Line fed permanent magnet synchronous type motor for scroll compressor with bypass ports

Abstract

A scroll compressor is provided with some capacity reduction technique such as a bypass port. The electric motor for driving the scroll compressor is not an induction motor, but rather a line fed permanent magnet synchronous motor is utilized. Such motors have a higher overall efficiency, and thus will be more efficient at reduced capacity operation.

1 . A scroll compressor comprising:
 a first scroll member having a base and a generally spiral wrap extending from said base;   a second scroll member having a base and a generally spiral wrap extending from its base, said generally spiral wraps interfitting to define compression chambers; and   an electric motor operable to drive a rotary shaft to in turn cause said second scroll member to orbit relative to said first scroll member, said electric motor being a permanent magnet synchronous motor, wherein said permanent magnet synchronous motor is a line fed motor, running directly from the mains without requirement of frequency inverter.   
   
   
       2 . Scroll compressor as set forth in  claim 1 , wherein a capacity reduction feature being incorporated into the scroll compressor to allow the reduction of capacity provided by the scroll compressor under certain conditions. 
   
   
       3 . The scroll compressor as set forth in  claim 1 , wherein bypass ports are provided to reduce the capacity of the scroll compressor. 
   
   
       4 . The scroll compressor as set forth in  claim 1 , wherein said second scroll member and said first scroll member are held together, but are movable away from each other in an axial direction. 
   
   
       5 . The scroll compressor as set forth in  claim 1 , wherein the wraps of said first and second scroll member are held together but are capable of moving radially away from each other.