Yes, that looks like the concept. It will be interesting to see how it turns out. I'll say that 100kW per wheel ought to be enough tear the pavement off the roadbed!
Peri -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Hoegberg Sent: 26 December, 2013 5:12 PM To: Electric Vehicle Discussion List Subject: Re: [EVDL] VW Bora will have Protean in-wheel motors > From: [email protected] > To: [email protected] > Date: Wed, 25 Dec 2013 08:04:54 -0800 > Subject: Re: [EVDL] VW Bora will have Protean in-wheel motors > > You could design a rear drive system with two large diameter motors and > still retain almost the same efficiency as in-wheel motors. Here's how. > > Use a CV joint in each wheel to allow a flexible connection to a half axel > drive shaft. On the other end of each shaft, mount one of the motors.. > Secure the motors to the chassis with a pivot connection, so that the > motor's angle can change as the wheel goes up and down. > > As I understand it, CV joints run better than 99% efficient. Without having > gear reduction, then, this means your drive train efficiency is 99% * > efficiency of tires. Probably the best you can get. > > The only problem I see with this design is making room for large diameter > motors. I'm not sure of the diameter of experimental in-wheel motors, but > I'll guess somewhere around 10-12". They might need to drop down and be > shielded with something strong (and heavy), or they might need to protrude > up a bit into a trunk space or bed area. Better yet, if the battery is > sandwiched under the floor, that gives a bit of vertical space to better > accommodate large diameter motors. > > One other possibility is to do this with front wheel drive instead. Can > that still be done with one CV joint per side? If so, there is much more > vertical space under the hood and it seems that two large diameter motors > could easily be fit in. Note this could be done with one motor if you add > another pair of CV joints. > > This is getting awfully close to a typical front wheel drive, I think. The > only real difference is the gear reduction. But, hey, if eliminating gear > reduction can save 10%, why not? > > Well, I'm not building this, but I think it would be fascinating to see if > it's possible to make this work and boost the efficiency of the drive train. > > Peri > Electroengine had direct drive with CV-joints in the SAAB Cabriolet in 2009 (?) Have a look, at the not soo good concept picture here: http://www.electroengine.com/about-us As I remember it back then, the motors was from some Swiss company, maybe Austria: http://www.electroengine.com/true-electric-technology/true-electric-motor https://www.youtube.com/watch?v=GpYICgS3XKI 1400 Nm or so, in 2 wheels/motors combined. I think it was about 200kW in the first prototype. Maybe it was a pack of 40Ah Thunderskys in this video. :-) I am not 100% sure if it was the same E.engine branded-motors in the SAAB 9-3 later, and BostonPower-Swing(?)-cells: https://www.youtube.com/watch?v=qNviw_gnWuA / John -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20131227/727933a0 /attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
