Rotary compressor and refrigeration apparatus including the same

Abstract

A rotary compressor includes a compression mechanism, a drive shaft, a motor having a rotor coupled to the drive shaft, and a balancer provided on the rotor. The compression mechanism has first and second cylinders sequentially arranged next to each other from a side closer to the rotor in an axial direction along an axis of the drive shaft, and first and second eccentric portions housed in the first and second cylinders. The balancer has a first balance weight disposed at one end portion of the rotor closer to the compression mechanism in the axial direction, and a second balance weight disposed at an other end portion of the rotor in the axial direction. A value of the product of the mass and eccentric distance of the second balance weight is smaller than a value of the product of the mass and eccentric distance of the first balance weight.

1 . A rotary compressor comprising:
 a compression mechanism configured to suck and compress a fluid;   a drive shaft configured to drive the compression mechanism;   a motor having a rotor coupled to the drive shaft; and   a balancer provided on the rotor,   the compression mechanism having
 a first cylinder and a second cylinder sequentially arranged next to each other from a side closer to the rotor in an axial direction along an axis of the drive shaft, 
 a first eccentric portion housed in the first cylinder, and 
 a second eccentric portion housed in the second cylinder, 
   the balancer having   a first balance weight disposed at one end portion of the rotor closer to the compression mechanism in the axial direction, and   a second balance weight disposed at an other end portion of the rotor in the axial direction,   the first eccentric portion and the first balance weight being eccentric to the axis of the drive shaft to one side, and the second eccentric portion and the second balance weight being eccentric to the axis of the drive shaft to an other side,   along with rotation of the drive shaft,
 the first eccentric portion eccentrically rotating in the first cylinder, and 
 the second eccentric portion eccentrically rotating in the second cylinder, and
     m 1× r 1> m 2× r 2, where
 
 
    a mass of the first balance weight is m1,
 an eccentric distance of a center of gravity of the first balance weight from the axis of the drive shaft is r1, 
 a mass of the second balance weight is m2, and 
 an eccentric distance of a center of gravity of the second balance weight from the axis of the drive shaft is r2. 
   
     
     
         2 . The rotary compressor of  claim 1 , wherein
 a maximum number of rotations of the drive shaft is 120 rps or more.   
     
     
         3 . The rotary compressor of  claim 1 , wherein
   1.2−0.002× N  max≤( m 2× r 2+ m 4× r 4)/( m 1× r 1+ m 3× r 3)≤0.98, where
   a mass of the first eccentric portion is m3,   an eccentric distance of a center of gravity of the first eccentric portion from the axis of the drive shaft is r3,   a mass of the second eccentric portion is m4, an eccentric distance of a center of gravity of the second eccentric portion from the axis of the drive shaft is r4, and   a maximum number of rotations of the drive shaft is Nmax rps.   
     
     
         4 . The rotary compressor of  claim 3 , wherein
   0.88≤( m 2× r 2+ m 4× r 4)/( m 1× r 1+ m 3× r 3).
   
     
     
         5 . The rotary compressor of  claim 1 , wherein
     Vcc/Φ   4 ≥3×10 −4 , where
   a sum of a volume of a first compression chamber formed between an inner peripheral surface of the first cylinder and the first eccentric portion and a volume of a second compression chamber formed between an inner peripheral surface of the second cylinder and the second eccentric portion is Vcc cc, and   a diameter of a main shaft portion of the drive shaft coupled to the rotor is Φ mm.   
     
     
         6 . The rotary compressor of  claim 1 , wherein
 the drive shaft has a main shaft portion coupled to the rotor, the main shaft portion having a diameter of 16 mm or less, and
   ( m 3× r 3+ m 4× r 4)/2≥600, where
 
    a mass of the first eccentric portion is m3 g,
 an eccentric distance of a center of gravity of the first eccentric portion from the axis of the drive shaft is r3 mm, 
 a mass of the second eccentric portion is m4 g, and 
 an eccentric distance of a center of gravity of the second eccentric portion from the axis of the drive shaft is r4 mm. 
   
     
     
         7 . A refrigeration apparatus comprising: a refrigerant circuit configured to perform a refrigeration cycle, wherein
 the refrigerant circuit includes the rotary compressor of  claim 1 .   
     
     
         8 . The rotary compressor of  claim 2 , wherein
   1.2−0.002× N  max≤( m 2× r 2+ m 4× r 4)/( m 1× r 1+ m 3× r 3)≤0.98, where
   a mass of the first eccentric portion is m3, an eccentric distance of a center of gravity of the first eccentric portion from the axis of the drive shaft is r3,   a mass of the second eccentric portion is m4, an eccentric distance of a center of gravity of the second eccentric portion from the axis of the drive shaft is r4, and   a maximum number of rotations of the drive shaft is Nmax rps.   
     
     
         9 . The rotary compressor of  claim 8 , wherein
   0.88≤( m 2× r 2+ m 4× r 4)/( m 1× r 1+ m 3× r 3).
   
     
     
         10 . The rotary compressor of  claim 2 , wherein
     Vcc/Φ   4 ≥3×10 −4 , where
   a sum of a volume of a first compression chamber formed between an inner peripheral surface of the first cylinder and the first eccentric portion and a volume of a second compression chamber formed between an inner peripheral surface of the second cylinder and the second eccentric portion is Vcc cc, and   a diameter of a main shaft portion of the drive shaft coupled to the rotor is Φ mm.   
     
