| 摘要 |
PURPOSE:To aim at improvement of the operational efficiency through lessening the generation of heat and the losses of power at the shaft seal part of a fluid machine by permitting a suction chamber to communicate with a motor chamber through a clearance in the back of a swing scroll and thus requiring no sealing device to be provided on a crankshaft-mounted rotary shaft which is also used as a motor shaft. CONSTITUTION:In No. 3 casing 3, a motor 12, the rotary shaft of which is also used as a crankshaft-mounted rotary shaft 4, is housed, and a suction chamber 1a, which is formed in No.1 casing 1, is permitted to communicate with said motor 12 chamber through a clearance 13 in the back of a swing scroll. Thereby, none of shaft sealing devices is required and also the machine can be of the oil free type. Owing to its construction mentioned above, particularly in the case where it is used as a vacuum pump, not only it is free from such generation of heat in large amounts and losses of power as is likely to be resulted from the installation of a shaft sealing device, especially of a mechanical seal, but also it can be of the oil free type to be realized as a vacuum pump. Therefore, since only a small amount of heat is to be conducted on the shaft, the interrelative clearance between scroll laps 1a, 8a is not required to be considerably large in size. Hereby, even immediately after the starting of the motor, disadvantages due to leakage at said part are small in the amount, and accordingly the operational efficiency can be improved.
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