Abstract: The invention relates to an arrangement pertaining to internal combustion engines (1) that include a supercharger (6) and an intermediate cooler (13) mounted in a casing (4). The intermediate cooler includes tubular elements (14, 15) through which coolant flows for cooling the combustion air compressed by the supercharger (6). Conventional arrangements of this kind take up a significant amount of space, which is difficult to find in a typically crowded engine space, and also result in undesirable heating of the engine space.

Abstract: A screw rotor compressor is provided that includes two mutually coacting helical screw rotors and a rotor housing (1). The housing (1) includes a first end wall (2) and a second end wall (3) and a barrel wall (7, 11) that interconnects the end walls. The housing (1) has internally the shape of two mutually intersecting cylinders and the first end wall (2) includes an inlet opening (19). The barrel wall (7, 11) includes an outlet opening (6) adjacent the second end wall (3), and also includes a further opening (9) which extends from the outlet opening (6) towards the first end wall (2) and widens over the two mutually intersecting cylinders of the internal shape of the housing.

Abstract: An oil-cooled disc clutch includes a first group of discs (21) interleaved by another group of discs (20). The first group of discs (21) are non-rotatably attached by splines to a central axial hub (39). The central axial hub is designed as a drum (39) to which the oil is supplied through a channel (35), and which is provided with apertures (40, 44) for axial distribution of the supply of oil to and between all the discs (20, 21).

Abstract: A rotor (2, 3) is provided with bearing trunnions (4, 5). The rotor is made of a material with limited strength properties, such as aluminum. At least one of the bearing trunnions (4) comprises a concentric sleeve (20) made of steel at one end of the rotor. The inner end (21) of the sleeve (20) is radially attached to the rotor end (22) by a trunnion (4) protruding into the sleeve, or by a groove (40) in the rotor end (22), into which groove the inner end (21) of the sleeve protrudes. The outer end of the sleeve (20) is kept by a screw (25, 27) screwed into the rotor (2, 3) and provided with a screw head (24) pressed axially in the direction towards the rotor end (22).

Abstract: A rotary screw compressor having a balancing piston device for balancing an axial gas force exerted on a pair of rotors during operation of the rotary screw compressor. The balancing piston device is exposed in one axial direction to a high pressure source on at least one first pressure surface, and in an opposite axial direction to one of a low pressure source and an intermediate pressure source on at least one second pressure surface. A valve is provided for selecting the low or the intermediate pressure source connection with respect to the at least one second pressure surface, whereby the thrust balancing force can be adapted to different working conditions such as starting up and full load operation in order to avoid underbalancing or overbalancing of the axial gas force.

Abstract: The rotary positive displacement compressor has an intermediate port (42) for fluid from an intermediate pressure channel (30) and has a bleed port (44) for recirculation of partly compressed fluid through a return channel (32). It is suggested to provide the compressor with valve means (36), selectively adjustable between two end positions. In a first end position it opens up a direct communication between these channels (30, 32) and opens the bleed port (44), whereby fluid flows directly from the intermediate pressure channel (30) to the return channel (32) simultaneously as fluid within the working space of the compressor flows to the return channel (32) through the intermediate port (42) as well as through the bleed port (44). In a second end position the bleed port (44) is closed and said direct communication is blocked. The disclosure also relates to a refrigeration plant comprising such a compressor.

Abstract: The invention relates to a pressure actuated lift valve in a rotary screw machine mounted in one of the end walls of the machine, e.g. for the purpose of controlling the built-in volume ratio of the machine. The valve contains a cylindrical valve member 11 displaceable in an axial boring 13 and an actuating piston 12 in a cylinder 14. The boring 13 extends between the working space 24 of the machine and said cylinder 14. Through channels 20, 21, 22 pressure fluid is supplied to the cylinder 14 whereby the actuating piston 12 affects the valve member 11 to take an open or a closed position.By making the actuating means as a unit separate from the valve member 11 the manufacture is facilitated.

Abstract: A rotary screw compressor has meshing male (2) and female (4) rotors operating in a working space limited by a high pressure end section (6), a low pressure end section (8) and a barrel section extending therebetween. The rotors (2, 4) have shaft extensions (22, 24, 26, 28) journalled in bearings (30, 32, 34, 36) in the end sections (6, 8). Oil is supplied to the bearing chambers (38, 40, 42, 44) for lubricating and cooling the bearings. The chambers (42, 44) in the low pressure end section (8) are drained to the working space through a first channel (50) and a first opening (52) in the walls (16) of the working space, and the chambers (38, 40) in the high pressure end section (6) are drained to the working space through a second channel (46) and a second opening (48) in the walls (16) of the working space.

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: The invention relates to a valve system for capacity control of an oil-injected screw compressor. One or more valves (17-20), preferably at least two valves, are located in the wall of the rotor barrel (12, 13). The pressure in the compressed-air tank of the compressor actuates control valves, which in their turn open or close the valves (17-20). When the valves are opened, a direct connection between two consecutive thread volumes of at least one of the rotors (14, 15) is established, whereby the closed space capable to be used for the internal compression, is reduced.

Abstract: Volume control valve for a screw compressor located in a cylindrical bore parallel to and spaced from the working space. The bore and the working space communicate through a number of axially distributed channels which are selectively closed by an adjustable valve member disposed in the bore.

Abstract: A screw rotor machine for an elastic working fluid in which the rotors are biassed towards the high pressure end wall by means of balancing pistons and interposed bearings.