In-depth AnalysisSimo motorsCarbon brushes: a key detail in determining powertrain stability

In the roaring industrial plant, a heavy motor is often regarded as the heart of the production line. However, many equipment maintenance personnel often ignore the fact that this expensive “heart” of the beating rhythm, often in the hands of an inconspicuous, relatively inexpensive small accessories - this is the carbon brush. For widely used in metallurgy, electric power and chemical industrySimo motorsThe selection of high-quality carbon brushes with matching specifications is not only the basis for routine maintenance, but also a decisive factor in ensuring efficient operation throughout the entire life cycle of the motor.

Why is the choice of “Sigma Motor Carbon Brushes” so important?

When the motor is running at high speeds, the carbon brushes bear the burden of conducting current between the stationary and rotating parts.Simo Motor Carbon Brushesis not a universal standard, but is based on Sigma motors (e.g. Z4)DC motorSeries, YRkkHigh voltage motorsThe product of precise matching of specific commutator materials, circumferential speeds and current densities (Series).

The delicate balance inside the motor can be easily disrupted if commercially available carbon brushes of inferior quality or mismatched models are used freely.Too hardThe commutator or collector ring surface can be violently abraded like sandpaper, resulting in expensive rework costs;Too low hardnessIf the carbon brushes wear out too quickly, the carbon powder generated in the winding gap, not only reduce the insulation properties, and may even lead to generator short-circuit burned.

Core selection index: the game of conductivity and wear resistance

When purchasing or replacingSimo Motor Carbon BrushesWhen, must pay attention to the following core technical indicators, which is directly related to the operational efficiency of the equipment:

1. Contact voltage drop: High-quality carbon brushes create a uniform layer on the contact surface of theoxide film. This film both conducts electricity and acts as a lubricant. Sigma's original or specified carbon brushes are formulated to ensure that this oxide film remains stable at high temperatures, thus inhibiting commutation sparks.
2. Coefficient of friction: Ideally, carbon brushes should have a low coefficient of friction to minimize mechanical losses and heat buildup.
3. Current Density: It must be ensured that the rated current-carrying capacity of the carbon brushes is slightly higher than the actual operating current of the motor to prevent the carbon brushes from overheating and becoming red due to overloading.

Case study: A painful lesson in “cost savings”

A large paper mill had the Z4 series for its critical work stations.Simo DC MotorReplacement of carbon brushes. The purchasing department, in an effort to reduce the cost of consumables, did not use the factory recommended specifications, but instead purchased a batch of inexpensive, general purpose D172 grade carbon brushes.

The consequences were apparent two weeks later: The motor began to show significant commutation sparks, even to the point of reaching the harmful Class 3 spark criteria. Maintenance personnel stopped and inspected the motor and found that the commutator surface had developed severeCauterizing and slottingThe phenomenon, and the inside of the casing is covered with conductive carbon powder. In the end, the factory not only scrapped this batch of poor-quality carbon brushes, but also forced to stop for three days on the commutator for fine-turning repair, resulting in the loss of production downtime is hundreds of times the difference in the price of carbon brushes.

Maintenance Points: Not Just Replacement, but Tune-Up

Having the rightSimo Motor Carbon BrushesJust the first step, proper installation and tuning is just as critical.

• Equalization of spring pressure: The spring pressure on the brush grips should be adjusted consistently. Uneven pressure can cause some of the carbon brushes to share too much current, resulting in bias grinding. It is usually recommended that the pressure be maintained at150g/cm² to 250g/cm²Between.
• Grinding radii: Before installing new carbon brushes, they must be ground with fine sandpaper so that the contact area between the contact surface and the surface of the commutator is75% and aboveIt is strictly prohibited to operate directly under load without grinding.
• Regular cleaning: Even high quality carbon brushes produce a small amount of wear powder, and regular cleaning of the inside of the motor with dry compressed air is necessary to prevent electrical failure.