ECOLOGY IN TRIBOLOGY: SELECTED PROBLEMS OFELIMINATING NATURAL OIL-BASED LUBRICANTS FROMMACHINE FRICTION COUPLES

The elimination of mineral oil-based lubricants from machines has multiple beneficial effects on the naturalenvironment. Firstly these lubricants are a direct threat to the environment in the event of leaks; secondly their elimination reduces the demand for crude oil from which they are obtained. In addition, in many cases,e.g. when replacing traditional lubricants with water, friction losses in the bearings can also be reduced due tothe lower viscosity of the water, which reduces the energy dissipation in machines.On the other hand, the introduction of self-lubricating materials or water-lubricated bearings causes problemsrelated to the need to adapt the design of machines and materials used to new operating conditions and changedproperties of the lubricants. In the paper, selected examples of problems related to the use of ecologicallubricants are discussed. The high cost of PEEK based polymers resulted in the emergence of cheapersubstitutes on the market; however, in the conducted research, the substitutes presented worse properties thanthose declared by their manufacturers.