When you hear the word motor, you probably think of a car, truck, or heavy duty equipment. These aren't the only types of equipment that use motors, though. Motors are everywhere you look. Computers use small electric motors to operate their fans and DVD drives. Even the mixer in your kitchen uses a motor.
Many small electric motors are built with carbon brushes. A carbon brush is the component that connects electricity to the moving part of the motor. Every motor has a rotor. In order for the rotor to function, its coils must connect to complete an electrical circuit. To complete that connection, there are slip rings attached to the shaft that press the brush onto the rings. This completes the electrical circuit so that the motor has access to electricity to run.
A carbon brush isn't a brush in the traditional sense of the word. It is actually a group of very small wires. When they were first invented, they were just called brushes and were usually made of copper. Over time, the brushes were changed and carbon and graphite were used to make them. This led to their being dubbed carbon brushes.
Today, different materials are used to make brushes depending on their purpose. Copper is sometimes used for its excellent electrical conductivity. Graphite and carbon are very common materials. These materials come from a powder form, and binders are often added to the powder to help the material retain its shape. Sometimes oil or resin is added to make the brushes more durable.
Developing a carbon brush is a very sensitive process, though. Even very minor changes in composition can significantly alter the properties of the brush, so it takes extensive knowledge and experience to develop a formula that results in a brush that is exactly right for its particular application.
Types of Carbon Brushes
There are a variety of types of carbon brushes. Here are some of the most common kinds.
1. Solid carbon brushes are the most basic type of carbon brush, and, therefore, they are used on the most basic types of machines.
2. Split brushes are made from multiple carbon brush units which are combined to obtain the best possible electrical contact. Splitting the brush results in a greater number of contact points for better electrical conduction.
3. Spread brushes are a type of split brush in which two brush sections are set at a particular angle with pressure applied to the top.
4. Tandem brushes are pairs of brushes that are each set individually in their own box, which results in a symmetrical brush pressure and even distribution of the electrical current.
5. Sandwich brushes are split brushes that have been bonded together with an insulating material, resulting in a greater cross resistance.
6. Carbon brushes with wear sensor alert the operator when the brush has reached its wear limit so that it can be replaced in a timely manner.
Helwig Carbon Products has been manufacturing carbon brushes for more than 85 years. We are the leaders in the market, and we know all there is to know about carbon brushes for small electric motors. We produce carbon brushes for many industries, including:
Whatever your carbon brush application, at Helwig Carbon we can help you to find the right brush. We keep thousands of replacement carbon brushes in stock so that we can ship them to you promptly and you can get back to business. When you need a replacement carbon brush, call Helwig Carbon. We'll make sure that you get the right brush, right away.