Are you asking what is the advantage of hub reduction.IE you can apply as much gear and differential gearing reduction as you like but the half shaft still has to deliver all the extra torque to the wheels.While if you reduce it at the hub you can reduce the torque loading on the half shaft while increasing it at the wheel.
+1
That’s why STGO’s on 6 x 4’s tractor units have 'em. Like he said, no strain on the half-shaft.
All the engine torque’s where it should be… at the wheels.
Are you asking what is the advantage of hub reduction.IE you can apply as much gear and differential gearing reduction as you like but the half shaft still has to deliver all the extra torque to the wheels.While if you reduce it at the hub you can reduce the torque loading on the half shaft while increasing it at the wheel.
+1
That’s why STGO’s on 6 x 4’s tractor units have 'em. Like he said, no strain on the half-shaft.
All the engine torque’s where it should be… at the wheels.
So this magic “torque” just appears at the wheels eh?
Does not have to be transmitted by the half shafts,it just appears!
How about a smaller diff crown wheel for better ground clearance on tippers and a reduced ratio level reducing gearbox dimensions on heavy tractors.Reduction hubs are far more power “greedy” than a straight hypoid diff,more gears to turn more power lost.
Are you asking what is the advantage of hub reduction.IE you can apply as much gear and differential gearing reduction as you like but the half shaft still has to deliver all the extra torque to the wheels.While if you reduce it at the hub you can reduce the torque loading on the half shaft while increasing it at the wheel.
+1
That’s why STGO’s on 6 x 4’s tractor units have 'em. Like he said, no strain on the half-shaft.
All the engine torque’s where it should be… at the wheels.
So this magic “torque” just appears at the wheels eh?
Does not have to be transmitted by the half shafts,it just appears!
How about a smaller diff crown wheel for better ground clearance on tippers and a reduced ratio level reducing gearbox dimensions on heavy tractors.Reduction hubs are far more power “greedy” than a straight hypoid diff,more gears to turn more power lost.
Bound to agree with the comments from Carryfast and Simon 1958. I knew people who worked at David Brown Gears in Huddersfield and was shown round the factory. Epicyclic gear sets as used in hub reduction are 97% efficient, very little difference from hypoid bevel or worm drive reduction gears according to them.
I did most of my training on the old Leylands with reduction hubs and those half shafts weren’t much bigger than cars in comparison to a straight out hub.
So the reduction hub “creates” torque
Why bother with an engine,just fasten a couple of reduction axles to a chassis and away ya go!
A reduction hub works on a lever principle as does all gearing The half shaft drives a planet carrier connected to a hub mounted annulus.
Usualy has about a 2.5 to 3 to 1 reduction ratio.This means the half shaft turns 3 times for one turn of the hub.All the torque is carried through the half shaft but the half shaft has to turn 3 times to each wheel revolution as in say a block and tackle,a lot of movement on the pull chain with low effort results in a small movement of the load chain with high effort.
All the “torque” is supplied by the bloke pulling on the chain ,but he has to pull the the chain ten feet to get one inch of movement on the load chain.
Thats how a small force applied over a large distance can lift a large mass over a short distance eg a lever.
Bking:
So this magic “torque” just appears at the wheels eh?
Does not have to be transmitted by the half shafts,it just appears!
How about a smaller diff crown wheel for better ground clearance on tippers and a reduced ratio level reducing gearbox dimensions on heavy tractors.Reduction hubs are far more power “greedy” than a straight hypoid diff,more gears to turn more power lost.
Blimey Biking torque ‘at the wheels’ without hub reduction is totally dependent on gear reduction at the gearbox and the final drive with the output side of the diff and half shafts having to then deliver all of that torque to the wheels.If you use hub reduction a lot of the resulting torque multiplication can take place at the output side of the reduction gearing in the hub.So for example 2:1 reduction at the hubs means a corresponding reduction in the torque loadings on the halfshafts because the hub does the torque multiplication not the final drive therefore the halfshafts don’t need to deliver it to the drive wheels.On that note yes it just magically appears at the hub.In just the same way that it ‘magically appears’ at the gearbox output flange in any gear less than direct drive and ‘magically appears’ at the output flanges of the final drive at a corresponding level with final drive reduction gearing.IE it’s called torque multiplication.
Bking:
So the reduction hub “creates” torque
Why bother with an engine,just fasten a couple of reduction axles to a chassis and away ya go!
