LGCY Series
Page 18
passing through the oil cooler. When the oil temperature rises to the lower limit (about 83 ° C) of the
temperature control valve opening temperature, the temperature control valve is gradually opened to the
passage of the oil cooler for cooling. Usually, the passage from the temperature control valve to the oil
cooler is fully opened when the oil temperature rises to about 86 ° C. At this moment, the oil will enter
the engine body after being cooled by the oil cooler.
2 Operating Principle
2.1 Air Intake Process:
The air intake of screw compressor is adjusted only by opening and closing an intake air throttle valve.
The intertooth space of male and female rotors is the largest when they rotate to the opening of
enclosure air intake end wall. At this moment, the intertooth space below the rotor is connected with the
free air of air inlet port. The air in the intertooth space is fully discharged during air exhaust, so the
intertooth space is at vacuum state after air exhaust. When the rotors rotate to the air inlet, the external
air will be absorbed and flows into the intertooth space of male and female rotors along the axial
direction. When the whole intertooth space is filled with air, the air inlet side end face of rotor will be
away from the air inlet of enclosure, and the air in the intertooth space will be sealed. The process is
called “air inlet process”.
2.2 Sealing and Conveying Process:
When the air intake is finished, the tooth peak of male and female rotors will be sealed with enclosure.
The air in the intertooth space does not flow externally, and this process is called “sealing process”.
Both rotors continue to rotate. Its tooth peak is coinciding with intertooth space at the air intake end, and
the coinciding surface gradually moves to the exhaust end. This process is called “conveying process”.
2.3 Compression and Oil Injection Process:
In the process of conveying, the mating surface gradually moves to the exhaust end, i.e., the intertooth
space between the mating surface and exhaust port is gradually reduced, the air in the intertooth space is
gradually compressed, and pressure is gradually increased, i.e., “compression process”. While
compression is carried out, the lubricating oil is also injected into the compression chamber and mixed
with the air.
The oil injection mainly has four functions:
A. Lubrication: Lubricating oil can form an oil film between the rotors, avoiding contact between the
rotors and reducing friction;
B. Cooling: Since the lubricating oil absorbs a large amount of compression heat, the compression
process is close to isothermal compression, which reduces the specific power of the compressor;
C. Sealing: The oil film produced by the lubricating oil can seal the compressed air and improve the
volumetric efficiency of the compressor;
D. Noise reduction: reducing the noise generated by high frequency compression
2.4 Exhaust Process:
When the exhaust port end face of the rotor is connected with the enclosure (the pressure of the
Summary of Contents for JCD-900 Series
Page 25: ...LGCY Series Page 23 8 Wiring diagram...
Page 31: ...LGCY Series Page 29...
