Variable displacement mechanism for scroll type compressor

摘要

In a scroll type compressor having a movable scroll member and a fixed scroll member, the movable scroll member and the fixed scroll member defines compression chambers therebetween. The compression chambers reduce in volume in accordance with orbital motion of the movable scroll member relative to the fixed scroll member. Thus gas is compressed. A variable displacement mechanism for the scroll type compressor has a by-pass passage, a pivotal plate and an actuator. The by-pass passage serves to interconnect the compression chamber in a process of volume-reducing and a suction pressure region. The pivotal plate has a communication hole that partially constitutes the by-pass passage and is selectively pivoted between a first pivotal position for opening the by-pass passage by the communication hole and a second pivotal position for closing the by-pass passage. The actuator serves to pivot the pivotal plate.