Overrunning wheel hubs?

[FlyingTrike]

I am trying to work out a problem with a direct drive setup on a motorcycle trike. It has a solid 2" axle that is very wide for a trike. I tried it with both wheels locked to the shaft and I could not takeoff from a stop and turn. It goes straight.

Then I made the right wheel turn free on the shaft and it turns, and easier to the right of course. The problem with that is that it now will not drive straight under any accelleration. It pushes hard to the right.

I believe that what I need is some sort of overrun clutch hub, maybe a bidirectional one, for each wheel, but I am not sure. Freeing one wheel makes it turn better, but it is still harder to turn left with the right free, so that is why I think that it needs two clutched hubs.

Maybe there is a way to adapt a mechanical clutch to each wheel, or maybe an electric clutch that can be operated by a switch to disengage each side as needed? Maybe a bidirectional overrun clutch?

Any suggestions will very much be appreciated.

Thank you!
Steve Thomas

http://www.flyingtrike.com

 

[SomeYahoo]

Perhaps I am missing something, but why not use a differential like the rest of the world?

 

[FlyingTrike]

I wasn''t going to mention it, but I cannot use a regular differential.

This is going to sound wierd to most, but this trike also flies through the air with a parachute wing. I will be landing at approximately 45 mph and normally on one wheel first, then the other.

With a regular differential the second wheel to touch down would be spinning backwards and would most likely cause me to twist and turn, and crash or roll over, or it would destroy the differential. That is the reason that I bought a trike conversion that uses a solid axle direct hookup to the wheels.

Now that I have the flying apparatus built and installed it is heavier than before and the direct drive will not turn under accelleration at all because of less pressure on the front tire.

I hope this makes it clearer.

Thaks for the reply.

Steve

 

[Fabrico]

We should have known with a name like FlyingTrike. Can you turn the seat around and go the other way?

Your assumptions about using a differential may be exaggerated. Off-road race cars literally fly every few seconds. Those in the desert fly for a hundred feet or more, and just as often as not, land on one wheel. This happens at all speeds and angles. Many of those cars are mid or rear engine. Many with a mid or rear engine have an open differential. Open means no traction devices.

The only way you will create reversed rotation is if the driveshaft is held to slow or no rotation. Simply landing with some throttle or in neutral would substantially eliminate this condition.

It is also likely that nothing you do will avoid all tugs at the chassis upon touch down. I would not be so quick to abandon the standard differential.

 

[FlyingTrike]

But, when one of those race cars are "flying" they are doing so because they left the ground at a high speed with the wheels already rolling, right? When I land I will be starting with the wheels stationary and they will spool up as they make contact with the ground.

The trike kit manufacturer is going to work on making me some sort of spider gear differential that will not spin one wheel backwards when one wheel makes contact with the ground and the other is still airborne.

I was just hoping that maybe someone in this group knew of a hub or clutch that I could install on the current shaft to work as a different option.

Thanks for the thought!

 

[Fabrico]

How about an ARB air controlled locking differential?

Differential action on the ground, locked for touchdown.

 

[kenre]

How about a limited slip type Differential?

Ken

 

[crysta1c1ear]

A one way clutch between body and wheel would prevent a wheel turning backwards. The wheel that touches down first will presumably accelerate from rest to road speed and the other would stay stationary. When it touches down, it would start rotating too. (This would make designing reverse difficult!)

I presume you are going to land in some sort of neutral condition, eg with a clutch lever pulled in, so that there is no mismatch between the speeds the engine and vehicle are doing when landing.

You haven't described how you launch and how you contol your angle of attack in the air, if the wheels are stationary. I have been told that when doing long jumps with a motorcycle the engine is used in the air to control the angle of flight: if the throttle isn't released somewhat the back driving wheel just accelerates forwards and the back accererates equally and oppositely, ie spins so thtat the raider can end up landing on his back; altrnatively, if the brakes were applied in the air the wheels would decelerate and the bike would dive nose down, maybe landing on the front wheel.

From the flying description I guess you have wings and I am trying to teach my grandmother how to suck eggs!

 

[SomeYahoo]

Now I understand...

Take a look at the ratcheting mechanism on your standard self-propelled, walk-behind mower. It has a gear and pawl setup that may work out for you. It allows the mower to turn both when on and off power.

You may have to tweak it some based on the amount of power you will be using; spring tension, width of gear, etc.

 

[FlyingTrike]

That is why I was asking about some sort of ratcheting or overrun mechanism, maybe built into a hub, that I might be able to buy off the shelf.

The trike kit manufacturer says that on a standard trike, which has a much narrower rear axle, there is no problem running with one wheel spinning free, like I have setup now. The wide axle and the extra 300 pounds above and behind the axle is screwing me.

After pondering this over the weekend, and speaking with a few folks like yourselves, I am leaning heavily toward reworking the swing arm to make it 18-24" longer. That will hopefully accomplish two things. 1, it will put the extra weight that I added in front of the rear axle so that when I accellerate it does not make the front wheel so light. 2, it should make the geometry closer match that of a standard narrow width trike. Right now my trike's footprint is actually wider than it is long, and I am sure that is making the push to the side on the front wheel so bad.

Surely by stretching out the swing arm it will accomplish at least the weight shift, so I think that it would be worth the effort.

I still need to ponder this for a little while longer and run the idea past the trike kit manufacturer for their advice.

I sure do appreciate all of the ideas from this forum so far, and I will appreciate anymore in the future.

Have a good one!
Steve Thomas

http://www.flyingtrike.com

http://www.americanspiritppc.com

 

[thundair]

If you want to keep the weight down I would think a Dog Bearing on each side would be the simplest but not cheap.

What loads will this drive see?

Another far-out thing that would work, is to use a slipper clutch pie (pie section) inside a brake drum on each side.



Cheers

I don't know anything but the people that do.

 

[FlyingTrike]

Well, the axle is connected to a Honda 750 that makes about 70 hp and the gross weight of the rig will be approx. 1300 pounds.