Continued growth

The BorgWarner group is a global leader in the development of powertrain solutions. In December 2010 it acquired the Stockholmheadquartered Traction Systems Division of Haldex Group, enabling it to expand its European customer base and range of all-wheel drive solutions.

The takeover by BorgWarner in 2010 transformed Haldex Traction into Borg Warner Traction Systems and brought significant benefits to the group. The move has boosted BorgWarner’s growth in the global AWD market – Haldex’s speciality – as well as front-wheel drive (FWD) based vehicles. It has added to the group’s base of FWD/AWD technologies and also allowed it to tap into Haldex’s well-established European customer base.

At the time of the acquisition, Timothy M. Manganello, chairman and CEO of BorgWarner, said: “This acquisition supports our continuing strategy to be a global technology leader in providing powertrain solutions. With the acquisition of Haldex Traction Systems, BorgWarner has added a strong and well-respected brand of all-wheel drive products that will complement our current portfolio as well as our customer and geographical mix.”

The BorgWarner Group’s global technology leadership continues apace. It is currently present in 19 countries worldwide with around 19,250 employees across 60 different sites. It achieved sales in 2011 of $7.11 billion. A global leader

Now operating as BorgWarner’s Traction Systems division, Haldex produces its worldrenowned electronically-controlled four-wheel or all-wheel drive systems for cars. These systems are controllable which means they can interact with other systems in the car, making them highly functional and versatile.

Haldex’s traction technology was patented by the Swedish engineer Sigvard Johannsson in 1998. It began by producing intelligent all-wheel drive (AWD) systems. The first generation Haldex Limited Slip Coupling (LSC) appeared in the VW Golf 4MOTION that year.

The first generation Haldex LSC was based on a unique patented differential pump that created a hydraulic flow proportional to the difference in velocity over the coupling. The ‘stiffness’ could be varied and the torque transfer controlled with the help of a linear valve throttle activated by a stepper motor. Subsequent generations of the LSC are still based around the original technology but with further developments such as pre-emptive torque capacity (Gen III) or a proportional pressure-reducing valve in place of the proportional throttle (Gen IV). Advanced AWD systems

The standard Haldex AWD systems run from the Gen I model to Gen V. They are all electronically controllable all-wheel drive coupling units for cars but with slightly different features as we move through the different generations. The Gen I includes an electronic control unit with vehicle dynamics software. It can be viewed as a hydraulic pump in which the housing and annular piston are connected to one shaft, and a piston actuator is connected to the other.

Moving on to the Gen V model, the front and rear axle of the car are connected via the wet multi-plate clutch which now makes it possible to vary the torque distribution between the two axles. The function of this generation system allows for greater functionality, as it is independent of the differential speed between the front and rear axle. This means that full locking torque is available at any given time and speed if it is needed. All of these systems can be customised to meet the needs of BorgWarner’s global automotive clients in terms of driving characteristics and traction.

Aside from the standard AWD systems, the eAWD is a new innovative concept for hybridisation and pure electrical drive. It allows for torque vectoring and the improvement of stability and vehicle dynamics. It is a system whereby AWD and hybridisation are carried out in one package to reduce the fuel consumption by up to 20 per cent.

As the Haldex website states: “The AWD system solves a dilemma facing electric and hybrid vehicle manufacturers: how to provide all-wheel drive traction and stability without adding the driveline losses that increase emissions and reduce fuel economy.”

The system consists of an electric traction motor that provides both propulsion and regenerative torque to the rear wheels through a planetary gear arrangement on each side. By locating the electric drive on the secondary gear axle, the system provides the benefits of all-wheel drive with minimal changes to the vehicle layout. n