation stopping mechanism includes: a support hole (42) drilled in either one of a base plate (16a) of the movable scroll and a pedestal part (4a) of the casing; a rotation stopping pin (38) that is fitted into the support hole, and is protruded to the side of the other of the base plate and the pedestal part; a restriction hole (46) drilled in the other of the base plate and the pedestal part, and loosely fitted with the rotation stopping pin; and a buffer member (44) interposed between the support hole and the rotation stopping pin.