Leading Stepper Motor Manufacturers

What is a Stepper Motor?

A stepper motor is an electrical motor, as shown in the figure below. The shaft protruding out of the motor is attached to a rotor that rotates following the concept of electromagnetism. This converts electrical energy into mechanical energy. Without the need for any sensor, the angular position of the shaft can be determined accurately by counting the rotation steps.

Steppers motors are available in a variety of sizes and materials to best suit the applications. As the name implies, the stepper divides one full rotation into smaller, equal rotations, also known as steps. This feature enables users to program it into moving only certain degrees hence controlling the motion.

Stepper Motors Operational Theory

Like all electric motors, stepper motors also consist of two main components. One is the stator which is a non-movable part. The other one is a movable part called a rotor. The rotor is usually a permanent magnet. It is encased by a stator. There are bar/teeth like structures on the stator which provide support for the coil, as shown in the figure below.

The stepper motor operates by generating the magnetic field in one of the stators. It is done by supplying electric current through the coil around the stator. The rotor moves towards the charged stator. The alternating current passing through the coil produces a magnetic field around the rotor. As a result, the rotor moves in steps depending on the magnetic field lines produced by the respective stator.

Types of Stepper Motors

The efficiency of stepper motors largely depends on how it's built. The following three types of stepper motors are based on structural differences. The type of rotor used determines the performance here.

Permanent Magnet Stepper Motor

In this type, the rotor is a permanent magnet. It easily lines up with the stator's magnetic force. This change ensures better torque production. Although it provides low speed and low resolution.

Variable Reluctance Stepper Motor

In variable reluctance motors, the rotor used is made up of an iron core. It is shaped to make it easier for the rotor to align with the magnetic field produced by stator bars. Unlike permanent magnet rotors, it produces higher speeds and resolution, but achieving better torque is impossible.

Hybrid Stepper Motor

These kinds of motors combine permanent magnet stepper motors and variable reluctance ones. It’s rotor consists of two caps made up of a permanent magnet shaped like a variable reluctance rotor. The mixture of design provides all the qualities and benefits of other motors. It has high speed, better torque, and good resolution. Since it is a hybrid and complex design, it costs more than the other stepper motors.

Benefits of Using Stepper Motors

Some of the benefits of stepper motors include:

• Stepper motors have a cleverly engineered internal structure that enables users to track angular position and rotations without sensors.
• These do not require extra maintenance.
• Unlike DC motors which do not offer good torque at less speed, stepper motors provide better torque even at lower speeds.
• Stepper motors usually are durable and have a long life.
• Precise positioning by stepper motors makes it usable in robotics and automated processes where extreme accuracy is required.

Applications of Stepper Motors

Stepper motors are different in their utilizations, yet probably the most widely recognized uses include:

• 3D printing equipment
• Textile machines
• Printing presses
• Gaming machines
• Medical imaging machinery
• Small robotics
• CNC milling machines
• Welding equipment