Scroll-type positive fluid displacement apparatus having lubricating oil circulating system

A scroll-type fluid displacement apparatus having a scroll-type fluid displacement means including a stationary scroll and a revolving scroll which in combination define fluid pockets a volume and position of which change in accordance with the revolution of said revolving scroll so as to compress and displace a fluid from a suction port to a discharge port as said revolving scroll revolves;

• an electric motor for driving said revolving scroll;
• a closed container containing said scroll-type fluid displacement means and said electric motor;
• and lubricating oil circulating means;
• said fluid displacement means further including further openings adapted to permit said fluid pockets to communicate with the closed container when the pressure in each fluid pocket is increased so as to enable a pressure in the closed container to be maintained at a pressure level intermediate the pressures at said suction and discharge ports, said openings being formed either in said stationary scroll or said revolving scroll;
• wherein said lubricating oil circulating means include:
• a lubricating storing means provided in said closed container;
• a first lubricating oil passage opened at a first end to said lubricating oil in said lubricating storing means and at a second end to a fluid passage of the suction side of said scroll-type fluid displacement means so as to enable lubricating oil to be drawn into the scroll-type fluid displacement means and form a sealing oil film between the stationary and revolving scrolls;
• oil separating means disposed at the discharge side of said scroll-type fluid displacement means and adapted to separate said lubricating oil from said fluid;
• and
• a second lubricating oil passage connected at a first end to said oil separating means and opened at a second end to the space inside said closed container.

A closed type compressor having a scroll-type fluid displacement means comprising:

• a scroll-type compression mechanism including:
• a stationary scroll having a mirror-finished surface and a scroll wrap formed on said surface to have a uniform height from the latter;
• a revolving scroll having a mirror-finished surface and a scroll wrap of the same height as said stationary scroll wrap;
• said stationary and revolving scrolls being disposed opposite to each other such that the ends of scroll wraps slidably contact said mirror-finished surfaces of the opposing scrolls, said scroll warps and said mirror-finished surfaces of said pair of scrolls defining fluid pockets a volume and positions of which change as said revolving scroll revolves, to thereby displace and compress a fluid supplied through a suction port to a discharge port by the movement of said fluid pockets;
• a crank shaft mechanism including a crank shaft adapted for causing a revolving action of said revolving scroll;
• a closed container constituting at its bottom portion a well for storing the lubricating oil and accommodating therein said scroll-type compression mechanism, crank mechanism and said electric motor;
• means for introducing said fluid to be compressed into said suction port of said scroll-type compression mechanism from the exterior of the latter;
• means for introducing the compressed fluid discharged from said discharge port of said scroll-type compression mechanism to the outside of said scroll-type compression mechanism;
• oil feeding means opened at a first end to the lubricating oil in said closed container and connected at a second end to said means for introducing said fluid into said scroll-type compression mechanism to feed said lubricating oil to said scroll-type compression mechanism upon mixing with said fluid to be compressed so as to enable the lubricating oil to form a sealing oil film between the mirror finished surfaces and opposed portion of the scroll wraps;
• oil separating means disposed at the same side of said scroll-type compression mechanism as said means for introducing the compressed fluid and adapted to separate said lubricating oil from said discharged fluid;
• and
• oil returning means connected at its one end to said oil separating means and opened at its other end into said closed container thereby to return said lubricating oil separated by said oil separating means back into said closed container.