Saving costs with plain bearings Part 7: Reducing lubrication or avoiding it altogether
Lars Butenschön | 9. December 2022
Lubricating grease and ensuring or maintaining lubrication represent a major cost factor for the operation of many devices and systems. Everything that moves is subject to the laws of friction and wear. To minimise these effects, bearings and other moving parts are often lubricated with grease or oil. In many cases, the sufficient supply of the right lubricant determines the functionality of the parts. In order to avoid even higher costs due to damage that may occur, even high costs incurred for lubrication are accepted.
Lubrication – Direct and indirect costs
The costs consist first of all of the actual lubricant. Particularly in applications in demanding environments, such as in the high-temperature range or in contact with foodstuffs, suitable lubricants cost a lot of money. But even without expensive special greases, lubrication means work. Design measures to ensure that the grease is kept in the bearing point as far as possible necessitate elaborate designs for seals and bearings. Another aspect consists of concepts such as the so-called loss lubrication. This technique is mainly used for construction machinery. In the process, lubricating grease is permanently pressed into the bearing points, which are relatively open to the outside. This permanently forces grease, that keeps dirt, dust and moisture away from the components, out of the bearing point and into the environment. Ecological damage, which in case of doubt also incurs monetary costs, has more importantly a lasting impact on the environment.
But that was not all. Lubrication also incurs additional costs. Providing the lubrication points with grease or oil costs time and effort for personnel. Depending on the complexity of the system, the work requires trained specialists who apply the right amount of lubricating grease at the right time – usually according to the maintenance plan. For this, the machines have to stop for a while. Time that cannot then be used for production. If errors occur or the work is not carried out on time or inadequately, expensive unplanned breakdowns and repairs are imminent. Central and automatic lubrication systems are an alternative, but they also cost money and require design measures and changes to components that – you guessed it – also cost money.
The solution: lubrication-free bearings
However, bearing points can often be designed in such a way that they do not require lubrication. Depending on the design and external environmental conditions, either initially lubricated “maintenance-free” bearings or dry-operating bushings and ball bearings can be used. The best-known products on the market are solid plastic bearings that have been “tribologically optimised” especially for use as plain bearings, or metal-composite bushings with an extremely thin PTFE gliding layer. Both solutions offer different advantages and disadvantages that need to be weighed up in the respective application. However, they both offer the great advantage of not requiring any additional lubrication. Thus, the above-mentioned costs are reduced to a minimum.
Beyond avoiding lubrication, there are of course many other ways to save costs. You can find more useful information on this in our white paper entitled “Seven tips for finding the hidden costs of your plain bearings and saving money easily”.