A dry vacuum pump is provided, including an oil sump; a pumping stage; two rotating shafts respectively holding a rotor extending in the pumping stage, the rotor being configured to rotate in a synchronised manner in opposite directions in order to carry a gas to be pumped between an intake and a discharge of the pump, the two rotating shafts being supported by bearings lubricated by a lubricant contained in the oil sump; and a lubricant sealing device inserted between the oil sump and a pumping stage at each shaft passage, the sealing device including a disc-shaped deflector mounted on a shaft of the two rotating shafts for rotation therewith, and a disc of the deflector has an annular end on a periphery thereof, extending towards the pumping stage, forming a retaining recess.

Technologies are generally described for clearance adjustments in twin-screw pump assemblies. A twin-screw pump assembly may include a conically shaped portion of a drive shaft enveloped by a bushing. For clearance adjustment, both clamping nuts of the drive shaft, which provide pretention to the bushing and secure an axial position of a threaded screw to the drive shaft, may be removed on the flow side of the pump assembly and the bushing loosened to adjust the angularity between bushing and drive shaft. The bushing may then be pushed over the conically shaped portion and both clamping nuts re-assembled. In some examples, a clamping nut of the driven shaft may be designed and used as removal/loosening tool for the drive shaft bushing.

A pump body assembly includes: a crankshaft, a first baffle plate and a second baffle plate. The crankshaft includes a first eccentric portion, a support shaft and a second eccentric portion which are arranged at intervals in an axial direction; the first baffle plate and the second baffle plate are arranged in sequence between the first eccentric portion and the second eccentric portion, a first round hole is arranged defined on the first baffle plate, the support shaft is arranged in the first round hole, so that the first baffle plate and the support shaft form a baffle plate bearing, and the baffle plate bearing has a stress relief structure for reducing a contact stress between the support shaft and the first baffle plate.

A compressor includes a drive shaft having a main shaft and an eccentric portion, and a compression mechanism having a fitted tubular portion into which a fitted shaft portion of the drive shaft is slidably fitted. The fitted shaft portion has first and second sliding surfaces formed as portions of an outer peripheral surface in the circumferential direction. The second sliding surface has a smaller axial width than the first sliding surface. A gap is adjacent to the second sliding surface into which a lubricating oil flows. An oil retainer is configured as a boundary portion between the first sliding surface and the gap to keep the lubricating oil in the gap from flowing out toward an end surface of the fitted shaft portion. The boundary portion has a central portion that protrudes further toward the first sliding surface than an end of the boundary portion in a lubricating oil flow-out direction.

A system for use in a scroll compressor is described. The system comprises a crankshaft with a first end portion, wherein the crankshaft defines an axis of rotation, and slider block having a recess, wherein the first end portion of the crankshaft and the recess in the slider block are configured for connecting the slider block to the first end portion. The first end portion of the crankshaft comprises a first flat contact surface portion and the recess of the slider block comprises a second flat contact surface portion, the first and second contact surface portions facing each other when the first end portion is connected to the slider block. The system is characterized in that at least one of the flat contact surface portions comprises a slit beneath the at least one flat contact surface portion. Further, a corresponding slider block and a corresponding crankshaft are described.

A sectional sealing system for water-spray type screw rotor compressor that is configured to prevent the intermixing of coolant and working fluid from a compression chamber with lubricant used to lubricate at least a bearing system of a rotor. The sealing system may include suction side and discharge side sealing portions that are positioned about first and second shafts, respectively, of the rotor. The suction side sealing portion may include a first seal, a first labyrinth seal, and a second labyrinth seal, the first seal being in proximity to a suction side of the compression chamber. The discharge side sealing portion may include a plurality of first seals, a second seal, a first labyrinth seal, and a second labyrinth seal, the plurality of first seals of the discharge side sealing portion being in proximity to a discharge side of the compression chamber.

An oil-free screw compressor has a screw rotor including a screw and a shaft, a bearing supporting the shaft, a first shaft seal device disposed between the screw and the bearing and including a first seal opposite to the shaft, and a first communication portion communicating the bearing side with respect to between the shaft and the first seal and the outer peripheral face of the first shaft seal device, and a second shaft seal device disposed between the first shaft seal device and the bearing and including a second seal opposite to the shaft, and a second communication portion communicating the screw side with respect to between the shaft and the second seal and the outer peripheral face of the second shaft seal device. A casing includes an atmosphere communication portion connected to both of the first communication portion and the second communication portion on the inner peripheral face of a shaft accommodation space, and communicating the first communication portion and the second communication portion with the atmosphere.

A compressor includes a drive shaft having a main shaft and an eccentric portion, and a compression mechanism having a fitted tubular portion into which a fitted shaft portion of the drive shaft is fitted. The fitted shaft portion and the fitted tubular portion slide relative to each other with an oil film interposed between. The fitted tubular portion has first and second sliding surfaces formed as portions of an inner peripheral surface of the fitted tubular portion in the circumferential direction. The second sliding surface has a smaller axial width than the first sliding surface. A sliding portion between the fitted shaft portion and the fitted tubular portion has a gap adjacent to the second sliding surface into which a lubricating oil flows, and an oil retainer to keep the lubricating oil in the gap from flowing out toward an end surface of the fitted tubular portion.

In the two-cylinder hermetic compressor, a main bearing is disposed on one surface of a first cylinder, an intermediate plate is disposed on another surface of the first cylinder, the intermediate plate is disposed on one surface of a second cylinder, and an auxiliary bearing is disposed on another surface of the second cylinder. A shaft is constituted by a main shaft portion which has a rotor attached thereto and is supported by the main bearing, a first eccentric portion having a first piston attached thereto, a second eccentric portion having a second piston attached thereto, and an auxiliary shaft portion supported by the auxiliary bearing. A thrust receiving portion is provided on a side of the second eccentric portion facing the auxiliary shaft portion, and the auxiliary bearing is provided with a thrust surface on which the end face of the thrust receiving portion slides while contacting therewith. The thrust surface is provided with a ring groove.

A compressor includes a drive shaft having a main shaft and an eccentric portion, and a compression mechanism having a fitted tubular portion into which a fitted shaft portion of the drive shaft is fitted. The fitted shaft portion and the fitted tubular portion slide relative to each other with an oil film interposed between. The fitted shaft portion has first and second sliding surfaces formed as portions of an outer peripheral surface in the circumferential direction. The second sliding surface has a smaller axial width than the first sliding surface. A sliding portion between the fitted shaft portion and the fitted tubular portion has a gap adjacent to the second sliding surface into which a lubricating oil flows, and an oil retainer to keep the lubricating oil in the gap from flowing out toward an end surface of the fitted shaft portion.