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JGM
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What would the torque on a driveshaft be for a 8 ton vehicle in park on a 16% grade? Tire radius is 19". Axle ratio it 7.1.
Welcome to the PF.JGM said:What would the torque on a driveshaft be for a 8 ton vehicle in park on a 16% grade? Tire radius is 19". Axle ratio it 7.1.
Trying to determine the loads on an output shaft of a transmission when parked on a grade with different axle ratios. Not for school work. Just general knowledge.berkeman said:Welcome to the PF.
Is this question for schoolwork? What is the context of the question?
jack action said:If the rear wheels support the entire load caused by the slope, the force acting at the rear tires is ##F_w = W\sin\theta##, where ##W## is the weight of the vehicle and ##\theta## is the angle of the slope (reference). ##100\tan\theta = \%slope## to find the angle of the slope (reference).
The wheel torque produced is ##T_w = F_w r##, where ##r## is the tire radius.
The gear ratio reduces the torque seen by the driveshaft, so ##T_d = \frac{T_w}{GR}##, where ##GR## is the axle gear ratio.
##\theta = \arctan\frac{16}{100} = 9.1°##
##F_w = (16000\ lb)\sin9.1° = 2530\ lb##
##T_w = (2530.5\ lb) * (1.583\ ft) = 4006\ lb.ft##
##T_d = \frac{4006\ lb.ft}{7} = 572\ lb.ft##
pounds is a unit for weight not mass, already includes gravity.JGM said:Shouldn't this include the acceleration of gravity?
F_w = 16000 Lbs* 32.174 ft/s2
That is because we don't use the same numbers:Baluncore said:I used SI units.
Mass = 8000 kg.
Force due to gravity = 8000 * 9.8 = 78400 Newton.
Wheel radius is 39” = conveniently 1 metre.
16% grade = 9.09 deg; Sin(9.09°) = 0.158
7:1 axle ratio.
Drive shaft torque = 1m * 78400N * 0.158 / 7 = 1769.5 Nm
1769.5 Nm = 1305.1 ft.lbs
This is quite different to jack action's 572. ft.lb
https://en.wikipedia.org/wiki/Short_tonBaluncore said:Are vehicle weights in the USA always specified in Short Tons = 907.18 kg = 2000 lbs ?
Prop Shaft load parked on a grade refers to the amount of weight and stress placed on a propeller shaft when a vehicle is parked on an incline or decline.
It is important to consider because the weight and stress placed on the propeller shaft can affect its performance and longevity. It can also impact the overall stability and safety of the vehicle.
The steeper the grade of the slope, the higher the prop shaft load will be. This is because the weight of the vehicle is distributed unevenly, causing more pressure on the propeller shaft.
Yes, there are steps that can be taken to reduce the prop shaft load parked on a grade. These include properly engaging the parking brake, using wheel chocks, and parking on a flat surface whenever possible.
If the prop shaft load parked on a grade is not taken into account, it can lead to premature wear and tear on the propeller shaft, causing it to fail. This can result in costly repairs and potential safety hazards while driving.