Two stage rotary compressor

Abstract

The invention provides a two stage rotary compressor which can improve tracing ability of refrigerating fluid imported into an advanced compressing portion, restrain pressure fluctuation in intermediate flow paths, and prevent running efficiency from reducing in low load running. The two stage rotary compressor (100) of the internal high-pressure type includes a low stage cover (19) that covers a low stage outlet port (16) and forms a low stage discharge space (20) therein. Further, the two stage compressor (100) includes a compression mechanism (3) provided with an intermediate passage (51) that connects the low stage discharge space (20) and the high stage compression chamber (35) and a bypass mechanism (a bypass port (23), a bypass valve (24), and a bypass valve guard (25) in the low stage cover (19), in which the bypass mechanism opens when a load is smaller than a predetermined load and in which the bypass mechanism connects the low stage discharge space (20) and a discharge pressure space (53).

Description

technical field [0001] The invention relates to a rotary two-stage compressor having two compression sections. Background technique [0002] Conventionally, there is a rotary two-stage compressor in which two compression sections (a low-stage compression section and a high-stage compression section) are provided in a compression mechanism section, and the low-stage compression section and the high-stage compression section are connected in series. In such a rotary two-stage compressor, the low-stage compression unit compresses the refrigerant sucked in from the heat pump cycle to a predetermined pressure (reach pressure). The attained pressure is determined by the setting of the compression chamber volume of the low-stage compression section and the compression chamber volume of the high-stage compression section. The high-stage compression unit further compresses the refrigerant compressed by the low-stage compression unit. In addition, in the case of an internal high-pre...

AI Technical Summary

Problems solved by technology

Therefore, the rotary two-stage compressor described in Patent Document 1 has a problem in that when the load of the refrigerant acts on the compression chamber, the degree of deflection of the drive shaft increases and the reliability of the bearing decreases.

[0014] In addition, in the rotary two-stage compressor described in Patent Document 2, the phase of the suction port of the high-stage compression part and the phase of the suction port of the low-stage compression part are shifted, so there is a problem that the compression chamber of the high-stage compression part Increased dead volume resulting in reduced compression efficiency

[0015] In addition, in the rotary two-stage compressor described in Patent Document 3, since the installation area of ​​the intermediate flow path is narrow, there is a problem that the flow path area of ​​the intermediate flow path is limited, and the efficiency decreases due to pressure loss.

Images