Scroll-type fluid machine with seal to aid lubrication

Abstract

A scroll-type fluid machine for an air conditioning machine comprises a hermetically closed vessel which houses therein an orbiting scroll member and a stationary scroll member forming together a compressor portion, an Oldham ring member for preventing the orbiting scroll member from rotating about its own axis, a driving motor having a driving shaft connected to the orbiting scroll member for driving the same, and a frame for supporting the shaft, a low pressure liquid introducing passage for making the interior of the hermetically closed vessel a low pressure chamber, and a high pressure fluid discharge passage. A sealing member is provided at the back of the orbiting scroll member with its surfaces slidably contacting the frame and the orbiting scroll member to form a chamber separated from the low pressure chamber. A fluid which is in mid course of being compressed and has an intermediate pressure between suction pressure and discharge pressure is introduced into the separated chamber to maintain the same at the intermediate pressure, thereby overcoming a thrust force exerted on the orbiting scroll member to press the same against the stationary scroll member and effecting a proper supply of lubricating oil to moving portions of the machine.