Original paper(Vol.45 No.10 pp.1113)
Fatigue life estimation of flexible coupling plates for power driving in electric cars
Ohba Hiroaki; Matsuyama Shinsaku
Abstract:Flexible coupling plates to transmit the rotating power between traction motor and pinion are often subjected to surface damages such as fretting and/or pitting corrosion which may very rarely lead to fatigue failure.
To evaluate the well-founded service life, specimens sampled from the coupling plates used during different service periods have been tested by a Schenck-type fatigue tester. The residual lives dominated by surface defects; fretting and/or pitting corrosion, have been estimated in the lower stress amplitude range than the fatigue limit which occurs in actual loading, using modified Miner's rule.
The permitted running distances after surface defects attain morphologically to a stable stage are evaluated to be 5x106 km for fretting and 3x106 km for pitting corrosion, in comparison with 12x106 km in case of no defect initiated, on the assumption that the upper half range in the maximum stress spectrum in service loading is effective to fatigue damage.
Key Words:electric cars, flexible coupling plates, fretting, pitting corrosion, fatigue life, modified Miner's rule