Rotary compressor and air conditioner having the same

Abstract

A rotary compressor is provided which uses a synchronous reluctance motor to provide a driving force. The motor includes a rotor and a stator, each formed by a respective plurality of laminated steel plates. A plurality of magnetic flux barriers are formed on the steel plates which form the rotor, and a crystalline plastic film is disposed between the stator and a coil of the driving motor, the coil being implemented by an enamel coating layer. Accordingly, deformation of the rotor is decreased when the driving motor is assembled, and degradation of compressor performance due to slippage between the rotor and the stator is decreased, and heat emission of the rotor is decreased.

1 . A rotary compressor, comprising:
 a casing which defines an inner space, wherein a suction pipe and a discharge pipe are each coupled to the casing;   a driving motor installed in the inner space of the casing;   at least one cylinder provided in the inner space of the casing;   a plurality of bearing plates coupled to the cylinder so as to form a compression space with the cylinder, wherein the plurality of bearing plates are configured to support a rotation shaft of the driving motor;   at least one rolling piston coupled to an eccentric portion of the rotation shaft and in linear contact with an inner circumferential surface of the cylinder; and   at least one vane in contact with the rolling piston and configured to divide the compression space into a suction chamber and a compression chamber,   wherein the driving motor includes:   a stator comprising a plurality of stator plates laminated together and configured to be inserted into an inner circumferential surface of the casing, each stator plate having a plurality of protruding poles on which a coil is wound;   a rotor comprising a plurality of rotor plates laminated together and configured to be rotatably disposed in the stator, wherein each rotor plate comprises a plurality of magnetic flux barriers formed therein, and wherein a width of each magnetic flux barrier in a radius direction and a width between adjacent magnetic flux barriers in the radius direction each increase towards the center of the driving motor; and   a rotation shaft coupled to the center of the rotor and.   
   
   
       2 . The rotary compressor of  claim 1 , wherein the stator of the driving motor comprises:
 a rotor insertion hole into which the rotor is inserted;   a plurality of protruding fixing portions extending from an outer circumferential surface of the stator in a circumferential direction and configured to be fixed to an inner circumferential surface of the casing; and   a plurality of cut-passages formed between the protruding fixing portions in a circumferential direction so as to form a gap with an inner circumferential surface of the casing, wherein a ratio (d 1 /w 1 ) between a diameter (d 1 ) of the rotor insertion hole and a width (w 1 ) of the protrusion fixing portion is greater than or equal to 2.1.   
   
   
       3 . The rotary compressor of  claim 2 , wherein the protruding fixing portion is formed so that an angle between both ends thereof and the center of the stator is 20°˜30°. 
   
   
       4 . The rotary compressor of  claim 2 , wherein the cut-passage is formed so that a ratio (QA 0 /QA 1 ) between a sum (QA 0 ) of a circumferential length of each cut-passage and a sum (QA 1 ) of a circumferential length of each protruding fixing portion is 0.3˜0.7. 
   
   
       5 . The rotary compressor of  claim 1 , wherein the rotor of the driving motor is formed so that a distance from an outer circumferential surface thereof to an end of each of the magnetic flux barriers is uniform. 
   
   
       6 . The rotary compressor of  claim 5 , wherein each of the plurality of magnetic flux barriers includes at least one bridge configured to connect an inner surface and an outer surface thereof. 
   
   
       7 . The rotary compressor of  claim 1 , wherein a distance from an outer circumferential surface of the rotor to an end of each magnetic flux barrier varies based on the respective magnetic flux barrier. 
   
   
       8 . The rotary compressor of  claim 7 , wherein at least one of the magnetic flux barriers includes at least one bridge configured to connect an inner surface and an outer surface thereof. 
   
   
       9 . The rotary compressor of  claim 1 , wherein the casing is configured to receive oil therein, and wherein oil is filled in the casing to a level higher than an upper side of the cylinder. 
   
   
       10 . The rotary compressor of  claim 1 , wherein a volume between an upper end of the stator and an inner a lower surface of an upper end of the casing is greater than 5000 mm 3 . 
   
   
       11 . The rotary compressor of  claim 1 , wherein a muffler configured to attenuate noise is installed at an uppermost bearing plate of the plurality of bearing plates, and wherein a gap between an upper end of the muffler and the coil which extends downward from the stator is greater than 3.2 mm. 
   
   
       12 . The rotary compressor of  claim 1 , wherein a refrigerant connection pipe of a refrigerating cycle is directly connected to an inlet of the suction pipe. 
   
   
       13 . The rotary compressor of  claim 1 , wherein the at least one cylinder comprises a plurality of cylinders, and wherein the suction pipe comprises a corresponding plurality of gas suction pipes respectively connected to the plurality of cylinders, wherein the plurality of suction pipes are connected to one refrigerant connection pipe. 
   
