Transmission and centrifugal compressor

A transmission, comprising:

• a transmission housing member;
• an annular ring portion that is provided in the transmission housing member and rotates as a low speed shaft rotates;
• a high speed shaft that is arranged on an inner side of the ring portion;
• at least three rollers that are provided between the ring portion and the high speed shaft and contact both of an inner circumferential surface of the ring portion and an outer circumferential surface of the high speed shaft;
• and
• roller bearings with which the at least three rollers are rotatably supported by the transmission housing member, wherein
• the at least three rollers include:
• at least one movable roller that moves, in response to rotation of the ring portion, between a first position and a second position that is spaced apart from the first position in a rotation direction of the ring portion;
• and
• at least two fixed rollers that are fixed so as not to move in the rotation direction of the ring portion,
• the roller bearings include a movable bearing that rotatably supports the movable roller,
• the transmission housing member includes, as surfaces that define a movable bearing accommodating chamber that accommodates the movable bearing:
• a bottom surface;
• and
• an accommodating side surface that extends from the bottom surface and includes the first supporting surface and the second supporting surface,
• the movable bearing accommodating chamber is arranged on an outer side of the high speed shaft in a radial direction of the high speed shaft,
• the accommodating side surface includes:
• a first supporting surface that contacts the movable bearing so as to support the movable bearing when the movable roller is at the first position;
• and
• a second supporting surface that is provided at a position spaced apart from the first supporting surface in the rotation direction, and contacts the movable bearing so as to support the movable bearing when the movable roller is at the second position,
• the accommodating side surface includes a separated surface provided at a position separated from the movable bearing and on an outer side of the movable bearing in the radial direction of the high speed shaft, and
• a clearance exists between the separated surface and the movable bearing regardless of a position of the movable bearing.