What Are the Key Operating Precautions for Brushed Motors?

Brushed motors are highly sensitive to power supply parameters—using incorrect voltage or current is the top cause of premature failure. First, check the brushed motor’s nameplate or manual to confirm its rated voltage (e.g., 6V, 12V, 24V) and never exceed ±10% of this value. Supplying too high a voltage causes the motor to spin too fast, generating excessive heat that burns out windings or damages brushes. Too low a voltage leads to insufficient torque; the motor may stall under load, drawing abnormal current that overheats the coil. Use a stable power supply with a current rating matching the brushed motor’s maximum current draw (starting current is typically 2-3 times the rated current). Install a fuse or circuit breaker in the power line to protect against current surges. Ensuring a steady, properly rated power supply keeps the brushed motor running within safe limits.

Lubrication is critical for reducing friction between the brushed motor’s rotating parts (armature, bearings, and bushings). Over time, lubricant degrades or dries up, causing metal-on-metal contact that increases wear and generates heat. Every 500-1000 operating hours, disassemble the brushed motor (following the manual) and apply the manufacturer-recommended lubricant—usually a light machine oil or grease. Focus on lubricating the bearing seats and armature shaft ends; avoid over-lubricating, as excess grease can attract dust or seep into the commutator and brushes, causing poor contact. For brushed motors in dusty or high-temperature environments, shorten lubrication intervals. Regular lubrication minimizes friction, extends the lifespan of moving parts, and prevents the brushed motor from overheating during operation.

Brushed motors are designed for specific load limits—overloading or prolonged stalling severely damages them. Overloading means the motor is forced to work harder than its rated capacity, increasing current draw and causing the windings to overheat. Prolonged stalling (when the motor can’t rotate despite being powered on) is even more harmful: the current spikes to 5-10 times the rated value, burning out windings or melting the commutator in minutes. To prevent this, ensure the load doesn’t exceed the brushed motor’s rated torque. Install a torque limiter or overload protection device if the motor operates under variable loads. If the motor stalls unexpectedly (e.g., due to jammed machinery), shut off power immediately to avoid damage. Avoiding overloading and stalls protects the brushed motor’s internal components and ensures reliable operation.

The brushes and commutator are the most wear-prone parts of a brushed motor—their condition directly affects performance and lifespan. Check the brushes every 300-500 operating hours: ensure they have sufficient length (replace if worn down to 1/3 of their original size) and are making good contact with the commutator. Worn, cracked, or unevenly worn brushes cause sparking, poor conductivity, and commutator damage. Inspect the commutator surface for wear, scratches, or carbon buildup—clean it gently with fine sandpaper or a lint-free cloth dampened with alcohol. If the commutator is severely worn or has deep grooves, it may need resurfacing or replacement. Ensure the brush springs are functioning properly (weak springs cause poor contact). Regular inspection and maintenance of brushes and commutator reduce sparking, improve efficiency, and extend the brushed motor’s service life.

Brushed motors generate heat during operation, and poor ventilation causes heat buildup that damages insulation and components. Ensure the motor’s cooling vents are clean and unobstructed—clear away dust, debris, or dirt that blocks airflow. For brushed motors installed in enclosed spaces, use a cooling fan or heat sink to dissipate heat. Protect the brushed motor from harsh environments: avoid exposing it to moisture, dust, or corrosive chemicals, which cause rust, short circuits, or brush degradation. Use a protective cover or enclosure for motors in outdoor or dusty settings; ensure electrical connections are sealed to prevent water ingress. For brushed motors in high-humidity environments, choose corrosion-resistant models or apply a rust inhibitor to metal parts. Good ventilation and environmental protection prevent overheating and corrosion, keeping the brushed motor in good working condition.