Centrifugal compressor

Abstract

A centrifugal compressor includes a housing, a rotary shaft accommodated in the housing, an electric motor including a motor rotor and a motor stator for rotating the rotary shaft, an impeller connected to one end of the rotary shaft and driven by rotation of the rotary shaft so as to compress fluid, a radial bearing rotatably supporting the rotary shaft in a radial direction of the rotary shaft, and a resolver including a resolver rotor and a resolver stator for detecting a rotation angle of the motor rotor. The resolver rotor is fixed to the other end of the rotary shaft opposite to the impeller. The rotary shaft includes a radial support member rotatably supported by the radial bearing, and a radius of the radial support member is larger than a radius of gyration of the resolver rotor.

What is claimed is: 
     
         1 . A centrifugal compressor comprising:
 a housing;   a rotary shaft accommodated in the housing;   an electric motor rotating the rotary shaft, the electric motor including a motor rotor fixed to the rotary shaft and a motor stator fixed to the housing;   an impeller connected to one end of the rotary shaft and driven by rotation of the rotary shaft so as to compress fluid;   a radial bearing rotatably supporting the rotary shaft in a radial direction of the rotary shaft in relation to the housing; and   a resolver detecting a rotation angle of the motor rotor, the resolver including a resolver rotor fixed to the rotary shaft and a resolver stator fixed to the housing, wherein   the resolver rotor is fixed to the other end of the rotary shaft opposite to the impeller,   the rotary shaft includes a radial support member rotatably supported by the radial bearing, and   a radius of the radial support member is larger than a radius of gyration of the resolver rotor.   
     
     
         2 . The centrifugal compressor according to  claim 1 , further comprising:
 a thrust bearing rotatably supporting the rotary shaft in an axial direction of the rotary shaft in relation to the housing, wherein   the rotary shaft includes a thrust support member rotatably supported by the thrust bearing,   the thrust support member is disposed at the rotary shaft closer to the impeller than the resolver rotor, the motor rotor, and the radial support member in the axial direction of the rotary shaft, and   an outside diameter of the radial support member is larger than an outside diameter of the motor rotor core of the motor rotor and smaller than an inside diameter of the motor stator core of the motor stator.   
     
     
         3 . The centrifugal compressor according to  claim 1 , wherein a shaft angle multiplier of 1× or 2× is applied to the resolver rotor.