Siemens' eCorner motor-in-hub concept
Now check this out. Sister blog Engadget found out about Siemens' cool next-gen car technology that crams all sorts of goodies into the wheel and hub (all right, Engadget found it through our good friends at Autoblog). The goodies include an electronic motor, an active suspension system, Siemens' very own electronic wedge brake and an independent steer-by-wire function. All of these technologies have existed independently for a while, but this is the first time they've been packed together in a wheel. It's a dangerous place for all these components, but if the thing works, the power needed to move a car would be lowered dramatically. You can read Siemens' full press release here.
[Source: Engadget, Hat Tip to Chris Nelson]
Reader Comments (Page 1 of 1)
Alex Nunez 1:04PM (8/17/2006)
I don't know how they'll ever make it so that it doesn't get completely trashed from day-to-day usage (Potholes, rain, winter weather, road debris, etc.), but it sure is cool.
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Howard Lee Harkness 3:05PM (8/17/2006)
I found it interesting that the folks who built the Aptera completely dismissed wheel-mounted motors as being impractical. I would like to see some real-world test data.
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cheezedog420 3:16PM (8/17/2006)
I think if they made this for regular production, it would be awfule.
First off, Putting the motors into the wheels would require the motors need to be able to handle being in a continous shock load situation. That because the motor is in a situation where it has to deal with constantly being jared by bumps, sharp corners, and potholes, it will have to be strong enough to handle those effects.
But being strong enought to deal with that means your going to end up make the motors so strong they now cause a unsprung weight problem.
The diffrence between unsprung weight, sprung weight is critical to good chassie design. Sprung weight is chassie weight, motor, transmission, and the body. Unsprung weight is the wheels, tires, and moving suspention parts connected to the wheels. Because this car makes the motors a part of the unsprung weight catagory, its unsprung weight to sprung weight ratio is now changed greatly.
And thats bad because the more unsprung weight you have, the chassie will have a harder time controling the wheels. The chassie will have to be may times stronger then we currently have to handle the weight of these super heavy tire/motor hubs. You will also need better, stronger, suspention parts, to be able to tie the whole system together. If they don't do that, the whole system could end up ripping apart as you turn a corners, accelerate, and/or stop.
Plus, Think about what would happen if you had an accident to one of the car's corner. Imagine replacing that wheel, motor, and all the electric gizmos that go with wheel in hub design.
There is of course a simpler solution. Mount the motors inboard. This way they don't have be quite as strong since the chassie is issolating them from road shock. You also keep your suspention problems simple to handle, as all you need to worry about is the normal wheel, tire, brake, and suspention wieght. And in case of a tire bending accident, your expensive electronics are are better isolate from dammage.
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jwer 9:06AM (8/18/2006)
Cheezedog: agreed on the unsprung weight and accident-severity issues... I'd be a lot more interested in this technology if they would mount the whole unit on the inboard end of the axle... the unsprung weight goes to practically nothing, the accident risk too. Yes, it's hard to work on inboard brakes (ask any Alfetta owner) but I'm thinking it's going to be hard for a dilettante to work on these units anyway (as a dilettante myself, that's actually my biggest issue with most post-1975 cars).
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cheezedog420 6:50PM (8/18/2006)
First off, holy F***king S***. Someone actually Responded to my post on this board! And not correct my engineerer type spelling!
Next, Yea, they really need move as much of the technology inboard as possible. Everything but the brakes that is. After all, After your tires, your brakes, are your secound line of defence against a accident.
I guess thats why most automobiles manufactured today carry there brakes within the wheel, so there is no reason to complicate matters any by moving them inboard. Maintain Brakes is such a important issue when dealing with automobile technology, the last thing you should do is move them into a possition where it will be more difficult to maintain.
Also, I did not know Alfetta had a design for inboard brakes. (I really need to look that up.)
But I do know that Hummer H1s use inboard brakes. They did this because of the unique design of the AWD system that puts the final gear ratio in the knuckle that holds each wheel. Add to that the presence of the CTIS (Central Tire Inflation System) that is able to inflate each wheel indavidualy, just left no room for the brake system. Instead they mounted the Brakes right next to the differentials.
It's strange but doing it this way allow Hummers nearly unparrallel 16 inches of of ground clearance, more than double what most four-wheel drives have. And for a Hummer Brake maintenance is not so much a issue since the Armed forces has a great maintenance plan for all of there equipment that makes sure the equipment always get the maintenance it needs before its safty can ever be put into question.
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