There are different types of electric motor, used in the most various industrial sectors and to operate machines of all kinds: industrial robots, medical devices, conveyor belts, automatic doors, rotary stirrers, agitators, data storage, etc.
An electric motor is an electromechanical device that converts incoming electrical energy into mechanical energy. The elements that compose it, stator and rotor, generate a magnetic field through the use of permanent magnets or electromagnets, allowing it to function.
How to choose correctly between the various types of electric motors?
Depending on the use and application purpose, the choice of the types of electric motor will be based primarily taking into account the type of movement to be obtained: fast, continuous or variable movements, precise, with more force, etc.
Based on the movement to be obtained, it will be necessary to define other technical aspects that are needed: power, torque, speed, resistance, dimensions and type of assembly of the motor.
Let’s see what are the main types of electric motors to choose from:
The AC motors is the best choice if you are looking for a simple motor that does not do positioning and that works at fixed or variable speed, if combined with an inverter. The synchronous and asynchronous motors are included in the group of alternating current motors. In the first types of electric motor, the rotation speed is synchronized with the electric frequency and the use of inverters is required for operation; on the contrary, in the second types of electric motor the angular speed is lower than the rotation speed of the magnetic field and no system of excitation of the rotor field is required, making it much easier to use.
For operations where speed control and adjustment is required, the DC motor ensures smooth movement from zero to full speed. It can also be used combined with an encoder or a driver for positioning.
If what you need is precision in angular displacement and rotational speed, the stepper motor, also often called a step or stepper, is the ideal choice. Moving in steps of 1.8 degrees (or smaller if managed electronically), a simple and economical positioning operation is guaranteed. For this reason they are mainly used in robotics, on telescopes and for servomechanisms.
Brushless motors, on the other hand, are direct current electric motors with a permanent magnet rotor and a rotating magnetic field stator. To work, they do not require any sliding electrical contact on the motor shaft and the switching of the current circulating in the stator windings takes place electronically. They are stepper-like motors and therefore used for precise angular movements even at high speeds. While compared to DC motors, they eliminate the possibility of sparking as the rotation speed increases and reduce the need for periodic maintenance.
Linear motors derive from the technology of the rotary brushless motor, electric motors that produce motion directly in a linear form, generating a thrust force. In this way the kinematic chain of the machine is reduced and a “direct drive” movement is obtained. The application of the motors allows to obtain performances, in terms of displacement speed, much higher than those obtainable with other types of electric motors.
For further information on the types of electric motors available, contact us at info@garnetitalia.com