Scroll compressor

Abstract

The present invention relates to a scroll compressor comprising a scroll pumping arrangement comprising two scrolls each having a scroll wall with inner and outer scroll wall surfaces which co-operate with respective outer and inner scroll wall surfaces of the other scroll wall providing two pairs of co-operating surfaces which, on relative orbiting motion of the scrolls, pump fluid from an inlet to an outlet of the arrangement, the scroll walls having a respective plurality of wraps I, II, III, IV, V between the inlet and the outlet and wherein the co-operating scroll wall surfaces of one of said pairs of at least one wrap are generally circular.

1 . A scroll compressor comprising:
 a scroll pumping arrangement comprising two scrolls, each scroll of the two scrolls including a respective scroll wall including a respective inner scroll wall surface and a respective outer scroll wall surface which co-operate with respective outer and inner scroll wall surfaces of the other scroll wall providing two pairs of co-operating scroll wall surfaces which, on relative orbiting motion of the scrolls, pump fluid from an inlet to an outlet of the arrangement, wherein each scroll wall of the respective scroll walls includes a respective plurality of wraps between the inlet and the outlet, and wherein the co-operating scroll wall surfaces of one pair of the two pairs of co-operating scroll wall surfaces of at least one wrap are generally circular.   
     
     
         2 . The scroll compressor of  claim 1 , wherein the respective scroll walls have an outer wrap adjacent the inlet and wherein the co-operating scroll wall surfaces of one pair of the two pairs of co-operating scroll wall surfaces of the outer wrap are circular. 
     
     
         3 . The scroll compressor of  claim 2 , wherein the respective scrolls comprise a fixed scroll wall and an orbiting scroll wall which is configured to move relative to the fixed scroll wall for pumping fluid from the inlet to the outlet, and wherein a radially inner co-operating scroll wall surface of the outer wrap of the fixed scroll wall and a radially outer co-operating scroll wall surface of the outer wrap of the orbiting wall are circular. 
     
     
         4 . The scroll compressor of  claim 1 , wherein one scroll wall of the respective scroll walls includes a radially inner co-operating surface which is involute and a radially outer co-operating surface which is circular. 
     
     
         5 . The scroll compressor of  claim 3 , wherein the fixed scroll wall defines one or more pumping channels between successive wraps thereof. 
     
     
         6 . The compressor of  claim 5 , wherein the scroll pumping arrangement includes a plurality of inlets through which fluid can be pumped along respective pumping channels, and an outer pumping channel is circular. 
     
     
         7 . The scroll compressor of  claim 5 , wherein one or more of the respective pumping channels are circular and converge to form a single involute pumping channel. 
     
     
         8 . The scroll compressor of  claim 5 , wherein the scroll pumping arrangement comprises one or more circular pumping channels and one or more involute pumping channels, and wherein the one or more circular pumping channels are deeper than the one or more involute pumping channels. 
     
     
         9 . The scroll compressor of  claim 1 , wherein the scroll pumping arrangement comprises one or more circular pumping channels and one or more involute pumping channels, and a flow intersection between the circular pumping channels and the involute pumping channels is in flow communication with a blow-off valve for releasing over pressure from the scroll pumping arrangement. 
     
     
         10 . A scroll compressor comprising:
 a scroll pumping arrangement comprising two scrolls each respective scroll of the two scrolls including a respective scroll wall including a respective inner scroll wall surface and a respective outer scroll wall surface which co-operate with respective outer and inner scroll wall surfaces of the other respective scroll wall providing two pairs of co-operating surfaces which, on relative orbiting motion of the two scrolls, pump fluid from an inlet to an outlet of the scroll pumping arrangement, wherein the respective scroll walls each includes a respective plurality of wraps between the inlet and the outlet and wherein the co-operating scroll wall surfaces of one pair of the two pairs of co-operating surfaces of at least one wrap have a rate of change of radius with respect to the angle which is less than the rate of change of the other wraps so that the compression ratio of the one pair of the two pairs of co-operating surfaces is less than for the other wraps.   
     
     
         11 . The scroll compressor of  claim 6 , wherein one or more of the respective pumping channels are circular and converge to form a single involute pumping channel. 
     
     
         12 . The scroll compressor of  claim 6 , wherein the scroll pumping arrangement comprises one or more circular pumping channels and one or more involute pumping channels, and wherein the one or more circular pumping channels are deeper than the one or more involute pumping channels. 
     
     
         13 . The scroll compressor of  claim 7 , wherein the scroll pumping arrangement comprises one or more circular pumping channels and one or more involute pumping channels, and wherein the one or more circular pumping channels are deeper than the one or more involute pumping channels. 
     
     
         14 . The scroll compressor of  claim 2 , wherein one scroll wall of the respective scroll walls includes a radially inner co-operating surface which is involute and a radially outer co-operating surface which is circular. 
     
     
         15 . The scroll compressor of  claim 3 , wherein one scroll wall of the respective scroll walls includes a radially inner co-operating surface which is involute and a radially outer co-operating surface which is circular. 
     
     
         16 . The scroll compressor of  claim 2 , wherein the scroll pumping arrangement comprises one or more circular pumping channels and one or more involute pumping channels, and a flow intersection between the circular pumping channels and the involute pumping channels is in flow communication with a blow-off valve for releasing over pressure from the scroll pumping arrangement. 
     
     
         17 . The scroll compressor of  claim 3 , wherein the scroll pumping arrangement comprises one or more circular pumping channels and one or more involute pumping channels, and a flow intersection between the circular pumping channels and the involute pumping channels is in flow communication with a blow-off valve for releasing over pressure from the scroll pumping arrangement. 
     
     
         18 . The scroll compressor of  claim 4 , wherein the scroll pumping arrangement comprises one or more circular pumping channels and one or more involute pumping channels, and a flow intersection between the circular pumping channels and the involute pumping channels is in flow communication with a blow-off valve for releasing over pressure from the scroll pumping arrangement. 
     
     
         19 . The scroll compressor of  claim 5 , wherein the scroll pumping arrangement comprises one or more circular pumping channels and one or more involute pumping channels, and a flow intersection between the circular pumping channels and the involute pumping channels is in flow communication with a blow-off valve for releasing over pressure from the scroll pumping arrangement. 
     
     
         20 . The scroll compressor of  claim 6 , wherein the scroll pumping arrangement comprises one or more circular pumping channels and one or more involute pumping channels, and a flow intersection between the circular pumping channels and the involute pumping channels is in flow communication with a blow-off valve for releasing over pressure from the scroll pumping arrangement.