Electric centrifugal compressor for vehicles

Abstract

A compact electric centrifugal compressor particularly suitable for a heat ventilation air conditioning system for vehicles provides a motor portion ( 20 ) and a centrifugal compressor portion ( 10 ) driven by the motor portion ( 20 ) through a shaft ( 15 ). The motor portion includes first and second radial bearingless motors ( 140, 150 ). An active axial magnetic bearing or an axial bearingless motor ( 130 ) is located between the first and second radial bearingless motors ( 140, 150 ). The motor portion is further equipped with auxiliary landing bearings ( 8 ).

1 . A compact electric compressor comprising:
 a motor portion, and   a centrifugal compressor portion driven by the motor portion through a shaft, wherein   the motor portion provides first and second radial bearingless motors spaced apart along the shaft and configured for rotating the shaft and maintaining it in a defined radial position in a contactless manner during functional operation of the electric compressor and axial electromagnetic means located between the first and second radial bearingless motors and configured for maintaining the shaft in a defined axial position, and wherein   auxiliary landing bearings are located at each end of the shaft in the vicinity of each of the first and second radial bearingless motors.   
     
     
         2 . The electric compressor according to  claim 1 , wherein the axial electromagnetic means provides an axial bearingless motor. 
     
     
         3 . The electric compressor according to  claim 1 , wherein the axial electromagnetic means provides an active axial magnetic bearing. 
     
     
         4 . The electric compressor according to  claim 1 , wherein separators are provided between the radial bearingless motors and the axial electromagnetic means. 
     
     
         5 . The electric compressor according to  claim 1 , wherein the radial bearingless motors each include a rotor portion having a plurality of pole pairs armatures and a stator portion having a core with slots for receiving windings configured to impress a motor torque and a radial bearing force. 
     
     
         6 . The electric compressor according to  claim 5 , wherein separate windings are provided in the slots of the stator portion for impressing a motor torque and an axial bearing force. 
     
     
         7 . The electric compressor according to  claim 5 , wherein common windings are provided in the slots of the stator portion for impressing a motor torque and an axial bearing force. 
     
     
         8 . The electric compressor according to  claim 1 , wherein the radial bearingless motors provides a rotor portion chosen among an induction rotor, a permanent magnet rotor, a hysteresis rotor and a reluctance rotor. 
     
     
         9 . The electric compressor according to  claim 1 , wherein the centrifugal compressor portion provides a wheel at a first end of the shaft and wherein
 control circuits associated with the radial bearingless motors and the axial electromagnetic means are located at a second end of the shaft and are connected to the radial bearingless motors and the axial electromagnetic means via a feedthrough.   
     
     
         10 . The electric compressor according to  claim 8 , wherein the centrifugal compressor portion provides tandem wheels. 
     
     
         11 . The electric compressor according to  claim 8 , wherein the centrifugal compressor portion provides double tandem wheels. 
     
     
         12 . The electric compressor according to  claim 9 , wherein the centrifugal compressor portion provides double wheels. 
     
     
         13 . The electric compressor according to  claim 2 , wherein the axial bearingless motor provides a rotor portion having a plurality of pole pairs armatures and first and second stator portions each having a core with slots respectively for receiving windings configured to impress a motor torque and an axial bearing force, and wherein
 the first and second stator portions are located on each side of the rotor portion.   
     
     
         14 . The electric compressor according to  claim 3 , wherein the active axial magnetic bearing provides a disc armature integral with the shaft and first and second stator electromagnets facing the disc armature in a contactless manner on each side of the latter. 
     
     
         15 . The electric compressor according to  claim 14 , further comprising a heat ventilation air conditioning system for vehicles.