Some Discussions on Slip Sinkage of the Driving Wheel of a Tractor (II)
On the Contact Pressure, Contact Length, Slippage and the Slip Sinkage
1974 Volume 35 Issue 4 Pages 335-344
Details
1974 Volume 35 Issue 4 Pages 335-344
The aim of this study is to find out the transient phenomenon of slip sinkage of the drive wheel in operation with drawbar pull.
In this paper, the following items were found experimentally and discussed:
1) Relation between the silppage, s and the potential sinkage h0 which is the sinkage at the steady state running of vehicle.
2) Transient phenomenon of slip sinkage of the driving wheel.
3) Relation between the contact length of the driving wheel, the contact pressure and the sinkage.
Results are summarized as follows:
1) A transient phenomenon of the slip sinkage of a driving wheel can be simulated approximately as equations (2) and (7). They are
dh/dt=K (h0-h) (2)
dh/dt=K1h (h0-h) (7)
2) Relation between the potential sinkage h0 and the slippage s when the initial static sinkage is not considered, can be exprssed as
h0=0.57s+3.44 (19)
3) Coefficients K and K1 are related to the slippage respectively as follows:
K=-0.15s+13.06 (20)
K1=-0.4 (s/75-1.0) (21)
K and K1 decrease with an increment of slippage s.
4) The contact length was almost constant in spite of an increment of sinkage. The ratio α/β is proportioanal to the sinkage (hs+h0) when the initial static sinkage hs is considered. This is the reason why the angle α increases when the wheel sinks.
5) The maximum contact pressure has a negative linear relation to the sinage (hs+h0) because the increase of sinkage promotes the slippage of the driving wheel and it results in the increase of an angle α.
