| 摘要 |
PURPOSE:To enable to control the capacity of a compressor, by providing a means for changing the level of pressure applied to at least one of a plurality of vane back-pressure chambers, and urging or disengaging the vane communicated to the back-pressure chamber to and from the inner surface of a rotor case. CONSTITUTION:When a high pressure is applied to a second vane back-pressure chamber 104 by a valve 106 disposed at a portion of an oil feed port 105, suction and compression of fluid is performed in the same way as in the conventional arrangements. On the other hand, when the valve 106 is shifted to a position where the second vane back-pressure chamber 104 is communicated with a low- pressure chamber 107 via the valve 106, two vanes out of four vanes (not shown) are not urged onto the inner surface of a rotor case (not shown) and the two vanes are rendered inoperative, so that the compressor functions substantially like a compressor having two vanes. Resultantly, the discharge quantity and hence the output of the compressor are both reduced. |
