DIFFERENTIAL OPERATION

Shannon News, 21 January 1929, Page 3

DIFFERENTIAL OPERATION

The new motorist, who may be puz Bed regarding the operation of thi differential, will find that it is not such a complicated piece of mechanism as the name might suggest. In the first place, it is not an essential, but a de sirable part of a car’s mechanical makeup. The power of the engine, oi course, is transmitted to the two real wheels, and when a car goes around a corner it is necessary that the outer wheel travels much faster than the inner one. To accomplish this wit born causing undue mechanical strains and tyre wear, a differential is fitted in the i ear axle. The most common form" consists of four bevel pinions mounted cd the differential spider, and contained in a case. In the case is mounted the driving gear, which is driven by the driving pinion on the end -of the propeller shaft. Bevel pinions on the ends of the axle shafts mesh witn the four “compensating,” or differential, gears. As long as the car travels straight, ahead, and the resistance of both rear wheels is the same, these gears do not turn. When going round a curve greater resistance is offered to the inside wheel, and the compensating gears permit the outside wheel to revolve faster trail the inside wheel. Actually the inside wheel could be stationary or even revolve backwards. The differential also divides the driving force de livered to the two rear wheels equally between them. If the road resistance is not equal at the two wheels one will slip on the road, and if the difference is very great one w r ill revolve rapidly while the other remains stationary, and the car will not move. For instance, if one wheel- is jacked up, the engine started, and a rear engaged, the wheel will revolve, no power at all being transmitted to the wheel which remains on the ground.