What are the complete daily maintenance schemes for magnetic powder brakes?

Magnetic Powder Brake is an electromagnetic torque braking component. With fine magnetic powder as the medium, the DC excitation current generates a magnetic field, and the magnetic powder forms rigid magnetic powder chains to transmit braking torque. The current and torque can be controlled linearly. It is mainly applied to unwinding tension control, load braking and simulation loading of coiled materials. It is widely used in slitting, film blowing, wire and cable, printing, hardware and film rewinding equipment.

Magnetic Powder Brake

Today we will talk about the complete daily maintenance plan for magnetic powder brakes.

1. Pre-shift / post-shift daily inspection

Temperature monitoring: Self-cooling housing ≤60℃, water-cooled housing ≤90℃. Shut down immediately for cooling if it feels hot, and inspect the cooling system.

For water-cooled models: Open drain valves to discharge scale in pipelines, check water pressure and leakage. Drain cooling water after shutdown to prevent frost cracking, internal condensation and magnetic powder agglomeration caused by moisture.

Observe tension stability: If tension fluctuates sharply under the same current, it is mostly caused by magnetic powder wear or moisture.

Listen for abnormal noise: Sanding or knocking sound during rotation indicates insufficient bearing lubrication or agglomerated magnetic powder.

Check wiring terminals: Fasten DC24V circuits, avoid wire breakage and short circuit.

2. Weekly Maintenance

Tighten all stator end cover and flange bolts; loose bolts will lead to magnetic powder leakage.

Clean dust on the fan filter of forced air cooling models to guarantee air volume.

Rotate the shaft manually to check axial play; replace bearings if axial play exceeds 0.2mm.

Clean oil stains on the shaft end, strictly prevent lubricating oil from penetrating into the cavity and contaminating magnetic powder.

3. Monthly Maintenance

Fill bearings with high-temperature grease in small quantity at a time; do not overflow into the magnetic powder cavity.

Flush scale inside water cooling pipelines to avoid heat dissipation failure and magnetic powder burnout caused by high temperature.

Calibrate the output current of the tension controller to eliminate zero drift.

4. Quarterly / Annual In-depth Maintenance (Replacement of Core Consumables)

Magnetic Powder Replacement (core consumable)

Replacement conditions: After 4500～7500 operating hours / torque drops by more than 15% under the same current / severe tension fluctuation

Operation: Disassemble both end covers, thoroughly blow away old magnetic powder residues with compressed air; add special magnetic powder according to standard dosage of the model (fine powder for low torque, coarse powder for high torque); run under no load for 30 minutes after assembly to break in seals.

Fully replace bearings and shaft oil seals to prevent oil leakage and water ingress.

Carry out hydraulic pressure test and leakage inspection for water-cooled models.