Filters in central lubrication systems
One of the biggest challenges in the central lubrication of machines, systems and vehicles is to avoid contamination in the lubricant. Both in the manufacturing process and in the lubrication process itself, particles can get into the lubricant and cause considerable damage to the lubrication points. As a rule, it is oil-insoluble solid particles or lubricant-specific aging products that get into the lubricant and cause massive damage. Both before starting up a system and during assembly, metal chips, paint residues or other particles can get into the lubricant and significantly deteriorate the quality. Above all, wear and oil aging cause problems during operation.
The consequences of contaminated lubricant should not be underestimated. Insoluble solid particles not only reduce the running times of machines and systems, but in many cases can even cause premature failures and accelerated aging of the lubricant. In order to prevent such damage and to ensure a high lubrication quality, filters are generally used in central lubrication systems which remove the solid particles and contaminants inherent in the lubricant. In this way, the service life of the system to be lubricated can be significantly increased. Bearings and friction points are treated carefully and have significantly less wear. Investing in a professional filter usually pays off after a short time.
Technical background to filters in central lubrication systems
A wide range of filters are used to clean the lubricant in central lubrication systems such as single-line or progressive systems. When choosing the right filter, a whole series of criteria play a critical role. The spectrum of lubricant filtering techniques ranges from sieve and gap filters to pressure filters and oil filters to foot filters.
There are various aspects to consider when choosing a filter. The most important variable is the nominal flow, i.e. the volume flow of lubricant in the operating state of the system. The pressure loss depending on viscosity and volume must also be taken into account. Other important points are the temperature range of the lubrication system, the required fineness of the filter, the filtration ratio and the dirt capacity ACFTD. The common filter systems are suitable for ambient temperatures from -30 to +100 ° C and operating pressures of up to 100 bar.
In general, it must be ensured that the filters in the system are easily accessible and the cartridges can be easily replaced.
Different types of filters in central lubrication
The most common oil filter is the standard filter according to standard DIN 24550. This type of filter essentially consists of a housing, a filter element and a screw to lock the system. The filter element inside the housing removes the dirt particles in the lubricant and, depending on the application, can consist of fiberglass or wire mesh. Volume flows of 40 to 100 liters are common for the standard filter.
The screen filter is generally used in intermittent lubrication systems with a non-continuous volume flow. Using a hexagon, the sieve can be easily removed and replaced without loosening the pipeline. In this way, the filter set can be cleaned particularly easily.
In addition to the filter types mentioned here, a number of other systems are used in central lubrication systems. Filters with a suction basket are mainly used on the suction side of pumps and protect them from coarse contamination. Gap filters can be used excellently for cleaning particularly heavily contaminated media and are flowed through from the outside in. Pressure filters are also often used in the main and secondary lines of lubrication systems.