Fig. 121 illustrates a double-reduction axle of one-ton capacity, which was placed on the market several years ago by the Weston Mott Company, and was used on the Menominee. Flint and other light commercial cars. This axle is also of the full floating type, but differs from the one described above in that straight-line drive cannot be obtained since the bevel gear set is mounted in front of the spur gear set instead of above it. The differential carrier has an extension on each side into which are placed the axle tubes, while a large cover is provided for inspection purposes. The brake spider has a hub which is keyed to the axle tube and upon which the spring seat can pivot, while the brake operating levers are also brought inside of the frame. The drive for the wheel is through a jaw clutch, the male member of which is forged integral with the drive shaft, while the female member is formed integral with the hub.
The Autocar is designed to take both torque and thrust through the spring, while the Weston Mott axle may be arranged with radius rods to take the thrust load and a torque arm to take the torque load.
The one-and-one-half ton White truck is also equipped with a double-reduction axle (Fig. 122) which differs from the above in that the bevel gears are in the customary place as in the pleasure car axle. The propeller shaft currying the spur pinion which has helical teeth, is mounted above the short shaft carrying the helical spur gear and bevel pinion. Both shafts are supported by ball bearings at each end and provision is made to take care of the thrust of these gears. This presents another method of approximately a straight-line drive, while the torque is taken through the springs and the driving thrust by radius rods.
The double-reduction drive, like the worm drive, will be found on both gasoline and electric vehicles, although its use seems to be mostly on vehicles of 5,000 lbs. capacity and under.
Fig. 120. Double Reduction Axle used on the Autocar.
Fig. 121. Weston-Molt Double Reduction Axle.
Fig. 122. White 11/2 Ton Doubly Reduction Axle with Helical Cut Spur Gears.