why we are always using carbon brush in motor instead of using copper or other material brushes. because there are multiple advantages behind in the carbon brushes. so here we will briefly discuss about what are the advantages in using carbon brush in dc motors.
Advantages of carbon brush:
There are 5 main advantages of carbon brush. so we will see one by one here.
- High Melting Point
The carbon metal usually having high melting point compared to copper and other metal. the carbon brush having nearly 3550 degree C melting temperature and copper having 1080 degree C only. we all are know the brushes in dc motor connected to nearly to the commutator. so whenever motor running it will produced the spark and friction between commutator and brushes. if temperature is increase then copper brush can not with stable that’s why we are using carbon brushes.
2. Soft metal
The carbon brush is generally very soft metal compared to copper. so whenever the motor running the friction produced between commutator and brush. as per the softness of carbon brush will not damage the commutator. incase if we are using copper brush it will damage the commutator because of its hardness.
3. Negative temperature co-efficient
The carbon brush having negative temperature co-efficient. it means whenever the temperature increases then resistance automatically reduced. we know motor running time friction and heat produced and it will increase the temperature of the motor. so carbon brush reduced resistance due to increasing temperature and current flow will increases.
4. shape adopting
The carbon brush generally coming with rectangular shape but its having softness nature. if we will fix the new carbon brush near to the commutator and once the motor starts to running its automatically adopt the circular shape of commutator.
5. self lubricating
The carbon brush is having self lubricating. so its not required any other Greece or lubricating oil for cooling purpose. so when ever the motor gets off then carbon brushes are automatically get cool down.