Centrifugal compressor

Abstract

A centrifugal compressor is provided with a ring member including a circumferential wall, a high-speed shaft located at an inner side of the circumferential wall, and rollers located between the circumferential wall and the high-speed shaft. Each roller includes a circumferential surface and first and second end surfaces. The circumferential surface of each of the rollers includes a contact surface that contacts a portion in a circumferential surface of the high-speed shaft, a first non-contact surface spaced apart from the circumferential surface of the high-speed shaft, and a second non-contact surface spaced apart from the circumferential surface of the high-speed shaft. The contact surface includes a center position located closer to the first flange than a center position of each of the rollers in an axial direction of the rollers.

1 . A centrifugal compressor comprising:
 a ring member including a circumferential wall, wherein the ring member is configured to rotate when a low-speed shaft rotates;   a high-speed shaft located at an inner side of the circumferential wall;   a plurality of rollers located between the circumferential wall and the high-speed shaft, wherein the rollers are configured to contact the circumferential wall and the high-speed shaft by means of oil;   an impeller configured to rotate integrally with the high-speed shaft;   a speed increaser housing member that accommodates the ring member, the rollers, and part of the high-speed shaft; and   an impeller housing member that accommodates the impeller, wherein:   the rollers each include a circumferential surface, a first end surface, and a second end surface, wherein the first end surface and the second end surface are defined by two end surfaces in an axial direction of the roller;   the high-speed shaft includes
 a first flange opposed to the first end surface of each of the rollers, and 
 a second flange opposed to the second end surface of each of the rollers and located farther from the impeller than the first flange in the axial direction of the high-speed shaft; 
   the circumferential surface of each of the rollers includes
 a contact surface that contacts a portion in a circumferential surface of the high-speed shaft between the first flange and the second flange, 
 a first non-contact surface defined by a portion of the circumferential surface extending from an edge of the contact surface to the first end surface and spaced apart from the circumferential surface of the high-speed shaft, and 
 a second non-contact surface defined by a portion of the circumferential surface extending from an edge of the contact surface to the second end surface and spaced apart from the circumferential surface of the high-speed shaft; and 
   the contact surface includes a center position located closer to the first flange than a center position of each of the rollers in an axial direction of each of the rollers.   
     
     
         2 . The centrifugal compressor according to  claim 1 , wherein
 a dimension in a radial direction of each of the rollers from a boundary of the first non-contact surface and the contact surface to a boundary of the first non-contact surface and the first end surface is referred to as a first dimension,   a dimension in the radial direction of each of the rollers from a boundary of the second non-contact surface and the contact surface to a boundary of the second non-contact surface and the second end surface is referred to as a second dimension, and   the second dimension is longer than the first dimension.   
     
     
         3 . The centrifugal compressor according to  claim 1 , wherein
 a dimension in the axial direction of each of the rollers from a boundary of the first non-contact surface and the contact surface to the first end surface is referred to as a third dimension,   a dimension in the axial direction of each of the rollers from a boundary of the second non-contact surface and the contact surface to the second end surface is referred to as a fourth dimension, and   the fourth dimension is longer than the third dimension.   
     
     
         4 . The centrifugal force according to  claim 1 , wherein
 a gap between the first non-contact surface and the circumferential surface of the high-speed shaft defines a first gap,   a gap between the second non-contact surface and the circumferential surface of the high-speed shaft defines a second gap, and   the second gap is larger than the first gap.