What Is a Solenoid Actuator?
A solenoid actuator is a device that uses electromagnetic force to achieve mechanical motion. Its structure and operation are simple, and it can directly drive a mechanical load, making the entire device small and simple.
There are two types of motion: rotary (rotary solenoid) and linear (linear motion solenoid). Compared to other drive systems, the DC solenoid has superior speed and response.
Uses of Solenoid Actuators
Solenoid actuators are often used when you want to downsize a device or make it move repeatedly at high speed.
Rotary solenoid actuators are used in locking mechanisms for doors, paper roll cutters, optical shutter drives for optical equipment, butterfly valve drives, and flag drives for passage switching.
Linear solenoid actuators are used to drive diaphragm pumps, rollers of card readers, friction brakes, solenoid valves such as air valves, and flow control mechanisms.
Principles of Solenoid Actuators
A solenoid is one of the mechanical components that moves by utilizing the fact that an electromagnet shows properties as a magnet only when the coil is energized. A solenoid has a movable pole made of magnetic material, a fixed pole as an iron core, and a coil around it. When the coil is energized, the fixed magnetic pole and the movable magnetic pole adsorb each other, and when the coil current is cut off, the adsorption force disappears and returns to the fixed magnetic pole to realize a linear reciprocating motion. In the case of rotation, the adsorption force is converted into a force in the direction of rotation.
Solenoid actuators are characterized by the fact that they operate simply by energizing the coil and do not require a driver or other control device like a motor. In the case of rotation, a motor can be moved endlessly, and its speed can be easily controlled by adjusting the voltage. Solenoids, however, can drive a load directly, and thus have high speed and high responsiveness.