A scroll assembly includes an orbiting scroll and a cross ring. The orbiting scroll is configured to have a bottom plate. A plurality of bayonets and two positioning slots are provided on the outer peripheral surface of the bottom plate. The bayonets are adapted to be clamped by a chuck of a turning tool. The cross ring is configured to have an annular body and two positioning pins. An annular groove adapted for being formed by turning is provided on the lower surface of the bottom plate of the orbiting scroll, and a chamfer is formed on the edge of the annular groove formed by the intersection of the circumferential vertical surface of the positioning groove and the lower surface of the bottom plate.

In some examples, a co-rotating scroll compressor includes a driver scroll having an axis aligned with the main axis and having a spiral involute, an idler scroll having an axis offset from the main axis and having a spiral involute intermeshed with the spiral involute of the driver scroll, and an Oldham coupling disposed between the driver scroll and idler scroll. The driver scroll may offset key slots so to engage with corresponding Oldham coupling keys. In another example, the Oldham coupling may offset driver scroll keys so to engage with corresponding key slots of the driver scroll.

A rotor for a mud motor includes a core having a first outer shape, and a shell positioned around the core, the shell having a second outer shape that is different from the first outer shape, the second outer shape defining one or more lobes and one or more cavities that are configured to engage a bore of a stator during rotation of the rotor relative to the stator. A thickness of the shell varies as proceeding around the core, from a non-zero minimum thickness to a maximum thickness.

A screw compressor has a slide valve movement mechanism that includes a cylinder provided in a casing body, a piston partitioning an interior of the cylinder into a first chamber and a second chamber, and a communication flow passage through which the second chamber communicates with a low-pressure space. The cylinder includes a first inflow hole, a second inflow hole, and a third inflow hole. The first chamber communicates with a high-pressure space through the first inflow hole, the second chamber communicates with the low-pressure space through the second inflow hole and the communication flow passage, and the second chamber communicates with the high-pressure space through the third inflow hole. The third inflow hole is located at a position at which the third inflow hole is closed by the piston when the piston lies at a stop position at which the piston moves toward the second chamber and stops.

A full-metal anti-high temperature cycloid downhole motor comprises an outer tube, a stator, a rotor, a partition plate, a flow distribution disc, and a flow guide mechanism. The inside of the stator is provided with N grooves, the inner side walls of the N grooves form an annular inner contour surface; the rotor is formed with N−1 rotating heads provided along the axial direction of the outer tube, and each rotating head is provided with an embedding slot, one side of the embedding slot is provided with a notch, a rotor copper rod that can be in rolling engagement with the inner contour surface through the notch is provided in the embedding slot, and there is a changing gap between the outer wall of the rotor copper rod and the inner wall of the embedding slot.

The scroll compressor (1) includes a fixed scroll (7); an orbiting scroll (8); a support arrangement (5) including a thrust bearing surface (9) on which is slidably mounted the orbiting scroll (8); a rotation preventing device configured to prevent rotation of the orbiting scroll (8) with respect to the fixed scroll (7), the rotation preventing device including a plurality of orbital discs (28) respectively rotatably mounted in circular receiving cavities (29) provided on the support arrangement (5), each orbital disc (28) being provided with an outer circumferential bearing surface (31) configured to cooperate with an inner circumferential bearing surface (32) provided on the respective circular receiving cavity (29); and a lubrication system configured to lubricate the inner and outer circumferential bearing surfaces (32, 31) with oil supplied from an oil sump (36), the lubrication system including a plurality of oil reservoirs (43) each arranged in a bottom surface of a respective circular receiving cavity, and a plurality of oil stirring arrangements each configured to stir oil contained in a respective oil reservoir (43).

A compressor is provided which is configured to allow lubrication of a thrust surface through an oil groove formed in a thrust surface of a fixed scroll. Also, a scroll compressor is provided which smoothly supplies oil to a thrust surface of a fixed scroll by including a fixed scroll having an oil groove formed in the thrust surface of a fixed scroll sidewall, and allows an injection pressure acting on an orbiting scroll in an upward direction to be added by supplying the oil guided to the oil groove to the thrust surface of the fixed scroll such that an overturn moment generated in the orbiting scroll may be offset.

An apparatus including a first piston member rotatable about a first rotational axis and a rotor with a first chamber and pivotable about a second rotational axis. The first piston member extends across the first chamber. The rotor and first piston member are rotatable around the first rotational axis, and the rotor is pivotable about the second rotational axis to permit a relative pivoting motion between the rotor and the first piston member linked to the rotor rotating about the first rotational axis.

A gear pump is capable of maintaining the pump volumetric efficiency for preferably supplying a hydraulic liquid while adequately securing a sealing area, even if a cross sectional area of a flow-in passage is increased. The cross section of a suction passage has a rectangular shape in a side close to a hollow space in a body, and has a circular shape in the outside of the body. The rectangular shape of the suction passage in the hollow space side in the body has a long side extending in a direction along the tooth width of the spur gears, and a short side extending along a direction perpendicular to the tooth width direction. The suction passage has a shape that smoothly connects the rectangular shape in the hollow space side in the body with the circular shape in the outside of the body.

A system and method for coupling a temperature monitoring system within a progressive cavity pump to combat dry-running. A temperature monitoring system for use in a progressive cavity pump for monitoring the internal temperature of an elastomeric stator. The temperature monitoring system includes a sleeve and a temperature sensor disposed therein. The sleeve is inserted into a shell portion of the stator before vulcanizing the elastomeric stator so that the sleeve is vulcanized to the elastomeric stator.