A reduction hub works on a lever principle as does all gearing The half shaft drives a planet carrier connected to a hub mounted annulus.
Usualy has about a 2.5 to 3 to 1 reduction ratio.This means the half shaft turns 3 times for one turn of the hub.All the torque is carried through the half shaft but the half shaft has to turn 3 times to each wheel revolution as in say a block and tackle,a lot of movement on the pull chain with low effort results in a small movement of the load chain with high effort.
All the “torque” is supplied by the bloke pulling on the chain ,but he has to pull the the chain ten feet to get one inch of movement on the load chain.
Thats how a small force applied over a large distance can lift a large mass over a short distance eg a lever.
You’ve answered your own question.The ‘lever’ in this case is the hub reduction gearing which multiplies the ‘smaller’ force’ ( torque ) at the final drive output and halfshafts into the larger amount of force ( torque ) required at the wheels.By making the halfshafts cover a greater distance than they would do without hub reduction.Have you got it yet.
While by your logic you’d could only end up with the same max torque at the wheels as you started with at the crankshaft regardless of all the combined gear reduction/torque multiplication in the transmission and final drive and/or hub reduction.
The fact is hub reduction means less torque required at the half shafts,to get the equivalent amount of torque at the wheels,as you’d need to apply to the halfshafts without it.Get used to it.
Bking:
So you get more torque (force) at the wheels than you get out the engine?
Haey carryfast you just invented a perpetual motion machine.Well done.
Put that “extra” force back into the loop and it will run forever.
Wouldn’t that be so if he had said more or equal energy at the wheel than from the engine?
I’m no Brian Cox but a cursory search produced this;-
Horsepower = (Torque x RPMs) / 5252
I had a small play around with the equation and I get;-
Torque= (horsepower x 5252) / rpms
1/ horsepower from an engine is fixed for the sake of the point.
2/ 5252 is a constant
3/ But the variable is the rpm which affects the torque. Vary one, affects the other which signifies it is quite possible to have an increase in torque from an gearbox out shaft than applied to the input shaft. The relationship varies with rpm.
Bking:
So you get more torque (force) at the wheels than you get out the engine?
Absolutely it’s called the law of leverage as you described yourself.Which is why we have the gearbox and final drive gear reduction.Without those and just given the puny pathetic 1,000-2,000 lb/ft of the engine the wagon is going nowhere and will also probably just break the the driveline somewhere in the chain between crankshaft and wheels.So good try at trying to invent a gearless direct drive wagon but no cigar.
Go back a few post’s boys. I did try to warn you. It feels good when you stop banging your head against a wall. Mind you, if I had my doubts before about bking, I’m now 100% convinced that he knows very little about how lorries or cars or anything else for that matter, move.
peterm:
Go back a few post’s boys. I did try to warn you. It feels good when you stop banging your head against a wall. Mind you, if I had my doubts before about bking, I’m now 100% convinced that he knows very little about how lorries or cars or anything else for that matter, move.
Bking reminds me of the late Herr Hitler in 1945, giving orders to armies that had already been wiped out by the Russians, threatening England with wonder weapons that didn’t exist, insisting that Germany was going to win.
Logic and facts are disregarded in order to maintain his self belief.
On the other hand, maybe he is just winding us all up by pretending ignorance?
peterm:
Go back a few post’s boys. I did try to warn you. It feels good when you stop banging your head against a wall. Mind you, if I had my doubts before about bking, I’m now 100% convinced that he knows very little about how lorries or cars or anything else for that matter, move.
Herr Hitler in 1945 threatening England with wonder weapons that didn’t exist,
It is just as well that he had interfered with development because things so easily could have been very, very different. The European war ended just in time. Some of the following if available would have brought about a complete reversal of fortunes.
We digress… The European war ended just in time for the Germans, I presume you mean, with the first a-bomb just a few months away, though it’s hard to see how it would have been used in Europe. The Nazis were nowhere near making their own bomb, largely due to the fact that the best scientists had been forced out of Europe by the Nazis’ policies, even though Germany once had the lead in nuclear research + I think, the Nazis’ physicists didn’t want to build a bomb for Hitler. They certainly had some nasty chemical weapons but feared retaliation + Hitler was squeamish about using them I believe.
"’ Calm Down ‘’ … Even the guy who invented the differential ended up in a comfortable home. French if I recall.
And No. It was’nt one o’ IImmigrant’s forefarther’s
