GM looks at wheel hub motors

Oct 8, 2003 12:00 PM

General Motors hopes to boost the power and performance of light trucks while simultaneously improving fuel economy and reducing vehicle weight through a new piece of technology: wheel hub motors.

At about 17-in. in diameter and weighing a little over 33 pounds, wheel hub motors can fit right inside the hub of any vehicle wheel – from cars to pickups – and can provide a range of benefits, Mike Milani, a project manager at GM’s Advanced Technology Center in Torrance, CA, said.

“Not only do you get highly improved torque, but you get better traction and control if each wheel is equipped with a hub motor,” he explained. “You can also provide better off-road 4x4 capability without the massive transfer case, differentials, and transmission needed for a typical off road vehicle.”

With wheel hub motors, torque is made available to the wheels instantly without the need for the engine to generate that power, he said. For example, by placing two wheel hub motors in the rear of a front-wheel drive four-cylinder vehicle, they would generate a 60% increase in torque – enabling a four-cylinder engine to perform like a six-cylinder engine. Another benefit of wheel hub motors is that they are “invisible” to drivers.

“You just get in a vehicle and go like you always do,” Milani said. “No change in driving habits is needed.”

Right now, wheel hub motors remain in the prototype stage. While the basic technology involved is relatively simple, he said, the real question is how well it will hold up over the 100,000-mile lifetime of a light truck operating in a harsh work environment. Should wheel motors hold up in testing, they could be found on GM trucks and cars as early as 2010.