Traction and Clutch Effects on the Natural Frequency and Vibration Stability of Limited Slip Differential Axles 2007-01-2295
The torsional natural frequencies of axles equipped with limited slip differential clutches depend on whether or not the tires and clutches are slipping since the effective inertia at each end of the axle is different for slipping and non-slipping conditions. Limited slip axle vibrations are typically analyzed for one tire slipping and the other not since that is the case for which the limited slip clutches are used. Vibrations often arise, however, during normal turning when both drive tires have good traction.
Models for estimating the torsional natural frequencies of limited slip axles are presented for the cases of:
Non-slipping clutches, neither tire slipping
Non-slipping clutches, both tires slipping
Non-slipping clutches, one tire slipping, one tire not slipping
Slipping clutches, neither tire slipping
Slipping clutches, both tires slipping
Slipping clutches, one tire slipping, one tire not slipping
Vibration frequencies varying from below 1 Hz to about 500 Hz are shown to arise due to differing conditions, and experimental data are presented that support the theoretical conclusions.
The damping on each axle provided by the clutches is shown to be the average damping rate of the clutches due to coupling through the differential. To ensure vibration stability the sum of the μ-v slopes of the clutches should be positive.
Understanding axle torsional vibrations under different operating conditions will assist in the development of future generations of lubricants that extend gear life and suppress vibration in limited slip differential axles.
Citation: Cameron, T., Hewette, C., McCombs, T., DeGonia, D. et al., "Traction and Clutch Effects on the Natural Frequency and Vibration Stability of Limited Slip Differential Axles," SAE Technical Paper 2007-01-2295, 2007, https://doi.org/10.4271/2007-01-2295. Download Citation
T. M. Cameron, C. Hewette, T. McCombs, D. DeGonia, T. C. Jao
Kettering University, Afton Chemical Corporation
SAE 2007 Noise and Vibration Conference and Exhibition