What Is Servo Motor? Why It Is Better Than Conventional Motor?

SERVO MOTOR

The motor is a device which is used for rotating and linear motion. Servo motor is one type of motor, but it can be termed as the advanced or modern engine. Servo motor is expensive than any regular motor because it provides precision motion control. Servo motors are used in robotics, automated manufacturing, automatic filling and sealing machines, etc. let’s see what is servo motor and how it works?

Ø Servo motor is nothing but simple DC brush motor with some extra parts. Servo motor consists DC brush motor, encoder, planetary reduction gear set. It has closed loop system (signal and feedback). The input signal may be analog or digital, and we can get output on the servo shaft (see diagram given below). Now here work of encoder start, it senses production and provides required feedback to the servo motor and depending this feedback servo can change its direction of rotation. Servo motor can be stopped at any second and can be rotated in the opposite direction at the same second. This is the benefit of the servo motor.

Ø Servo motor provides both linear actuation and rotary motion. Rotary motion can be easily got by connection of shaft with servo motor, but to get linear actuation or to convert rotation of servo in linear motion SCREW, AND NUT mechanism is used. Now let’s see an example ( refer below figure ).

Assume a piston cylinder arrangement in which piston is operated by the servo motor. In this case, a screw is fastened to servo motor shaft but it is free to rotate, and it is connected with a nut. This bolt is held by piston arrangement so it can’t turn but it can actuate (individual arrangement eliminates here linear motion of screw & rotation motion of the ball). Because of this when servo motor nut rotates a bolt will go up or down (will not rotate), so as a piston. Here as we learn above servo motor’s rotation can be controlled, due to this, we can also control actuation of the piston. See highlighted area again, when a piston is reached at required height servo motor is stopped and starts rotating in the opposite direction (so the disk will go down).