Patent ID: 6053715
Filing Date: 2000-04-25
Classification: F04C

Abstract:
A scroll compressor which performs gas injection through an injection port into compression chambers formed between a fixed scroll and an orbiting scroll which is made to orbitally move in relation to the fixed scroll at a variable speed, comprising:wraps provided to the fixed scroll and the orbiting scroll, respectively, for forming a pair of compression chambers therebetween;an offset surface provided in the wrap so as to open one of the compression chambers to an inlet port side with a prescribed space, said offset surface extending on the wrap from a position on a spiral length that satisfies a required compression ratio for one of the pair of compression chambers in a prescribed low speed operation to an end of the spiral of the wrap; anda control means for timely shutting off and resuming gas injection; whereinthe injection port is positioned such as to open to an unsealed area in one of the pair of compression chambers, said unsealed area being created by said offset surface.