Refrigerant compressor with return opening

Abstract

A refrigerant compressor includes a rotating body, a non-contact bearing rotatably supporting the rotating body, and a housing having an inner space to accommodate the rotating body. The rotating body includes a shaft, and a protruding part that extends from the shaft in a radial direction and that is configured to rotate together with the shaft. The housing forms a suction inlet to supply a refrigerant to the inner space, a discharge outlet to discharge the refrigerant from the inner space, and a return opening that is positioned lower than the protruding part of the rotating body in a vertical direction.

1 . A refrigerant compressor for a refrigerant circulation system, the refrigerant compressor comprising:
 a rotating body including a shaft, and a protruding part protruding from the shaft in a radial direction and configured to rotate together with the shaft;   at least one non-contact bearing rotatably supporting the rotating body;   a housing having an inner space accommodating the protruding part;   a suction inlet opening into the inner space and configured to supply a refrigerant to the inner space;   a refrigerant passage fluidly coupled with the suction inlet and an evaporator;   a discharge outlet configured to discharge the refrigerant from the inner space; and   a return passage fluidly coupling the inner space and the evaporator via a return opening provided in the inner space,   wherein the return opening is positioned lower than the protruding part in a vertical direction of the refrigerant compressor.   
     
     
         2 . The refrigerant compressor according to  claim 1 , wherein the return passage and the refrigerant passage form a continuous passage that extends from the evaporator to the suction inlet in a flow direction of the refrigerant in gas form. 
     
     
         3 . The refrigerant compressor according to  claim 1 ,
 wherein the at least one non-contact bearing includes a pair of bearings including a first bearing and a second bearing disposed along an axial direction of the shaft, and supporting the shaft in the radial direction,   wherein the inner space includes a first inner region, a second inner region, and a third inner region fluidly coupled with each other in the axial direction,   wherein the second inner region is positioned between the pair of bearings in the axial direction,   wherein the first bearing is positioned between the first inner region and the second inner region, in the axial direction,   wherein the second bearing is positioned between the second inner region and the third inner region, in the axial direction,   wherein the suction inlet is fluidly coupled with the third inner region, and   wherein the discharge outlet is fluidly coupled with the first inner region.   
     
     
         4 . The refrigerant compressor according to  claim 1 , wherein the return passage extends downward through the housing in the vertical direction from the inner space. 
     
     
         5 . The refrigerant compressor according to  claim 3 , wherein the discharge outlet is fluidly coupled with the first inner region via a discharge port that extends downward through the housing in the vertical direction, from the inner space at a position different from a position of the return opening. 
     
     
         6 . The refrigerant compressor according to  claim 5 , wherein an inner wall surface of the housing includes an inclined part sloping downward toward the return opening between the discharge port and the return opening. 
     
     
         7 . The refrigerant compressor according to  claim 3 , wherein the discharge outlet is fluidly coupled with the first inner region via a discharge port that extends upward through the housing in the vertical direction from the inner space. 
     
     
         8 . The refrigerant compressor according to  claim 1 , wherein the suction inlet is formed in the housing at a position that is higher than the return opening. 
     
     
         9 . The refrigerant compressor according to  claim 1 ,
 wherein the return opening is formed in the housing at a lowest position of the inner space, and   wherein the return passage extends downward from the return opening toward the evaporator.   
     
     
         10 . A refrigerant compressor comprising:
 a rotating body including a shaft and a protruding part configured to rotate together with the shaft, wherein the protruding part extends from the shaft in a radial direction;   at least one non-contact bearing configured to rotatably support the rotating body; and   a housing having an inner space configured to accommodate the rotating body,   wherein the housing forms a suction inlet configured to supply refrigerant to the inner space from an evaporator, a discharge outlet configured to discharge a refrigerant from the inner space and a return opening configured to direct liquefied refrigerant from the inner space to the evaporator, and   wherein the return opening is positioned lower than the protruding part of the rotating body in a vertical direction of the refrigerant compressor.   
     
     
         11 . The refrigerant compressor according to  claim 10 ,
 wherein the shaft of the rotating body extends substantially in a horizontal direction of the refrigerant compressor,   wherein the protruding part corresponds to a radial projection having an outermost edge in the radial direction that forms a lowest position of the rotating body in the vertical direction, and   wherein the return opening is positioned lower than the lowest position of the rotating body in the vertical direction.   
     
     
         12 . The refrigerant compressor according to  claim 10 , wherein the protruding part forms an impeller. 
     
     
         13 . The refrigerant compressor according to  claim 12 ,
 wherein the rotating body further includes a thrust collar, and   wherein the return opening is located lower than both the thrust collar and the impeller.   
     
     
         14 . The refrigerant compressor according to  claim 13 ,
 wherein the thrust collar is located at a first end portion of the shaft of the rotating body,   wherein the impeller is located at a second end portion of the shaft opposite the first end portion, and   wherein the return opening is located in a region of the inner space of the housing, that is formed adjacent to the first end portion of the shaft.   
     
     
         15 . The refrigerant compressor according to  claim 10 ,
 wherein the inner space has an inlet region that includes the suction inlet that is fluidly coupled with the evaporator, and an outlet region located opposite the inlet region in an axial direction of the shaft of the rotating body, and   wherein the return opening is formed in the inlet region of the inner space.   
     
     
         16 . The refrigerant compressor according to  claim 10 , further comprising a refrigerant passage extending from the evaporator to the suction inlet in a flow direction of the refrigerant in gas form,
 wherein the suction inlet forms the return opening, to return the liquified refrigerant to the evaporator via the refrigerant passage.   
     
     
         17 . The refrigerant compressor according to  claim 15 , wherein the discharge outlet is fluidly coupled with the outlet region via a discharge port that is positioned lower than the protruding part of the rotating body in the vertical direction, to further direct the liquified refrigerant out from the inner space. 
     
     
         18 . The refrigerant compressor according to  claim 10 , wherein at least one of the suction inlet or discharge outlet is located at a higher position than the return opening in the vertical direction. 
     
     
         19 . The refrigerant compressor according to  claim 10 ,
 wherein the housing includes an inner wall surface that forms the inner space, and   wherein a lower portion of the inner wall surface slopes downwardly toward the return opening, in an axial direction of the shaft of the rotating body.   
     
     
         20 . The refrigerant compressor according to  claim 10 , further comprising a return passage that extends downward from the return opening toward the evaporator.