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Brushless DC Motor Applications

Electric Motors Design & Engineering

Whether it is referred to as a brushless DC motor, ECM or BLDC motor, today’s engineers are familiar with the multitude of advantages this type of motor offers over traditional brush-type motors. BLDC motors are longer-lasting, quieter, smaller and more efficient than their brushed counterparts. However, mechanical engineers may be less aware of the significant advances made possible by BLDC motors. Here are a few achievements that owe their thanks to brushless DC motors:

Improving sleep for apnea sufferers. BLDC motors played a key role in the development of the Continuous Positive Airway Pressure (CPAP) Respirator, a device that regulates airway pressure in response to the wearer’s breathing patterns. Brushless DC motors are more reliable for such applications because they require no commutators or brushes to transfer energy to electromagnets. As these parts are in contact with the rotating shaft in a regular DC motor, they tend to wear out quite quickly. When a patient depends upon a motor’s continual operation, brushless DC motors are the most reliable choice.

Powering electric vehicles. Brushless DC motors are more responsive than traditional DC motors. This, in addition to their compact size and increased efficiency, makes BLDC motors the natural choice for electric scooters, electric bicycles and even cars.

Preventing blood clots in hospitalized patients. Brushless motors power pneumatic compression socks, which are placed on patients’ legs to maintain proper blood circulation. The problem is this: After surgery, when patients are bedbound, natural circulation flounders and the likelihood of blood clot development increases. Pneumatic compression socks provide intermittent compression to maintain proper circulation. The quiet operation of brushless motors allows healthcare facilities to meet low noise level standards while preventing deadly clotting in patients.

Adjusting solar arrays on space vehicles. Brushless DC motors last far longer than traditional DC motors, so NASA and other space agencies rely on them for interstellar applications. For instance, brushless DC motors may be used to rotate solar arrays so as to maintain alignment with the sun as the vehicle orbits a planet.

Providing mobile breathing assistance. Before the use of BLDC motors, assisted breathing apparatuses were too bulky to be used while patients were transferred between facilities. The compact nature of BLDC motors allowed portable ventilators to shrink in size – many are now smaller than a shoebox. Moreover, brushless DC motors do not suffer the sparking that comes with the friction of brushed DC motors. When working in an oxygen-rich, highly flammable environment, anti-sparking BLDC technology is key.

These are only a few of the many modern uses of brushless DC motors. BLDC motors may also be found in computer disk drives, robotics, aeronautics, factory automation, portable communication devices and military applications. However, despite all of the advantages listed above, brushed DC motors are still more common, mainly because they are less expensive than brushless DC motors. One factor in the higher cost of brushless DC motors is that they require a controller circuit. Still, brushless DC motors are gaining popularity, partially because they decrease downtime and allow for higher operation speed.

Contributed by: Sinotech