| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor-driven turbomachine to provide an increased life through reduction of a thrust load exerted on a bearing and perform safe operation for a long time. SOLUTION: The stator 4A of an electric motor 4 is disposed in a state to deviate a relative position to a rotor 4B to the opposite side to an impeller 2. By exciting the electric motor 4 by an inverter 15, an electromagnetic force in an axial direction is exerted on the rotor 4B in a manner to correct a deviation from the stator 4A. Namely, the rotor 4B is attracted to the opposite side to an impeller and by compressing gas through rotation of the impeller 2, an action is carried out in a direction in which a force exerted on the impeller 2 and pushing up a rotary body is offset by a differential pressure generated between a cascade surface (an upper surface) and its back (an under surface). By selecting a deviation amount between the rotor 4B and the stator 4A such that a thrust load exerted on a rotary body through a differential pressure generated in the compressor work of the impeller 2 and a thrust load exerted on the rotor 4B are matched with each other, other thrust load than a load exerted on the bearings 6 and 7 by a spring 22 is reduced and an increased life is provided for a bearing.
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