Lubricating mechanism for a scroll-type fluid displacement apparatus

Claim 1

In a scroll-type fluid displacement apparatus including a pair of scrolls, each comprising a circular end plate and a spiral wrap extending from one side of said end plate, said spiral wrap having a first groove formed in the axial end surface thereof along the spiral curve, a seal element carried in said first groove, said spiral wraps interfitting at an angular and radial offset to make a plurality of line contacts which define at least one pair of sealed off fluid pockets, driving means operatively connected to one of said scrolls for orbiting said one scroll relative to other scroll and for preventing rotation of said one scroll to change the volume of the fluid pockets, the improvement comprising a second groove formed in the axial end surface of one of said spiral wraps in communication with said first groove, said second groove extending close to the outer terminal end of said one spiral wrap, said axial end surface of one of said spiral wraps having said second groove forming a contact surface for contacting the circular end plate of the opposing scroll and said second groove supplying lubricating oil to said contact surface, and the cross-sectional shape of said second groove being different from the cross-sectional shape of said first groove to prevent the movement of said seal element in said first groove.