1st ICAI 2020

International Conference on Automotive Industry 2020

Mladá Boleslav, Czech Republic

and decreases by 78 ns when the load changes from 2 kN to 10 kN. Effect of viscosity is not presented here due to its bias caused by temperature effect and manipulation with the system between the tests. This systematic bias shall have minor effect on the two depicted responses.

Figure 4: Response of signal mean value to change of parameter level

Source: Own elaboration (2020) Comparison of two propagation time signals at two different bearing speeds is depicted in Figure 5. Noticeable difference is that minimum value in low-speed record is by 60ms lower than the minimum value at high speed. On the other hand, a maximum value increases with speed only marginally, i.e. 20 ns at maximum. Figure 6 shows a progress of signal variance normalised by mean value for 3 tested oil viscosities and dry bearing during speed ramp tests. Signal was evaluated in blocks with duration driven by change of the speed by 50 rpm. Figure 5: Comparison of signals at two bearing speeds for oil viscosity 46 cSt. Signals are plotted in normalised time-scale to allow for comparison at two different speeds

Source: Own elaboration (2020)

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