Compressor

Abstract

A screw-type compressor ( 10 ) for compressing refrigerant, which comprises: an electric motor ( 14 ), which has a rotor ( 16 ) and a stator ( 18 ); a drive shaft ( 20 ); and a compressing device ( 22 ) having a compressor screw ( 24 ); wherein the compressor screw ( 24 ) and the rotor ( 16 ) of the electric motor ( 14 ) are arranged against or on the drive shaft ( 20 ), wherein the drive shaft ( 20 ) is rotatably supported by a first, a second, and a third radial bearing ( 27, 28, 30 ), wherein the first radial bearing ( 27 ) is arranged between the rotor ( 16 ) of the electric motor ( 14 ) and the compressor screw ( 24 ), wherein the second radial bearing ( 28 ) is arranged on a side of the compressor screw ( 24 ) opposite the first radial bearing ( 27 ), and wherein the third radial bearing ( 30 ) is arranged on a side of the rotor ( 16 ) of the electric motor ( 14 ) opposite the first radial bearing ( 27 ), wherein the first radial bearing and the second radial bearing are both designed as rolling-element bearings, and the third radial bearing ( 30 ) is designed as a plain bearing.

1 . A screw compressor for compressing refrigerant, comprising an electric motor, which has a rotor and a stator, and also a drive shaft and a compressing device with a compressor screw, wherein the compressor screw and the rotor of the electric motor are arranged against or on the drive shaft, wherein the drive shaft is rotatably mounted by means of a first, a second and a third radial bearing, wherein the first radial bearing is arranged between the rotor of the electric motor and the compressor screw, wherein the second radial bearing is arranged on a side of the compressor screw opposite the first radial bearing, and wherein the third radial bearing is arranged on a side of the rotor of the electric motor opposite the first radial bearing, wherein the first radial bearing and the second radial bearing are each designed as rolling bearings, and the third radial bearing is designed as a plain bearing. 
     
     
         2 . The compressor as claimed in  claim 1 , wherein the plain bearing communicates with a lubricant inlet and with a lubricant outlet, wherein the lubricant inlet communicates with a first volume which can be subjected to a first pressure, in particular for example a compression end pressure of the compressor, and/or the lubricant outlet communicates with a second volume which can be subjected to a second pressure, in particular for example a suction pressure of the compressor. 
     
     
         3 . The compressor as claimed in  claim 2 , wherein the lubricant outlet communicates with a closed compression work chamber. 
     
     
         4 . The compressor as claimed in  claim 1 , wherein the compressor has a lubricant collection chamber for lubricant of the plain bearing. 
     
     
         5 . The compressor as claimed in  claim 4 , wherein the lubricant collection chamber communicates with a lubricant outlet 
     
     
         6 . The compressor as claimed in  claim 1 , wherein the plain bearing and the lubricant collection chamber are sealed off from the environment. 
     
     
         7 . The compressor as claimed in  claim 1 , wherein the plain bearing is arranged in a bearing bushing which has a first end, through which the drive shaft extends, and a second end, wherein the bearing bushing is sealed off from the environment both at its first end and at its second end, wherein the seal at the first end, through which the drive shaft extends, is embodied by means of a first cover, which has a drive shaft passage and a radial shaft seal. 
     
     
         8 . The compressor as claimed in  claim 4 , wherein the lubricant collection chamber is delimited by an inner wall of a bearing bushing and by a first and second cover, which are arranged at radial ends of the bearing bushing. 
     
     
         9 . The compressor as claimed in  claim 1 , wherein the plain bearing, in particular for damping vibrations, is designed as a hydrodynamic plain bearing.