US Patent 9353751 Sealed scroll compressor for helium

A suction chamber and the oil injection port are linked, under a certain range of revolution angle, via a suction working chamber formed in the radially outer side by a orbiting scroll outer curve and a fixed scroll inner curve under a certain range of revolution angle. An opening of the oil injection port is provided on a bottom surface between teeth of the fixed scroll so that the suction working chamber formed, in a radially inner side, by a orbiting scroll inner curve and a fixed scroll outer curve and the suction chamber are positioned not to be linked with the oil injection port.