At least a third of new cars built in Europe will be equipped with electric steering by 2007. Demand is being fuelled by a range of factors, not least that electric systems are more economical to run, lighter, recyclable and easier to package and install compared to conventional hydraulic systems. Matthew Beecham reports.
During the last 15 years, there has been a slow evolution in power steering but recent engine-independent electro-hydraulic power steering (EHPS) and electric power steering systems (EPS) have marked a major change in the technology.
Go deeper with GlobalData
Electrically power-assisted steering systems also have the potential to save manufacturers money, reduce customers’ fuel bills and save designers valuable space. TRW Automotive believes switching to electric can save carmakers $5-$10 per car, because the units are quicker to install, eliminate complex set-up engineering and have less moving parts. TRW’s EPHS module is fully filled with hydraulic fluid and takes GM about 30 seconds to install and connect the module to the vehicle’s electrical system. Delphi estimates its own system cuts four minutes off the assembly time of a vehicle and reduces component parts stocked from 15 to only two. Delphi also reckons that its system can deliver fuel savings of .21 to .41 kilometers per 100km, because it draws less power from the engine. Electric steering could also be safer, as it still works if the engine stalls, unlike hydraulic systems.
Delphi anticipates that worldwide adoption rates of EPS will reach 20% of the light vehicle market by 2007. European penetration during that timeframe could reach as high as 33%, says Delphi. Koyo Seiko also anticipate exponential growth for EPS; predicting that electric they will be fitted to more than 30% of new cars built worldwide in 2005, equivalent to 20 million vehicles. Looking further ahead, TRW Automotive forecast that by 2010, 50% of cars produced worldwide will incorporate some form of electrical assistance integrated into the steering system.
While EPS and EPHS have made significant inroads in Europe and Japan, US vehicle makers have been reluctant to replace their proven hydraulic systems with the more costly electric ones because they claim the benefits are largely unnoticeable and the added cost unjustifiable to customers.
TRW is the largest supplier of electrically assisted steering systems, closely followed by Koyo Seiko, NSK, Delphi and ZF Lenksysteme.
TRW claims it is the dominant supplier in the European EPS arena, with more than a third of an estimated $1.5 billion market. The company’s column drive EPS systems are in production on Renault, Nissan and Fiat models, with a number of launches planned for this model year. TRW says it is in discussions with a number of carmakers regarding its rack drive technology that will deliver EPS for D segment vehicles. The company is also working to develop enhanced power output for our column drive EPS system for upper C segment models. In total, in Europe, TRW has EPS contracts with three vehicle makers for 11 platforms. In Asia Pacific, the company has EPS contracts with two vehicle makers for three platforms. Last year, TRW doubled its sales for these products over the year. The company’s EPHS is fitted to vehicles in Europe, North America, Asia-Pacific and South America.
Koyo Seiko claims to have become the European market leader in steering systems, and was the first parts manufacturer to design and produce the new generation of electric power steering systems.
NSK sold 1.4 million EPS units in 2001, 1.8 million units in 2002 and expects to sell some 3.3 million units in 2006 and 6 million in 2011, of which around 70% will be produced outside Japan. In 2001, NSK spun off its EPS business into a separate company, NSK Steering Systems Co Ltd, in a bid to accelerate development and production.
Since 1999, Delphi has produced more than 2.5 million electric power steering systems. Delphi’s EPS is currently available on five European models. Delphi also secured new EPS contracts last year worth $1 billion over the life of the contracts. The company believes that its EPS system’s combination of a compact, modular design and flexible tuning capability enables it to reduce the number of variations required for various models within a given platform. Therefore, using a single, common EPS component set, very specific vehicle or brand characteristics can be achieved via rapid laptop tuning.
In pushing back the technical boundaries, Delphi has joined the Active Steering business (started by BMW and ZF Lenksysteme on the new 5-series), and launched its own version of the technology. Delphi’s Active Front Steering (AFS) uses a planetary gearbox like BMW’s that varies the steering ratio from 7:1 to 15:1 depending on the driving situation. Central to the Delphi design has been the elimination of friction and the incorporation of its so-called Magnasteer valve, which provides variable torsional rate in the steering gear using magnetic principles. Specially designed gears have also minimised the amount of friction inherent in the planetary gearbox design. AFS does not require OEMs to upgrade existing hydraulic steering pumps or systems, making it more likely to appeal to customers who have pre-existing hydraulic systems.
The 50/50 joint venture between ZF and Bosch, ZF Lenksysteme, claims to lead the European steering systems market for commercial vehicles (over 6-tonnes) with a 70% share. The German supplier claims a 20% share of the total European steering market. Last year, the company launched the volume ramp-up of the Servoelectric electric power steering for the VW Group’s PQ35-platform (Golf, Touran, Audi A3, etc). The company also supplies EPS to Audi (A3) and BMW (5 Series and Z4).
The likelihood of a future dominated by electric steering systems is prompting some market participants to strengthen their presence in the market, investing in new plant and equipment and forming new joint ventures. For example, ThyssenKrupp recently acquired a 60% stake in the Mercedes-Benz Lenkungen steering system subsidiary from DaimlerChrysler, adding €300 million a year in sales to its growing Presta steering system business. In 2002, Toyota and three of its partners have formed a new joint-venture, called Favess, to develop, manufacture and sell drive-by-wire electric power steering systems.
|
