What is a carbon brush?
A carbon brush, also known as a sliding contact, is a crucial component in many electric motors, generators and electrical machines. It usually consists of a block of pressed carbon, often with copper or other metallic additives to improve electrical conductivity. The material is valued for its wear resistance and good electrical conductivity.
The primary function of a carbon brush is to transfer electrical current between a fixed and a moving part, typically between a stationary part of the motor, such as the brush holder, and a rotating part, such as the commutator or slip ring.
The carbon brush enables the motor to transmit power and signals efficiently by ensuring a continuous but flexible electrical connection. Typically, carbon brushes are standardized, with specific industry standards applied to ensure compatibility with various electric motors and devices.
Carbon brushes - a portrait of materials and functions
The materials of carbon brushes can vary in order to meet different technical requirements, for example with regard to sparking, conductivity, hardness and abrasion resistance. Carbon brushes are mainly made of graphite, carbon, copper or a mixture of these materials - often supplemented by other metals or additives to improve the properties.
A key advantage of carbon brushes is their ability to handle high current densities while being mechanically soft enough to protect the commutator from wear. Their physical properties allow them to slide easily during operation, ensuring continuous and efficient transmission of electrical current.
The effectiveness and durability of carbon brushes are therefore crucial for the performance and reliability of motors in numerous applications, from industrial machinery to household appliances.
What do carbon brushes do in an electric motor?
In an electric motor, a carbon brush serves as a moving conductor that transfers the current to the rotating part of the motor. By positioning it in a holder, it is constantly pressed against the rotating commutator, enabling a continuous flow of current.
From household appliances to rail transportation - areas of application for carbon brushes
Carbon brushes are used in a variety of industries where electric motors and dynamic power transmission systems are required. In the automotive industry, for example, they are essential for starter generators and window regulators. They are also of central importance in household appliances such as vacuum cleaners and washing machines.
In industry, carbon brushes are used in large motors for production plants, in power generation and transmission, for example in generators and turbines. They also play an important role in railroad technology, where they are used in the drive systems of trains.