Asynchronous non-constant-pitch spiral scroll-type fluid displacement machine

Abstract

A scroll-type spiral fluid displacement machine having at least one pair of interfitting scroll elements. The scroll vanes of the scroll elements are constructed upon a base line spiral defined by the equation: L=K 0 φ K1 e −φ/ K2 where L is the distance from the spiral's origin to any point on the spiral curve, φ is the angular displacement of the spiral, K 0 is a constant greater than 1, K 1 , is a constant greater than 1, and K 2 is a constant greater than 10.

1 . A scroll-type fluid displacement device comprising:
 a first scroll and a second scroll, each scroll having an end plate from which a spiral projects transversely from the end plate;   said first scroll and said second scroll being opposingly arranged to interfit said spirals;   said spirals being opposingly symmetrical about a central axis;   a base line for each spiral be defined by the equation:
     L=K   0 φ K1   e   −φ/     K2      
   wherein L is the distance from said central axis to any point on the base line curve, φ is the angular displacement of the base line curve, K o  is a constant greater than 1, K 1  is a constant greater than 1, and K 2  is a constant greater than 10.   
   
   
       2 . The device according to  claim 1  further comprising an orbital movement generating mechanism that moves at least one of the scrolls so that said first scroll moves in a non-rotating orbital path perpendicular to said central axis, relative to said second scroll. 
   
   
       3 . The device according to  claim 1  further comprising a housing to which one of said scrolls is rigidly affixed. 
   
   
       4 . The device according to  claim 2  wherein said orbital movement generating mechanism is a rotationally driven crankshaft. 
   
   
       5 . The device according to  claim 1  further comprising a third scroll and a fourth scroll that are defined and interfit in the same manner as said first and second scrolls;
 wherein said first and third scrolls are rigidly affixed to a housing; and   wherein said second and fourth scrolls are driven in a non-rotating orbital path perpendicular their respective central axes, relative to said first and third scrolls.   
   
   
       6 . The device according to  claim 5  wherein the central axes of said second and fourth scrolls are parallel;
 wherein said second and fourth scrolls are driven in the same direction on their respective orbital paths and at an angular phase difference of 180 degrees.   
   
   
       7 . The device according to  claim 5  wherein said second and fourth scrolls share a common central axis. 
   
   
       8 . A method of designing scroll elements for a scroll-type fluid displacement device, the steps comprising:
 designing a base line spiral for first and second scroll elements, the base line spiral being defined by the equation:
     L=K   0 φ K1   e   −φ/     K2      
   
     wherein L is the distance from a central axis to any point on the base line curve, φ is the angular displacement of the base line curve, K o  is a constant greater than 1, K 1 , is a constant greater than 1, and K 2  is a constant greater than 10;
 designing inner and outer spirals to define spiral walls that create fluid pockets having a desired change in volume when said first and second scroll elements are fit and orbitally rotated together in the scroll-type fluid displacement device.