Swash plate of a swash plate type compressor and the swash plate type compressor

Abstract

The object of the present invention is to provide a swash plate which fulfils the basic properties required for a swash plate, which are stable boundary lubricating state by lubricating oil, without forming a metal spray coating layer comprising a copper type or aluminum type material on the surface of the substrate 3 a forming the swash plate 3 of the swash plate type compressor as an intermediate layer. The substrate 3 a of the swash plate 3 comprises a disk-shaped steel sheet formed by pressing a rolled steel sheet into a disk shape, and both surfaces of the disk-shaped steel sheet is ground. Thus, resin coating layers 10 containing fluororesin, which has superior seizure resistance, can be strongly fixed to the substrate without the need to form a metal spray coating layer on the surface of the substrate. This improves the durability of the swash plate type compressor using carbon dioxide gas as a refrigerant.

1 . A swash plate of a swash plate type compressor in which the swash plate is mounted directly to a rotary shaft or indirectly to the rotary shaft through a coupling member so as to be oblique to or perpendicular to the rotary shaft in a housing in which a refrigerant exists, the swash plate being in sliding contact with shoes such that the rotary motion of the swash plate is converted to reciprocating motion of pistons through the shoes, thereby compressing and expanding the refrigerant, characterized in that said swash plate comprises a substrate formed by pressing a rolled steel into a disk shape, the disk-shaped steel sheet having sliding surfaces on both sides thereof on which the shoes slide, said sliding surfaces being formed by grinding, said swash plate further comprising low-friction resin coating layers formed on the respective sliding surfaces, said coating layers containing 40 to 50% by weight of fluororesin in the form of powder having a particle diameter of 30 μm or less, said low-friction resin coating layers each having a thickness within the range of 8 to 30 μm. 
     
     
         2 . The swash plate of  claim 1  wherein both side surfaces of the disk-shaped steel sheet are ground using a two-head grinding machine. 
     
     
         3 . The swash plate of  claim 1  wherein both sides of the disk-shaped steel sheet are ground by a driving type two-head grinding method in which top and bottom surfaces of the disk-shaped steel sheets as the sliding surfaces are simultaneously ground with grinders, while rotating the disk-shaped steel sheet with its center held in position. 
     
     
         4 . The swash plate of  claim 1  wherein the ground surfaces of the disk-shaped steel sheet on both sides thereof are ground to a flatness of 8 μm or less and a parallelism of 10 μm or less. 
     
     
         5 . The swash plate of  claim 1  wherein the surfaces of the substrate before the low-friction resin coating layers are formed thereon are subjected to shot blasting. 
     
     
         6 . The swash plate of  claim 1  wherein the disk-shaped steel sheet is made of SAPH440C. 
     
     
         7 . The swash plate of  claim 1  wherein the coating film forming the low-friction resin coating layers contains 40 to 50% by weight of fluororesin, 45 to 55% by weight of matrix resin, and 1 to 10% by weight of graphite, relative to the coating film. 
     
     
         8 . The swash plate of  claim 1  wherein the coating film forming the low-friction resin coating layers comprises 40 to 50% by weight of fluororesin and 1 to 10% by weight of graphite, relative to the coating film, the balance being matrix resin and impurities. 
     
     
         9 . The swash plate of  claim 7  wherein said fluororesin is polytetrafluoroethylene resin, wherein said matrix resin is polyamideimide resin, and said graphite is graphite containing 97.5% or more of fixed carbon. 
     
     
         10 . The swash plate of  claim 9  wherein said graphite is artificial graphite containing 98.5% or more of fixed carbon. 
     
     
         11 . A swash plate type compressor including the swash plate of  claim 1 . 
     
     
         12 . The swash plate type compressor of  claim 11  wherein no lubricating film is formed between the swash plate and the surface of any of the shoes which is in sliding contact with the swash plate.