Friday, August 28, 2009

Selection of lubricant for the gearboxes.

The selection of lubricants are very essential requirement for the mechanical engineers for the mechanical reducers / gear boxes. The lubricant which is selected can provide lubrication for both the gears and bearings as well.

Here are the essential parameters were given for choosing the proper lubricant.

1. Extended Drain Intervals:
The lubricant that is filled in the gearbox must have a tendency to retain its property over a long duration of time. This will enable the lubricant to be used for a long period of time without changing the oil. The intervals between the oil changes in the gearbox should be relatively long. This also reduces the cost involved in changing the lubricant.

2. Seal and Paint:
Compatibility: All gearboxes have an oil seal to prevent oil from escaping outside and to prevent the external dirt from entering the gearbox. The Oil Seal is normally made up of rubber. Similarly, all gearboxes are painted on the inner surface where the lubricant is contained. The lubricant should be chemically neutral which will prevent it from reacting with the paint and the oil seal.

3. Superior Demulsibilty:
A majority chunk of the gearboxes work in a atmosphere containing high humidity levels. There is every chance of water entering into the gearbox via its breather and mix with the lubricant. The lubricant must have a high demulsibilty, which prevents it from mixing with water.

4. Exceptional Temperature Stability:
The lubricant must have good temperature stability i.e. it must have a flatter viscosity temperature slope. This will enable the lubricant to retain the viscosity even at higher temperatures.

5. Good Oxidation and Non- Foaming Stability:
The lubricant must have good oxidation stability, which will prevent it from oxidizing with contaminants in the lubricant. Non Foaming stability is required to keep the oil from over flowing out of the gearbox.

6. Cooler Running of the Gearbox:
The lubricant must possess good thermal conductivity. The heat generated in the gears must be effectively carried from them and transferred to the casing of the gearbox for conduction of the heat to the atmosphere. The real properties of the lubricant that need to be looked into before selecting them for use in a gearbox.