What is a brush motor? How is the applicability?

Brushed motors are widely used in household electrical appliances and hand tools. So what is a brush motor? How is the applicability? Let’s find out with Tnhelearning.edu.vn now!

What is a charcoal brush?

Charcoal brushes are components that are designed like small brushes or brooms, made from coal and wrapped around copper wires.

The brush is responsible for transmitting power and connecting the stator and rotor components, it is often installed in AC motors and DC motors.

In fact, depending on the current and load of the device, the material and structure of the brush can be changed accordingly, such as double brush, single brush, split brush and sandwich texture brush .

Brush motor is a motor with a coil located on the rotor , working based on the contact mechanism between the commutator and the brush , thereby supplying electricity to the coil.

In which, the brush element is pushed by the coil spring or leaf spring to keep sliding and contacting on the surface of the commutator (or the contact slip ring), thereby maintaining the power to the rotor.

In general, the brush motor has a simple structure , is easily controlled by a switch without using a separate controller, for stable machine performance at 75 – 80% .

Structure of the carbon brush

Charcoal brushes are designed in the shape of a brush , made from coal consisting of carbon and some other compounds (such as copper or nickel), and many copper wire cores wrapped around .

The brush provides the load power to the commutator through a spring (forms of leaf spring, coil spring or pecking spring). The inside of the brush contains an electrical conductor with one end that will be glued (or used a latch) placed inside with a length of about 3 – 5 mm .

While, outside the brush is a carbon plate that will be marked so that the user can recognize the wear as well as when it is necessary to replace the new carbon brush.

Working principle of carbon brush

The coal (carbon) end of the brush will be pushed out , to contact and slide on the power commutator, conducting power to the rotating part of the motor.

When the push spring comes into contact with the commutator, there will be a gap of about 0.8 – 1 mm between the brush and the support surface, which makes it easier for the brush to move and perform its job.

In case, the gap does not ensure the width is from 0.8 – 1 mm, which easily makes the brush work unstable and may be damaged. As follows:

• Gap width less than 0.8 mm : The carbon brush will expand due to the heat generated during the operation of the device, causing the brush to get stuck and cause damage to both the holder and the brush.
• Gap width greater than 1 mm : Brushes will be shaken, if this situation is prolonged, it can easily lead to wear, even sparks that cause motor circuit damage.

What are carbon brushes used for?

Brushes are conductive components, widely used in electric tools, household appliances and motor motors such as:

• Hand-held power tools : Drills, cutters, grinders, polishers, saws,…
• Household appliances : Blender, hair dryer, vacuum cleaner, …
• Industrial equipment : Generators, industrial vacuum cleaners, industrial cutters, …
• Starter motors and wiper motors for cars and motorcycles.

Hopefully, the above information will help you understand more about what a brush motor is and its benefits when appearing in motors and electrical equipment!