Reciprocating compressor and refrigerating apparatus having the same

Abstract

Disclosed are a reciprocating compressor and a refrigerating apparatus having the same, a ball bearing ( 300 ) can be easily stably installed between thrust surfaces ( 213, 227 ) of a cylinder block ( 210 ) and a crank shaft ( 220 ) so as to enhance efficiency of the compressor. Also, a ball bearing ( 300 ) can be installed by being inserted into thrust surfaces ( 213, 227 ) so to shorten a moment arm that much, thereby decreasing a frictional loss at a journal bearing surface ( 215 ), resulting in an energy efficiency of the reciprocating compressor and the refrigerating apparatus having the same. In addition, as an oil hole ( 226 c ) of the crank shaft ( 220 ) is veiled by the journal bearing surface ( 215 ) of the cylinder block ( 210 ), even if a ball bearing ( 300 ) is employed, oil leaked between the thrust surfaces ( 213, 227 ) can be reduced, thereby further enhancing the efficiency of the compressor and the refrigerating apparatus having the same.

1 . A reciprocating compressor comprising:
 a cylinder block provided with a shaft bearing hole to define a journal bearing surface and having a thrust surface on an upper end of the shaft bearing hole;   a crank shaft provided with a plate-shaped extending portion extending wider than the shaft bearing hole of the cylinder block, a lower surface of the plate-shaped extending portion defining a thrust surface conformable to the thrust surface of the cylinder block; and   a bearing assembly disposed between the thrust surface of the cylinder block and the thrust surface of the crank shaft, the thrust surfaces facing each other, and support the crank shaft in the shaft direction with respect to the cylinder block,   wherein at least one of the thrust surface of the cylinder block and thrust surface of the crank shaft is provided with a bearing locking portion for locking at least part of the bearing assembly in the radial direction.   
     
     
         2 . The compressor of  claim 1 , wherein the beating locking portion is configured as an annular protrusion to be contactable with an outer circumferential surface or an inner circumferential surface of the bearing assembly, or comprises at least three or more arcuate protrusions along a circumferential direction. 
     
     
         3 . The compressor of  claim 1 , wherein a bearing insertion groove is formed at least one of the thrust surface of the cylinder block or the thrust surface of the crank shaft so that at least part of the bearing assembly is inserted therein. 
     
     
         4 . The compressor of  claim 3 , wherein a height of the bearing insertion groove in the shaft direction is defined such that a minimum interval in the shaft direction between the thrust surface of the cylinder block and the thrust surface of the crank shaft is not greater than a height of the bearing assembly in the shaft direction. 
     
     
         5 . The compressor of  claim 1 , wherein at least one oil passage is formed within the crank shaft, at least one oil groove is formed at an outer circumferential surface of the crank shaft, the oil passage and the oil groove communicating with each other via at least one oil discharge hole and at least one oil introduction hole,
 wherein the oil introduction hole is formed at an oil groove, of the at least one oil groove, communicated between the thrust surface of the cylinder block and the thrust surface of the crank shaft, at least part of the oil introduction hole being veiled by the journal bearing surface of the cylinder block.   
     
     
         6 . (canceled) 
     
     
         7 . The compressor of  claim 5 , wherein the oil groove has a plurality of inclination angles, wherein an inclination angle at a portion adjacent to the oil introduction hole, among the plurality of inclination angles, is relatively smaller than an inclination angle at a portion away from the oil introduction hole. 
     
     
         8 . The compressor of  claim 5 , wherein an edge between the journal bearing surface and the thrust surface of the cylinder block is chamfered or round. 
     
     
         9 . The compressor of  claim 5 , wherein a bearing insertion groove in which part of the bearing assembly is inserted is formed either at the thrust surface of the crank shaft or at the thrust surface of the cylinder block. 
     
