Brushes in an electric motor play a very important role. Their useful life may depend on various reasons. The faster the speed of the vacuum cleaner, the faster the wear of the brushes usually occurs. It is believed that with proper use of brush technology, you can not change 5 years. There are cases when they have not been changed for 10 years or more. High wear of the brushes leads to their replacement. There are a number of reasons for the failure of brushes, consider them in more detail.
Electricity is supplied to the anchor windings of the electric motor using a collector assembly. During operation of the device, the anchor rotates, contact appears, the number of revolutions is quite large, this leads to strong friction. The brushes form a “sliding” contact, which translates the mechanics into electrical energy. Their main task is: to remove and supply current to the collectors. Electric current is also removed from the contact rings. The main thing is that the brushes are correctly installed. The kit with them includes lugs with wires, aimed at high-quality fastening mechanism of the bolts located on the brushes.
There are various types of them:
- graphite - aimed at simple switching, composed of graphite;
- coal-graphite - characterized by low strength, they are often used on equipment with minimal loads;
- electro-graphite - are high strength, withstand medium contact mode;
- copper-graphite - have good strength, have strong protection, which saves from gases, as well as various liquids.
There are also advanced models of brushes in a plastic case. By types, they are no different from the above, only have protection in the form of a housing or shell made of plastic.
Abnormal sparking of an electric motor
Sparks appear during mechanical action of the brush and collector. This phenomenon is formed even with a working engine. The brush moves along the collector, forms in turn, and then breaks the connection with the contacts. A small number of sparks that burn is considered an acceptable phenomenon for a working unit, but if it sparks a lot, it is necessary to diagnose the vacuum cleaner.
The actual cause of the breakdown may be an incorrect angle. Correct position: two brushes rotate parallel to each other and along one path. In the case of a long process of operation of the apparatus, the brushes in it can move, so it is necessary to control this process so that there is no distortion. If claps occur, strong sparking appears, the product body blackens, we can talk about interturn closure.
It is difficult to fix such a problem yourself; it is better to contact specialists or replace the motor.
Another cause of malfunction is wear on parts. In this case, the vacuum cleaner is completely disassembled. Brushes create contact between special electrodes, they are components of an electric motor, so first you need to diagnose it, replace old parts and continue to use the technique. Some experts advise to buy additional spare parts in the kit for the new product.
Bad contact between the elements of the technique can occur when new brushes are installed. They must be tightly installed. The malfunction occurs in the presence of dust, in this case, regularly clean the contacts. If the contact is bad, then you can let the device work for 10 minutes at neutral speeds.
Excessive stress, which is associated with high friction, creates dirt. The more carbon deposits appear, the faster the unit breaks. Contacts should always be clean.
Dirt (soot) is removed with sandpaper or chalk, then the surface must be degreased.
Brush holder selection
The main task of the brush holders is to provide pressure on the brush, its correct pressing, free movement, as well as free access to replace the brush. Brush holders differ in their pressing mechanisms and windows under the brush. Such elements are designated by letters, where the first letter is the general name of the element, the second is its type (radial, inclined, etc.), the third is the type of mechanism (tension, compression spring, etc.).
Brush holders are divided for use in industry and transport. For industrial vacuum cleaners, common industrial ones are used, we will not list their types, we will focus only on one of the effective ones - RTP. It has a coil spring of constant pressure. In this regard, you can use high brushes (up to 64 mm), which increase the life of the units. This type of holder has found its application in many electric machines, in particular vacuum cleaners.
Vacuum cleaner malfunctions can be caused by a cracked holder. We just change it to a new one. If it has shifted due to weakened fastenings, then we return it to its original state, we strengthen the fastening on both sides.
You can learn more about how to replace the brushes on the engine from a vacuum cleaner.