Abstract: This invention relates to a thrust bearing arrangement in which a thrust bearing (17, 18) is brought to a given position on an axle or shaft (15, 16) and secured firmly in this position by means of a locking ring (23, 24) capable of being displaced along the axle or shaft. In order to enable this arrangement to be achieved quickly and easily, the locking ring has the form of a shrink ring (23, 24) which is heated to an appropriate temperature and then slid along a smooth part of the axle (15, 16). The shrink ring is dimensioned so that it will shrink firmly around the axle (15, 16) when cooled to normal operating temperature, so as to be immovable on the axle when subjected to axial forces occurring in operation. The thrust bearing (17, 18) is positioned, according to the invention, in a bearing seating, which enables the transverse insertion of a feeler gauge or corresponding device to provide a given clearance at a selected end of the bearing (17, 18) prior to shrink fitting the locking ring (23, 24).

Abstract: Rotary positive displacement machine for a compressible working fluid comprising two tapered, internally intermeshing members (26, 28) with eccentric axes (48, 50). The members (26, 28) have spiral grooves (34, 38) and intervening lands (36, 40) which cooperate to form closed chambers (66) varying in volume while moving axially from one end to the other. The inner member (28) has a hypocyclic movement in relation to the outer member (26). The radial depth of the grooves (34, 38) varies axially along the members (26, 28) and in each transverse plane is equal to twice the eccentricity of the axes (48, 50) of the members (26, 28) and the pitch angle of the spiral at the pitch cone varies continuously in the axial direction.

Abstract: In a convention throttle-controlled internal combustion engine (1, 2) equipped with a supercharger which has the form of a compressor (10) provided with screw rotors (14, 15) arranged in a compression chamber, the supercharger is inactive at part engine loads. Since the engine normally operates at part loads for about 95% of its running time, efficiency is correspondingly poor. This drawback is overcome with the arrangement according to the invention in which the screw compressor (10) is provided on the inlet side (20) thereof with a capacity regulating device (22) which is operated by a gas pedal, or accelerator, and which when the engine is only partially loaded, is adjusted to a corresponding position in which the compressor (10) operates as an expander (3) of variable throttle effect on the engine inlet side (3) and transmits power to the engine, thereby replacing the conventional gas throttle.

Abstract: A screw compressor for intermittent operation, preferably for supplying a pneumatic brake system of an automotive vehicle with compressed air, comprises, in the high pressure end wall (4) of the compressor, a wall plate (14) which seals against the casing wall (2) of the compressor and which can be withdrawn axially of the compressor out of sealing engagement with the casing wall and into a space (16) which is provided in the high pressure end wall, the space (16) communicating with the compressor inlet (12), to thereby fully unload the compressor.

Abstract: The invention relates to a method for a refrigerant system having a circulation circuit comprising a screw compressor (1), a condenser (4), an expansion valve (5) and an evaporator (6). In a refrigerant process, in which an oil injected compressor is connected it is impossible to prevent oil from flowing together with the refrigerant out into the circulation circuit, which among others impairs the operation of the evaporator. According to the invention a drastic reduction of the amount of circulating oil has been obtained together with an improved cooling of the compressor by supplying the low pressure side of the compressor with refrigerant liquid with a pressure and temperature lower than the pressure and temperature of the refrigerant in the condenser in such amounts per unit of time that the required cooling and sealing of the compressor is obtained, the effect of the circulating oil being restricted merely to lubricating.

Abstract: A screw compressor lubrication channel for lubrication of a rotor bearing on the compressor's low pressure side, which is supplied with refrigerant droplets containing oil accompanying the inlet gas. This kind of lubrication is usually carried out by permitting a limited amount of gas and oil to flow from the high pressure side to the low pressure side via the bearings located on the low pressure side, and further to the inlet. By this working mode compressor capacity as well as compression work deposited is lost. This is avoided when the compressor according to the present invention is provided with a special, smaller inlet channel (7), which via the rotor bearing (3) opens out in a specific inlet port (8) located at an expanding rotor thread presenting a lower pressure than the inlet (6) pressure of the compressor.

Abstract: An oil-free rotary gas-compressor system includes an oil-free rotary gas-compressor (2) having a high, built-in pressure ratio and an injector arrangement (13) for injecting a vaporizable liquid, preferably water, into the compressor (2) for cooling the gas during the compression process. It is known in high-speed compressors to utilize water injection which is so restricted that the water is completely vaporized, to thereby obtain a good cooling effect. The efficiency of the compressor is limited, however. In known systems, high compressor efficiencies are obtained by injecting large quantites of water, although the compressor speed must then be considerably reduced, resulting in a lower compressor capacity.

Abstract: A refrigeration type plant comprises a rotary, positive displacement machine which as at least one rotor provided with spiral lobes and intervening grooves. The plant further comprises a condenser communicating with an outlet port (60) of the compressor through a high pressure channel (14), an evaporator communicating with an inlet port (58) of the compressor through a low pressure channel (18), a vessel for an intermediate pressure communicating with an intermediate port (38) of the compressor through an intermediate pressure channel (36), the intermediate port (38) being spaced from the inlet port (58) as well as from the outlet port (60), and a pressure reducer for decreasing the high pressure in the condenser to the intermediate pressure in the vessel and to the low pressure in the evaporator, respectively. A selectively adjustable valve (40) is provided for forming a communication between the intermediate channel (36) and the low pressure channel (18).

Abstract: Adjusting means for the sector plate sealing members of rotary regenerative heat exchangers, wherein at least one sensing means is attached to each sealing member, adjacent a circumferential metal flange supported by the regenerator body. The sensing means is connected to a control circuit for actuating a servo device for controlling the position of the sealing member in response to the capacity fluctuations in an electrical circuit comprising the space between the sensing means and the metal flange.