Load and rotation speed play important roles in bearing are using properties. PV is their product, extreme PV is the highest PV value of bearing execution, which is an important indicator of sliding bearing. To guarantee the safety of operating, the working PV of bearing is lower than extreme PV value, and the bearing is easy to damage when working higher than PV value. Extreme PV value has close relation with bearing materials, bearing size,sustained operating time, lubrication and bearing materials.
There is small difference between macromolecule bearing materials heat dissipation and heat conduction. Once the bearing material is certain, PV value is mainly related to friction coefficient, environment temperature and bearing sizes. The smaller the friction coefficient is, the lower the heat generation is, operational PV value is higher; the higher the environment temperature is, the harder the heat dissipation is, the PV value is relatively lower; the thicker the bearing material, the longer the length is, the poorer the heat dissipation is, the lower the PV value is.
In view of many parameters and complex working condition, as well as having put forward to too many assumptions and approximates, therefore, it is hard to calculate accurately and give exact values. The PV values of materials can only get under limited conditions. It is far from precise to give materials PV values without conditions.
For the convenience of construction design and application, we conducted tests of bearing PV value on MPV50 bearing test machine. Assuming that when the temperature rises to 110 ℃, the materials are no longer suitable for usage. Fig 4-2 shows the PV-t curve ofAncoPX bearing in dry sliding.
the PVT Curve ofAncoPX bearing in drysliding
