Abstract: The invention relates to an arrangement at oil-injected screw compressors for high pressures. The arrangement is characterized in that the length/diameter ratio of the rotors is lower than 1,3:1, that taper roller bearings in pairs (19-21) are used at both shaft ends (15-18) of the rotors, that the bearings (19,21) at the high-pressure end (13) of the rotors are arranged so that the wider edges of the inner rings of the bearings are facing toward each other and are capable to take up both radial and axial forces, that the bearings (20,22) at the low-pressure end (14) of the rotors are arranged so that the narrower edges of the inner rings of the bearings are facing toward each other and are capable to take up only radial forces, and that oil-pressure actuated balancing pistons (23,24) are provided at the shaft ends (16,18) on the low-pressure end of the rotors to take up the major part of the axial forces initiated by the compressor.

Abstract: Intermeshed helical screw rotors are mounted for rotation by anti-friction bearings surrounding integral shafts extending axially outward of the ends of the intermeshed screw rotors and within respective high pressure outlet and low pressure inlet bearing housings, sealed to the exterior. Oil from a separator/sump at or near compressor discharge pressure feeds via a closed passage to annular cavities surrounding the rotor shafts upstream of the outlet housing bearings. Oil seeps through very narrow annular gaps functioning as self-cleaning upstream capillaries to the outlet bearing cavities with the pressure reduction causing oil mist lubrication of the confined bearings within the outlet bearing housing. Further passages fluid connect the outlet bearing housing cavities to similar cavities within the inlet bearing housing where mist lubrication of the inlet bearings occurs.

Abstract: A vane compressor is provided which includes a rotor which has an internal space formed at its central portion and communicating with a plurality of vane-inserted slits formed in its outer peripheral surface, and first and second axial through holes extending from the internal space to its opposite end surfaces. The drive shaft extends through an end wall member of the pump housing and has its end portion rigidly fitted in the first axial through hole of the rotor. The second axial through hole of the rotor receives a support shaft projecting from the other or opposite end wall member of the pump housing. Thus, the rotor is radially supported at its one end by the drive shaft and at its other end by the support shaft, respectively.

Abstract: An improved rotor compressor, particularly a screw-type compressor, for compressing a gas is disclosed. The compressor is provided with a housing having an annular drain space surrounding rotor shafts at a location between each shaft bearing and the working space for removing escaping lubricant and gas. The drain space is connected through a drain passage to a closed collecting chamber which is substantially under the intake pressure of the compressor. A return passage is provided for returning gas to at least one of the intake and the working space of the compressor and for returning lubricant to a lubrication circuit.

Abstract: In a scroll type compressor unit including two interfitting fixed and orbiting scroll members in the compressor housing, a crank shaft projecting from the interior of the compressor housing and rotatably supported by a radial bearing, a crank pin on the inner end of the crank shaft on which the orbiting scroll member is rotatably supported by another radial bearing, and a rotation preventing mechanism for preventing the orbiting scroll member from rotating, an oil accumulating chamber is provided in the compressor housing to connect with the fluid inlet port of the compressor housing in order to lubricate those radial bearings and other moving parts. A shaft seal assembly is mounted on the crank shaft in a shaft seal cavity which is communicated with the oil accumulating chamber through a first oil passageway formed in the wall of the compressor housing.

Abstract: An oil pool in a rotary vane, oil sealed mechanical vacuum pump casing is cooled by air drawn by a relatively low pressure and low speed laminar flow fan mounted on a motor shaft for the pump and positioned in a shroud between end plates for the motor and casing. The air pumped by the fan flows axially relative to the shaft through a horizotally extending slot at the bottom of the shroud and vertically extending slots on the sides of the shroud. The pumped air flows against vertically and horizontally extending fins respectively on the pump casing bottom and sides. The vertically extending fins at the bottom of the casing have bases slightly above the horizontal slot at the bottom of the housing so air flowing through that slot flows against the bases of the fins at a shallow angle. A vertical surface of the housing remote from the fan and the shroud has vertically extending fins that are aligned with the vertically extending fins on the bottom of the casing.

Abstract: A mechanical rotary vane vacuum pump has high and low vacuum stages for a pumped gas. Each stage includes a rotor for vanes cyclically driven about a common axis that is eccentric to a cylinder of a stator; the stator of each stage includes an inlet and outlet for the pumped gas. An oil seal between inlets and outlets for each stage is in a narrow gap between the stator and rotor. An interstage structure includes a flow path between the stages for the pumped gases and a shaft drivingly connected the rotors of the stages. An oil flow path comprises a first passage through the interstage structure leading radially to the shaft. The shaft includes diametrically opposed oil metering flats or cavities longitudinally aligned with an outlet of the first passage. A second passage through the interstage structure is longitudinally aligned with the cavities and leads tangentially from the peripheries of the shaft and a bore for the shaft.

Abstract: The invention consists of providing two lubrication circuits, a main circuit for lubricating the compression chamber and the various components of the compressor when operating under load and a secondary circuit for lubricating the components disposed on the suction side when operating under no load.The invention is used in air compressors.

Abstract: A rotor is eccentrically mounted in a bore of a housing and formed with radial slots in which vanes are slidably retained. An oil passageway leads from an oil sump through the radially inner portions of the slots to a fluid inlet passageway, the oil sump communicating with an oil separation chamber which constitutes part of a fluid outlet passageway. The high pressure in the oil separation chamber forces oil through the oil passageway to lubricate the vanes and urge the vanes into sealing engagement with the inner wall of the bore. Oil sucked from the inlet passageway into the bore and entrained in the working fluid lubricates the outer ends of the vanes and flows into the oil separation chamber. The fluid outlet passageway is formed so that the fluid flow path reverses direction in the oil separation chamber. The oil entrained in the fluid is unable, due to its higher density and inertial force, to negotiate the reversal of direction, is thereby separated from the fluid and returned to the oil sump.

Abstract: A rotary vane compressor in which the pressure difference between inlet and outlet passages is utilized to accomplish lubrication without a supplementary oil pump comprises a housing with a cylindrical bore, a hollow rotor eccentrically rotatable on a shaft in the bore and at least one vane radially slidable in a slot in the rotor and sealingly engaging with the inner surfaces of the bore to define fluid chambers of varying volume. The compressor further has inlet and outlet passages communicating with the bore and an oil sump disposed below the bore. A first passageway connects the outlet passage with the sump, and the hollow of the rotor constitutes a second passageway. A third passageway connects the sump with one end of the hollow and a fourth passageway connects the other end of the hollow with the inlet passage.