Scroll-type apparatus with hydrodynamic thrust bearing

In a positive fluid displacement apparatus into which fluid is introduced through an inlet port for circulation therethrough and subsequently withdrawn through a discharge port, and comprising a stationary scroll member having an end plate and an involute wrap and an orbiting scroll member having an end plate and an involute wrap affixed to the inner surface thereof, driving means for orbiting said orbiting scroll member with respect to said stationary scroll member whereby said involute wraps make moving line contacts to seal off and define at least one moving pocket of variable volume and zones of different fluid pressure on both sides of said moving line contact, coupling means to maintain said scroll members in fixed angular relationship, axial force-applying means for providing an axial force to urge said involute wrap of said stationary scroll member into axial contact with said end plate of said orbiting scroll member and said involute wrap of said orbiting scroll member into axial contact with said end plate of said stationary scroll member thereby to achieve radial sealing of said pockets, and tangential sealing means for effecting tangential sealing along said moving line contacts, the improvement comprising flat plate hydrodynamic thrust bearing means serving as said axial force-applying means, said thrust bearing means having a bearing surface in force-applying engagement with at least a portion of the outer surface of said orbiting scroll member end plate serving as a journal surface, either said bearing surface or said journal surface having intersecting groovings for carrying an oil lubricant, the pattern of said groovings being such that when said orbiting scroll member undergoes motion all points on that surface contacting the surface having said groovings intersect a sufficient number of said groovings to ensure that said bearing and journal surfaces are lubricated with a thin, essentially continuous film of said oil lubricant when said orbiting scroll member is driven by said driving means.

A positive fluid displacement apparatus, comprising in combination

• a. a stationary scroll member having an end plate and an involute wrap;
• b. an orbiting scroll member having an end plate and an involute wrap affixed to the inner side thereof;
• p1 c. driving means, incorporating a main shaft and an orbiting scroll member shaft parallel therewith, for orbiting said orbiting scroll member whereby said involute wraps make moving line contacts to seal off and define moving pockets of variable volume and zones of different fluic pressure on both sides of said moving line contact, said driving means including radial compliant linking means between said main shaft and said orbiting scroll member shaft to provide a centripetal force to counterbalance a predetermined fraction of the centrifugal force acting upon said orbiting scroll member thereby to attain tangential sealing along said moving line contacts;
• d. high-pressure fluid conduit means communicating with the zone of highest pressure and low-pressure fluid conduit means communicating with the zone of lowest pressure;
• e. coupling means to maintain said scroll members in fixed angular relationship;
• f. flat plate hydrodynamic thrust bearing means acting upon said orbiting scroll member to provide an axial force opposing axial forces within said moving pockets, said thrust bearing means having a bearing surface on its contacting side in force applying contact with a journal surface on the outer side of said end plate of said orbiting scroll member, either said bearing surface or said journal surface having intersecting groovings for carrying a lubricating oil, the pattern of said groovings being such that when said orbiting scroll member undergoes orbiting motion all points on that surface contacting in surface having said groovings intersect a sufficient number of said groovings to ensure that said bearing and journal surfaces are lubricated with a thin, essentially continuous film of said lubricating oil when said orbiting scroll member is driven by said driving means;
• and
• g. lubricating oil circulating means for supplying lubricating oil to said intersecting groovings.