Experimental Data Analysis Of Rolling Bearing Friction Torque

Friction torque is one key performance parameter of a rolling bearing. Some important functions of the rolling bearing, such as rotating stability and precision are affected by it. However, some special bearings, such as satellite bearing, rocket bearing, aircraft bearing and wind power bearing require higher quality of the friction torque. As we know, almost all the mechanical products need to use bearing. Therefore, the improvement of bearing's quality has an important effect on the whole mechanical performance. In order to design bearings with higher quality, more research must be done on the friction torque.Because friction torque is affected by different kinds of uncertain factor, the changing trend of the friction torque is random and uncertain. Thus, it is quite difficult to calculate an exact result through the calculation formula. However, Compared with the calculation formula the actual experiment is more close to working condition, and more accurate and scientific. So we use the actual experiment to get test data of friction torque. Testing program is as follows: First do friction torque experiment with KAT and KBT the two types of rolling bearings at three different kinds of speeds, and then collect experimental data. At last, analyze carefully the uncertainty and nonlinear of the test data.Probability distribution and changing trend rules of friction torque of rolling bearing is unknown, which belongs to poor information system. Poor information theory can solve these poor information problems, such as small sample or probability distribution unknown, so it is a good way to use poor information theory to research uncertainty of rolling bearing friction torque in the article, including: friction torque's dynamic fluctuation range average Umean, entropy, and so on, and do deeply analysis on the research results in order to reveal the important characters of the friction torque. Research shows that both dynamic fluctuation range average Umean and entropy go up with the increase of speed. Nonlinear factor affect friction torque, so rolling bearing friction torque is nonlinear. Chaos theory can solve this kind of nonlinear problem, so chaos theory can be used to research it. If the calculated max Lyapunov index is more than zero, it proves that rolling bearing friction torque system is chaotic. On that basis, nonlinear parameters including correlation dimension and box dimension are researched in order to analyze rolling bearing friction torque's nonlinear dynamics problems. Research shows: correlation dimension presents saturation phenomenon, and this can also distinguish that friction is chaotic. Besides, correction dimension and box dimension also go up with the increase of speed.Do the related analysis between the uncertainty and nonlinear evaluation results in the end, and find the quantitative relationship between them. From the calculation of grey confidence level between rolling bearing friction toque's uncertainty and nonlinear, we get the result that the grey confidence level between uncertainty and nonlinear is quite high, all above 80%. There is a certain grey relation between rolling bearing friction torque's uncertainty and nonlinear.Elementary theories and methods studied by this paper are of versatility and feasibility. Poor information theory and chaos theory accord with rolling bearing's uncertainty and nonlinear characters. The analysis of friction torque experimental data can establish a further foundation to rolling bearing's uncertainty and nonlinear characters. It is more important to improve bearing's life span, precision and so on.