COMPONENT OPERATION / Axle

When the machine is steered, as the inner wheel turns with a smaller radius, the outer wheel needs to rotate faster for smooth steering. Suppose the rear wheel drives by directly installing the gear to the propeller shaft with a shaft having no differential. Suppose the rear wheel, with installing gear to propeller shaft directly is driven by the shaft having no differential.

In this case, the outer wheel and the inner wheel rotate the same amount. So when the machine is steered, the outer wheel cannot rotate more than the inner wheel, and skidding sideways or tire wear takes place. As the axle shaft is subjected to torsional stress, transmission of drive force becomes unstable.

On the other hand, in case a differential is installed, as the inner and the outer wheels can rotate at different rotating speeds, the problem mentioned above can be eliminated.

T3-7-3

• Principle of Differential Operational principle of the differential is explained comparing it to the racks and the pinion gear in the drawing.

When load W is equally applied to racks A and B, if C is moved upward by the distance of H, racks A and B move by the same distance of H in unison with the pinion together.

If moved by removing the load to rack B, the pinion rotates on rack A (with load applied) and moves rack B upward. At this time, the distance where rack B moves is longer than the distance where the pinion moves while rotating.

Distance where rack B moves can be calculated by using the equation of H+H=2H. This principle is applied to the differential.

• Operation of Differential In Traveling Straight

In case resistances applied to axle shafts (7, 8) connected by spline to differential side gears (2, 3) are the same, or in case the machine is traveling straight on plane roads, differential pinion gears (1, 4) do not rotate.

Differential pinion gears (1, 4) and side gears (2, 3) remain fixed by being mutually geared, and rotate with housing (6) connected with ring gear (9). In case all parts are rotating solidly like this, differential function of the differential does not work, and gears (1, 2, 3, 4) play only the role of joints to connect axle shafts (7, 8).

T3-7-4

In Steering

COMPONENT OPERATION / Axle

When the machine is turned, uneven resistances are applied to the drive wheels. Therefore, due to the difference of the resistances applied to the inner and outer wheels, differential pinion gears (1, 4) start revolving on side gears (2, 3), while rotating round the pinion shaft. Consequently, in case the resistance force applied to shaft (7) is large, pinion gears (1, 4) rotate in the same direction as the rotational direction on side gear (2) of shaft (7). The speed of shaft (7) is lowered, the amount of the speed reduction is applied to shaft (8) and the differential function is performed. Suppose ring gear (9) is driven by drive pinion (10) at the speed of 100. In the condition of the machine traveling straight, the drive wheels on the both sides rotate at the same speed. However, in case the machine is turned and the speed of the right drive wheel is lowered to 90, the left wheel turns at the speed of 100+(100 90)=110 as the speed of 10(100 90=10) is added to the speed of the left wheel.

If ring gear (9) rotates at the speed of 100, the summation of the speeds of the left and right wheels becomes always 200 regardless of movement of the respective wheels.

T3-7-5