Pneumatic actuators that convert the pressure energy of compressed gas into mechanical energy and generate rotary motion in pneumatic transmission. The commonly used air motor is a positive displacement air motor, which uses the volume change of the working chamber to do work, and is divided into vane type, piston type and gear type.
An air motor is a device that converts the pressure energy of compressed air into rotational mechanical energy. Its function is equivalent to an electric motor or a hydraulic motor, that is, the output torque is used to drive the mechanism for rotational motion.
The main differences between air motors and electric motors (or motors) are:
1. Small size can produce high power.
2. High adaptability, small temperature rise, the speed can be changed with the load, and will not cause any damage to the air motor until the overload stops, so a lower safety factor can be considered when choosing.
3. Emergency start and emergency stop, especially suitable for occasions with frequent start, and the direction change is very easy.
4. Simple stepless speed regulation, from zero to maximum, flexible operation.
5. The starting torque is large, and it can start with load.
6. The structure is simple, and the service life of the air motor is particularly long.
7. Not affected by the external environment, even in harsh environments such as water, dusty, humid, dirty, etc., because the internal pressure of the air motor is larger than the external pressure when it is running.
8. Safe, explosion-proof, the air motor does not produce sparks, overheating, explosion, short circuit (electricity) and other dangerous factors, especially suitable for environments with flammable and explosive substances or high temperature, such as stirring of solvents, paints, chemicals, etc.
The above points are the main advantages of air motors over electric motors and why they are used in many industrial fields. The disadvantages of air motors are: small output power, large air consumption, low efficiency, high noise, and easy vibration.
Features
The air motor is a prime mover with compressed air as the working medium. It is a power device that uses the expansion of compressed gas to convert pressure energy into mechanical energy.
Although various types of air motors have different structures and working principles, most air motors have the following characteristics:
1. Stepless speed regulation is possible. As long as the opening of the intake valve or the exhaust valve is controlled, that is, the flow of compressed air is controlled, the output power and speed of the motor can be adjusted. The purpose of adjusting speed and power can be achieved.
2. It can rotate forward and reverse. Most air motors can realize the forward and reverse rotation of the output shaft of the air motor, and can change the direction instantaneously, as long as the control valve is used to change the direction of the motor intake and exhaust. During forward and reverse transitions, the shock is small. A major advantage of the commutated operation of the air motor is its ability to ramp up to full speed almost instantaneously. Vane air motors can be brought to full speed in one and a half seconds; piston air motors can be brought to full speed in less than a second. The forward and reverse rotation can be realized by changing the direction of the intake air by using the control valve. The time to realize forward and reverse rotation is short, the speed is fast, the impact is small, and there is no need to unload the load.
3. Work safety, not affected by vibration, high temperature, electromagnetic, radiation, etc., suitable for harsh working environment, can work normally under unfavorable conditions such as flammable, explosive, high temperature, vibration, humidity, dust, etc.
4. With overload protection, it will not fail due to overload. When the motor is overloaded, the speed of the motor is only reduced or stopped. When the overload is removed, it can resume normal operation immediately without any failures such as mechanical damage. It can run continuously with full load for a long time, and the temperature rise is small.
5. With high starting torque, it can start directly with load. Quick start and stop. Can be started with load. Start and stop quickly.
6. The power range and speed range are wide. The power is as small as a few hundred watts and as large as tens of thousands of watts; the speed can be from zero to ten thousand revolutions per minute.
7. Easy to operate, easy to maintain and repair. The air motor has the advantages of simple structure, small size, light weight, large horsepower, easy operation and convenient maintenance.
8. Using air as the medium, there is no difficulty in supply, the used air does not need to be treated, and there is no pollution in the atmosphere. Compressed air can be supplied centrally and transported over long distances