Studies on the Running Resistance of Wheel Having the Angle for the Travelling Direction (III)

Effect of the Differential Gear on the Drafting Character

Abstract

To Study on the effect of the differential gear for traction performance of tractor, we gave the weight difference on the wheels of each side of the differential gear for light compact car, and also let the wheels have deflection angles for the running direction, likely as the report 2 of this series. It is the same also that we tested about 2 features of weight difference, that is, heavier or lighter downhill wheel than uphill wheel.
(1) Pulling the test tractor with another one, the coefficient of traction resistance is not influenced by the differential gear, being due to its inner friction.
The coefficient of side force decleases with the increase of weight difference under the condition of heavier downhill wheel, but increases under the condition of heavier uphill wheels. It is due to the force of the uphill wheels to apt to run to the travelling direction.
(2) Driving by himself pulling some load, not light load, the coefficients of traction force, side force and driving force decrease with the weight difference, and yet under the heavier downhill wheel, reduction of the running speed is larger, and then the traction efficiency is inferior compared with the condition of heavier uphill wheel. These are due to the working of differential gear.
Now, we can calculate the traction force and the driving force etc. by using the equations in this report. And from the test results, we can say that the weight difference on the each wheels must be kept as less as possible, for the purpose of the larger traction force. It is the same advice as the results of the report 2.