Application of Air Bearing in Suspension Blower

The air suspension blower is a blower in which the air rotates at a high speed of the blower rotor, which will produce a dynamic pressure effect between the rotor and the surface of the foil bearing, forming a high-pressure air film and floating the rotor! The air suspension blower originated in South Korea and is a product separated from the technology of aircraft turbine engines. Most of its research and development personnel are the 'Samsung (National) Aerodynamic Technology Research Institute' (originally responsible for the research and development of military aerospace technology) located in South Korea. unit). During the Cold War between the East and the West, South Korea, as a member of the Western camp led by the United States in Asia, gave South Korea great support in technology and trade, and put some military projects in South Korea for domestic research and development to support South Korea The research and development unit includes the Samsung Research Institute, which is responsible for the research of aerodynamic technology in aerospace. Later, due to the disintegration of the former Soviet Union and the end of the Cold War between the East and the West, some military scientific research projects in South Korea were also dismantled. product is not commercially available. The air suspension centrifugal blower is one such product. 1. Principle and composition of air suspension blower Air suspension blower mainly includes impeller, air suspension bearing, frequency converter, high-speed permanent magnet motor and its structural control system. The main shaft of the motor is coaxial with the impeller of the fan, and the high-speed rotor system is directly supported by the air suspension bearing. Its main core technologies are air suspension bearing technology, high-speed permanent magnet synchronous motor and its control technology. The air suspension bearing uses air as the working medium, the elastic flat foil as the supporting surface, and the elastic wave foil as the supporting member. Initially, the impeller rotor is in contact with the bearing, but when the rotor enters a high-speed rotation state, due to the viscosity of the air and the action of the wedge, there will be a dynamic pressure effect between the planes. On the surface of the foil and rotor, the flat foil and corrugated foil are elastically deformed, the flat foil is pushed away, and then the rotor is in a suspended state. Uneven circumferential air pressure makes foil bearings capable of carrying loads. Or, to put it more simply, during high-speed rotation of the rotor, a high-pressure gas film is formed between the rotor and the foil, which lifts the rotor. It can be seen from the above that although the impeller rotor is free of friction after the air suspension blower operates normally, it does not mean that the equipment is completely free of friction during the whole process. During the start and stop phases of the foil bearing, when the speed is below the critical speed, the dynamic pressure effect is not sufficient to fix the rotor. At this point, there will still be contact friction between the inner surface of the foil bearing and the rotor. The time is short, but there is still flat foil. Wear problems of the membrane can shorten the service life, so frequent start and stop operations must be minimized when using air suspension blowers. At the same time, in order to improve the service life of the hydrodynamic bearing, a high-quality lubricating coating must also be applied to the bearing surface. 2. Technical Features of Air Suspension Centrifugal Fan 1. Energy-saving and high-efficiency Suspension bearing is adopted, without contact loss and mechanical loss, realizing high-speed stepless speed adjustment, so that the operating efficiency of the fan can be as high as about 95%. 2. Low noise, small size, easy installation All components (high-speed motor, inverter, suspension bearing) are integrated and installed on the common base, no special fixed foundation is required, the equipment is small in size, light in weight, easy to install and operate, and low noise during operation And no vibration, noise level <80dB. 3. High system integration The blower itself has integrated on-site control and frequency conversion system, and there is no need to set up a frequency conversion cabinet and an operation cabinet separately. Through the fan's own control panel, you can set various functions and query parameters such as fluid temperature, motor revolutions, air outlet pressure, air volume, power consumption, etc., high-efficiency filter, cooling system, automatic anti-surge The system, power failure and fault protection systems are all centrally installed inside the fan cabinet, which brings convenience to the operators and reduces the occurrence of operation accidents. 4. Simple to use, easy to maintain, low cost, long service life The blower motor is directly connected to the impeller, no gear speed increase device, no mechanical contact, no lubricating oil system, no wear and energy loss, low maintenance cost, and power transmission efficiency above 95. The impeller is made of high-strength aviation aluminum and Ti material, which has excellent wear resistance and deformation resistance, and has a service life of more than 30 years. The frequency converter is used to adjust the air volume, which is more energy-saving than the throttle valve, and the air volume adjustment range is wide, generally 50%-100%.