The first generation of electromotors surfaced in the early 19th century. They use mechanical elements to produce unidirectional motion. Advancements in technology led to the changing of the mechanical aspects to the more efficient solid-state components. This advancement resulted in the emergence of brushless AC motors and DC engines. What are the features that make the brushless technology preferable?

Brushed vs. Brushless

You will appreciate the difference between these two technologies by taking a closer look at their structures and operating principles.
  • An engine that uses mechanical motors consists of an armature made of winding wires, a static ring, and permanent magnets. Other component includes a communicator, a cylinder mounted on the shaft that joins with the armature, and graphite-based brushes.
  • This type of device works by energizing the armature to create a magnetic field that turns the rotor. The rotation goes for a half-circle after which it must reverse. The brushes come to play at the zero-torque point by acting with the communicator to switch the current. This is how the current produces continuous torque without the need to change direction.
The structural composition of a brushless motor is similar to the configurations above with its movable and stationary components.

They both have the rotor and the stator. However, the brushless drives make use of semiconductor-based transistors instead of brushes.
  • Since the device now lacks mechanical elements to commutate, power is derived directly from the stator coils and also creates a magnetic field from there. When the magnetic field interacts with the rotor magnets, it results in rotational movements
  • In this case, the transistors handle the job of reversing amperage at the half turn to produce continuous torque in the same direction.

The difference between the two technologies:

  • The brushed models are bulky because of the many mechanical parts. The brushless motor, have lighter weight and smaller dimensions.
  • The many rubbing parts leads to considerable loss of capacity in the brushed model. The brushless types have a high power to mass and torque to mass ratios.
  • The mechanical-based design limits the maximum RPM in brushed models. But the minimum rotor inertia allows for maximum velocity in brushless models.
  • The sliding contacts in brushed motors cause sparks which is risky inflammable atmosphere but the brushless models do not spark because the transistors handle commutation.
  • The Graphite element in brushed motors gets worn out quickly while the brushless types, lacking wearable parts, are more durable.

What are the brushless AC motors benefits?

By replacing the mechanical-based communicators with solid-state electronics, the following improvements are achieved.
  • Smaller size
  • Increased efficiency
  • Enhanced safety
  • Low maintenance and increased durability
  • High level of flexibility, and low operating noise due to fewer -moving parts.

FMI brushless engines

The motors used in the FMI series by Rozum Robotics has a proprietary design and uses brushless communication that minimizes power loss resulting from friction.
  1. It gives low noise while functioning does not have the risk of sparking and has high levels of controllability.
  2. It was constructed specially to be durable and equipped with a hollow shaft for easy integration.
  3. It uses a star winding model that allows for high torque delivery, even a slow rotation.
  4. It has an in-running configuration and rare-earth magnets that give it a compact dimension and ultra-high efficiency.
  5. It has in-built temperature sensing elements that monitor the temperature to prevent demagnetization.
The AC synchronization subtype allows for smooth rotation without noise, cogging, or electromagnetic interference. It also has a high level of efficiency. Thanks to the superior power to mass ratio and torque density.

If you need advanced motor to be designed exclusively for your technical demands, it can easily be done after the technical consultation with Rozum experts.