Multistage rotary compressor

Abstract

The present invention relates to a multistage rotary compressor. In the multistage rotary compressor, a motor-operating element 5 and a rotary compressing element 6 are provided at upper and lower portions in a closed vessel 1. In the rotary compressing element 6, a low stage side rotary compressing element 9 and a high stage side rotary compressing element 11 are positioned on the upper and lower sides respectively. An upper supporting member 12 is attached onto the low stage side rotary compressing element 9, and a substantially cup-shaped cover material 16 is attached onto the upper supporting member 12 to close an opening surface of a muffling chamber 12 b formed in the upper supporting member 12. The substantially cup-shaped cover material 16 is formed in a high dimension so that the upper end of the cover material 16 is positioned at an upper end or near an upper end of a bearing portion 12 a formed in the upper supporting member 12. Further, a discharge hole 16 b for discharging a refrigerant gas is provided in the upper end surface of the cover material 16 near an outer diameter portion of the bearing portion 12 a. Consequently, the level h of the oil surface for oil filled in the closed vessel 1 can be set so as to be near the upper end of the cover material 16. According to the present invention, the amount of oil filled in the closed vessel can be increased and the oil separation in the closed vessel can be efficiently made.

1 . A multistage rotary compressor comprising a plurality of rotary compressing elements in a closed vessel, discharging a discharge refrigerant gas in any one of said rotary compressing elements into the closed vessel, and discharging the refrigerant gas in other rotary compressing elements outside the closed vessel, 
 wherein said rotary compressing elements are positioned on upper and lower portions, a cover material, which has a discharge hole for discharging a refrigerant gas into said closed vessel, and defines a discharge muffling chamber, is mounted onto the upper rotary compressing element, and when oil is filled into said closed vessel, the oil level of said filled oil is designed so as to be slightly lower than the discharge hole in said cover material.    
     
     
         2 . A multistage rotary compressor configured so that a motor-operating element in a closed vessel and rotary compressing elements driven by said motor-operating element are provided on upper and lower portions respectively, a low stage compressing element in said rotary compressing elements is positioned on the upper side and an high stage compressing element in said rotary compressing elements is positioned is on the lower side, an intermediate pressure refrigerant gas compressed by said low stage side rotary compressing element is discharged into said closed vessel, the intermediate pressure refrigerant gas discharged into said closed vessel is taken outside the closed vessel and then is cooled and supplied to said high stage side rotary compressing element to be compressed into high pressure, and the high pressure refrigerant gas is discharged outside said closed vessel, 
 wherein an upper supporting member is attached onto the upper side of said low stage side rotary compressing element, and to the upper side of said upper supporting member is attached a substantially cup-shaped cover material, which closes an opening surface of a muffling chamber formed in the upper supporting member, an upper end of said cover material being positioned on an upper end or near the upper end of a bearing portion formed in said upper supporting member, and a discharge hole for discharging a refrigerant gas is provided on an upper end surface of said cover material and near an outer diameter portion of said bearing portion.    
     
     
         3 . A multistage rotary compressor configured so that a motor-operating element and rotary compressing elements driven by said motor-operating element are provided on upper and lower portions respectively in a closed vessel, a high stage compressing element in said rotary compressing elements is positioned on the upper side and an low stage compressing element in said rotary compressing elements is positioned is on the lower side, an intermediate pressure refrigerant gas compressed by said low stage side rotary compressing element is taken outside the closed vessel and then is cooled and supplied to said high stage side rotary compressing element to be compressed into high pressure, and the high pressure refrigerant gas is discharged into said closed vessel and the high pressure refrigerant gas discharged into said closed vessel is discharged outside said closed vessel, 
 wherein an upper supporting member is attached onto the upper side of said high stage side rotary compressing element, and to the upper side of said upper supporting member is attached a substantially cup-shaped cover material, which closes an opening surface of a muffling chamber formed in the upper supporting member, an upper end of said cover material being positioned on an upper end or near the upper end of a bearing portion formed in said upper supporting member, and a discharge hole for discharging refrigerant gas is provided on an upper end surface of said cover material and near an outer diameter portion of said bearing portion.