Different Types of Servo Motors: DC Servo Motor and AC Servo Motor

In simple words, the servo motor is an individual electric motor. The main purpose of using this motor in industries is to rotate and push the machine parts wherein, as well as task must be defined. This is one of the most extensively used motors in applications like industrial manufacture, automation development, etc. Even though these are proposed and planned to utilize in the applications like motion control for high precision positioning, rapid reversing and outstanding performance. The applications of servomotors include in robotics, automated industrialized systems, radar systems, tracking systems, machine apparatus, computers, CNC machines, etc. This article discusses an overview of what is a servo motor and different types of servo motors

What is a Servo Motor?

Another name of the servo motor is controlled motor, because these are employed in feedback control systems like output actuators & doesn’t utilize for continuous energy alteration. The working principle of the servomotor and electromagnetic motor are same except the structure and the function are dissimilar. The power rating of these motors will changes from a watt to a few hundred watts.

Servo Motor
Servo Motor

When the rotor inactivity in the motor is small then the response will be high. Similarly, the rotor of the servomotor is high then the motor has a lesser diameter. They function at less speed or zero speed sometimes. Servo motors are applicable in radar, machine tool, computers, robot, tracking, processing controlling, guidance systems, etc. Please refer the link to know more about Servo Motor – Working, Advantages & Disadvantages

Different Types of Servo Motors

Generally, these motors are categorized into two types based on the supply used for its function such as AC servo motors & DC servo motors. These motors are suitable for many applications due to the progress of the microprocessor, power transistor & high precision control. These motors include three wires power, ground, and control. Based on the size and outline, these motors are used in various applications. The most frequently used servo motor is RC servo motor which is mostly used in hobby applications. The main features of this motor include affordability, simplicity, and consistency.

Types of Servo Motors
Types of Servo Motors

DC Servo Motor

Generally, the DC servo motor includes a DC source separately in the field of the armature winding. The motor can be controlled either by managing the field current otherwise the armature current. The armature control has some benefits compare with field control. Similarly, field control has come benefits compare with armature control. The controlling of this motor can be done based on the application used. This motor offers a quick and accurate response to begin or end command signals because of the small armature inductive reactance. These motors are utilized in several devices and numerically controlled equipment.

Types of DC Servo Motors

The DC servo motors are classified into different types which are

  • Series Motors
  • Split Series Motors
  • Shunt Control Motor
  • Permanent Magnet Shunt Motor
DC Servo Motors
DC Servo Motors

Series Motors

The series type DC servo motors include high starting torque as well as draws huge current. The speed regulation of this motor is very less. Turnaround can be attained by overturning the field voltage polarity using split series field winding. The efficiency of this motor can be reduced by using this method.

Split Series Motors

These types of motors are the DC series motors with a few partial kilowatts and rated with the split field. These motors can function as an individually energized field controlled motor. The motor armature can be supplied with a stable current supply. This motor has a common curve with torque speed. This specifies high stall torque & a fast decline in torque by amplifying in speed. These will consequence in excellent damping.

Shunt Control Motor

The shunt control servo motor is not dissimilar from any kind of DC shunt motor. This motor includes two windings such as field windings and armature windings. Field windings are located on the stator of the machine whereas the armature windings are located on the rotor. The connection between these two windings can be done to a DC source. In a DC shunt motor, the two windings are connected across the DC source in parallel.

Permanent Magnet Shunt Motor

This is a permanent excitation motor wherever the field is in fact supplied by a stable magnet. The motor performance is same to armature controlled permanent field motor that we are going to recognize in the next segment.

AC Servo Motor

AC servo motor includes an encoder which is used by the controllers to give the feedback as well as closed loop control. AC motor can be located to high accuracy as well as controlled accurately as necessary for the applications. These motors have superior designs in order to achieve better torque. The AC servo motor applications mainly include in robotics, automation, CNC equipment, and many more applications.

Types of AC Servo Motors

The AC servo motors are classified into different types which are

  • Positional Rotation Servo Motor
  • Continuous Rotation Servo Motor
  • Linear Servo Motor
AC Servo Motors
AC Servo Motors

Positional Rotation Servo Motor

The most common kind of servo motor is Positional rotation motor. The output of the shaft in motor rotates with 180 degrees. This type of motor mainly comprises includes physical stops that are placed in the gear mechanism to prevent rotating outside to protect the rotation sensor. The applications of positional rotation servo motor include in robots, aircraft, toys, controlled cars, & many more applications.

Continuous Rotation Servo Motor

Both common positional rotation servo motor and continuous rotation servo motor are same, except it can go in every direction without a fixed limit. The control signal alternately locates the static point of the servo to understand the direction as well as the speed of rotation. The variety of potential commands will cause the motor for rotating in the directions of clockwise otherwise anticlockwise as chosen by altering speed, based on the control signal. The application of continuous rotation servo motor includes a radar dish. For example, if you are traveling single on a robot otherwise you can employ one like a drive motor over a mobile robot.

Linear Servo Motor

The Linear servo motor is one kind of motor and it is similar to the positional rotation servo motor, however with extra mechanisms for changing the output from circular in the direction of back-and-forth. We cannot find these motors easily, although occasionally you can discover them at hobbyist stores everywhere they are used like actuators within advanced model airplanes.

Thus, this is all about types of servo motors. This motor is a division of servomechanism and coupled with some type of encoder for providing positioning, speed feedback as well as some fault correcting apparatus which activates the supply signal. The basic characteristics to be required for any servo motor includes, the output torque of the motor must be proportional to the applied voltage. The torque direction which is expanded by the motor must be depending on the instantaneous polarity of the control voltage. Here is a question for you, what are the applications of servo motor?