To understand the basic distinction between the two technologies, it is essential to know their structural and operating particulars. A mechanically commutated engine comprises a rotating wire-wound armature and a fixed-in-place ring with electromagnets or permanent magnets.
In addition, the device includes a commutator, a shaft-mounted cylinder linked to the armature winding, and a couple of brushes, typically made of non-hard conductive substances e. As the armature is energized, a magnetic field is generated, making the rotor turn. The rotation continues in the same direction for half of the full circle, at which point current has to be reversed. This is the zero-torque point where brushes come into play, interfacing with the commutator to switch current.
In this way, rotating motion goes on without interruptions, thus enabling the engine to produce torque continuously without changing it direction. A brushless motor is identical to the previously described class in that both engines have moveable and stationary components. Namely, a rotor and a stator. However, brushless drives, in full concordance with the name, have no brushes to provide commutation.
Instead, engines of the type are fitted out with semiconductor-based transistors. Since mechanically engaged elements are no longer there to commutate, power is fed immediately to the stator coils, where it creates a magnetic field.
Rotational movement results from the field interacting with the rotor magnets. Once the half-turn reference is reached, transistors do the job of reversing or disconnecting amperage, producing torque in the same direction.
Major improvements achieved through replacing the mechanics-based commutation with solid-state electronics are associated with the following characteristics:. The data below summarizes the distinctions between the two technologies based on the above specifications:.
A computer then charges the electromagnets in the stator to rotate the rotor a full degrees. Brushes eventually wear out, sometimes causing dangerous sparking, limiting the lifespan of a brushed motor. Brushless DC motors are quiet, lighter and have much longer lifespans.
Because computers control the electrical current, brushless DC motors can achieve much more precise motion control. Because of all these advantages, brushless DC motors are often used in modern devices where low noise and low heat are required, especially in devices that run continuously. We'll find the right solution based on your needs and explain the alternatives. Order Online My Account.
Exact Match Any Related. Linear Slides Slide Only. Compact Electric Cylinders. Rotary Actuators Hollow Rotary Actuators. Axial Fans Axial Fans. Enclosure Fans Enclosure Fans. Thermostats Thermostats. AC Motor vs. Brushed Motor. Brushless DC Motor vs. Brushed Motor? Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Solid State Electronics. The brushes eventually wear out. Having the electromagnet in the center of the motor makes it harder to cool.
The use of brushes puts a limit on how many poles the armature can have. The poles on the stator of a two-phase BLDC motor used to power a computer cooling fan. The rotor has been removed. Because a computer controls the motor instead of mechanical brushes, it's more precise.
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