     
         10 . The compressor of  claim 1 , wherein the bearing assembly comprises a ball cage fotuied in an annular shape with a preset thickness, and at least three balls each having a diameter greater than the thickness of the ball cage and coupled to the ball cage;
 wherein a bearing insertion groove in which part of the bearing assembly is inserted is formed either at the thrust surface of the crank shaft or at the thrust surface of the cylinder block, a depth of the bearing insertion groove being deep enough that at least part of the ball cage is inserted.   
     
     
         11 . (canceled) 
     
     
         12 . The compressor of  claim 10 , wherein the bearing assembly comprises a washer in an annular shape fondled at least one of both sides of the balls in the shaft direction to be contactable with the balls, at least one washer being located at an outer periphery of the bearing insertion groove. 
     
     
         13 . The compressor of  claim 12 , wherein a thickness of the washer located at the outer periphery of the bearing insertion groove is not thinner than a height of the bearing locking portion. 
     
     
         14 . The compressor of  claim 1 , wherein a thrust surface without the bearing locking portion formed, of the thrust surface of the cylinder block or the thrust surface of the crank shaft, the thrust surfaces facing each other, is formed to be flat. 
     
     
         15 . The compressor of  claim 14 , wherein the crank shaft is provided with a journal bearing surface inserted into the shaft bearing hole of the cylinder block, wherein a bearing supporting portion greater than an outer diameter of the journal bearing surface is integrally twined or assembled between the journal bearing surface and the plate-shaped extending portion of the crank shaft. 
     
     
         16 . The compressor of  claim 14 , wherein the bearing supporting portion has a length in the shaft direction which is not longer than the length of the bearing assembly in the shaft direction. 
     
     
         17 . The compressor of  claim 14 , wherein an oil pocket larger than a diameter of the shaft bearing hole is formed at an edge between the journal bearing surface and a flat surface in the shaft direction of the cylinder block,
 wherein the bearing supporting portion and the bearing locking portion support the bearing assembly in the radial direction such that a center of the bearing assembly in the shaft direction is located out of the range of the oil pocket.   
     
     
         18 . The compressor of  claim 14 , wherein the bearing assembly comprises a ball cage formed in an annular shape with a preset thickness, and at least three balls each having a diameter greater than the thickness of the ball cage and coupled to the ball cage. 
     
     
         19 . The compressor of  claim 18 , wherein washers are provided at both side surfaces of the balls in the shaft direction to be contactable with the balls, each washer being supported by the bearing supporting portion or the bearing locking portion in the radial direction. 
     
     
         20 . (canceled) 
     
     
         21 . A reciprocating compressor in which a crank shaft for transferring a rotational force is supported by a cylinder block in a radial direction and a shaft direction, a connecting rod is coupled to the crank shaft to convert a rotary motion into a linear motion, and a piston coupled to the connecting rod reciprocates within a cylinder to compress a refrigerant,
 wherein at least one oil passage is formed within the crank shaft, at least one oil groove is formed at an outer circumferential surface of the crank shaft, the oil passage and the oil groove communicating with each other via at least one oil discharge hole and at least one oil introduction hole,   wherein the oil introduction hole is formed at an oil groove, of the at least one oil groove, communicated between the thrust surface of the cylinder block and the thrust surface of the crank shaft, at least part of the oil introduction hole being veiled by the journal bearing surface of the cylinder block.   
     
     
         22 . (canceled) 
     
     
         23 . The compressor of  claim 21 , wherein the oil groove has a plurality of inclination angles, wherein an inclination angle at a portion adjacent to the oil introduction hole, among the plurality of inclination angles, is relatively smaller than an inclination angle at a portion away from the oil introduction hole. 
     
     
         24 . A refrigerating apparatus comprising:
 a compressor;   a condenser connected to a discharge side of the compressor;   an expansion apparatus connected to the condenser; and   an evaporator connected to the expansion apparatus and to a suction side of the compressor,   wherein the compressor is configured according to  claim 1 .