US Patent 7815423 Compressor with fluid injection system

A scroll compressor includes a housing, a non-orbiting scroll member including a first spiral wrap, and an orbiting scroll member including a second spiral wrap. The first and second spiral wraps are interleaved to define at least one moving fluid pocket that decreases in size as it moves from a radially outer position to a radially inner position. A vapor-injection system may include a shell fitting in fluid communication with a fluid passageway of the non-orbiting scroll member via a vapor injection tube. The vapor injection tube may be fixed for movement with the non-orbiting scroll member for communicating vapor into the moving fluid pockets.