SEED Guides Component Selection - Chain Drives < >

The performance of a chain assembly is much improved by lubrication. It reduces friction and can act as a coolant and so will help to prolong life. There are four basic methods which are employed, namely manual, drip feed, oil bath and pressure spray lubrication and each differ in their effectiveness and in installation and maintenance costs.

Manual operation - This method does not need any special implementation requirements and the oil is periodically applied by brush, aerosol or oil can. The frequency of lubrication should be such that the chain is kept wet thus enabling clean lubricant to penetrate the chain joints. The use of too thin an oil viscosity can lead to lubricant 'flinging' off as the chain rotates.

Drip Lubrication - This requires an oil reservoir and pipe feed system to enable a regular, and preferably a controlled quantity of oil lubricant to drip onto the chain.

Oil Bath - The chain assembly is usually contained in a sealed housing in which the lower portion contains a sump of oil lubricant that just covers the chain at its lowest position. The chain passes through the oil bath each revolution which also has a beneficial cooling effect

Pressure Spray - A continuous supply of oil is directed onto the chain from a pumped supply system. Ideally the stream of oil should be supplied to the inner part of the chain just prior to engagement thereby helping to cushion the impact between rollers and teeth. The centrifuging effect on the oil as it is forced around the chain sprocket aids penetration through the chain members and also improves the rate of cooling.

Because the different lubrication methods vary in effectiveness it affects the operating performance in terms of the power and speed at which a chain drive can operate at. The limiting operating boundaries are illustrated on the Chain Drive Rating Chart shown later.