Electric motors range from an alternate current (AC) motor to a direct current (DC) motor. Focusing on DC motors consisting of brushed motors and brushless direct current (BLDC) motors, these technologies represent the historical evolution and modern advancements in electric motor design.
Motor Designs and Operations
A brushed motor comprises four essential parts: carbon brushes, a wound or magnetic field, an armature, and a commutator. The brushes transfer an electrical current, generating a magnetic field to rotate the armature. Over time, the brushes are worn and require maintenance. Engineers invented BLDC motors to overcome the limitations of brushed motors. Brushless DC motors have been around since the late 1970s and have continued to evolve. BLDC motors can also be called electronic commutation motors (ECM or EC motors) and synchronous DC motors. A BLDC motor uses a permanent magnet rotor with an electronically controlled stator to create a rotating magnetic field, thus eliminating the brushes, and providing better control.
Comparing Motor Technologies
The elimination of brushes is just one example of BLDC benefits. Each motor type has its advantages and disadvantages. The benefits of brushed motors are their simple and reliable design and generally lower costs. The downside is its limited control over speed and torque, as well as the increased heat and friction, which reduces the efficiency and lifespan of the motor.
Brushless motors run cooler and quieter, leading to higher efficiency and a longer lifespan. These motors also have more torque, control, and precision. The cons of BLDC motors are the more complex designs and higher upfront costs. Brushless DC motors typically require some type of motor controller, which adds to the cost and complexity. Ultimately, the manufacturer must weigh the cost, performance needs, and long-term maintenance to select a brushed or brushless motor.
Industry BLDC Applications
Automotive Industry
The automotive industry has demonstrated the advantages of using brushless DC motors over brushed motors. The notable automotive applications are fuel pumps, water pumps, blower motors, and coolant pumps. Along with a longer life, BLDC motors require less energy, operate quieter, and can provide diagnostic feedback, which is extremely important in all vehicles, especially EVs.
Power Tool Applications
Similarly, power tools have been transitioning from brushed motors to brushless. The BLDC motor has allowed for cordless drills. Previously, power tools were corded and ran off AC power. Cordless power tools have become more powerful with a more compact design for higher efficiency and better speed control.
Odawara’s BLDC Contributions
The Odawara Group delivered its first high-volume production machines for BLDC motors during the late 1980s. In 1989, Odawara provided winding equipment to a large motor manufacturer for a BLDC blower motor for electronic devices, computers, and circuit boards. Odawara also provided winding equipment for a new ECM motor in 2004.
Over the years, The Odawara Group has delivered hundreds of BLDC systems. With our extensive comprehension of brushless motors, Odawara has helped customers improve their designs. Through design for manufacturing (DFM) guidance, we have also made the motors easier to mass produce. These technological milestones demonstrate Odawara’s longstanding commitment to advancing BLDC motor manufacturing capabilities across multiple industries and applications.
The evolution from brushed to brushless DC motors represents a significant advancement in electric motor technology, with each type offering different advantages for specific applications. Since the late 1980s, Odawara has played a pivotal role in this transformation by developing high-volume production machines and specialized winding equipment for BLDC motors. The automotive and power tool industries demonstrate the ongoing development of BLDC motors.
