Centralised lubrication devices and centralised lubrication systems

Centralised lubrication systems

Centralised lubrication devices and centralised lubrication systems

A centralised lubrication unit is used anywhere, where machines and technical equipment need supply of lubricants. The advantages of a centralised lubrication plant are the automised supply of the bearings with lubricants and that the effort of maintenance and reparations decreases.
Thus costs of maintenance for a plant sink, for the automation through a centralised lubrication plant guarantees a reliable lubrication with the right quantity of grease and within short and regular time intervals.
Even though centralised lubrications systems, which are available on the market, differ from one another in terms of application and construction, every system is based on the same kind of setting: A central storage container saves the needed number of lubricants. As key element of the centralised lubrication plant, a pump is used, which transports the lubrications out of the storage, using a transportation- or pumping element. Now the plant's control system distributes the measured amount of lubricant (either using a progressive plunger metering device or a different kind of distributor) through a pipe system to the particular bearings.

Suitable lubricants for a centralised lubrication unit

Lubricating oil are used very frequently, but they need a centralised lubrication unit, which can deliver oils in different viscosity ranges. Viscosity means that oil flows differently when temperature changes. Almost every oil is thin fluid when it's warm but more viscous when they cool down, which means that they are more semifluid. The operating temperature has an essential influence on the oil's viscosity and the more viscous the oil is when distributed, the higher are the demands of the centralised lubricant plant's pump.

Lubrication greases have quite a few advantages in regard of oils. They are less dependent on temperature and stay, after being distributed by the control system and the distributors, longer at the bearings than oils do. The grease forms a collar around the lubricating point which prevents particles of dirt and dust from ingression. Through the constant and regular delivery of a small quantity of grease through the centralised lubrication device this ring of lubricant grease is constantly renewed and thus provides best protection.

At some machines and technical plants, for example in the steel industry, a centralised lubrication device is used, which creates a mix of air and oil. Rapidly turning chains, bearings with high rotation speed or at large points with high friction this mix ensures a permanent supply of oil for the bearings.
Due to the air pressure, such points stand under high pressure so that dirt particles cannot ingress.

The choice of the right lubricants or the mix of lubricants should be made individually and in concern of the purpose of application.

Setting of different centralised lubrication units

The initiation-lubricant device is widely spread in common engineering. For example it is used with presses or packaging machines, machine tools or machines to clean bottles. This lubrication unit is suitable for up to 100 lubricating points, a pipeline of 30 metres length plus a pump pressure of 160 bar. The pump in the centralised lubrication device distributes the lubricants through a main pipeline along the machine into the distributors, which are located closely to the lubricating points. Lubrication is carried out by the pump pressuring the main pipeline. The advantage of this lubrication device is the uncomplicated extension or decrease of distribution points. This centralised lubrication unit can of cause be controlled automatically with adjustable downtimes or by trigger impulse.

A centralised lubrication unit with progressive distribution device supplies the particular lubricating points one after the other. This centralised lubrication system is useful for grease of the NLGI class 2 or oil and can supply up to 100 lubricating points. The lubrication unit with progressive distributor is used in stamping machines, scissors, woodworking machines or machine tools. The ongoing distribution of lubricants starts again after one run of the block's or segment's distributor at the first lubricating point. The big advantage of this kind of centralised lubrication device is the relatively low costs. Those are caused by the need of only one main pipeline and simple pumps and distributors.

A centralised lubrication unit is also available as lubrication system for chains, using oil or grease. Oil-lubrication systems for chains stand out through the possibility of giving only very small quantity of oil to the lubricating points during one interval of lubrication. They are used in the automobile industry for example. A chain-lubrications system based on grease needs only few moveable parts and is often used in conveying systems. Here, the lubrication unit's task is to guarantee a constant lubrication during switch phases of the sprocket wheel. Application areas are plate conveyers or conveyers for sugar beets.

A centralised lubrication unit can be equipped with a multi-line system, so that small groups of machines or units can be supplied. This kind of centralised lubrications devices are called multi-line lubrication system. Frequently, the lubricated machine can be used as a drive for the multi-line lubrication system.

More Information:
Centralized Lubrication Systems