What Is a Rotary Solenoid?
A rotary solenoid is a device that achieves reciprocating rotary motion within a specific angular range, unlike continuous rotation seen in motors. Originally, “solenoid” referred to a densely wound wire coil. Today, it describes mechanisms where a metal core moves within a coil when an electric current is applied. Rotary solenoids rotate this core, enabling applications requiring quick, angular motion.
Applications of Rotary Solenoids
Rotary solenoids are essential in applications like high-speed shutters in scientific instruments, sorting systems in manufacturing, and mechanisms requiring precise, repetitive movements. They convert rotary to linear motion using gears, ideal for tasks needing controlled angular movement, such as stamping machines.
These solenoids offer a simpler, more reliable alternative to motors for achieving precise linear reciprocation, as they can easily control motion within a set angular range without complex mechanisms.
Principle of Rotary Solenoids
Rotary solenoids operate through electromagnetic force between arranged magnetic poles and a current-carrying coil. This setup allows for simple yet precise control over rotation angle and torque, with minimal mechanical contact outside of bearings. The result is accurate positioning, reduced operation errors, minimal maintenance, and extended lifespan.
Structure of Rotary Solenoids
The structure includes a case enclosing the coil, with bearing balls housed in ball races within the case, balanced at three points. Application of voltage to the coil propels these balls, initiating rotation via a push on the ball race. This design contributes to the solenoid’s efficiency and reliability.
Other Information on Rotary Solenoids
Differences from Motors
Unlike motors, which achieve continuous rotation by alternating current direction based on rotor position, rotary solenoids lack a mechanism for continuous motion control, stopping rotation after reaching a predetermined angle. This fundamental difference simplifies control and structure, making solenoids preferable for applications requiring fixed angular movement.