Compressor

Abstract

A compressor may include a crankshaft, a lower bearing, an oil sump, an oil pump and a pressure equilibrium tube. The crankshaft may include an oil supply passage formed therethrough. The lower bearing may rotatably support a lower part of the crankshaft. The oil sump may be disposed proximate the lower part of the crankshaft. The oil pump may include an inlet, an outlet, an intake chamber and a discharging chamber. The inlet may be positioned below a level of oil in the oil sump and in fluid communication with the intake chamber. The discharging chamber may be in fluid communication with the oil supply passage at the lower part of the crankshaft through the outlet. The pressure equilibrium tube provides fluid communication between a space above the level of oil in the oil sump and the intake chamber.

What is claimed is: 
     
         1 . A compressor comprising:
 a crankshaft having a first end, a second end, and an oil supply passage extending through the first and second ends;   a bearing rotatably supporting the second end of the crankshaft;   an oil sump located proximate the second end of the crankshaft;   an oil pump having an oil inlet, an oil outlet, an oil intake chamber and an oil discharging chamber, wherein the oil inlet is positioned below a level of oil in the oil sump and in fluid communication with the oil intake chamber, and the oil discharging chamber is in fluid communication with the oil supply passage through the oil outlet; and   a pressure equilibrium tube providing fluid communication between a space above the level of oil in the oil sump and the oil intake chamber.   
     
     
         2 . The compressor according to  claim 1 , wherein the pressure equilibrium tube is arranged outside of the oil pump and the crankshaft. 
     
     
         3 . The compressor according to  claim 1 , further comprising:
 a lower bearing assembly with an upper portion thereof forming the bearing and a lower portion thereof extendedly forming a case of the oil pump;   an impeller assembly including an upper section for attaching to the second end of the crankshaft such that the impeller assembly rotates with the crankshaft, a lower section for forming an impeller, and a middle section located between the upper section and the lower section, wherein the oil intake chamber is defined by a space between the outer circumference surface of the middle section of the impeller assembly and an inner circumference surface of the case, and the oil discharging chamber is defined by a space between the outer circumference surface of the impeller and the inner circumference surface of the case; and   a pump cover fitted in the case and located below the impeller.   
     
     
         4 . The compressor according to  claim 3 , further comprising:
 at least one guiding channel provided on one side of the impeller adjacent to the middle section of the impeller assembly; and   a static passage provided on one side of the pump cover adjacent to the impeller,   wherein the impeller assembly includes a central passage longitudinally formed therethrough, the upper end of the central passage defines the oil outlet and the lower end of the central passage adapts to be in fluid communication with the static passage; wherein, the oil intake chamber, the guiding channel, the oil discharging chamber, the static passage and the central passage sequentially define an oil flow path of the oil pump.   
     
     
         5 . The compressor according to  claim 4 , wherein an interior wall of the lower bearing assembly defines a first circumference region for supporting the crankshaft, a second circumference region having a smaller diameter than that of the first circumference region, and a third circumference region having a larger diameter than that of the first circumference region; and
 wherein the oil intake chamber is defined between the second circumference region and the outer circumference surface of the middle section of the impeller assembly, the oil inlet of the oil pump radially extends through the second circumference region from the exterior wall of the lower bearing assembly.   
     
     
         6 . The compressor according to  claim 5 , wherein a venting hole radially extends through the second circumference region from the exterior wall of the lower bearing assembly, and the pressure equilibrium tube is in fluid communication with the oil intake chamber via the venting hole. 
     
     
         7 . The compressor according to  claim 6 , wherein the pressure equilibrium tube includes a substantially L-shape, an end of a transverse portion of the pressure equilibrium tube is inserted into the venting hole, and an end of a vertical portion of the pressure equilibrium tube extends above the level of oil in the oil sump. 
     
     
         8 . The compressor according to  claim 6 , wherein the oil discharging chamber is defined between the third circumference region and the outer circumference surface of the impeller. 
     
     
         9 . The compressor according to  claim 1 , wherein the pressure equilibrium tube is arranged inside of the oil pump and the crankshaft. 
     
     
         10 . The compressor according to  claim 9 , further comprising:
 a lower bearing assembly with an upper portion thereof forming the lower bearing and a lower portion thereof extendedly forming a case of the oil pump;   an impeller assembly comprising an upper section for attaching to the lower part of the crankshaft such that the crankshaft and the impeller assembly rotate together, a lower section for forming an impeller, and a middle section located between the upper section and the lower section, wherein the oil intake chamber is formed by recessing the bottom of the impeller at central portion thereof, and the oil discharging chamber is defined by a space between the outer circumference surface of the impeller and an inner circumference surface of the case; and   a pump cover fitted in the case and located below the impeller, wherein the oil inlet is defined by a central opening in the pump cover.   
     
     
         11 . The compressor according to  claim 10 , further comprising:
 at least one guiding channel provided on one side of the impeller adjacent to the pump cover; and   a static passage defined by a space between the outer circumference surface of the middle section of the impeller assembly and the inner circumference surface of the case,   wherein the oil outlet is formed by longitudinally extending through the upper section of the impeller assembly, and   wherein the oil intake chamber, the guiding channel, the oil discharging chamber, the static passage and the oil outlet sequentially define an oil flow path of the oil pump.   
     
     
         12 . The compressor according to  claim 11 , wherein the interior wall of the lower bearing assembly defines a first circumference region for supporting the crankshaft, a second circumference region having a smaller diameter than that of the first circumference region, a third circumference region having a larger diameter than that of the first circumference region, and a fourth circumference region having a larger diameter than that of the third circumference region;
 wherein the static passage is defined between the second and third circumference regions and the outer circumference surface of the middle section of the impeller assembly, and the oil discharging chamber is defined between the fourth circumference region and the outer circumference surface of the impeller.   
     
     
         13 . The compressor according to  claim 12 , wherein the impeller assembly has a central passage longitudinally formed therethrough for being in fluid communication with the oil intake chamber, and a lower end of the pressure equilibrium tube is inserted into the central passage. 
     
     
         14 . The compressor according to  claim 13 , wherein the oil outlet, which is formed in the upper section of the impeller assembly and in fluid communication with the oil supply passage, is positioned outside of the central passage in the radial direction of the impeller assembly. 
     
     
         15 . The compressor according to  claim 14 , wherein a venting hole is formed at the lower part of the crankshaft, an opening of the venting hole on the exterior wall of the crankshaft is above the level of oil in the oil sump, and an upper end of the pressure equilibrium tube is inserted into a portion of the venting hole through the oil supply passage. 
     
     
         16 . A method of operating a compressor comprising:
 rotating a crankshaft of the compressor at a first rotational speed;   rotating said crankshaft at a second rotational speed;   supplying oil through an oil supply passage extending between first and second ends of said crankshaft at a flow rate while said crankshaft is rotating at said first rotational speed; and   supplying oil through said oil supply passage at substantially the same flow rate while said crankshaft is rotating at said second rotational speed.   
     
     
         17 . The method of  claim 16 , wherein said first rotational speed and said second rotational speed are between about 1800 and 3900 revolutions per minute. 
     
     
         18 . The method of  claim 17 , wherein said first rotational speed is about two times greater than said second rotational speed. 
     
     
         19 . The method of  claim 16 , further comprising rotating an impeller of an oil pump at said first rotational speed while said crankshaft is rotating at said first rotational speed, and rotating said impeller at said second rotational speed while said crankshaft is rotating at said second rotational speed. 
     
     
         20 . The method of  claim 16 , further comprising communicating a gas between a chamber of an oil pump and a space above an oil level of an oil sump of the compressor.