Technical Knowledge

The difference between brushless motor and brushed motor
Release Date : 2020-06-17 18:05:46


There is no doubt that the biggest difference between brushed and brushless motors is brushes. But what does that mean?





In other respects, the principle of internal work of brushed and brushless motors is basically the same. When the motor winding is energized, a temporary magnetic field is generated to repel or attract the permanent magnet. This magnetic force is converted to shaft rotation, which causes the motor to function. When the shaft rotates, current is transmitted to different winding groups, thereby keeping the electromotive force repelling or attracting, forcing the rotor to rotate continuously.
 
 

History of brushed and brushless motors

Brushed DC motors have been used since 1856 and are still frequently used in electric propulsion, cranes, paper machines and steel rolling mills. However, because their brushes wear out and require frequent replacement, brushless DC motors that use electronic speed controller devices have replaced brushed motors for many applications. Due to application requirements and high discharge noise (also known as ESD, especially in aerospace applications), brush wear has become a serious disadvantage, and a new motor has been born.
 
Brushless motors have been invented in the era of electronic information. With the advancement of solid-state technology, in the early 1960s, TG Wilson and PH Trickey invented the first BLDC motor in 1962, which was called "DC motor with solid-state commutation". The key element of the brushless motor is that it does not require a physical commutator, so it has become the best choice for computer disk drives, robots and aircraft.
 
 

Advantages of brushless motors

Since brushless DC motors are free of brush wear, compared with brushed motors, brushless motors have higher efficiency and performance, and are less sensitive to mechanical wear.
 
Brushless motors have other advantages, including:
 
Higher torque to weight ratio
Increased torque per watt of input power (increased efficiency)
Improve reliability and reduce maintenance requirements
Reduce operation and mechanical noise
Longer life (no brush and commutator corrosion)
Eliminate the ionization spark (ESD) generated by the commutator
Almost eliminates electromagnetic interference (EMI)
 

Today's brushless motors

Despite their reliability, the disadvantage of early brushless motors was that they could not generate a lot of power. When better permanent magnet materials came out in the 1980s, they made brushless motors produce the same power (or more) as previous brushed motors on the market.
 
In the late 1980s, Robert E. Lordo (Robert E. Lordo) built the first large brushless DC motor, its power is 10 times the earlier brushless motor.
 
Today's brushless motors solve many of the limitations of brushed motors by combining higher output power, smaller size and weight, better heat dissipation and efficiency, wider operating speed range, and very low noise operation. Brushless motors have no electrical contacts designed for wear and tear, and offer huge advantages for commercial and industrial applications in terms of reliability and equipment maintenance.
 
 

BLM series integrated brushless motor

NiMotion's integrated brushless motors use an integrated design to provide first-class power, performance and efficiency. From design redundancy standards and fail-safe, to effective load capacity and thrust performance, BLM series integrated brushless motors have a longer service life, higher efficiency and higher effective load.
 
The series is designed to provide market-leading high-performance and zero-vibration brushless motors, thus achieving maintenance-free use and market-leading performance.