     
         11 . The rotary compressor of  claim 3 , wherein
     Vcc/Φ   4 ≥3×10 −4 , where
   a sum of a volume of a first compression chamber formed between an inner peripheral surface of the first cylinder and the first eccentric portion and a volume of a second compression chamber formed between an inner peripheral surface of the second cylinder and the second eccentric portion is Vcc cc, and   a diameter of a main shaft portion of the drive shaft coupled to the rotor is Φ mm.   
     
     
         12 . The rotary compressor of  claim 4 , wherein
     Vcc/Φ   4 ≥3×10 −4 , where
   a sum of a volume of a first compression chamber formed between an inner peripheral surface of the first cylinder and the first eccentric portion and a volume of a second compression chamber formed between an inner peripheral surface of the second cylinder and the second eccentric portion is Vcc cc, and   a diameter of a main shaft portion of the drive shaft coupled to the rotor is Φ mm.   
     
     
         13 . The rotary compressor of  claim 8 , wherein
     Vcc/Φ   4 ≥3×10 −4 , where
   a sum of a volume of a first compression chamber formed between an inner peripheral surface of the first cylinder and the first eccentric portion and a volume of a second compression chamber formed between an inner peripheral surface of the second cylinder and the second eccentric portion is Vcc cc, and   a diameter of a main shaft portion of the drive shaft coupled to the rotor is Φ mm.   
     
     
         14 . The rotary compressor of  claim 9 , wherein
     Vcc/Φ   4 ≥3×10 −4 , where
   a sum of a volume of a first compression chamber formed between an inner peripheral surface of the first cylinder and the first eccentric portion and a volume of a second compression chamber formed between an inner peripheral surface of the second cylinder and the second eccentric portion is Vcc cc, and   a diameter of a main shaft portion of the drive shaft coupled to the rotor is Φ mm.   
     
     
         15 . The rotary compressor of  claim 2 , wherein
 the drive shaft has a main shaft portion coupled to the rotor, the main shaft portion having a diameter of 16 mm or less, and
   ( m 3× r 3+ m 4× r 4)/2≥600, where
 
    a mass of the first eccentric portion is m3 g,
 an eccentric distance of a center of gravity of the first eccentric portion from the axis of the drive shaft is r3 mm, 
 a mass of the second eccentric portion is m4 g, and 
 an eccentric distance of a center of gravity of the second eccentric portion from the axis of the drive shaft is r4 mm. 
   
     
     
         16 . The rotary compressor of  claim 3 , wherein
 the drive shaft has a main shaft portion coupled to the rotor, the main shaft portion having a diameter of 16 mm or less, and
   ( m 3× r 3+ m 4× r 4)/2≥600, where
 
    a mass of the first eccentric portion is m3 g,
 an eccentric distance of a center of gravity of the first eccentric portion from the axis of the drive shaft is r3 mm, 
 a mass of the second eccentric portion is m4 g, and 
 an eccentric distance of a center of gravity of the second eccentric portion from the axis of the drive shaft is r4 mm. 
   
     
     
         17 . The rotary compressor of  claim 4 , wherein
 the drive shaft has a main shaft portion coupled to the rotor, the main shaft portion having a diameter of 16 mm or less, and
   ( m 3× r 3+ m 4× r 4)/2≥600, where
 
    a mass of the first eccentric portion is m3 g,
 an eccentric distance of a center of gravity of the first eccentric portion from the axis of the drive shaft is r3 mm, 
 a mass of the second eccentric portion is m4 g, and 
 an eccentric distance of a center of gravity of the second eccentric portion from the axis of the drive shaft is r4 mm. 
   
     
     
         18 . The rotary compressor of  claim 5 , wherein
 the drive shaft has a main shaft portion coupled to the rotor, the main shaft portion having a diameter of 16 mm or less, and
   ( m 3× r 3+ m 4× r 4)/2≥600, where
 
    a mass of the first eccentric portion is m3 g,
 an eccentric distance of a center of gravity of the first eccentric portion from the axis of the drive shaft is r3 mm, 
 a mass of the second eccentric portion is m4 g, and 
 an eccentric distance of a center of gravity of the second eccentric portion from the axis of the drive shaft is r4 mm. 
   
     
     
         19 . The rotary compressor of  claim 8 , wherein
 the drive shaft has a main shaft portion coupled to the rotor, the main shaft portion having a diameter of 16 mm or less, and
   ( m 3× r 3+ m 4× r 4)/2≥600, where
 
    a mass of the first eccentric portion is m3 g,
 an eccentric distance of a center of gravity of the first eccentric portion from the axis of the drive shaft is r3 mm, 
 a mass of the second eccentric portion is m4 g, and 
 an eccentric distance of a center of gravity of the second eccentric portion from the axis of the drive shaft is r4 mm. 
   
     
     
         20 . The rotary compressor of  claim 9 , wherein
 the drive shaft has a main shaft portion coupled to the rotor, the main shaft portion having a diameter of 16 mm or less, and
   ( m 3× r 3+ m 4× r 4)/2≥600, where
 
    a mass of the first eccentric portion is m3 g,
 an eccentric distance of a center of gravity of the first eccentric portion from the axis of the drive shaft is r3 mm, 
 a mass of the second eccentric portion is m4 g, and 
 an eccentric distance of a center of gravity of the second eccentric portion from the axis of the drive shaft is r4 mm.