Benefits Beyond Just Cooling
While heat removal is the primary goal, an effective cooling system provides secondary crucial benefits:
- Maintains Oil Viscosity: Cooler oil maintains its designed viscosity, ensuring it can properly form a protective film between metal surfaces.
- Removes Contaminants: As the oil circulates through the cooler and its associated pump and filter, it helps keep abrasive wear particles in suspension so they can be removed by the oil filter.
- Increases Oil Life: By keeping temperatures down, the oil oxidizes much more slowly, extending its useful service life and reducing operating costs.
- Enables Higher Loads: Effective cooling allows the gearbox to handle higher torque and power demands without overheating, maximizing its design potential.
Maintenance Considerations for Gearbox Oil Coolers
- External Fouling (Air Cooled): Keep the fins clean from dirt, dust, and debris to maintain airflow.
- Internal Fouling (Both Types): Monitor oil quality. Degraded oil can form sludge and varnish that clogs the cooler’s internal passages.
- Leaks (Water Cooled): Regularly check for signs of oil in the coolant or coolant in the oil (a milky, creamy substance on the dipstick or fill cap), which indicates a failure of the cooler.
- Monitoring: The most important maintenance activity is monitoring oil temperature (in and out of the cooler if possible) and pressure drop across the cooler. A rising temperature or increasing pressure drop signals a potential problem with the cooler or the oil itself.