Subtopic: Three point hitches – free link and restrained link operations
Question Statement:
A fully-mounted mouldboard plough has a weight of $W_i = 6.0\text{ kN}$ with its center of gravity located $1.20\text{ m}$ behind the tractor rear axle. During plowing, the horizontal soil draft is $D = 12.0\text{ kN}$ acting at a depth of $0.20\text{ m}$ below ground level. The tractor wheelbase is $L = 2.00\text{ m}$. Under draft control operation, the total dynamic weight added to the rear drive axle ($R_{r,\text{add}} = W_i \frac{L + 1.20}{L} + D \frac{h_d}{L}$ with $h_d = 0.20\text{ m}$) in $\text{kN}$ is ________ (round off to 2 decimal places).
Answer Key:
10.80
Step-by-Step Solution & Explanation
1. Weight transfer due to implement overhang:
$\Delta W_{\text{overhang}} = W_i \times \frac{L + 1.20}{L} = 6.0 \times \frac{2.00 + 1.20}{2.00} = 6.0 \times 1.60 = 9.60\text{ kN}$
2. Weight transfer due to horizontal draft moment:
$\Delta W_{\text{draft}} = D \times \frac{h_d}{L} = 12.0 \times \frac{0.20}{2.00} = 1.20\text{ kN}$
3. Total dynamic weight added to rear axle:
$R_{r,\text{add}} = 9.60 + 1.20 = 10.80\text{ kN}$