Shanghai Denair Compressor Co.,Ltd.
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Chapter One
Screw Air Compressor Introduction
One. Screw Compressor Summary
Oil injection screw compressor has the features of high reliability, fewer wearing parts, good balance of motive
power, little vibration, low noise and high efficiency. During the compressing process, it will ceaselessly infuse
lubricating oil to the compressing chamber and bearings by the pressure difference generated by itself. The design
has the following features:
a.
Infused lubricating oil can form oil slick between rotors, and the female rotor can be directly driven by male
rotor and plays the sealing effects.
b.
Lubricating oil can reduce the noise produced by high-frequency compression.
c. Lubricating oil can absorb large amount of compression heat.
d. Lubricating oil is applied to lubricate bearings of rotary screw, and the high-quality lubricating oil can reduce
the bearing abrasion and lengthen its service life.
Two. Screw Compressor Structure
A.
Basic Structure
Oil Spouting Screw Compressor is a kind of double-shaft volumetric returnable compressor. The air inlet is above
the main case while the air outlet is at the bottom. A pair of male and female rotor of high precision is horizontally
and parallel placed in the inner of the main case. The male rotor has five shaped teeth while the female rotor with six.
As for the diameter size, the male rotor is much larger than that of the female rotor. The rotary shaped teeth encircle
the outer edge of rotors and mesh with each other. The two terminals of female and male rotors are supported by
bearings with a pin roller bearing at the air inlet and a four-point bearing and a pin roller bearing at the air outlet.
Rolling bearing bears radial force and four-point bearing is responsible for axial thrust.
B. meshing
The male rotor is driven by the motor through coupling、overdrive gear or belts. Because of the two rotors
meshed together, the male rotor directly drives the female rotor to rotate together. The cooling lubricating oil directly
infuse into the meshed part between rotors from the bottom of compressor main case through the nozzle, mix with
air and bring the heat produced by compression to reach cooling effects. Meanwhile, it forms oil slick to prevent the
direct connection between rotors and the distance between the closed rotors and main cases. The infused
lubricating oil can also reduce noise generated by high-speed compression, and the weight of spurting oil should be
about 5-10 times than that of air.
Three. Compressing Principle of Screw Compressor
A. Air absorbing process
The air inlet design of the screw compressor can make the compressing chamber absorb air absolutely. The air
suction is only adjusted by on-off of the regulating valve. When the rotor is rotating and its alveolus rotates to the air
inlet, the space is the largest, and the rotor alveolus space freely communicates with air inlet, which is because the
air in the alveolus has been discharged out totally during venting process, and after venting, the alveolus is at the
vacuum state. When rotating to the air inlet, the outer air is absorbed to the alveolus along the axial direction. With
the rotor rotating, the air will fill the whole alveolus, and the tooth space of male rotor begins to mesh with the
alveolus of female rotor to integrate step by step until the action line and air in the alveolus was totally closed.
B. Sealing and Transporting Process
