Go Back   EcoModder Forum > EcoModding > Hybrids
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 09-12-2012, 06:57 AM   #61 (permalink)
Master EcoModder
 
NeilBlanchard's Avatar
 
Join Date: May 2008
Location: Maynard, MA Eaarth
Posts: 7,907

Mica Blue - '05 Scion xA RS 2.0
Team Toyota
90 day: 42.48 mpg (US)

Forest - '15 Nissan Leaf S
Team Nissan
90 day: 156.46 mpg (US)

Number 7 - '15 VW e-Golf SEL
TEAM VW AUDI Group
90 day: 155.81 mpg (US)
Thanks: 3,475
Thanked 2,950 Times in 1,844 Posts
It would be hard to see how a gear reduction drive train could be retrofit onto a typical drum brake rear wheel?

__________________
Sincerely, Neil

http://neilblanchard.blogspot.com/
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 09-12-2012, 07:12 AM   #62 (permalink)
Master EcoModder
 
Join Date: Aug 2010
Location: Philippines
Posts: 2,173
Thanks: 1,739
Thanked 589 Times in 401 Posts
Too complex. The whole point of the MTSU design is to integrate seamlessly into the rear hub.
  Reply With Quote
Old 09-12-2012, 01:31 PM   #63 (permalink)
Master EcoModder
 
Join Date: Jan 2012
Location: United States
Posts: 1,756

spyder2 - '00 Toyota MR2 Spyder
Thanks: 104
Thanked 407 Times in 312 Posts
Quote:
Originally Posted by niky View Post
Too complex. The whole point of the MTSU design is to integrate seamlessly into the rear hub.
I don't see how adding that thing to the rear hub is any simpler than putting a ring gear on the wheel and bolting a support to the spindle. Universal fit across rim sizes. Or, you could add a gear to the hub instead, and rather than put all those electromagnets around the hub, have the electric motor more or less directly attached to the spindle.

Having separate components that are commercially available drops the cost as well, and so does using low torque high speed motors.
  Reply With Quote
Old 09-12-2012, 10:00 PM   #64 (permalink)
Master EcoModder
 
Join Date: Aug 2010
Location: Philippines
Posts: 2,173
Thanks: 1,739
Thanked 589 Times in 401 Posts
You're putting a ring gear to mate with a motor mounted on the suspension? Problematic if the wheel flexes or starts wobbling... and adding that mechanical component to a relatively robust electric-only system would simply be adding something to break.

The prototype looks messy, but the idea is that it will be sold as a completely sealed package.
  Reply With Quote
Old 09-13-2012, 01:44 AM   #65 (permalink)
Master EcoModder
 
Join Date: Jan 2012
Location: United States
Posts: 1,756

spyder2 - '00 Toyota MR2 Spyder
Thanks: 104
Thanked 407 Times in 312 Posts
Quote:
Originally Posted by niky View Post
You're putting a ring gear to mate with a motor mounted on the suspension? Problematic if the wheel flexes or starts wobbling... and adding that mechanical component to a relatively robust electric-only system would simply be adding something to break.

The prototype looks messy, but the idea is that it will be sold as a completely sealed package.
Sure, you're adding something to break, but a ring gear that deals with low torque can easily be designed with a high safety factor and one can use "compressible" (like bump stops) mountings to deal with minor flexing.

But I still don't see how it'll be so easy to integrate a hub motor into undriven wheels with no shafts to attach things to. You have to keep brake rotor functionality. There will be an equal amount of custom attachments required except fully integrating the motor into the hub will make said attachments more difficult to manufacture.
  Reply With Quote
Old 09-13-2012, 02:38 AM   #66 (permalink)
Master EcoModder
 
Join Date: Aug 2010
Location: Philippines
Posts: 2,173
Thanks: 1,739
Thanked 589 Times in 401 Posts
The premise given is that you install it between the brake and the wheel, but it looks like it actually replaces the brake. The half of the motor on the strut side is stationary, just like the brake calipers or shoes are stationary, while the half on the wheel side moves with the hub. Simplicity itself.
  Reply With Quote
Old 09-13-2012, 05:11 AM   #67 (permalink)
Master EcoModder
 
Join Date: Jan 2012
Location: United States
Posts: 1,756

spyder2 - '00 Toyota MR2 Spyder
Thanks: 104
Thanked 407 Times in 312 Posts
Quote:
Originally Posted by niky View Post
The premise given is that you install it between the brake and the wheel, but it looks like it actually replaces the brake. The half of the motor on the strut side is stationary, just like the brake calipers or shoes are stationary, while the half on the wheel side moves with the hub. Simplicity itself.
I don't consider replacing the brake simplicity, because that involves making a rather specific hub motor for every car. Besides, reduced braking function on the rear wheels is quite a large compromise, that I think sensible people would consider unacceptable. Weight transfer may leave the rear axle with perhaps under 40% of the weight for taller vehicles, but the hub motor is never going to be able to apply enough torque to lock the wheels even in that case. Losing even 20% of braking capacity is huge. And on RWD cars (I know I know, most people here think RWD is stupid or something), you absolutely cannot replace the brake because the front does more braking.

Many cars aren't coming with drum brakes anyhow, because they suck. The secondary drum brakes used for the handbrake are not going to suffice either. Heck, the Honda Accord (current one at least) has rear disk brakes.

Even if braking performance weren't an issue, is embedding the motor armature into a new "brake" hub really easier than just bolting a motor to the spindle and using gears?

Last edited by serialk11r; 09-13-2012 at 05:26 AM..
  Reply With Quote
Old 09-13-2012, 11:24 AM   #68 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,562
Thanks: 7,738
Thanked 8,554 Times in 7,041 Posts
A cross-section drawing of this invention would answer a lot of questions.

If there is that much room between the drum and the rim, your brakes are too small.
  Reply With Quote
Old 09-13-2012, 12:57 PM   #69 (permalink)
Pokémoderator
 
cfg83's Avatar
 
Join Date: Dec 2007
Location: Southern California
Posts: 5,864

1999 Saturn SW2 - '99 Saturn SW2 Wagon
Team Saturn
90 day: 40.49 mpg (US)
Thanks: 439
Thanked 530 Times in 356 Posts
freebeard -

Quote:
Originally Posted by freebeard View Post
A cross-section drawing of this invention would answer a lot of questions.

If there is that much room between the drum and the rim, your brakes are too small.
Until I see more I will be cautiously optimistic.

CarloSW2
__________________

What's your EPA MPG? Go Here and find out!
American Solar Energy Society
  Reply With Quote
Old 09-13-2012, 06:21 PM   #70 (permalink)
EV OR DIESEL
 
Join Date: Dec 2007
Location: South Louisiana
Posts: 1,758

FarFarfrumpumpen - '03 Volkswagen Jetta Wagon GLS Premium

Quorra - '12 Tesla Model S P85
Thanks: 57
Thanked 113 Times in 86 Posts
Send a message via AIM to dremd
Very cool, I owned an Accord Wagon like that before, great car, fantastic idea. When someone complains about unsprung weight I direct them to the nearest body on frame SUV / truck with the live axle.

__________________
2016 Tesla Model X
2022 Sprinter
Gone 2012 Tesla Model S P85
Gone 2013 Nissan LEAF SV
2012 Nissan LEAF SV
6 speed ALH TDI Swapped in to a 2003 Jetta Wagon
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com