The Wheel Has Been Reinvented - Electric In-Wheel Motors
December 6, 2008 by admin
The Michelin tire company is getting very close to releasing its electric wheel concept into commercially available cars. The company has been showing off versions of what they call “Active Wheel” since 2004. The system contains virtually all of the components necessary for a vehicle to propel or stop: an electric motor, suspension coils and springs, and braking components. It localizes the entire suspension, springs, dampers, geometry and all, plus an electric-drive motor and of course the brakes inside the envelope of the wheel, freeing all sorts of space for hauling passengers and luggage. The only thing missing is the source of energy.
Fed by lithium ion batteries or fuel cells, the Active Wheel’s electric motor will output 30 kilowatts of power per wheel. The system is flexible in that it can be configured with two Active Wheels up front, two at the back, or all four wheels. This allows manufacturers to offer both two- and four-wheel drive setups.
There are quite a few advantages, including reduction of energy losses, greater all-wheel drive capabilities, better regenerative braking, and extra space. With most mechanicals out of the way or eliminated, designers can expand the cabin and possibly have two trunks, one in front and one in back. In addition, the technology offers the possibility of easier conversions of gas-powered cars to electric power.
The disadvantages are mostly speculative at this point, but they include things like the un-sprung weight, which affects ride and handling. However you could attach them to a bogie-type carriage, or for that matter directly to a sub-frame. The motor, braking package, and suspension bits inside the wheel would NOT count towards un-sprung weight; the wheel and tire itself would be the only un-sprung weight. As yet there is no mention of how much each in-wheel motor unit weighs, although it will likely be around 30 Kg.
Michelin presented two vehicles, the Venturi Volage and Hueliz Will, using the Active Wheel at the 2008 Paris Auto Show in October. While the idea of placing motors directly into wheels seems revolutionary, the concept has actually been around from the early days of automotive history.
Below is a small sample of the many vehicles, mostly concepts, which use electric in-wheel motors.
Lohner-Porsche Elektromobil
In an interesting symmetry of history, the Paris Exposition of 1900 featured the Lohner-Porsche Elektromobil, which would later become one of the first hybrid cars. It was designed two years earlier by a 23-year-old engineer, unknown at the time, named Ferdinand Porsche. Exposition records show that Porsche’s vehicle could travel 38 miles solely on electricity. Porsche integrated battery-powered electric motors directly into the front wheel hubs, producing one of the first front-wheel drive cars. He later added an internal combustion gasoline engine to drive a generator, which charged the batteries.
Lightning GT
The Lightning GT Electric might is in the Supercar league of electric in-wheel motors. With 700 horsepower, there will be three models available: a luxury version, a sports version, and an extended range version. The lightweight sports model will run from 0-60 in less than 4 seconds. The GT will only be available in the UK starting initially, but if the company does well you can eventually expect them to make it to the States. The pricing is not officially set yet, but expect something around $300,000.
Venturi Volage
The Volage, which produces the equivalent of 300 horsepower, accelerates from 0 to 60 in less than five seconds. It is a four-wheel drive two-seater roadster using four Active Wheel systems. It has a range of approximately 200 miles.
Using the Michelin Active Wheel system, it uses one motor to drive a reduction gear that is also inside the wheel while the other motor handles the active suspension. The Volage can readily adapt to different road surfaces and driving style. Batteries for this electric car are 45 kWh worth of liquid-cooled polymer lithium and are said to provide for 320 Km (199 miles) of driving at a “stabilized” 90 Kph (56 Mph). The car is has a top speed of 150 Km (93 Mph). The Volage is slated for a limited production run in 2012. Prices have not been announced yet.
Heuliez Will
The Michelin-Heuliez-Orange Will is a front-wheel drive all-electric vehicle that seats five, and features front and rear trunks. Heuliez intends to produce the Will, which uses an Opel Agila body shell, with a 20kW-hr battery pack good for a 93-mile range.The motors in each front wheel of the Heuliez Will concept can produce 30kW continuous, 60kW peak (40/80 hp). Cost, at volumes of 100,000 or more is estimated to roughly equal that of a conventional drivetrain car, including the battery pack, thanks to savings in engine, transmission, and suspension parts.
According to Michelin, drivers will be able to choose from four different wheel packages, with driving ranges from about 100 to 250 miles. The first Will prototypes are scheduled for production in 2009, with plans for the production of a few thousand units in France by 2010.
Mitsubishi MIEV
MIEV (Mitsubishi In-wheel motor Electric Vehicle) or MiEV (Mitsubishi innovative Electric Vehicle) is the name given by Japanese automaker Mitsubishi Motors to its alternative propulsion technologies in general. This Mitsubishi i MIEV, is a test bed for an electric vehicle scheduled to be introduced for 2010. There is a 30-vehicle test fleet that’s running around Tokyo right now. Since introducing the car at the 2007 Tokyo Auto Show, Mitsubishi has pulled the electric motors from the wheels, but the company is still intent on bringing the all-electric vehicle to market by 2010. Expect about 75 miles of range and a top speed of 80 miles per hour.
A video from 2006 showing the MIEV concept car (as it was then)
Volvo ReCharge
Volvo’s ReCharge, a plug-in hybrid, made its public debut at the Frankfurt Motor Show in 2007. Electric motors are housed in each wheel. Volvo Cars is introducing the Volvo ReCharge Concept, a plug-in hybrid with individual electric wheel motors and batteries that can be recharged via a regular electrical outlet for maximum environmental benefit. Recharging allows the car to be driven about 100 kilometres on battery power alone before the car’s four-cylinder Flexifuel engine is needed to power the car and recharge the battery. The car can do 0-60 mph in about nine seconds, with a top speed of 100 mph. Drivers can also toggle manually between electric and internal-combustion modes.
Video explaining the ReCharge In-Wheel Electric Motor Concept
what about the damage that could be caused by potholes?
and how about when it comes to changing the tire?
This is a good example of the new possibilities that are opened up in the move away from ICE to electric motors
Theres another good video on the imiev now on youtube:
http://www.youtube.com/watch?v=KGqPtzF1tlY
Worth a watch.