AUTOMOBILE DIFFERENTIAL DRIVE

A automobile differential drive is a gear box that allows wheels to rotate at different speeds while maintaining torque distribution.

There are several types of automobile differential drive and they are; open, limited slip, locking and electronic (eDiff) differential drive.

Open differential drive allows wheels to rotate at different speeds while splitting torque equally between them. They allow speed difference between the wheels so as to allow for smooth cornering.

Limited slip differential (LSD) drive allows wheels to rotate at different speeds while transferring torque to the wheel with more grips. They send ample power to the wheel with traction, allow speed difference with torque bias and have better traction than open differentials. They provide improved handling on slippery surfaces and enhanced cornering performance.

Locking differential drive locks booth wheels together forcing them to rotate at same speed. The wheel rotates together, creating maximum traction, which is best for low grip surfaces. However locking differential drive have issues cornering on hard surface, thereby creating stress on the drive train, which may eventually lead to damage.

Electronic differential drive (eDiff) uses electronic controls to manage torque distribution between wheels. They are fast to respond to torque and speed requirement of both wheels, hence improving cornering and stability. They also are able to adapt quickly to driving conditions as they occur. However they are complex and expensive to procure and maintain.

The advantages of automobile differentials are; they provide for improved traction (eg. LSD, locking diffs), better handling (eg. eDiff in AWD systems) and optimized torque distribution of the wheel power.

The main disadvantages of automobile differential drives are; its complexity especially as in electronic differential drives and the prohibitive cost to maintain and operate all differential drives on rough terrain are quite daunting.

Automotive differential drives find applications in the following; on road vehicles as open differentials for normal driving and LSD/eDiff for performance. Off-road vehicles and locking differentials for maximum traction. AWD/4WD vehicles use eDiff for stability and traction. While electric vehicles use eDiff for optimized torque distribution.

The future of the automobile differential drive depends on the advances and development of the following technologies; electrification of automobile differentials drives especially eDiff in electric vehicles, and hybrids for efficiency. Autonomous driving would in future require advanced differential control algorithms for self-driving applications. Also automobile differentials capable of torque vectoring will be required for enhanced handling operations via eDiff. Integration of automobile differentials with automotive driver assistance system (ADAS) will be required for improved stability and safety in the future.

SOURCES:

• Automotive transmissions by Harald Naunheimer, Bernd Bertsche, and Joachim Ryborz.
• Vehicle dynamics by Dieter Schramm, Manfred Hiller and Roberto Bardini.
• Automotive engineering by David A. Crolla.
• Differential gear mechanism by William F. Milliken.
• Automotive engineering fundamentals by Richard Stone and Jeffrey K. Ball.