DC Brushless Motors For Reliable Power And Versatility
DC brushless motors are a type of electric motion control device that converts electrical energy into mechanical energy or torque. They are used in many different applications, including those that are fairly simple and standard to more complex and critical settings.
Brushless motors are some of the most common motion control devices in use today. This is because of their reliability, longevity, and versatility, along with many other advantages that are a direct result of their design and operational capabilities.
DC brushless motors are one variety of synchronous motor. This means the rotation of their shaft will synchronize with the frequency of the electric current. This can be altered so that the device will function like an induction or asynchronous motor. Brushless motors can also be built to work as a switched reluctance motor.
Sometimes called BLDC motors, brushless DC motors are an improvement over brushed motors, which use a carbon brush as their commutator. This component conducts current to the stator and contributes to the generation of an electromagnetic field, which creates continuous resistance with the permanent magnets of the rotor. This action will then generate rotational motion which can be applied as torque.
Brushed DC motors are still in use today. They are most often incorporated into low-power and non-critical propulsion applications. For more vital capacities, they have been gradually phased out in favor of brushless motors.
This phase-out occurred with the development and adoption of solid-state electronics. This innovation eliminated the need for a mechanical brush commutator. In a brushed motor, a carbon commutator significantly limits the operational life of the device. This component will gradually wear with use. Additionally, this part can cause sparking and will contribute to increased friction, heat, and electrical resistance, as well as the motor’s weight and size.
These limitations and disadvantages are alleviated by removing the brush as the motor’s commutator. Instead, the current is fed to the motor and the stator’s field is altered through an electronic servo system. Many advantages are gained from this change.
DC brushless motors last longer, run quieter, do not spark, and operate more efficiently. Fewer mechanical parts amount to reduced friction, heat, weight, and less wear. Without the carbon brush to wear out, the operational life of BLDC motors is really only limited by the motor’s bearings, especially when properly suited to the specific application.
DC brushless motors are highly efficient and easy to maintain. This makes them useful in applications that require reliable, continuous operation.
Brushless motors are widely in use across the transportation industry. They are integral to the propulsion of electrical and hybrid vehicles, including cars, golf carts, electric bicycles, scooters, and more. Brushless motors are also used on electric aircraft and marine vessels. Additionally, they are applied to RC and autonomously operated equipment.
Since brushless motors can be scaled up without excessive heat, noise, or weight, which is a common limitation of brush motors, they can be used for high-power or high-torque motion control. High-torque low-RPM motors are often brushless motors. These devices are used for the carefully controlled lifting and movement of heavy loads in limited spaces.
Common placements of these high-power, low-speed brushless motors are in pumps used for petroleum drilling and hydrodynamic systems. They are also used as lift, crane, elevator, and belt propulsion devices in automated systems, which are incorporated into a range of industrial, infrastructure, and manufacturing applications.
The efficiency, low-heat, and low weight of DC brushless motors are advantageous for scaling up high-power electric motors as well as making them more compact. This is useful for the development of smaller appliances and handheld electrical tools.
DC brushless motors are used to power cordless drills, rotary tools, hand saws, and even various motorized medical and dentistry devices. Depending on their design, these motors may be configured to suit long or short-duty cycles where continuous power is needed.
In equipment that needs a quick, responsive, and smooth start-up, positional sensors can be added to precisely synchronize the rotor with the motor’s controller. This creates a highly accurate, closed-loop feedback cycle that suits high-efficiency, moderate speed operation. Sensored brushless motors will require the use of a compatible controller to function effectively and are best suited to applications that need only limited duty cycles.
Conversely, sensorless brushless motors are used for long-duty cycle, continuous operation. They are applied to pumps, fans, and motorized drums used for heating and cooling, refrigeration, ventilation, mixing, and other purposes where high-speed motion is needed for extended cycles.
These operational capabilities, along with their versatility, have given DC brushless motors a reputation as the workhorse motor for many equipment and appliance settings.
While they are commonly used in such high-load, continuous operational speed capacities, they can also be used for more precise positioning and actuation systems. Brushless DC motors have been applied to robots and similar equipment. This is possible when they are configured to function as stepper motors or servo motors. These motors will almost always use positional sensors to carry out more precise motion controls.
If any type of brushless motor is meant for use in a critical application, such as in aerospace, military, medical, or heavy-duty industrial settings, special consideration should be given to the motor’s essential components as well as its insulation. This helps to ensure optimal reliability and exceptional endurance when used for vital functions.
DC brushless motors can be obtained from many sources. They are widely available as commercial off-the-shelf devices from major electronics manufacturers and parts distributors. Depending on the end application, brushless motors can be easily paired within a system once parameters like phase, voltage, speed, and dimensional requirements are determined.
For original equipment manufacturers developing new systems, or when standard motors fall short of certain application demands and need to be replaced with an upgraded version, DC brushless motors can be modified and customized to suit especially demanding or unique requirements. Such devices are best acquired from electric motor manufacturers that also offer design and engineering services in addition to standard motor production.