Introduction of semi-closed screw-shaft air compressor
    Screw-shaft air compressor has simple structure, less wear and tear of components, reliable operation, long life span, the overhaul interval can reached from 40.00 to 80, 000 hours and can work in big pressure difference and pressure ratio state, the exhaust gas temperature is low, the refrigerant contains much insensitive lubricant oil (often called a wet journey), with good regulation of input gas quantity. It has quickly occupied the scope of use of the piston air compressor with high capacity, and kept expanding the range of capacity, widely used for refrigeration equipment such as chilling, keeping cool, air conditioning and chemical engineering.
    Inside the cylinder of the screw air compressor fitted with a pair of positive and negative spiral rotor pairs that have some  concave teeth, rotate in two opposite directions, the distance between two rotors and the distance between the rotor and the casing is 5-10 strings, the main rotor (also called convex rotor or negative rotor), through the movement driving of electric motors or engine (most are electric engines) while another rotor (also called concave rotor or negative rotor) is driven by the main rotor through oil spray oil membrane, or by synchronous driving of the main rotor of the concave rotor. So there is no metal contact in the movement transmission (in theory); the length and diameter of the rotor of semi-closed screw-shaft air compressor decide the waste amount of air compressor (traffic) and waste pressure. The longer rotor is, the higher the pressure is; the bigger the rotor diameter is, the bigger the flow is.
    Concave groove of the rotary rotor will filled with gases through gas suction gate. When the rotor turns, the concave groove of rotor is enclosed by machine casing, forming the compressed air chamber, after the rotor groove is sealed, the lubrication oil will be injected into the compressed gas chamber that have effects of sealing, cooling and lubrication. When the rotor turns, it compresses the lubricant + gas (referred to as compressed gas mixture), the capacity of the pressure chamber reduces, compresses the gas mixture into the exhaust gate. When compressed air chamber passes through the exhaust gas gate, then the air mixture will be discharged out from the air compressor. The process of gas suction- gas compression- gas emission is completed.
    Each rotor of screw-shaft air compressor is supported by friction reduction bearings that are fixed at the end near the rotation axis. Gas input is supported by cylindrical roller bearings, gas output is supported by conical roller bearings, usually the bearings of the output gas locates the rotor and bearing bearings, subject to pushing force of the shaft, radial load and the create necessary distance for axis operation.