   
       14 . The rotary compressor of  claim 1 , wherein a ratio between a diameter of the rotation shaft excluding the eccentric portion and a diameter of the eccentric portion is between 16:20˜18:30. 
   
   
       15 . The rotary compressor of  claim 1 , wherein an eccentric amount of the eccentric portion of the rotation shaft is within a range of 1.5˜5 mm. 
   
   
       16 . The rotary compressor of  claim 1 , wherein the at least one cylinder and the plurality of bearing plates are formed of gray pig iron, the rolling piston is formed of an alloy of molybdenum, nickel and chrome, and the vane is formed of a high speed steel having undergone a nitriding process. 
   
   
       17 . The rotary compressor of  claim 1 , wherein an upper bearing plate of the plurality of bearing plates includes a discharge port configured to discharge a fluid compressed in the compression space, wherein a diameter of the discharge port is 5 mm when a volume of the compression space is 6 cc, and the diameter of the discharge port is 8 mm when the volume of the compression space is 9 cc. 
   
   
       18 . The rotary compressor of  claim 1 , wherein the at least one cylinder comprises a plurality of cylinders which have different capacities. 
   
   
       19 . The rotary compressor of  claim 1 , wherein the at least one cylinder comprises a plurality of cylinders, and wherein if a length of the casing is greater than two times an outer diameter of the casing, a thickness of a base plate which supports the casing on an installation surface is between 2.6˜4.0 mm. 
   
   
       20 . The rotary compressor of  claim 1 , wherein the stator and the rotor of the driving motor have a gap of 0.4˜0.8 mm therebetween. 
   
   
       21 . The rotary compressor of  claim 1 , wherein upper and lower end plates positioned at upper and lower ends of the rotor, respectively, have a thickness of approximately 1˜4 mm, and wherein a gap between a lower surface of the lower end plate and an upper end surface of an uppermost bearing plate is between 2˜6 mm. 
   
   
       22 . The rotary compressor of  claim 21 , wherein a balance weight eccentric at a certain angle in a circumferential direction is integrally formed on an outer surface of at least one of the upper or lower end plate, wherein a thickness of the balance weight is less than two times a thickness of the respective end plate. 
   
   
       23 . The rotary compressor of  claim 21 , wherein a balance weight eccentric at a certain angle in a circumferential direction is coupled to at least one of the upper or lower end plate during a post-assembling process, and wherein a thickness of the balance weight is less than two times a thickness of the respective end plate. 
   
   
       24 . The rotary compressor of  claim 21 , wherein one of the end plates is configured to completely cover the plurality of magnetic flux barriers. 
   
   
       25 . The rotary compressor of  claim 21 , wherein one of the end plates is configured to partially cover the plurality of magnetic flux barriers so as to form a path in the rotor in upper and lower directions. 
   
   
       26 . The rotary compressor of  claim 1 , wherein a vertical distance between the center of the rotor and the center of the stator is between −2˜3 mm. 
   
   
       27 . The rotary compressor of  claim 1 , wherein a length from an upper end of the stator to a lower surface of an uppermost bearing plate of the plurality of bearing plates is approximately 110˜140 mm. 
   
   
       28 . The rotary compressor of  claim 1 , wherein the rotation shaft is coupled to the rotor by shrinkage fit. 
   
   
       29 . The rotary compressor of  claim 1 , wherein the suction pipe comprises a plurality of suction pipes respectively connected to a plurality of cylinders, and wherein the plurality of suction pipes are connected to one accumulator. 
   
   
       30 . The rotary compressor of  claim 29 , wherein the plurality of suction pipes have different curvatures. 
   
   
       31 . The rotary compressor of  claim 1 , wherein the at least one cylinder comprises a plurality of cylinders, and wherein the suction pipe is respectively connected to the plurality of cylinders at one end thereof, and to one refrigerant connection pipe connected to an outlet of an evaporator at another end thereof. 
   
   
       32 . The rotary compressor of  claim 31 , wherein the suction pipe comprises a plurality of suction pipes having different curvatures and being respectively connected to the plurality of cylinders. 
   
   
       33 . The rotary compressor of  claim 1 , wherein the driving motor is configured to be synchronously rotated by a reluctance torque in a direction in which magnetic resistance is minimized. 
   
   
       34 . The rotary compressor of  claim 1 , wherein the at least one rolling piston is configured to perform an orbiting motion within the compression space. 
   
   
       35 . The rotary compressor of  claim 1 , wherein the at least one cylinder is directly connected to a suction pipe which provides fluid to be compressed in the compression space. 
   
