Scroll fluid machine

Abstract

A gap between opposing wrap portions is narrowed to increase compression efficiency, and an amount of machining time is reduced to thereby increase productivity. A plurality of proximate portions 8 are formed, at spacings in a spiral direction, on an outer peripheral surface 3 B of a wrap portion 3 of a fixed scroll 1 . Flat surfaces 8 A are used to connect adjacent proximate portions 8 . Similarly, a plurality of proximate portions 14 are formed, at spacings in the spiral direction, on an outer peripheral surface 13 B of a wrap portion 13 of an orbiting scroll 11. Flat surfaces 14 A are used to connect adjacent proximate portions 14 . In this way, the outer peripheral surfaces 3 B and 13 B of the wrap portions 3 and 13 can be formed in polyangular shapes, so as to reduce a gap between the wrap portions 3 and 13 and simplify the shapes. As a result, an amount of machining time can be reduced.

1 . A scroll fluid machine comprising: a first scroll having a wrap portion projecting axially from an end plate, said wrap portion being wound spirally from a radially inner side toward a radially outer side of said end plate; and a second scroll provided facing said first scroll, said second scroll having a wrap portion projecting axially from an end plate, said wrap portion being wound spirally from a radially inner side toward a radially outer side of said end plate so as to overlap the wrap portion of said first scroll to define a plurality of compression chambers;
 wherein a plurality of proximate portions are formed at least on an outer peripheral surface of the wrap portion of the first scroll, the plurality of proximate portions being adapted to make contact with or come closest to an inner peripheral surface of the wrap portion of the second scroll and being spaced apart in a winding direction;   the adjacent proximate portions are connected by flat surfaces or convex surfaces; and   the flat surfaces or convex surfaces are positioned farther than the proximate portions away from the second scroll.   
   
   
       2 . A scroll fluid machine according to  claim 1 , wherein a plurality of flat, concave, or convex proximate surfaces are formed on an inner peripheral surface of the wrap portion of the second scroll, the plurality of flat, concave, or convex proximate surfaces being adapted to make contact with or come closest to the proximate portions formed on the outer peripheral surface of the wrap portion of the first scroll and being spaced apart in the winding direction. 
   
   
       3 . A scroll fluid machine according to  claim 1 , wherein a film-like soft coating, which is made of a material softer than that of the proximate portions, is applied to at least either the outer peripheral surface of the wrap portion of the first scroll or the inner peripheral surface of the wrap portion of the second scroll. 
   
   
       4 . A scroll fluid machine according to  claim 1 , wherein the proximate portions are formed such that a pitch thereof in the winding direction is narrow on the radially inner side and wide on the radially outer side. 
   
   
       5 . A scroll fluid machine according to  claim 1 , wherein the proximate portions are formed at equal angular spacings throughout the wrap portion from the radially inner side to the radially outer side. 
   
   
       6 . A scroll fluid machine according to  claim 1 , wherein the proximate portions are formed only on a part of the wrap portion away from the end plate in the axial direction, the wrap portion projecting from the end plate. 
   
   
       7 . A scroll fluid machine according to  claim 1 , wherein the proximate portions are formed only on the radially inner side of the wrap portion in the winding direction, and an involute curved surface is formed along an involute curve on the radially outer side of the wrap portion.