| 摘要 |
PROBLEM TO BE SOLVED: To minimize the fluctuation of clearances between sliding surfaces of a fixed shaft and a rotary shaft in a rotary fluid machine caused by thermal expansion. SOLUTION: The rotary fluid machine comprises a rotor rotatably accommodated in a casing, the hollow rotary shaft 113 rotated together with the rotor, and the fixed shaft 102 relatively rotatably engaged with an inner periphery of the rotary shaft 113. The rotary shaft 113 is structured in such a manner that an outside sleeve 21 made of metal is shrinkage-fitted to an outer periphery of an inside sleeve 85 made of ceramic or the like having a lower coefficient of thermal expansion relative to metal, and the fixed shaft 102 is structured in such a manner that an outside sleeve 88 made of metal is shrinkage-fitted to an outer periphery of an inside sleeve 87 made of ceramic or the like having a lower coefficient of thermal expansion relative to metal. By tensile residual stress of the outside sleeves 21, 88 engaged with the outer peripheries of the inside sleeves 85, 87, the thermal expansion of the outside sleeves 21, 88 is prevented, and a state of close contact between the outside sleeves 21, 88 and the inside sleeves 85, 87 is thus maintained.
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