LUBRICATING IN MULTI-TASKING MACHINE TOOLS
In multi-task machine tools, hydraulic oil makes both lubricating and power transmission functions, realizing a lubricating film that, due to its constant thickness, permits to limit vibrations and allowances, contributing to the machine precision. Usually very fine pressure filters are installed to protect the system. A customer of us, called us claiming that filter cartridges clog very frequently, thinking that this was due to a poor filter cartridge quality. We tested the fluid both before and after the filter cartridges: going outside from the filter cartridges, the fluid was really clean but coming to the filter cartridges, it was highly polluted with solid particles.
A microscope check was made: the fluid was contaminated by elastomers and metal particles both coming principally from the milling spindle. The customer, following these indications, made a check on this area and found that the gasket that should protect metal particles coming from the machined piece, was broken and small metal particles goes inside the system, risking to ruin it.
Once the gasket was replaced with a new one, the filter cartridge consumption, returned to stabilize at a normal level.