Compressor and air conditioner

Abstract

A compressor includes a casing having a cylindrical shape and end plates at both ends, a compression mechanism housed in the casing, and a muffler disposed between a fluid outlet of the compression mechanism and a space in the casing. A size of the casing or the muffler is set so that in an entire range of a first resonance mode in which a resonance frequency changes as an oil level of lubricant oil stored in the casing changes, the resonance frequency of the first resonance mode is different from a resonance frequency of a second resonance mode in which the resonance frequency does not change as the oil level of the lubricant oil changes.

1 . A compressor comprising:
 a casing having a cylindrical shape and end plates at both ends;   a compression mechanism housed in the casing; and   a muffler disposed between a fluid outlet of the compression mechanism and a space in the casing,   a size of the casing or the muffler being set so that in an entire range of a first resonance mode in which a resonance frequency changes as an oil level of lubricant oil stored in the casing changes, the resonance frequency of the first resonance mode is different from a resonance frequency of a second resonance mode in which the resonance frequency does not change as the oil level of the lubricant oil changes.   
     
     
         2 . The compressor of  claim 1 , further comprising:
 an electric motor disposed above the compression mechanism, the electric motor being configured to drive the compression mechanism,   the resonance frequency of the first resonance mode being a resonance frequency of which parameters are a volume of the muffler and a volume of a primary space formed between a lower end of the electric motor and a bottom surface of the casing and changing in accordance with the oil level, and   the resonance frequency of the second resonance mode being a resonance frequency of which a parameter is an inner diameter of part of the casing forming the primary space.   
     
     
         3 . The compressor of  claim 1 , wherein
 the resonance frequency of the first resonance mode is lower than the resonance frequency of the second resonance mode at an oil level reached by an amount of oil initially supplied into the casing.   
     
     
         4 . The compressor of  claim 1 , wherein
 the resonance frequency of the first resonance mode is higher than the resonance frequency of the second resonance mode with no lubricant oil being stored in the casing.   
     
     
         5 . The compressor of  claim 1 , wherein
 the compression mechanism is a single-cylinder compression mechanism.   
     
     
         6 . An air conditioner including the compressor of  claim 1 , the air conditioned further comprising:
 a refrigerant circuit configured to perform a vapor compression refrigeration cycle, the refrigerant circuit including the compressor.   
     
     
         7 . An air conditioner comprising:
 a refrigerant circuit configured to perform a vapor compression refrigeration cycle,   a compressor of the refrigerant circuit including
 a casing having a cylindrical shape and end plates at both ends, 
 a compression mechanism housed in the casing, and 
 a muffler disposed between a fluid outlet of the compression mechanism and a space in the casing, 
   the compressor having
 a first resonance mode in which a resonance frequency changes as an oil level of lubricant oil stored in the casing changes and 
 a second resonance mode in which the resonance frequency does not change as the oil level of lubricant oil stored in the casing changes, and 
   the resonance frequency of the first resonance mode is lower than the resonance frequency of the second resonance mode at an oil level at which lubricant oil in the refrigerant circuit is collected in the compressor.   
     
     
         8 . An air conditioner comprising:
 a refrigerant circuit configured to perform a vapor compression refrigeration cycle, wherein   a compressor of the refrigerant circuit including
 a casing having a cylindrical shape and end plates at both ends, 
 a compression mechanism housed in the casing, and 
 a muffler disposed between a fluid outlet of the compression mechanism and a space in the casing, 
   the compressor having
 a first resonance mode in which a resonance frequency changes as an oil level of lubricant oil stored in the casing changes and 
 a second resonance mode in which the resonance frequency does not change as the oil level of lubricant oil stored in the casing changes, and 
   the air conditioner being configured to operate to control an oil level of the compressor so that the resonance frequency of the first resonance mode is lower than the resonance frequency of the second resonance mode at all times during a steady operation in an entire operation range.   
     
     
         9 . An air conditioner comprising:
 a refrigerant circuit configured to perform a vapor compression refrigeration cycle,   a compressor of the refrigerant circuit including
 a casing having a cylindrical shape and end plates at both ends, 
 a compression mechanism housed in the casing, and 
 a muffler disposed between a fluid outlet of the compression mechanism and a space in the casing, 
   the compressor having
 a first resonance mode in which a resonance frequency changes as an oil level of lubricant oil stored in the casing changes and 
 a second resonance mode in which the resonance frequency does not change as the oil level of lubricant oil stored in the casing changes, and 
   the air conditioner being configured to operate to control an oil level of the compressor so that the resonance frequency of the first resonance mode is higher than the resonance frequency of the second resonance mode at all times during a steady operation in an entire operation range.   
     
     
         10 . An air conditioner comprising:
 a refrigerant circuit configured to perform a vapor compression refrigeration cycle,   a compressor of the refrigerant circuit including
 a casing having a cylindrical shape and end plates at both ends, 
 a compression mechanism housed in the casing, and 
 a muffler disposed between a fluid outlet of the compression mechanism and a space in the casing, 
   the compressor having
 a first resonance mode in which a resonance frequency changes as an oil level of lubricant oil stored in the casing changes and 
 a second resonance mode in which the resonance frequency does not change as the oil level of lubricant oil stored in the casing changes, and 
   the air conditioner being configured to avoid an operation of the compressor and not perform a steady operation at a point at which the resonance frequencies of the first resonance mode and the second resonance mode match each other.   
     
     
         11 . The air conditioner of  claim 7 , wherein
 the compressor includes an electric motor disposed above the compression mechanism, the electric motor being configured to drive the compression mechanism,   the resonance frequency of the first resonance mode is a resonance frequency of which parameters are a volume of the muffler and a volume of a primary space formed between a lower end of the electric motor and a bottom surface of the casing and changing in accordance with the oil level, and   the resonance frequency of the second resonance mode is a resonance frequency of which a parameter is an inner diameter of part of the casing forming the primary space.   
     
     
         12 . The air conditioner of  claim 8 , wherein
 the air conditioner is configured to operate to control a rotational speed of the compressor to avoid a point at which the resonance frequencies of the first resonance mode and the second resonance mode match each other, thereby controlling the resonance frequency of the first resonance mode.   
     
     
         13 . The air conditioner of  claim 8 , wherein
 the air conditioner is configured to operate to adjust an amount of oil returned to the compressor from an oil return circuit including an oil separator connected to a discharge side of the compressor, thereby controlling the oil level to control the resonance frequency of the first resonance mode.   
     
     
         14 . The air conditioner of  claim 7 , wherein
 the compressor is a single-cylinder compressor.   
     
     
         15 . The air conditioner of  claim 6 , wherein
 a rotational speed N of the compression mechanism is 120≤ N.