When i first saw this my Initial reaction was that that was simply not possible. The pancake style DC motors are not light, and the tire, and rim still need to be there. How could that not just be added weight.If you read my previous post the additional weight is just 4.4 lbs.
I read your post after submitting my post ... The article that I was mentioning was based on an analysis of Mitsubishi's iMIEV Colt EV from 2005. (I don't recall the source.) Quoting from an article on Wikipedia: MIEV motors are constructed using an in-wheel motor rotor, an in-wheel motor stator, a rotor bracket, stator bracket and inverter directly behind the brakes. (Source: http://en.wikipedia.org/wiki/MIEV)If you read my previous post the additional weight is just 4.4 lbs. In addition, these are not even in mass production yet. Wait until all the major automotive companies and their vendors start optimizing the design. I predict that in 10 years 4-wheel-hub motor configurations will be standard on all cars and that their un-sprung wheel weight will be of no concern.
Sounds like a great idea - hopefully it can get past the various transportation regulators ...Since the unlikely failure of the fly-by-wire braking system would result in the vehicle being transported back to the shop for extensive repairs I recommend a one-use emergency braking system. I'm thinking along the lines of the new table saws that stop the blade if you accidentally touch your skin to it. These brake systems disintegrate and have to be replaced if used. I think this type of disintegrating system would be a perfect match. It only has to be used to stop the car once and would have to be replaced along with the other major components, should the fly-by-wire brake system fail.
I'm thinking along the lines of the new table saws that stop the blade if you accidentally touch your skin to it. These brake systems disintegrate and have to be replaced if used. I think this type of disintegrating system would be a perfect match.
I can't say this for certain, but it seems to me that an ABS brake could only be pulsed dozens of times a second, whereas a motor could be pulsed many, many times that, or it might be able to apply a continuous rolling drag with no pulsing at all.As a side note. I wonder if ABS would be easier or harder to implement with a regen system.
Well, if you have the wheel-hub motors on all corners then you might as well use them. Why use brake pads in the back and waste that energy? Are you suggesting just using two wheel-hub motors? If so for cost? Having complete control over all four wheels gives you all kinds of options for safety and performance. You can also have smaller motors in each hub. If you only have two hub motors they will need to be twice as powerful and thus more massive. I think having four wheel hub motors is the way to go to for safety, redundancy, performance, etc. Of course the cost could be an issue but inexpensive cars will probably just have one central motor anyway. We will just have to wait and see what the engineers come up with. Can't wait to see them on the show room floor! The thought of making a very light rail car using production wheel-hub motors and a powerful nanotechnology lithium-ion (or other technology) battery keeps me smiling. Probably the kid in me.Regen braking only on the front wheels will still recover most braking energy. As your auto mechanic will attest by the relative wear of your brake pads, your front brakes do about 75% of the braking. This is because the vehicle's weight shifts forward during deceleration, giving the front tires way more traction. That's why ABS, when it kicks in, usually has to back off the rear brakes, as they can't do much braking without locking up the rear wheels.
Guy, I love this concept and have been following it for a while but can you please give us the reference to where you heard that the project is a go? I'm pretty sure it's still at concept status but I really hope I'm wrong! An advanced hybrid with 4 wheel-hub motors is top on my list, even at a steep premium....is slated to go into production in 2010.
Sounds like Midas will have a new service to provide to replace oil change and brakes - motor maintainance, be it in-hub or otherwise.Please do tell when the first hub motors are announced for a production vehicle. I need to know when to implement my hub motor replacement stand idea (Easy-hub)