Abstract:
A rotor for a rotary screw machine having helical lobes and intermediate grooves, the rotor having a core including a shaft 1 of a first material and a rotor body 2 of a second material mounted on the shaft. The surface of the rotor is coated with a plastic layer 3.
Abstract:
A helical screw compressor is provided having a first compressor stage and a second compressor stage. The helical screw compressor includes a first male rotor and a first female rotor in the first compressor stage, and a second male rotor and a second female rotor in the second compressor stage. A connecting duct is provided between an outlet of the first compressor stage and an inlet of the second compressor stage, and a conduit is provided having a first end communicating with the connecting duct and a second end branching off into a first line and a second line. The first line is coupled to the first compressor stage for injecting liquid into the first compressor stage, and the second line is coupled to the second compressor stage for injecting liquid into the second compressor stage. In addition, a pump is provided in the conduit for transporting liquid precipitate from the connecting duct to the first and second compressor stages, and a heat exchanger is provided in the conduit between the pump and the first and second lines.
Abstract:
The present invention relates to a variable capacity helical screw compressor for compressing a gaseous medium, usually air. The compressor includes at least one lift valve (1) which connects with a first compression chamber in the compressor. The lift valve (1) includes a valve housing (2), a valve head (6) which can move reciprocatingly in the valve housing (2), a valve stem (5) whose one end is connected to the valve head (6) and whose other end projects out of the housing (2), a valve body (7) that has a valve area (21) at the other end of the valve stem (5), said valve area (21) facing towards the first compression chamber, and a first passageway (28) whose opening (17) opens into the valve housing (2) adjacent a first side of the valve head (6) and whose other end is in selecive fluid contact with either a compressor outlet passageway or with a compressor inlet passageway, a second passageway (19) which connects the valve housing (2) in or adjacent to a second, opposite side of the valve head (6) with a second compression chamber. The compressor includes an elastic device (12) disposed between the other side of the valve head (6) and the valve housing (2), and the first and the second compression chambers are one and the same compression chamber.
Abstract:
The invention relates to a rotary screw machine that is completely oil-free. Known rotary screw machines with cooling, sealing, lubrication of the screw rotors and oil-lubrication and oil-cooling of the bearings have been replaced with water-lubricated and water-cooled bearings. Each screw rotor (102) is mounted in a water-lubricated radial slide bearing (1) and one trunnion (31) of the rotor co-acts with a water-lubricated thrust bearing (9, 10) which acts both as an hydrodynamic and an hydrostatic bearing. The trunnion bearing housing (21) is in fluid connection with the rotor housing, both along the trunnion and via a conduit (27) from the bearing housing interior to the gas inlet (108) of the screw rotor or via a channel which is cut-off from said inlet.
Abstract:
A rotary displacement compressor having an inlet channel for introducing low pressure gas, an outlet channel through which compressed gas escapes, and at least one rotor mounted in bearings and operating in a working space. The compressor includes a liquid injector for injecting liquid into the working space, a liquid separator provided in the outlet channel for separating liquid from the compressed gas, and a pressure liquid conduit connecting the liquid separator and the liquid injection port. A bearing lubrication circuit includes a tank, a pump, a supply conduit for supplying liquid from the pump to the bearings in which the rotor is mounted, a withdrawal conduit for withdrawing liquid from the bearings to the tank, and a pump inlet conduit for supplying liquid from the tank to the pump. The bearing lubrication circuit further includes a leakage path connecting the tank to a first cavity in the working space and a drainage connection connecting the tank to a second cavity in the working space, the first cavity having a higher pressure than the second cavity.
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.