| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a screw compressor which has a variable internal compression ratio and furthermore has high sealability of an action space.SOLUTION: A screw compressor 1 includes: a casing 2 in which a piston hole 7 opened to a rotor chamber 3 in a direction vertical to a shaft of a screw rotor 4, is formed; and a piston valve 8 which is slidably fitted in the piston hole 7. At least a part of an end face at the rotor chamber 3 side of the piston valve 8 configures a part of an inner wall of the rotor chamber 3 and seals at least a part of the opening of the piston hole 7 when the piston valve 8 moves to the rotor chamber 3 side. The piston valve 8 opens the entire opening of the piston hole 7 to thereby define a low compression ratio radial port 16 communicated with a discharge flow passage when the piston valve 8 moves to a side opposite to the rotor chamber 3.</p> |
