When seeking motors for an application, some people opt for brush-type motors over brushless DC motors because of the assumed cost savings. While embedded controller BLDC motors are initially more expensive than high-quality brush motors, they end up being more cost efficient when one considers the direct and indirect savings.

Brushless DC Motors versus Brush Motors

• Efficiency: BLDC motors are up to 95 percent efficient, including losses in the motor controller, while brush motors have an efficiency of 75 to 85 percent. Brushless motors generally remain cooler and require less maintenance than brush-type motors.
• Size: BLDC motors are between 10 and 20 percent smaller than brush motors.
• Longevity: Brushless motors last between 20,000 and 40,000 hours, depending on when the bearings break down. Brush motors that use precious metals only last 1,000 to 2,000 hours.
• Controller: While some brush-type motors use a controller, it is a necessity with brushless motors.
• Explosion resistance: BLDC motors are explosion-resistant, but brush-type motors are not.
• Torque and speed: Brushless motors can achieve high levels of torque at low speeds using an external rotor or outrigger, which may eliminate the need for a gearbox, while brush-type motors cannot.
• Electromagnetic interference (EMI): In regards to EMI, brushless motors need little to no filtering. Brush-type motors may need filtering because of the commutator’s electrostatic discharge.

The advantages that brushless DC motors offer over brush motors, even those considered high-grade, make them a competitive choice. Contact Sinotech to learn how BLDC motors can benefit your applications and save you money.

Interested in learning more about this topic? Read Sinotech president Michael Bloom’s article Think Your Project Can‘t Afford A BLDC Motor? Think Again! featured in e-DriveOnline.com.

Mr. Bloom is certified by the U.S. Small Business Administration as a Global Trade Counselor and by NASBITE International as a Certified Global Business Professional (CGBP).  He is the former President and current Board member of the Northwest China Council and an advisor to Portland’s Small Business Development Center.