Technical Requirements And Maintenance Of Generator Brush Device

The brush device is the conductive part that rotates the generator, and is composed of parts such as a brush, a brush holder, a brush rod and a brush rod seat. A device that connects circuits and fixed parts such as commutators, slip rings, etc. In a DC motor, brushes connect the rotating armature to an external circuit, so that current is input to or output from the armature through the brushes. In the synchronous motor, the excitation current is input to the rotor coil through brushes and slip rings.

1. Brush pressure.

The brushes must have proper pressure in contact with the commutator or slip ring. Excessive pressure will accelerate the wear of the brush and the commutator or slip ring. If the pressure is too small, the brush will easily cause vibration and poor contact, resulting in sparks and burn out the commutator or slip ring. Usually the brush spring pressure is 20~25kPa (0.2~0.25kgf/㎠).

2. The cooperation between the brush and the brush holder.

The inner surface of the brush holder should be smooth without dents and burrs, the brush should be able to slide up and down freely in the brush holder but not swing, and the gap between the brush holder should generally be 0.15~0.3mm. If the clearance is too large, the brush is prone to tilt, resulting in poor contact with the commutator or slip ring, which is likely to cause vibration. Too little clearance can cause the brushes to get stuck and make poor contact with the commutator or slip ring. Both conditions will cause brush sparks.

For brushes with too large gaps (that is, the size of the cross-sectional area of the brushes), the appropriate brushes should be replaced. For the gaps that are too small due to the large cross-sectional area of the brushes, glass fine sandpaper can be used to grind them to a suitable value.

3. The distance between the lower edge of the brush holder and the commutator or slip ring.

The lower edge of the brush holder is generally 2~3mm away from the surface of the commutator or slip ring. If the distance is too large, it is easy to cause vibration and sparks when the commutator or slip ring rotates.

4. The correct position of the brush is generally on the axis of the magnetic pole. If the position of the brush is incorrect, it will cause sparks under the brush, the commutator and the brush will heat up violently, and the generator voltage will be too low or cannot be established. Therefore, when disassembling the overhauled motor, pay attention to the position of the brush and mark it well. When assembling, the brush is installed in the original position.

Guangxi Dingbo Generator Set Manufacturing Co.,Ltd. was founded in 2006 and is one of the earliest manufacturers of generators and diesel generator sets in China. The company has a registered capital of 9.5 million yuan. The main products are diesel engines, generator sets, and diesel generators, providing users with a one-stop service of design, supply, debugging and maintenance at any time. Dingbo has always insisted on using first-class talents, building first-class enterprises, manufacturing first-class products, creating first-class services, and making every effort to build a first-class domestic enterprise. If any question please feel free to visit our website https://www.dieselgeneratortech.com/ or send email to sales@dieselgeneratortech.com.