Permanent Magnet vs Variable Reluctance vs Hybrid Stepper Motor

As is known to everyone, three main types of stepper motors are available in the market. They are permanent magnet (PM) stepper motor, variable reluctance (VR) stepper motor, and hybrid stepper motor. Do you know which one you should use for your project? If you are uncertain which one best suits your need, you should first understand their respective characteristics and major differences. ACT Motor will introduce the three types of stepper motors and analyze their differences.

PM Type
With simple construction and inexpensive manufacture cost, this type of stepper motor has its rotor made from two permanent magnet rotors which are slightly offset from each other. A PM type stepper motor is often used for simple positioning since its resolution is larger than other types.
Advantages: Compact and small in size, making it useful in many applications; reduced losses and maintenance due to the absence of any external excitation; able to operate in a wide range of speed and torque.
Disadvantages: Due to limitations in permanent magnet, it cannot be used for high power applications; limited service life; limited torque.

VR Type
This is a stepper motor which offers the simplest design among the three types of stepper motor discussed here. It provides teeth on the rotor and stator where the magnetic forces are concentrated. A VR type stepper motor has no magnets, so it’s unable to output holding torque at standstill.
Advantages: Enhanced acceleration rates; quick dynamic response; cost-effective; more proportion of torque to inertia.
Disadvantages: Capacity is minimal when there are huge inertial loads; limitation on output power.

Hybrid Type
The hybrid stepper motor combines the design and advantages from both permanent magnet type and variable reluctance type stepper motors, which means that the hybrid type stepper motor uses both the permanent magnet rotor and toothed rotor in the design.
Advantages: Smaller step length; greater torque; higher efficiency at a lower speed.
Disadvantages: Higher inertia; increased weight of the motor; high cost as compared to the VR type.

Conclusion
Stepper motor drive manufacturers find that the hybrid stepper motor has become the most popular stepper motor in the market as it offers the best performance. Of course, you should consider your individual needs when choosing a stepper motor.


Post time: Jul-07-2022