Look Ma: No Hydraulics Electric steering systems move into the market

If steering system engineers have their way, you won't notice the significant changes about to unfold in the steering business.

Next-generation light vehicles will feel the same to drivers behind the wheel, but a radical difference will be in place. New electrically-assisted steering (EAS) systems will be guiding an increasing number of high-volume production vehicles over the next 10 years, signaling what is perhaps the beginning of the end for hydraulic steering.

The EAS market is only beginning to take shape. But in just seven years, it is expected to capture as much as a third of the worldwide light-vehicle steering demand, growing to almost 45% by 2010. That 2010 volume could displace some 29.3 million hydraulic steering systems that traditionally provide power assistance.

In an effort to meet the anticipated market shift, TRW Inc. and LucasVarity plc have teamed up to create TRW LucasVarity Electric Steering Ltd. - a UK-based joint venture created to develop and manufacture column-drive and pinion-drive electric steering systems for light vehicles.

TRW, 51%-owner in the venture, will market and distribute the joint venture's two primary products: a column-drive electronic power steering (EPS) system and a pinion-drive EPS. LucasVarity takes the remaining 49% ownership and a $50 million payout for bringing its column-drive torque-sensing technology to the table.

That technology, says James Handy-sides, vice president and general manager of electrically assisted steering at TRW's steering, suspension and engine group, is what made the fit between the two companies.

"TRW is well represented in the steering industry. LucasVarity has the technology and human resources - the technical talent. But we have the customer base," he says. TRW will market pinion- and column-drive EPS systems produced by the joint venture along with its own rack-drive EPS system and a hybrid system that combines electric power with hydraulics (EPHS).

This collateral combination gives TRW a full portfolio of products, allowing it to go after all light-vehicle classes, Mr. Handysides says. And that means EAS systems will be popping up all over the vehicle spectrum, regardless of segment or price tag.

"Unlike most new technologies, which sort of goes in at the BMW 7-series level in Europe and filters down, it is actually displacing technology right in the highly-competitive mass-volume part of the market where cars are extremely price-sensitive," says Managing Director of the TRW/LucasVarity joint venture Brendan Connor.

"You'll first see systems appearing in A, B and C class cars with a transaxle weight (front axle loads) below 900 kilos (2,000 lbs). Broadly, any cars with a transaxle weight below 900 kilos are candidates," says Mr. Connor.

The new TRW/Lucas collaborative effort doesn't have a corner on the electronic steering market. Delphi Automotive Systems and Siemens Automotive also offer similar products to automakers.

Siemens offers a three-pronged package, including a fully electric system, an electric assist on a hydrualic system and an electric pump used on a hydraulic system. Siemens says it is expanding its efforts into vehicles with higher front axle loads.

EAS sales are expected to jump quickly first in Europe, where the demand is driven largely by the average 2% gain in fuel economy that EAS systems promise.

The technology cuts fuel consumption because it is essentially an on-demand steering system calling for power only when the vehicle is turning. This replaces the current hydraulic technologies that load pressure into an open loop system with a relief valve that bleeds pressure, even when the car is moving in a straight line.

"The EPS consumes no energy while you aren't applying any torque, and therefore the amount of energy you consume is very very low - about a 0.05% penalty for having an EAS system over no power steering, compared with 5% to 6% for a hydraulic system," says Mr. Connor.

The pressure on fuel consumption, combined with an increasing demand for power-steering systems in Europe, makes the market ripe for electric steering applications, says Mr. Connor. By 2010, the Western Europe EPS market is expected to reach roughly 7 million units year, or around 40% of the total market.

Those market pressures are expected to be mirrored in Asia/Pacific, where car buyers face similar dilemmas. Demand in the region - including Japan, Australia and South Korea - should reach 33% of the total steering market in 2010, he believes.

But EAS systems have other benefits beyond fuel economy. On the manufacturing end, automakers are presented with a laundry list of reasons to think about applying electric steering technology to future platforms.

One of the first benefits is seen in the suspension tuning process, typically an engineering ordeal that can take several months with existing technology.

Normally, a vehicle suspension performance review would send engineers back to the machine shop to rebuild the steering gears and valve assembly to modify the amount of assist in a hydraulic system.

With an EAS system, engineers can literally dial in different suspension algorithms, tweaking the steering "feel" until it hits the mark. "With the old system, you might go through a dozen or so (gearing) swaps. You need special grinding machines and months in development. Now you are talking about minutes," says Mr. Handysides.

That's not all. Because EAS systems can adapt to different handling parameters, the same basic unit can be fit into similar vehicles with different engine options, tires, suspension systems and performance characteristics.

That potentially gives automakers extraordinary economies of scale across a number of similar platforms.

At assembly time, the installation rate for EAS systems is dramatically lower than rates for hydraulic systems, maintains Mr. Connor.

"In the column (EPS) mount, the drop fit is one operation. A module that has a steering column attached to it can be placed into a vehicle and connected in about 4 minutes with only one or two line stops," says Mr. Connor. "With a traditional hydraulic system, you are looking at putting between 30 and 40 separate components on the vehicle, and, depending on the automaker, that is probably about half-an-hour of assembly time," he says.

But unlike other electronic applications - antilock brakes, traction control and even air bags - EAS systems aren't pointed at the luxury market where the cost can be absorbed in a premium sticker price and passed on to the consumer. In the cost-conscious mid-price market, even safety systems often have trouble making it into standard equipment.

"In the market that we are going for - the A, B and C class - automakers will not pay a premium for any new products. Therefore we have to devise a system that is cost-effective against the standard hydraulic alternatives," says Mr. Connor.

"And that is something that is very much in our minds in developing the products. The engineering has ensured that the products have a materials cost that is competitive with hydraulics," he says.

If the engineers do their job right, consumers may only notice the difference at the fuel pump, and nowhere else. "You don't want the driver to feel the difference (between EPS and hydraulics). Our target is to be as good a performer or better than a hydraulic in tuning and total performance," says Mr. Handysides.

If fuel economy and manufacturability aren't enough for some automakers, EAS systems come with still more corollary benefits - particularly in the environmental category. One of the first advantages electric systems have over hydraulics: no hydraulics. The red-brown viscous fluid that spills out of scrapyards and into our water tables is completely eliminated. In fact, a full-fledged EPS system can be scrapped and melted down right along with the car.