Scroll Fluid Machine

Abstract

Disclosed is a scroll fluid machine configured from inexpensive materials and provided with a rotation prevention mechanism with excellent durability. In the scroll fluid machine, a fixed scroll, the spiral body of which has been vertically disposed on one end surface of an endplate, and a movable scroll, the spiral body of which has been vertically disposed on one end surface of the endplate, are arranged eccentrically to and out of phase with each other such that the spiral bodies engage with each other and the movable scroll turns relative to the fixed scroll. The scroll fluid machine is characterized by being provided with a rotation prevention mechanism comprising a movable-side pin that protrudes from the other surface of the endplate of the movable scroll, a fixed-side pin that protrudes from the housing side towards the other surface of the endplate of the movable scroll, and a rotation prevention member held from both sides by the movable-side pin and the fixed-side pin.

1 . A scroll-type fluid machine, wherein a fixed scroll, which is provided with a scroll body standing on an end surface of an end plate, and a movable scroll, which is provided with a scroll body standing on an end surface of an end plate, are provided eccentrically out of phase by engaging scroll bodies with each other so that said movable scroll is rotated relative to said fixed scroll, wherein the machine comprises a rotation-preventing mechanism comprising a movable-side pin protruding from another end surface of said end plate of said movable scroll, a fixed-side pin protruding from a housing-side toward another side of said end surface of said end plate of said fixed scroll, and a rotation-preventing member which is supported between both sides of said movable-side pin and said fixed-side pin. 
     
     
         2 . The scroll-type fluid machine according to  claim 1 , wherein said rotation-preventing member has a movable-side depressed part which engages said movable-side pin and a fixed-side depressed part which engages said fixed-side pin. 
     
     
         3 . The scroll-type fluid machine according to  claim 2 , wherein at least one of said movable-side depressed part and said fixed-side depressed part is formed as a part of a hole in said rotation-preventing member. 
     
     
         4 . The scroll-type fluid machine according to  claim 2 , wherein either or both depths of said movable-side depressed part and said fixed-side depressed part 
     
     
         5 . The scroll-type fluid machine according to  claim 4 , wherein a difference between said minimum value (Lor) of said center distance (L) between said movable-side pin and said fixed-side pin, and said swing radius (AOR) of said movable scroll is within 0.1 mm. 
     
     
         6 . The scroll-type fluid machine according to  claim 4 , wherein a difference between said minimum value (Lor) of said center distance (L) between said movable-side pin and said fixed-side pin, and said swing radius (AOR) of said movable scroll is set smaller than a difference between a depth (B 1 ) of said movable-side depressed part and an axial radius (R 1 ) of said movable-side pin. 
     
     
         7 . The scroll-type fluid machine according to  claim 4 , wherein a difference between said minimum value (Lor) of said center distance (L) between said movable-side pin and said fixed-side pin, and said swing radius (AOR) of said movable scroll is set smaller than a difference between a depth (B 2 ) of said fixed-side depressed part and an axial radius (R 2 ) of said fixed-side pin. 
     
     
         8 . The scroll-type fluid machine according to  claim 1 , wherein movable-side pins and fixed-side pins are plurally placed along circumferences of placement-pitch circles having placement-pitch angles (Ap), which are equal to each other, and diameters, which are equal to each other. 
     
     
         9 . The scroll-type fluid machine according to  claim 8 , wherein said fixed-side pin and said movable-side pin are placed out of phase with each other by a predetermined angle (θ) satisfying Formula 1 toward a direction to eliminate a distortion of said movable scroll relative to said fixed scroll.
   θ≦2·tan−1[( AOR−Lor )/ Dp]   [Formula 1]
 
 
     
     
         10 . The scroll-type fluid machine according to  claim 1 , wherein said fixed scroll and said movable scroll are assembled so that an initial value of a center distance (L) between said fixed-side pin and said movable-side pin is set to a minimum value (Lor) for one rotation-preventing member while said initial value of said center distance (L) between said fixed-side pin and said movable-side pin is set to a swing radius (AOR) of said movable scroll for another rotation-preventing member. 
     
     
         11 . The scroll-type fluid machine according to  claim 1 , wherein a thickness of said rotation-preventing member in an axial direction is set to a maximum value under a condition where an axial interval between said movable scroll and a housing is kept equal to or greater than an oil film thickness as not interfering within a dimensional tolerance.