Heavy Construction & Quarrying Industries
Special attention must be given to the impact of wear and tear, dust, dirt, heavy loads and wet conditions. In lubrication terms this combination is one of the most challenging. These challenges need to be met with the correct combination of products to ensure maximum protection is afforded at all times.
“Heavy Industry” in general uses large, slow-moving bearings in large machinery working in dirty and, in many instances, wet conditions. The working environment for heavy mobile plant, even in the U.K. and Ireland can also mean extreme temperatures ( -20˚C in the winter and hot +30˚C in the summer).
Slow rotation poses a problem with lubrication (particularly for grease). The relative speed of the moving element, this may be a pin and bush or a rolling element bearing, is not fast enough to create a separating film of oil between the two surfaces. When the speed of movement is very low a lubricating film cannot be created by the oil, regardless of the viscosity. Under this speed the additive package or the extreme pressure (EP) properties of the grease becomes very important. It is often recommended that solid lubricants that provide “barrier lubrication” such as Mos2 additives, graphite additives or Teflon additives be used to provide anti-wear protection and to prevent metal-to-metal contact.
In addition to lubricating an important role of grease in a dirty-wet environment is its ability to block the path of contamination into the bearing and to carry away the contamination. To provide contamination protection the grease does not have to be going to the bearing; it can be applied to the external seals or cavity beside the bearing to prevent and push away dirt before it gets to the bearing.
Another important factor to consider is that machine vibration and shock loading play a major role in heavy plant lubrication. In a machine that runs smoothly, a reservoir of grease is built up, when a bearing experiences vibration or shock from external sources, it causes the grease to slump into the moving parts at a much greater frequency, causing basic multi-purpose greases to break down much faster. More crucially it can cause the grease to purge away faster from the bearing cavity. Another concern is that constant vibration can cause oil separation from the body of the grease, rendering the grease ineffective.
MDS Europe have spent many years developing a range of products specifically designed to overcome these unique challenges and ensure the highest levels of performance and protection for heavy plant and machinery.