The lubrication system for ball mills in cement plants is critical for ensuring smooth operation, reducing wear, and extending the lifespan of mill components. Here’s a detailed breakdown:
—
1. Key Components Requiring Lubrication
– Main Bearings (Trunnion Bearings) – Support the rotating mill shell.
– Girth Gear & Pinion – Transmit motor power to the mill.
– Motor & Reducer Bearings – Drive system components.
– Slide Shoe Bearings (in some designs) – Alternative to trunnion bearings.
—
2. Types of Lubrication Systems
# (A) Centralized Lubrication System (Automatic)
– Used for continuous lubrication of girth gear, pinion, and bearings.
– Common types:
– Oil Circulation System (Forced Lubrication)
– Pumps oil to trunnion bearings via filters and coolers.
– Includes temperature and pressure monitoring.
– Oil Mist Lubrication
– For girth gear/pinion; creates an oil mist for even distribution.
– Grease Lubrication (for smaller mills or auxiliary components)
# (B) Manual Lubrication (Less Common in Large Mills)
– Used for smaller mills or backup systems.
– Requires periodic greasing of bearings/gears.
—
3. Lubricants Used
– Trunnion & Slide Shoe Bearings: High-viscosity EP (Extreme Pressure) gear oils (ISO VG 220–460).
– Girth Gear & Pinion: Open gear lubricants (sprayable semi-fluid grease or high-adhesion oils).
– M
r/Reducer: Synthetic or mineral oils (ISO VG 68–150).
—
4. Critical Considerations
1. Oil Filtration & Cooling
– Contaminants cause bearing failure → Use filters and magnetic separators.
– Oil coolers maintain optimal temperature (~40–50°C).
2. Alignment & Load Distribution
– Misalignment increases friction → Proper mill alignment is essential.
3. Monitoring & Maintenance
– Sensors for oil flow, pressure, temperature, and debris detection.
– Regular oil analysis to check viscosity, water content, and metal particles.
4. Girth Gear Spray System