   
       36 . The rotary compressor of  claim 1 , wherein a fluid to be compressed in the compression space is a hydro-fluorocarbon (HFC) or a hydro-chlorofluorocarbon (HCFC)-based refrigerant, and wherein a fatty acid-ester oil is used for lubrication if the HFC-based refrigerant is used, and a fatty acid-mineral oil is used for lubrication if the HCFC-based refrigerant is used. 
   
   
       37 . The rotary compressor of  claim 36 , wherein the fatty-acid ester oil has a viscosity of 2˜70 cSt at a temperature of 40° C., and a viscosity of 1˜9 cSt at a temperature of 100° C., and is ester-coupled in a molecule at least two times, and wherein the fatty-acid mineral oil has a viscosity of 32˜68 cSt at a temperature of 40° C. and is ester-coupled in a molecule at least two times. 
   
   
       38 . The rotary compressor of  claim 1 , wherein the plurality of magnetic flux barriers penetrate the respective rotor plate in which they are formed. 
   
   
       39 . The rotary compressor of  claim 1 , wherein an insulation film formed of a crystalline plastic film having a separation transition temperature greater than 50° C. is disposed between the stator and the coil. 
   
   
       40 . The rotary compressor of  claim 1 , wherein the coil comprises an enamel coating layer having a separation transition temperature greater than 120° C. 
   
   
       41 . The rotary compressor of  claim 2 , wherein the protruding fixing portions each have substantially the same shape and area, and the plurality of cut passages each have substantially the same shape and area and are spaced apart from each other at substantially equal intervals. 
   
   
       42 . A rotary compressor, comprising:
 a hermetic casing having an inner space to which a suction pipe and a discharge pipe are connected;   a motor installed in the inner space of the casing, wherein the motor is configured to be synchronously rotated by a reluctance torque;   at least one cylinder installed in the inner space, wherein the suction pipe is directly connected to the cylinder for compression of a fluid;   a plurality of bearing plates coupled to the at least one cylinder so as to form a compression space and to support arotation shaft of the motor;   at least one rolling piston coupled to an eccentric portion of the rotation shaft and in linear contact with an inner circumferential surface of the cylinder; and   at least one vane in contact with the rolling piston and configured to divide the compression space into a suction chamber and a compression chamber, wherein the driving motor includes:   a stator comprising a plurality of steel stator plates laminated together and configured to be inserted into an inner circumferential surface of the casing, each of the steel stator plates having a plurality of protruding poles on which a coil is wound;   a rotor comprising a plurality of steel rotor plates laminated together and configured to be rotatably disposed in the stator, each of the plurality of steel rotor plates having a plurality of magnetic flux barriers formed therein, wherein a width of each magnetic flux barrier in a radius direction and a width between adjacent magnetic flux barriers in the radius direction each towards the center of the motor, and further comprising at least one bridge configured to connect an inner surface and an outer surface of at least one of the plurality of magnetic flux barriers; and   a rotation shaft coupled to the center of the rotor and supported by a frame.   
   
   
       43 . A rotary compressor, comprising:
 a hermetic casing having an inner space to which a suction pipe and a gas discharge pipe are connected;   a motor installed in the inner space and configured to be synchronously rotated by a reluctance torque;   at least one cylinder provided in the inner space, at one side of the motor, wherein the suction pipe is directly connected to the cylinder so as to compress a fluid therein;   a plurality of bearing plates coupled to the cylinder so as to form a compression space, wherein the plurality of bearing plates are configured to support a rotation shaft of the motor;   at least one rolling piston positioned in the compression space of the cylinder, coupled to an eccentric portion of the rotation shaft and in linear contact with an inner circumferential surface of the cylinder; and   at least one vane in contact with the rolling piston and configured to divide the compression space into a suction chamber and a compression chamber, wherein the motor includes:   a stator comprising a plurality of steel stator plates laminated together and configured to be inserted into an inner circumferential surface of the casing, each of the plurality of steel stator plates having a plurality of protruding poles on which a coil is wound;   a rotor comprising a plurality of steel rotor plates laminated together and configured to be rotatably disposed in the stator, the plurality of steel rotor plates having a plurality of magnetic flux barriers formed therein, wherein a width of each magnetic flux barrier in a radius direction and a width between adjacent magnetic flux barriers in the radius direction each increase towards the center of the motor, and wherein a width from an outer circumferential surface of each steel rotor plate to an end of each of the magnetic flux barriers is different; and   a rotation shaft coupled to the center of the rotor by shrinkage fit and supported by a frame.   
   
   
       44 . An air conditioner comprising the rotary compressor of  claim 1 .