GKN is the first tier one supplier to design, develop, manufacture and integrate a complete all-wheel drive system into a customer’s vehicle. The system that underpins FCA’s Jeep Renegade and Fiat 500X delivers specific brand characteristics based on GKN’s tuning capabilities.
System integration is the secret to the world’s smallest all-wheel drive disconnect system
Global demand for smaller, more efficient SUVs is growing. For many consumers, all-wheel drive (AWD) in a more compact, efficient vehicle is now the most intelligent option. The question for automakers is how do you integrate all-wheel drive into a tighter package – and deliver the maximum possible efficiency?
Simply sourcing and assembling all the usual components will not deliver the right results. It takes a different level of system integration and innovation.
GKN understands the challenges better than most. The company developed the world’s first Disconnect AWD system for A-, B- and C-segment vehicle platforms. The first applications were the Fiat 500X and the Jeep Renegade crossovers.
Its compact packaging was achieved by physically integrating key components that are normally sourced separately. This enabled GKN to replace a standard power transfer unit (PTU) with an advanced monoblock concept that fully integrates the propshaft’s constant velocity joint. The arrangement also improves NVH and refinement.
How it works
GKN Driveline’s Disconnect AWD system includes a PTU, linked to the transmission’s final drive differential. The PTU contains a fast-disconnect device and brake that can bring the all-wheel drive system to rest upstream of the PTU’s hypoid gears.
An electro-mechanically actuated clutch located in the rear axle both biases drive torque and disengages the all-wheel drive system downstream of the hypoid gears to save fuel.
A dedicated driveline control unit continuously monitors vehicle dynamics and environmental conditions, disconnecting the AWD system during steady-state driving speeds when the AWD function is not needed. If the driver or conditions require more traction, the AWD system reconnects within 300 milliseconds.
An active torque biasing function provides precise control of the distribution of torque between the front and rear wheels, optimising traction, stability and performance. Torque vectoring between the individual rear wheels is also possible with GKN’s Twinster system, already introduced on the Range Rover Evoque and Ford Focus RS.
The system responds to driver inputs and road conditions, connecting and disengaging drive to the rear axle on demand. By eliminating rotating losses from the driveline, during steady state cruising fuel efficiency can be improved by up to 4% compared to permanent all-wheel drive systems.
System integration innovation
GKN’s solution enables vehicles to combine the enhanced traction, dynamics and stability of all-wheel drive with improved on-highway fuel efficiency. The same hardware can support models that share a common platform, but have different performance requirements. GKN’s software engineers simply fine-tune the electronic control to deliver specific brand characteristics.
GKN’s Disconnect AWD system and the company’s system integration expertise are helping automakers open new markets. Its development of more compact, higher performance systems is enabling manufacturers to launch a new generation of more capable and dynamic vehicles with improved fuel-efficiency and CO2 emissions.