Is it normal for a brushed DC motor to produce sparks at the brushes during operation?

During high-speed contact between the Brushed DC Motor and commutator, small sparks are normal due to the physical characteristics of contact resistance, friction, and arc discharge. However, it is necessary to distinguish between normal micro-sparks and abnormal large sparks.

1. Normal Micro-Sparks:

Cause: This is an unavoidable phenomenon due to the physical contact between the brush and commutator. A weak arc discharge will occur when normal current passes through.

Judgment Criteria: The sparks are small and discontinuous, usually occurring only at the trailing edge of the brush (i.e., the side where the brush has just left the commutator). It has little impact on the normal operation and lifespan of the motor.

2. Large sparks under abnormal conditions:

Causes: May be due to incompatible brush material, excessive pressure, poor contact, or excessive load.

Judgment criteria: Excessive and persistent sparks may be accompanied by increased motor noise or unstable operation. Inspection should be carried out promptly.

3. Prevention and maintenance measures:

Select appropriate brush material: Ensure the brush hardness and conductivity match the motor model.

Adjust brush pressure: Excessive pressure increases friction and arc discharge, leading to excessive sparks. Adjust to the manufacturer's recommended optimal range.

Keep the commutator clean: Prevent carbon buildup that leads to uneven contact and reduces sparks.