Abstract: A drive support unit of a turbo compressor includes at least one bearingless motor. The at least one bearingless motor includes a rotor-stator pair constituted by a rotor and a stator, and is configured to rotationally drive a drive shaft and to support a radial load of the drive shaft in a contactless manner. Accordingly, it is possible to provide a turbo compressor to which a bearingless motor is applied.

Abstract: A compressor includes a first-stage compression unit configured to compress a refrigerant, a second-stage compression unit configured to compress the refrigerant compressed by the first-stage compression unit, a shaft member connected to the first-stage compression unit and the second-stage compression unit, and a cover member configured to cover the shaft member. A first passage is provided between the first-stage compression unit and the second-stage compression unit. A front chamber is provided around the cover member. The front chamber is connected to the first passage and to a second passage to which the refrigerant from an economizer is sent. The second passage is provided with a passage structure configured such that a flowing direction of the refrigerant supplied through the second passage to the front chamber is an avoidance direction. The avoidance direction is a direction that differs from a direction toward the shaft member.

Abstract: An electric motor includes a stator, and a rotor having a plurality of magnetic poles. Each magnetic pole includes a rotor core having through holes arranged circumferentially side by side, and a permanent magnet inserted into each through hole. A length of a portion of the rotor core in a radial direction of the rotor is shorter than a length of the permanent magnet in the radial direction of the rotor. The length of the portion of the rotor core is measured between an inner surface of each of the through holes adjacent to an outer periphery of the rotor and an outer peripheral surface of the rotor. The permanent magnets generate a magnetic flux in a magnetic circuit showing a smaller magnetic resistance in a portion of the rotor radially outward of the permanent magnets than in a portion of the rotor radially inward of the permanent magnets.

Abstract: A drive support unit of a turbo compressor includes at least one bearingless motor. The at least one bearingless motor includes a rotor-stator pair constituted by a rotor and a stator, and is configured to rotationally drive a drive shaft and to support a radial load of the drive shaft in a contactless manner. Accordingly, it is possible to provide a turbo compressor to which a bearingless motor is applied.