Screw compressor and refrigeration apparatus

Abstract

A compressor includes a casing having a bottom portion with a reservoir to store oil, an electric motor housed in the casing, a compression mechanism disposed between the electric motor and the reservoir, and a resonance muffler provided in the compression mechanism. The compression mechanism compresses sucked gas refrigerant and to discharges the compressed gas refrigerant into the casing. A refrigerant space is formed above the reservoir in the casing. The refrigerant space is configured so that the gas refrigerant discharged from the compression mechanism flows through. The muffler includes a cavity in which a resonance chamber is formed, and a first opening communicating with the resonance chamber and opening to the refrigerant space. The first opening is formed on a lower surface or an outer peripheral surface of the compression mechanism.

1 . A compressor comprising:
 a casing having a bottom portion with a reservoir provided therein, the reservoir being configured to store oil;   an electric motor housed in the casing;   a compression mechanism disposed between the electric motor and the reservoir, the compression mechanism being configured to compress sucked gas refrigerant and to discharge the compressed gas refrigerant into the casing; and   a resonance muffler provided in the compression mechanism,   a refrigerant space being formed above the reservoir in the casing, the refrigerant space being configured so that the gas refrigerant discharged from the compression mechanism flows therethrough,   the muffler including
 a cavity in which a resonance chamber is formed, and 
 a first opening communicating with the resonance chamber and opening to the refrigerant space, and 
   the first opening being formed on a lower surface or an outer peripheral surface of the compression mechanism.   
     
     
         2 . The compressor of  claim 1 , wherein
 the muffler further includes a first communication passage communicating with the resonance chamber, and   the first opening is formed at an end portion of the first communication passage.   
     
     
         3 . The compressor of  claim 1 , wherein
 the compression mechanism includes a plurality of members arranged so as to overlap with each other,   the plurality of members includes a first member,   the first member includes a recess formed at an end surface of the first member in a direction in which the plurality of members overlap with each other, and   an internal space of the recess forms part of the cavity.   
     
     
         4 . The compressor of  claim 1 , wherein
 the compression mechanism includes a plurality of members arranged so as to overlap with each other,   the plurality of members includes a second member,   the second member includes a through hole penetrating the second member in a direction in which the plurality of members overlap with each other, and   an internal space of the through hole forms part of the cavity.   
     
     
         5 . The compressor of  claim 1 , wherein
 the compression mechanism includes
 a cylinder, 
 a first closing member configured to cover an opening surface of one end of the cylinder in an axial direction, and 
 a second closing member configured to cover an opening surface on an other end of the cylinder in the axial direction, and 
 the cavity is formed by at least one of the cylinder, the first closing member, and the second closing member. 
   
     
     
         6 . The compressor of  claim 1 , wherein
 the muffler further includes a second opening, which communicates with the cavity and through which the oil flows in and out, and   the second opening is formed below the first opening.   
     
     
         7 . The compressor of  claim 6 , wherein
 the first opening is formed below an initial supply position of an oil surface in the reservoir reached at a time of shipment, and the first opening communicates with the refrigerant space when an oil level in the reservoir lowers.   
     
     
         8 . The compressor of  claim 6 , wherein
 the muffler further includes a second communication passage communicating with the cavity, and   the second opening is formed at an end portion of the second communication passage.   
     
     
         9 . The compressor of  claim 6 , wherein
 the compression mechanism has a plurality of members overlapping with each other,   the plurality of members includes a third member, which is a lowermost one of the plurality of members,   the cavity is formed in the third member, and   the second opening is formed on a lower surface of the third member.   
     
     
         10 . The compressor of  claim 1 , wherein
 the muffler includes a first muffler and a second muffler,   the first opening of the first muffler is formed below the first opening of the second muffler, and   a resonance frequency of the first muffler is lower than a resonance frequency of the second muffler.   
     
     
         11 . A refrigeration apparatus including the compressor of  claim 1 . 
     
     
         12 . The compressor of  claim 2 , wherein
 the compression mechanism includes a plurality of members arranged so as to overlap with each other,   the plurality of members includes a first member,   the first member includes a recess formed at an end surface of the first member in a direction in which the plurality of members overlap with each other, and   an internal space of the recess forms part of the cavity.   
     
     
         13 . The compressor of  claim 2 , wherein
 the compression mechanism includes a plurality of members arranged so as to overlap with each other,   the plurality of members includes a second member,   the second member includes a through hole penetrating the second member in a direction in which the plurality of members overlap with each other, and   an internal space of the through hole forms part of the cavity.   
     
     
         14 . The compressor of  claim 3 , wherein
 the compression mechanism includes a plurality of members arranged so as to overlap with each other,   the plurality of members includes a second member,   the second member includes a through hole penetrating the second member in a direction in which the plurality of members overlap with each other, and   an internal space of the through hole forms part of the cavity.   
     
     
         15 . The compressor of  claim 2 , wherein
 the compression mechanism includes
 a cylinder, 
 a first closing member configured to cover an opening surface of one end of the cylinder in an axial direction, and 
 a second closing member configured to cover an opening surface on an other end of the cylinder in the axial direction, and 
 the cavity is formed by at least one of the cylinder, the first closing member, and the second closing member. 
   
     
     
         16 . The compressor of  claim 3 , wherein
 the compression mechanism includes
 a cylinder, 
 a first closing member configured to cover an opening surface of one end of the cylinder in an axial direction, and 
 a second closing member configured to cover an opening surface on an other end of the cylinder in the axial direction, and 
 the cavity is formed by at least one of the cylinder, the first closing member, and the second closing member. 
   
     
     
         17 . The compressor of  claim 4 , wherein
 the compression mechanism includes
 a cylinder, 
 a first closing member configured to cover an opening surface of one end of the cylinder in an axial direction, and 
 a second closing member configured to cover an opening surface on an other end of the cylinder in the axial direction, and 
 the cavity is formed by at least one of the cylinder, the first closing member, and the second closing member.