| 摘要 |
PURPOSE:To enable to prevent drop of efficiency due to heating of fluid on the fluid inlet side, by closing an oil passage between a slide valve and a rotor casing at an intermediate portion thereof by shifting the slide valve. CONSTITUTION:Oil introduced from an inlet 71 is passed through an oil groove 72 and ejected from an injection port 75 into a work space formed on the outside of a male rotor 4 and a female rotor 5. Here, arrangement is such that the injection port 75 can be shifted by moving a slide valve 32 to the right. Therefore, in case of operating a compressor under partial load, the injection port 75 is shifted to a proper position where it is not communicated to a suction space. In this state, oil is carried through an oil passage 76 via oil grooves 72, 73, 74 and supplied into the work space on the outside of the male and female rotors 4, 5 at a position displaced one pitch to the outlet side from the end wall of the suction side. Therefore, leakage of lubricating oil can be prevented and fluid at the suction side is not heated by high-temperature lubricating oil, so that it is enabled to prevent the drop of the efficiency of the screw compressor. |
