I can't get my head round this diff unit drawing. Does anyone (Darren) understand how it works/ if it works/ is it feasible as a useable unit for our trikes???
John
John
Differential apparently- Anyone explain it?
- Thread starter jonrev
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Possibly however I am hopeless at this stuff.
The big sprocket has an axle that has the nearest left to us cog keyed to it so they rotate together
The right cog nearest us rotates on an axle mounted to spin freely on both sides of the big sprocket so is driven by the left cog.
The axle to the right cog passes through the sprocket and so drives the back left cog with what looks like a chain from the right cog ?
As these are pedals forces and there are loads of ' non ' bicycle parts I doubt it would work ? or for long ?
Paul
The big sprocket has an axle that has the nearest left to us cog keyed to it so they rotate together
The right cog nearest us rotates on an axle mounted to spin freely on both sides of the big sprocket so is driven by the left cog.
The axle to the right cog passes through the sprocket and so drives the back left cog with what looks like a chain from the right cog ?
As these are pedals forces and there are loads of ' non ' bicycle parts I doubt it would work ? or for long ?
Paul
As the main gear is driven the two nearest gears circle each other with the middle one stationary and the outer one orbiting because of the pin through it. That outer cog turns as it orbits which drives the rear gear on the other side which drives the one attached to the axle via the small chain. If the far side is unable to move at the speed it should (say the inside wheel in a corner) then the rear cog on the small chain doesn't orbit as fast as it should meaning it turns the orbiting cog on this side which in turn drives the axle mounted cog at this side. It works in reverse of that for the opposite corner. A neat idea in theory BUT any crap in the meshing gears and you have problems and you also have a very real engineering issue of passing that rear pin through a drive gear as it needs to rotate freely and provide the strength to drive. It will need bearings necessitating a substantially sized drive cog to provide the real estate to mount a bearing housing. The main drive cog will probably need to be motorcycle in origin to allow for all the stress that that drive pin will place on it. You will also have the issue at high speeds of an imbalanced main drive cog rotating with a large bearing housing, bearing, pin and two cogs offset to one side of it. You also have the small chain being whipped around the axle.
I would suggest the two freewheel system is a more practical way.
I would suggest the two freewheel system is a more practical way.
Err- nope. Can't get my brain to follow at all. I can see that as the main sprocket is driven the small cog and small sprocket will be trying to turn in opposite directions but each is prevented by being fixed to the other. Both half shafts (axles) will therefore be driven in the same direction till one of them feels more drag and then.......I get a headache!
All this is purely academic to me as I would certainly go for a two freewheel system which gives the grippy wheel the power rather than the vehicle losing traction as one wheel loses grip. I just hadn't seen this setup anywhere before and it intrigued me. The drawbacks as explained above probably are the reason.
Don't know if anyone has not come across this site before but there's a very long thread on velo's (120 pages) which I'm enjoying.
motorbicycling.com
Thanks guys
John
All this is purely academic to me as I would certainly go for a two freewheel system which gives the grippy wheel the power rather than the vehicle losing traction as one wheel loses grip. I just hadn't seen this setup anywhere before and it intrigued me. The drawbacks as explained above probably are the reason.
Don't know if anyone has not come across this site before but there's a very long thread on velo's (120 pages) which I'm enjoying.
Velocars and other interesting vehicles.
I would imagine that Threadcromancy isn't permitted by the moderators so I thought I'd begin a new thread to follow on from this old one here ....... http://motorbicycling.com/f44/wild-idea-24508.html The modern velomobile is far too hi-tech and expensive for me to even consider for a...
motorbicycling.com
Thanks guys
John
It would work in theory but be 100% useless.
The mechanical advantage working against the tiny sprocket would shred it to bits.
A perfect title for this patent would be "A Device to Stretch or Snap Small Chains".
The mechanical advantage working against the tiny sprocket would shred it to bits.
A perfect title for this patent would be "A Device to Stretch or Snap Small Chains".
No doubt you are all correct about being too weak for the job it needs to do. Don't know if this was a 'to scale' type drawing and maybe a really large main sprocket could have been used so the smaller sprockets were larger/stronger than they look? The drawing was offered as if it was a method for making a diff and nothing about it being experimental or theoretical at all.
As I say it was just something that annoyed me because I couldn't see how it worked (and still can't to be honest) but I wouldn't dream of making it as I much prefer the two freewheel method if I needed to use a diff system (which I don't).
John
As I say it was just something that annoyed me because I couldn't see how it worked (and still can't to be honest) but I wouldn't dream of making it as I much prefer the two freewheel method if I needed to use a diff system (which I don't).
John
...oh yes you do... said Mr. Punch.
Oh no I don't! Single drive to one rear wheel is nice and simple- like me, is fine for traveling on flattish surfaces- like me, works well in the dry weather- like me, is nice and lightweight- like.... Well three out of four aint bad.
John
John