In addition to wiring work and the bearings, the universal motor is composed of two major components: a stator and a rotor. While the stator does not move, it surrounds the rotor which is the center part. However, both have electromagnets, otherwise known as field windings, which fire on when there is presence of power.
Due to the magnetic attraction, the rotor is pulled toward repelling magnets located in the motor. A torque is created and the rotor spins. To keep it spinning and enable adjustment of rotation direction as well as speed, there is activation of the electromagnets by commutation.
Since the stator is fixed, it can get power supply through a connection of wires. On the other hand, the rotor is a moving component. Therefore, it gets its power supply through carbon brushes located against the commutator’s surface. Like in any other corded or cordless brushed motors, the commutator has different segments with the gaps between them responsible for timing and sequencing of the powering process of the rotor electromagnets through occasional contact.
The stators in brushed cordless Makita power tools do not have windings since the small size of the magnets do not call for power. If provided with rare-earth magnets, the efficiency of permanent-magnet motors rises to top form. In addition, they have magnetic self-braking and perfect low-speed torque.
The brushless motor’s rotor has permanent magnets while the stator has electromagnetic windings. To get a clearer picture, think of it as a permanent-magnetic motor but this time turned inside out. Since the magnets need no power, a commutator and brushes are not required.
Keep in mind that a brushless motor does not have the mechanical switching present in a rotating commutator. Instead it is fitted with a very small onboard computer—known as a microprocessor—that enables electronic commutation through electronic switching. To control the speed and direction of the motor, the electrical pulses that pass to the electromagnets in the rotor are timed by electronics which monitor the position of the rotor.
Brushless Makita power tools come with numerous benefits. Since there is no rubbing of brushes against the commutator while there is the precision that comes with computer control, efficiency is enhanced. This is in addition to powerful but less noisy performance which can be improved by the addition of more features including multiple speed settings as well as soft –start and soft-fade. Brushless motors have also proved to be more durable simply because there is no wearing out of brushes. To learn more about the wide assortment of Makita tools, you can find more information on the Mississauga Hardware website.