The importance of greasing bearings when they are moving is often not understood or is overlooked. There is a possibility that the importance is understood but is not done due to practical constraints such as moving machinery and OH&S regulations.
Grease introduced into a stationary bearing will take the path of least resistance. Many housings only have one grease entry point. Grease is typically pumped in by a high-pressure grease gun or lube system at a higher than necessary volume, in a short time. It is hoped that the new grease will make it into the bearing and remove the older grease. Some of the grease may enter the bearing but if there is any sort of constraint to its entry, it quite possibly may instead simply pass out the closest seal.
Older grease in the bearing will tend to block the entry of new grease. This older grease is likely to be on the peripheries of the rolling surfaces, not on the areas of contact where lubrication is needed. This means that the older grease, which may be oil depleted, additive-depleted, contaminated or oxidised, remains. Not only is it limited as a lubricant, but its presence impedes the entry of new grease into the rolling elements. In short, the bearing may not have been lubricated even though grease has been added to the housing.
The optimal time to grease a bearing is when it is moving. A moving bearing has less resistance to grease input. Slow and progressive grease input at low pressure into a moving bearing allows the grease to be taken up into the moving bearing elements. Grease added slowly and regularly will provide continuous purging of grease that has reached the end of its useful life. As a result, older grease is prevented from remaining in the bearing long enough to become depleted or contaminated, or worse, to harden, and become a lubrication maintenance problem.
Correctly lubricating a bearing in this manner will also reduce grease requirement as the grease is more efficiently used. The actual amount of grease needed to lubricate the contact surfaces is quite small. To achieve this improved efficiency, however, the grease must be introduced slowly and continuously. Lower grease use results in less contamination clean up, being better for both the environment and costs.
The benefit of lubricating bearings slowly and continuously, when they are moving, can be measured in terms of reduced failures and productivity increases.
GreaseMax lubricators provide an effective and proven method of reliably providing continuous lubrication in all industries and operating environments.