Sahkohiili

Sahkohiili, also known as carbon brush, is a sliding electrical contact used in electric motors and generators. It is typically made of carbon or graphite, often with additives like copper or metal powder to improve conductivity and wear resistance. Sahkohiili is essential for transferring electrical current between a stationary circuit and a rotating component, such as an armature or commutator.

The primary function of sahkohiili is to maintain continuous electrical contact while allowing for rotation. As the motor or generator operates, the sahkohiili slides against the commutator segments, completing the electrical circuit. The pressure applied to the sahkohiili ensures a consistent connection, even under varying operating conditions. Over time, the sahkohiili wears down due to friction and arcing, and it needs to be replaced periodically to maintain the proper functioning of the electrical machine.

Different types of sahkohiili exist, tailored for specific applications. Factors influencing the choice of sahkohiili include the operating voltage, current density, speed of rotation, and environmental conditions. For instance, applications requiring high conductivity might use metal-impregnated carbon brushes, while those with lower current demands might opt for pure graphite. The design and material selection of sahkohiili are crucial for the efficiency, longevity, and reliability of electric motors and generators.