A non-lubricated system for pumping a gas, includes a stationary stator with a housing that includes a rotor cavity and at least one rotatable rotor element incorporated within the rotor cavity. The stator includes at least one self-supporting sealing element, incorporated within the rotor cavity between an end face of at least one of the rotor elements and an interior wall of the housing to form a seal along the corresponding end face. At least one self-supporting sealing element is provided with an abradable coating on at least one side facing the rotor.

A scroll compressor includes a scroll compression element including a movable scroll, a drive shaft configured to allow the movable scroll to rotate, a boss portion, and a sliding bearing. The boss portion is connected to a back surface of the movable scroll. The boss portion is configured to rotatably support an upper end portion of the drive shaft. The upper end of the drive shaft is configured as an eccentric shaft portion. The sliding bearing is provided between the boss portion and the eccentric shaft portion. An axially central portion of the boss portion is more rigid than a connection portion of the boss portion connected to the movable scroll. The boss portion is shaped so that the central portion projects outward.

A pump having at least two fluid drivers and a method of delivering fluid from an inlet of the pump to an outlet of the pump using the at least two fluid drivers. Each of the fluid drives includes a prime mover and a fluid displacement member. The prime mover drives the fluid displacement member to transfer fluid. The fluid drivers are independently operated. However, the fluid drivers are operated such that contact between the fluid drivers is synchronized. That is, operation of the fluid drivers is synchronized such that the fluid displacement member in each fluid driver makes contact with another fluid displacement member. The contact can include at least one contact point, contact line, or contact area.

Dual- or multi-shaft vacuum pump comprising an engine, a first shaft and at least one second shaft, wherein the first shaft and the second shaft are synchronously driven by the motor via a common drive belt. The first shaft has a pumping element and the second shaft likewise has a pumping element which cooperates with the pumping element of the first shaft in order to convey a gaseous medium from an inlet to an outlet. The first shaft has a first emergency running gear and the second shaft likewise has a second emergency running gear which meshes with the first emergency running gear.

A scroll compressor comprising a fixed scroll (15); an orbiting scroll (16) supported in a manner allowing for orbiting motion; a discharge port through which a fluid compressed by the two scrolls (15, 16) is discharged; an end plate step portion (16E) provided on an end plate of the orbiting scroll (16) formed so that a height of the end plate is higher on a center portion side in the direction of a spiral wrap and lower on an outer end side; and a wrap step portion (15E) provided on a wall portion of the fixed scroll (15) that corresponds to the end plate step portion (16E) so that a height of the wall portion is lower on the center portion side of the spiral and higher on the outer end side; wherein the orbiting scroll (16) is treated for surface hardening and the fixed scroll (15) is not treated for surface hardening.

A rotary positive displacement pump (1) comprises a pump enclosure (10) and at least one rotating member (20). The pump enclosure (10) has an inlet (12) and an outlet (14). The rotating member (20) is arranged for, when being rotated, causing a transfer of a liquid from the inlet (12) to the outlet (14). The rotary positive displacement pump (1) has internal sliding surfaces (16, 24, 26, 32, 34) that during operation are exposed to the liquid and are exposed to a sliding contact relative to other internal sliding surfaces (16, 24, 26, 32, 34) of the rotary positive displacement pump (1). At least a part of the internal sliding surfaces (16, 24, 26, 32, 34) has a surface region composed by a nitrided or nitrocarburized steel intercalated with a solid lubricant. A method for manufacturing a rotary positive displacement pump is also disclosed.

A scroll compressor comprising a fixed scroll (15); an orbiting scroll (16) supported in a manner allowing for orbiting motion; a discharge port through which a fluid compressed by the two scrolls (15, 16) is discharged; an end plate step portion (16E) provided on an end plate of the orbiting scroll (16) formed so that a height of the end plate is higher on a center portion side in the direction of a spiral wrap and lower on an outer end side; and a wrap step portion (15E) provided on a wall portion of the fixed scroll (15) that corresponds to the end plate step portion (16E) so that a height of the wall portion is lower on the center portion side of the spiral and higher on the outer end side; wherein the orbiting scroll (16) is treated for surface hardening and the fixed scroll (15) is not treated for surface hardening.

A rotor and/or stator dampening system includes a stator and/or rotor with a liner selected of one or more materials to achieve a desired dampening effect. In one implementation, a progressive cavity motor or pump includes a stator with an internal axial bore therethrough. The stator has a liner along an axial length thereof with an inwardly facing surface defining the internal axial bore therethrough. The liner has a plurality of axial sections with at least two of the plurality of axial sections being constructed of different materials. A compression resistant mechanism, such as a spring or spring-like device, is disposed within at least one of the axial sections of the liner. The progressive cavity motor or pump also includes a rotor that is disposed and is rotatable within the internal axial bore of the stator to form a moving chamber between the rotor and the stator.

A rotary compressor may include a rotary shaft; a plurality of plates that supports the rotary shaft; a cylinder provided between the plurality of plates to define a compression space, and provided with a vane slot; a roller slidably coupled to the rotary shaft inside of the cylinder, and having a hinge groove on an outer circumferential surface thereof; and a vane, a first end of which is slidably coupled to the vane slot of the cylinder, and a second end of which is rotatably coupled to the hinge groove of the roller. At least one of first and second axial end surfaces of the roller facing the plurality of plates is provided with a dimple portion having a predetermined depth. With this structure, contact surfaces between the roller and the plate may be prevented from being in close contact with each other, preventing the roller or the plate from being damaged or a performance of the compressor from deteriorating due to friction loss, thereby improving reliability and performance of the compressor.

A rotary compressor may include a rotary shaft; a plurality of plates that supports the rotary shaft; a cylinder provided between the plurality of plates to define a compression space, and provided with a vane slot; a roller slidably coupled to the rotary shaft inside of the cylinder, and having a hinge groove on an outer circumferential surface of the roller; and a vane, a first end of which is slidably coupled to the vane slot of the cylinder, and a second end of which is rotatably coupled to the hinge groove of the roller. When an imaginary line passing through an axial center of the rotary shaft and a hinge center of the vane is a first center line, and a radial center line of the vane slot passing through the hinge center of the vane is a second center line, the vane slot is disposed such that the second center line is intersected by a predetermined tilting angle with respect to the first center line. With this structure, a roller reaction force is canceled to suppress an increase in side pressure or side wear between a vane and a vane slot into which the vane is inserted.