The lubrication system of a Loesche vertical roller mill (VRM) in a cement plant is critical for ensuring smooth operation, reducing wear, and prolonging the lifespan of key components. Below is an overview of the lubrication system in a Loesche mill:
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1. Key Components Requiring Lubrication
– Grinding Rollers & Table (Grinding Track): High-pressure hydraulic systems and oil lubrication for bearings.
– Main Reducer (Gearbox): Oil circulation system for gear and bearing lubrication.
– Hydraulic Tensioning System: Ensures proper grinding pressure.
– Roller Swing-Out Mechanism: Grease lubrication for pivot points.
– Classifier (if applicable): Bearings and gears require lubrication.
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2. Types of Lubrication Systems
# (A) Gearbox Lubrication System
– Uses a circulating oil system with pumps, filters, and coolers.
– Oil grade: Typically ISO VG 220 or 320 (depends on manufacturer specs).
– Functions:
– Lubricates gears & bearings.
– Removes heat via oil coolers.
– Filters contaminants to prevent wear.
# (B) Roller Bearing Lubrication
– Grease lubrication: Automatic greasing systems for roller bearings.
– Oil lubrication (for larger mills): Circulating oil with centralized systems.
# (C) Hydraulic System
– High-pressure oil for grinding force adjustment.
– Filters & coolers maintain oil quality.
# (D) Centralized Lubrication System
– Automated grease distribution to bearings, pivot points, and sliding surfaces.
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3. Common Lubricants Used
| Component | Lubricant Type | Typical Grade |
|———–|—————|—————|
| Gearbox | Mineral/Synthetic Oil | ISO VG 220/320 |
| Roller Bearings | High-Temp Grease / Oil | NLGI 2 / EP Grease |
| Hydraulic Unit | Anti-wear Hydraulic Oil | ISO VG 46/68 |
| Swing Mechanism | Lithium-based Grease | NLGI 1/2 |
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4. Maintenance & Monitoring
– Oil Analysis: Regular checks for contamination, viscosity, and wear metals.
– Filter Replacement: Prevents clogging and ensures clean oil flow.
– Greasing Intervals: Follow Loesche recommendations (often automated).
– Temperature Monitoring