The source of pollutants in the system Solid particles are the main source of pollutants, which are generated by:

1, in the process of processing the remaining equipment processing iron filings, dust, impurities, etc .;

2, due to friction between parts or seals wear debris generated;

3, due to pipeline corrosion, rust and the resulting small particles. These particles will directly affect the reliability of the system at work and part of the life of the components. For example: the particles plug the spool, affecting the movement of the machine process, the particles of the pump with the oil pan damage, so that the machine produces a lot of noise, and affect the pump life and so on. In order to improve the life of the machine and reduce unnecessary particles, so the machine must have the choice of installation filters.

With the hydraulic system in a variety of precision valves such as proportional valve, servo valve a lot of use. Hydraulic system failure caught our attention. This failure is more obvious after using the proportional valve and servo valve. Therefore, the correct choice of filters in the design process is to ensure the normal operation of the hydraulic system and extend the life of hydraulic equipment, the key.

The role of hydraulic filters filter hydraulic system in a variety of impurities. The main sources are: mechanical impurities remaining in the hydraulic system after cleaning, such as water rust, sand, welding slag, iron filings, paint, paint and cotton yarn scraps, external impurities into the hydraulic system, such as the filling port and Dust and other places into the dust; the work process of impurities, such as seals by the formation of hydraulic debris, the movement of the metal particles produced due to wear and tear, the oil due to oxidative deterioration of the gum, asphaltene, carbon residue . The impurities mixed with hydraulic oil, along with the role of hydraulic oil circulation, will play a destructive everywhere, seriously affecting the normal operation of the hydraulic system, such as hydraulic components in the relative movement between the components of a small gap (in μm) and Flow holes and cracks stuck or blocked; destruction of the relative motion of the oil film between the components, scratch the gap surface, increasing internal leakage, reduce efficiency, increase heat, aggravate the chemical reaction of the oil, the oil metamorphism. According to the production statistics, more than 75% of the faults in the hydraulic system are caused by the impurities mixed in the hydraulic oil. Therefore, it is very important for the hydraulic system to maintain the oil liquid and prevent the oil pollution.

When we choose the filter, it is usually to consider the filtering accuracy of the filter. In fact, it is also important to select the filtering efficiency of the filter and the service life of the filtering material. At present, the β value of the filter is usually used internationally to represent the filtration efficiency of the filter. The beta value is the ratio of the number of particles greater than a certain size in the fluid at the filter inlet to the number of particles larger than a certain size in the fluid at the outlet of the filter. Therefore, the larger the value of β, the higher the filtration efficiency of the filter.

For the filter in the hydraulic system configuration, usually the following:
1, suction filter, the main role of protection of the pump, in order to prevent the pump due to blockage caused by suction empty.
2, the pressure filter, mainly for the valve accuracy of the system requires a higher, especially with proportional servo valve system.
3, back to the oil filter, this filter has played an indirect role in protecting the entire system.
4, a separate loop filter, which is a dedicated pump and filter independent of the entire hydraulic system of the filter circuit, this filter device is generally applicable to large machines.

In addition to the above oil filter, the fuel tank should also be installed on the air filter used.
During hydraulic system design, the filter can not be considered ancillary components and ignore it, ignore it. We should make good use of it according to the actual situation, try our best to make the life and performance of the machine better, and make the lowest cost of the machine.