Screw compressor with sliding bearings

Abstract

A screw compressor with sliding bearings includes a female rotor and a male rotor; a suction end-face of the male rotor and suction and exhaust end-faces of the female rotor are respectively provided with recessed holes, in which radial sliding bearings are arranged and matched with suction and exhaust side projecting shafts embedded; a thrust sliding bearing is arranged on an end-face of the suction side projecting shaft; passages are connected to the recessed holes are provided in the female and male rotors along the axis direction, and radial passages are provided to connect axial passages and rotor chamber. Using sliding bearings inside the rotors can simplify compressor structure and reduce occupied space and cost. Besides, the passages provided inside rotors simplify the liquid return structure of sliding bearings while cool the rotors, reduce the thermal deformation of the rotors, and improve the reliability and performance of the compressor.

What is claimed is: 
     
         1 . A screw compressor with sliding bearings, comprising: a body, screw rotors, and a sliding support structure for supporting the screw rotors in the body, wherein the sliding support structure comprises radial sliding bearings which are arranged in recessed holes on suction end-faces or/and exhaust end-faces of the screw rotors and coaxially rotate with the screw rotors; or the sliding bearing structure has the recessed holes, as bearing bushes of the radial sliding bearings, located on the suction end-faces or/and the exhaust end faces of the screw rotors; body projecting shafts fitted with the radial sliding bearings are arranged on a suction side or/and an exhaust side of the body, and the body projecting shafts and the radial sliding bearings form radial gaps at fitting positions; the radial gaps are connected to a lubricant inlet disposed on the body; passages are provided inside the screw rotors, and a rotor chamber between the screw rotors and the body is connected to the recessed holes through the passages. 
     
     
         2 . The screw compressor, as recited in  claim 1 , wherein liquid supply grooves respectively connecting the radial gaps and the lubricant inlet are disposed on the projecting shafts of the body. 
     
     
         3 . The screw compressor, as recited in  claim 1 , wherein the sliding support structure comprises a radial sliding bearing at a suction side of a male rotor ( 3 ), a radial sliding bearing at a suction side of a female rotor ( 15 ) and a radial sliding bearing at an exhaust side of the female rotor ( 10 ), wherein the recessed holes for fixing the radial sliding bearings are provided on a suction end-face of the male rotor, a suction end-face and a exhaust end-face of the female rotor in the screw compressor, or the suction end-face of the male rotor, the suction end-face and the exhaust end-face of the female rotor have the recessed holes as the bearing bushes of the radial sliding bearings; the body projecting shafts matching with the radial sliding bearings are respectively arranged on the suction side and the exhaust side of the body. 
     
     
         4 . The screw compressor, as recited in  claim 1 , wherein the sliding support structure further comprises thrust sliding bearings disposed in the recessed holes on the suction end-faces of the screw rotors, and the thrust sliding bearings match with thrust faces at bottoms of the recessed holes where the thrust sliding bearings are disposed. 
     
     
         5 . The screw compressor, as recited in  claim 4 , wherein the thrust sliding bearings are connected to end-faces of the corresponding body projecting shafts, or the thrust sliding bearings are directly processed on the end-faces of the body projecting shafts. 
     
     
         6 . The screw compressor, as recited in  claim 1 , wherein the passage comprises axial passages connected to the corresponding recessed holes in a male rotor and a female rotor of the screw compressor, and radial passages disposed in the male rotor and the female rotor of the screw compressor; wherein one end of the radial passages is connected to the axial passages, and the other end of the radial passages is connected to the rotor chamber. 
     
     
         7 . The screw compressor, as recited in  claim 6 , wherein a number of the radial passages is determined by lubrication and sealing requirements in the rotor chamber, and positions of the radial passages towards the rotor chamber are determined by a injection flow rate through the radial passages; the axial passages are connected to bottoms of the recessed holes and extend along axes. 
     
     
         8 . The screw compressor, as recited in  claim 1 , wherein the sliding support structure further comprises a radial sliding bearing, which matches with one end of a male rotor of the screw compressor which extends out of the body, and is fixed to the exhaust side of the body.