2205B0JE-DA-J-N_2014.05.
2 Structure and Specifications of the Compressor
Screw Compressor J-series
2.5 Mechanisms
2-24
2.5 Mechanisms
2.5.1 Basics of the Screw Compressor
The screw compressor is a positive displacement rotary compressor. It has the features of both the
reciprocating and centrifugal compressors.
As shown in Figure 2-16 and Figure 2-17, the refrigerant (gas) is continuously compressed by changing
the volume between the casing, male and female meshed screw rotors, which have different profiles.
The rotor with five lobe sections is called the male (M) rotor while the one with six lobe sections is called
the female (F) rotor.
Figure 2-16 Compressor Mechanisms
The compressor is driven by a 2 pole type motor connected to the M rotor shaft and drives the
compressor at 2,950 min
-1
(50Hz) or 3,550 min
-1
(60Hz).
The 170/220J-series compressor is normally driven by a flange motor and is able to operate
continuously at variable rotation speed control when used with a variable speed driver. (The flange
motor is not available for the 280J-series.)
The newly developed J profile optimizes the rotor profile and mating, thereby improving the compressor
efficiency significantly.
Figure 2-17 J Profile
