Modified wrap scroll-type machine

A scroll-type apparatus comprising:

• a fixed scroll member having a first spiral wrap;
• and
• a second scroll member having a second spiral wrap, said first and second spiral wraps each having an inner end and an outer end, said second scroll member being mounted for movement along a predetermined cyclical path with respect to said first scroll member, said second wrap being intermeshed with said first wrap so that when said second scroll member is moved with respect to said first scroll member at least one fluid pocket is formed which carries fluid from a peripherally located inlet of said apparatus to a centrally located outlet of said apparatus, said first and second spiral wraps having a wrap length such that a minimum of two and a maximum of three line contacts between said wraps occur during a full cycle of said movement of said second scroll member, said first and second spiral wraps each having an inner end comprised of a concave arcuate shape and a convex arcuate shape, said arcuate shapes being configured to reduce the volume of said fluid pocket to a theoretical zero volume immediately prior to separation of said wraps, said wraps differing from said configuration by the provision of a conical cutout section on one of said spiral wraps adjacent said outlet and formed substantially along the entire height of said wrap, said conical cutout section being oriented to converge toward said outlet.

A scroll-type apparatus comprising:

• a fixed scroll member having a first spiral wrap;
• a second scroll member having a second spiral wrap;
• said first and second spiral wraps each having an inner end and an outer end, said second scroll member being mounted for movement along a predetermined cyclical path with respect to said first scroll member, said second wrap being intermeshed with said first wrap so that when said second scroll member is moved with respect to said first scroll member at least one fluid pocket is formed which carries fluid from a peripherally located inlet of said apparatus to a centrally located outlet of said apparatus, said first and second spiral wraps each having a wrap length such that a minimum of two and a maximum of three contacts between said wraps occur during a full cycle of said movement of said second scroll member;
• and
• a discharge valve located in said outlet, said discharge valve being designed to permit the flow of fluid through said outlet to a discharge line when the pressure in said fluid pocket exceeds the pressure of said discharge line;
• said first and second spiral wraps being symmetrical in configuration and said inner ends comprising a convex arcuate shape and an adjacent concave arcuate shape;
• wherein said wraps form first and second moving contacts which move progressively toward each other during movement of said second scroll member, said arcuate shapes being configured to reduce the volume of said fluid pocket to a theoretical zero volume just prior to separation of said wraps, said wraps differing from said configuration by the provision of a cutout section in one of said wraps defining a recess in the flank surface of said one of said spiral wraps adjacent the inner end thereof and formed substantially along the entire height of said wrap, said recess insuring a flowpath between said fluid pocket and said outlet as said first and second moving contacts merge into a single line contact.

A scroll-type apparatus comprising:

• a fixed scroll member having a first spiral wrap;
• a second scroll member having a second spiral wrap;
• said first and second spiral wraps each having an inner end and an outer end, said second scroll member being mounted for movement along a predetermined cyclical path with respect to said first scroll member, said second wrap being intermeshed with said first wrap so that when said second scroll member is moved with respect to said first scroll member at least one fluid pocket is formed which carries fluid from a peripherally located inlet of said apparatus to a centrally located outlet of said apparatus, said first and second spiral wraps being involutes of a straight line and having a wrap length such that a minimum of two and a maximum of three contacts between said wraps occur during a full cycle of said movement of said second scroll member;
• and
• a discharge valve located in said outlet, said discharge valve being designed to permit the flow of fluid through said outlet to a discharge line when the pressure in said fluid pocket exceeds the pressure of said discharge line;
• said first and second spiral wraps being symmetrical in configuration and said inner ends comprising a convex circular shape and an adjacent concave circular shape, said convex circular shape having a radius RO defined as:
• ##EQU3## and said concave circular shape having a radius RI defined as:
• RI=ROR+RO
• where
• ROR=radius of orbital movement of said second scroll member
• A=length of said straight line
• R.theta.=initial radius
• E=thickness of wrap
• wherein said wraps form first and second moving contacts which move progressively toward each other during movement of said second scroll member until said first and second contacts merge to a single contact whereby substantially all of said fluid is discharged through said outlet and said outer ends of said first and second wraps form a second and third moving line contact thereby creating a new pair of fluid pockets, said single contact subsequently terminating and causing said pair of fluid pockets to become a single fluid pocket and wherein one of said spiral wraps include a cutout section adjacent said outlet and formed substantially along the entire height of said wrap.

A scroll-type apparatus comprising:

• a fixed scroll member having a first spiral wrap;
• a second scroll member having a second spiral wrap;
• said first and second spiral wraps each having an inner end and an outer end, said second scroll member being mounted for movement along a predetermined cyclical path with respect to said first scroll member, said second wrap being intermeshed with said first wrap so that when said second scroll member is moved with respect to said first scroll member at least one fluid pocket is formed which carries fluid from a peripherally located inlet of said apparatus to a centrally located outlet of said apparatus, said first and second spiral wraps having a wrap length such that a minimum of two and a maximum of three contacts between said wraps occur during a full cycle of said movement of said second scroll member;
• and
• a discharge valve located in said outlet, said discharge valve being designed to permit the flow of fluid through said outlet to a discharge line when the pressure in said fluid pocket exceeds the pressure of said discharge line;
• said first and second spiral wraps being symmetrical in configuration and said inner ends comprising a convex arcuate shape and an adjacent concave arcuate shape;
• wherein said wraps form first and second moving contacts which move progressively toward each other during movement of said second scroll member until said first and second contacts merge to a single contact whereby substantially all of said fluid is discharged through said outlet and said outer ends of said first and second wraps form a second and third moving line contact thereby creating a new pair of fluid pockets, said single contact subsequently terminating and causing said pair of fluid pockets to become a single fluid pocket and wherein one of said spiral wraps includes a conical cutout section adjacent said outlet and formed substantially along the entire height of said wrap, said conical cutout section being oriented to converge toward said outlet.