Scroll type fluid machine, method and device for forming elastic coating thereon

Abstract

A coating solution that contains 10 to 20% by weight of epoxy resin serving as a thermosetting resin, 20 to 30% by weight of MoS 2 , and 5 to 10% by weight of graphite, with a remainder thereof constituted by an organic solvent, is sprayed onto a wrap portion side face of an orbiting scroll from a spray nozzle . While spraying the coating solution, the orbiting scroll is rotated on a rotating table and the spray nozzle is moved along a rectilinear movement path toward a radial direction outer side of the orbiting scroll while maintaining an attitude thereof from the start of the spraying process. After applying the coating solution, the coating solution is dried by baking, whereupon a break-in operation is performed. As a result, an elastic coating is formed at a coating thickness that enables elastic deformation in accordance with a clearance between the wrap portion side faces.

1 . A scroll type fluid machine in which an elastic coating is formed on a side face of a spiral wrap portion, wherein the elastic coating is obtained by dispersing a powdered solid lubricant in a synthetic resin that possesses elasticity and is more flexible than a scroll base material constituting the wrap portion, and is formed at a coating thickness that enables elastic deformation relative to an opposing wrap portion side face of another scroll during an operation while ensuring that a clearance is not generated between the wrap portion side faces. 
     
     
         2 . The scroll type fluid machine according to  claim 1 , wherein the elastic coating is formed by applying a coating solution obtained by dissolving constituent components of the elastic coating in a solvent, to the wrap portion side face at a coating thickness that exceeds the coating thickness enabling elastic deformation during an operation, drying the coating solution, and then finishing the coating solution to the coating thickness enabling elastic deformation by performing a break-in operation. 
     
     
         3 . The scroll type fluid machine according to  claim 1 , wherein the elastic coating is formed by applying a coating solution containing 10 to 20% by weight of a synthetic resin having epoxy resin as a main component and 25 to 40% by weight of a powdered solid lubricant having MoS 2  as a main component, with a remainder thereof constituted by the solvent, to the wrap portion side face, and then hardening the coating solution by baking. 
     
     
         4 . The scroll type fluid machine according to  claim 3 , wherein the coating thickness of the elastic coating following a break-in operation is between 30 and 80 μm. 
     
     
         5 . The scroll type fluid machine according to  claim 3 , wherein a processing subject gas is air, and lubricating oil is not used. 
     
     
         6 . A method for forming an elastic coating on a scroll type fluid machine, in which the elastic coating according to  claim 1  is formed on a side face of a spiral wrap portion, comprising:
 a preliminary step of fixing a scroll constituted by the wrap portion and an endplate to a rotating table and rotating the scroll about a spiral center of the wrap portion; 
 a coating solution spraying step of moving a spray nozzle in a radial direction of the scroll while spraying a coating solution obtained by dissolving constituent components of the elastic coating in a solvent, onto the rotating scroll toward the wrap portion side face using the spray nozzle; and 
 a coating thickness adjusting step of keeping a coating thickness of the coating solution constant by adjusting a rotation speed of the scroll in accordance with a radial direction movement of the spray nozzle. 
 
     
     
         7 . The method for forming an elastic coating on a scroll type fluid machine according to  claim 6 , wherein a movement speed of the spray nozzle is kept constant, and the rotation speed of the scroll is adjusted in accordance with the movement speed. 
     
     
         8 . The method for forming an elastic coating on a scroll type fluid machine according to  claim 6 , wherein the spray nozzle is moved in an outside direction from the spiral center of the wrap, and the rotation speed of the scroll is gradually reduced in accordance with a movement speed of the spray nozzle. 
     
     
         9 . The method for forming an elastic coating on a scroll type fluid machine according to  claim 6 , wherein the spray nozzle is moved from an outer diameter side toward a center of the scroll, and the rotation speed of the scroll is gradually increased in accordance with a movement speed of the spray nozzle. 
     
     
         10 . The method for forming an elastic coating on a scroll type fluid machine according to  claim 6 , wherein the spray nozzle is moved rectilinearly without varying an attitude thereof. 
     
     
         11 . A device for forming an elastic coating on a scroll type fluid machine, in which the elastic coating according to a  claim 1  is formed on a side face of a spiral wrap portion, comprising:
 a rotation device that includes a rotating table on which a scroll constituted by the wrap portion and an end plate is placed fixedly and a driving device for driving the rotating table, and that rotates the scroll placed fixedly on the rotating table about a spiral center of the wrap portion; 
 a coating solution spraying device having a spray nozzle for spraying a coating solution obtained by dissolving constituent components of the elastic coating in a solvent, onto the rotating scroll toward the wrap portion side face, and a driving device for moving the spray nozzle in a radial direction of the scroll; and 
 a controller that keeps a coating thickness of the coating solution constant by controlling a rotation speed of the rotating table and a movement speed of the spray nozzle. 
 
     
     
         12 . The device for forming an elastic coating on a scroll type fluid machine according to  claim 11 , wherein the coating solution spraying device comprises a uniaxial system driving device that moves the spray nozzle along a rectilinear path without varying an attitude of the spray nozzle. 
     
     
         13 . The device for forming an elastic coating on a scroll type fluid machine according to  claim 11 , wherein the spray nozzle comprises a slit-shaped discharge port, and a long side of the discharge port has a dimension that corresponds to a height of the wrap portion side face.