US Patent 7210913 Scroll fluid machine with a silencer

A scroll fluid machine comprises a housing, a drive shaft, a stationary scroll fixed to the housing, and an orbiting scroll driven by the drive shaft. A gas from the outer circumference of the housing is introduced between the stationary and orbiting scrolls, and sent to the center by revolving the orbiting scroll in engagement with the stationary scroll. On the rear surface of the stationary scroll, there are provided a plurality of cooling fins that radially extend. Between the adjacent cooling fins, a silencer is provided to prevent noise caused by discharge of the gas.