narrow/flange hub motor mount

[slomobile]

I'm looking for examples of motor/tire/axle/wire/swingarm assemblies minimizing protrusions and width, maximizing smoothness. No sharp axle bolts or QR skewers or wire loops.

The important consideration is that the mounted width of the motor, tire, and axle(or other wheel mount, including wire stickout) are as close to each other in width as possible. I'm going for optimum packaging. Trying to fit the maximum width of walking human between 2 side by side wheels without banging ankles on axle ends.

Perhaps something like this RoboWheel Hub Motor for Robotics but more powerful.
Or a front through axle with wires integrated into the fork. Or a single sided swingarm with wires integrated.

The vehicle is a physical therapy/rehab (high) mobility device. For people with walking/running difficulty, but a need for stimulating off road walking/running exercise, and a need to get back home after their legs give up.
Something like a gait trainer Grillo Gait Trainer Support Walker For Adults And Children | Ormesa and AbleChair -
mixed with
Outrider USA Coyote and EZRaider HD4 - EZ Raider
in a form factor most similar to RAD RaceRunner Running Bike given the E bike treatment.

The current problem is finding space for shin troughs or foot pegs to hop on while in motion. Transitioning from walking to riding in one smooth motion like boarding a trolley.

500-8kw hub motor, 48-72v, 8-45mph top speed, 800-1200GVWR, 2 or 3 or 4 wheel drive, 12-29" rolling tire diameter, 20% grade hill climbing. Most things have a fairly wide range of acceptable parameters that can be compensated by other parameters, but overall width is strictly limited to less than 28" by ramps and doorways. 24" preferred. I need 19.5" absolute minimum free space between wheel axles. 22.5" preferred. For walking between wheels. Soft, air filled tires desired, but I'll take what I can get.

Maybe this is the wrong subforum, but I figure you all know more about the structure of hub motors and how it can be altered to suit a particular need.

 

[Dui ni shuo de dui]

The current problem is finding space for shin troughs or foot pegs to hop on while in motion. Transitioning from walking to riding in one smooth motion like boarding a trolley.

Well then why not turning this problem to your advantage? The axle itself would make a perfect anchoring point for a foot peg. Bolt your pegs on it an then cut the unused lenghts of the axle. You can 3D print a plastic cap to hide the nut and smooth any sharp edge.

500-8kw hub motor, 8-45mph top speed

8kw motor for a therapy/rehab walking device?? 45mph? on this thing?:


Do you plan on doing rehab or sending people to rehab?
250W-500W is already way more than needed. Even my most powerful motorcycle doesn't have a 8KW motor. I don't think you realize what kind of power that would be.

 

[gromike]

Are you trying to build the bestest mobility scooter ever?
I do think there is a future there, albeit one with high liability.

 

[Chalo]

overall width is strictly limited to less than 28" by ramps and doorways. 24" preferred. I need 19.5" absolute minimum free space between wheel axles. 22.5" preferred.

So... frame plus wheels totaling less than 3/4" wide, each side, preferred? For a vehicle with ~1000 lbs GVW?

 

[slomobile]

Yes, you understand the problem. It becomes an issue of balancing undesirable qualities to within tolerable limits.

Wheel axles as footpegs is good if the wheel radius is within a comfortable step height for a person with foot drop. That is a pretty small wheel.
A wider, larger diameter wheel can be used if it is single sided with negative offset like modern car wheels. The foot platform can be inside the wheel rim. That also allows a motor to fit within the wheel, but not necessarily centered on the axle. A friction drive to the inner rim surface is a desirable possibility that allows it to declutch for towing.

Placing the foot platform in front of the walker may be better. Perhaps retractable like SUV electric steps.

A rigid shell incorporating motor mount forward of axle similar to wheel pants (small aircraft), a rigid monocoque surrounding the upper wheel. Fender as frame.

The high motor power is to allow for turn in place differential steering. Wheel scrub friction can be very large. Typical 24v power wheelchairs with 14" rolling diameter use up to 120A per wheel at somewhere around 20:1 and that is still often not sufficient to clear a 1" curb without momentum. The best have a 7.5mph top speed. Most top out at 4mph. Brushed 2 or 4 pole motors often rated at 22.5v for 200-300w continuous, 2000-3800w for 10 seconds. Current foldback is always programmed 10s or less. That is the baseline comparison I'm operating with. Going brushless direct drive 48v is a different ballpark.

45mph speed is not a priority or even expected to be possible. 8-12mph is the reasonable target top speed. But if using direct drive motors, the wattage to achieve reasonable turn in place performance might allow significantly higher top speeds, which unlocks dramatically different use cases. I have some ideas how to begin managing stability at speed, but that is a problem far down the road. The easy solution is to electronically limit top speed to whatever empirical evidence suggest is safe. Then make incremental improvements.

"bestest mobility scooter ever?" Maybe. It would be nice. I'm still thinking it through.