The Axle.—Axles are of two kinds, generally designated as “live,” when they turn the wheels; and “dead” when they do not turn the wheels, but simply support the weight of the frame and of the body.
Dead axles are used with double chain drive, as, in that case, the sprocket wheels are attached directly to the sides of the wheels and the wheels turn on the studs, or ends of the dead axle.
Live Axles.—1. Plain live axles originally consisted of a shaft without differential gearing, having one wheel fast on it, the other turning. Modern construction shows two axle shafts in a housing, the weight of the car, and the tooth pressure of the differential being carried by the axle shafts.
2. Semi-floating axles have the weight of the car carried by the axle shafts, whereas the tooth pressure of the differential is supported by the housing, and only the turning effect or torsion is transmitted by the axle shafts.
Fig. 7. Floating Axle.
Fig. 8. Semi-floating Axle.
3. Full floating axles carry the full weight of the car, and the differential bevel gear teeth pressure with the housing, so that the axle shafts carry no load but only the torsional stress.
Both full and semi-floating constructions are applied to rear axles only. The front wheels are now universally applied to knuckles, which swing on vertical pivot pins at the ends of the dead axles.