Hill Climbing Primer

CalG · Apr 20, 2014

SPYDERLK said:
]Matching downward force on the ring gear face and bearings.] Net effect Zero

net effect ZERO! Ahhh!

The voice of reason.

SPYDERLK · Apr 20, 2014

Egon said:
(With a little scrutiny it can be noted that within the consolidated chassis every up force has a corresponding down force.)

Do a summation of forces and remember the torque figures in.

What torque beyond that already accounted for?

Egon · Apr 20, 2014

The tractor is capable of rotating around the rear axle by the rotational forces on the pinion!

Dem levers mentioned also rotate on the back axle.

Must perplexing trying to educate an uneducated farm boy when he don't know squat eh?

(removed) would have the answere!

vtsnowedin · Apr 20, 2014

Take a look at this.
Tractor wheelie - YouTube

SPYDERLK · Apr 20, 2014

vtsnowedin said:
Take a look at this.
Tractor wheelie - YouTube

Very high pull point. He should lower it a little bit because the traction gain of weight transfer does not increase after the front rises ... and the tip resistance decreases as it goes up. Makes it less stable. The offseting performance advantage of this dangerous hi wheelie setup is that if youre skillful you can jerk as the front falls after every save. This quick arrest thrusts the drive wheels down harder momentarily. :thumbsup:

larry

SPYDERLK · Apr 20, 2014

Egon said:
The tractor is capable of rotating around the rear axle by the rotational forces on the pinion!

Dem levers mentioned also rotate on the back axle.

Must perplexing trying to educate an uneducated farm boy when he don't know squat eh?

(removed) would have the answere!

Still harping on that wrong perspective I see.

Egon · Apr 20, 2014

SPYDERLK said:
Still harping on that wrong perspective I see.

Nope; never harp!:thumbsup:

But I do watch wrong perspective's.

And try and give reasonable explanations.

:thumbsup:

ovrszd · Apr 20, 2014

SPYDERLK said:
No. You are misinterpreting your experiences. That easy explanation is wrong. Its the combination of drive lever and load lever as explained in prior posts.-- And on hills the position and height of the center of mass becomes much more important than in level situations because it affects the load lever.
larry.

Again, no flame intended. What I've explained happens everytime you step on the gas to move your rear axle driven vehicle forward, whether it's a tractor, car, truck, buggy, ATV, whatever. It's a natural reaction to the effort it requires to propel the vehicle. First thing that happens is the pinion tries to climb the ring gear, which in turn lightens the front of the vehicle. That's why dragsters do wheelies. It's also why my buggy will tip over backwards if this torque is wrongly applied. I've saw buggies destroy their suspension without moving because the torque applied and traction attained was greater than the strength of the suspension setup.

Unlike you Larry, I will not proclaim that you are "wrong" as you have done to me. We might even be agreeing, just using different terminology. But I am not "wrong".

CalG · Apr 20, 2014

ovrszd said:
Again, no flame intended. What I've explained happens everytime you step on the gas to move your rear axle driven vehicle forward, whether it's a tractor, car, truck, buggy, ATV, whatever. It's a natural reaction to the effort it requires to propel the vehicle. First thing that happens is the pinion tries to climb the ring gear, which in turn lightens the front of the vehicle. That's why dragsters do wheelies. It's also why my buggy will tip over backwards if this torque is wrongly applied. I've saw buggies destroy their suspension without moving because the torque applied and traction attained was greater than the strength of the suspension setup.

It is a mis-observation to attribute the lightening of the front end of any vehicle with the "climbing action" of a pinion on a ring.

Again, weld the axle shaft to the housing, apply engine power, and describe the result on the tractor.
The pinion still tries to climb the ring, that is true. But, the tractor shows NOTHING of it. All reaction is taken out withing the gear box.

An accurate description of cause and effect will be less confusing. And the only external forces are concentrated at the point where the tires touch the ground.

An observation: The Fordson E27n has large, direction reversing bull gears for each axle within the rear end. does this direction reversing mechanism cause the pinion gear to push the tractors front end down? Hmmm, now that would be a great feature if it were true.

Question? What is the resulting action of the pinion climbing effect on the front wheel drive axle of a "typical" SUV or similar. That is a RWD vehicle with MECHANICAL front wheel drive ?
(Just like a Four wheel drive tractor. Where does the "pinion climbing the ring action" show it's self? I've never been able to abserve it, only that the tires spin on slippery surfaces just like the rears do.

SPYDERLK · Apr 20, 2014

ovrszd said:
Again, no flame intended. What I've explained happens everytime you step on the gas to move your rear axle driven vehicle forward, whether it's a tractor, car, truck, buggy, ATV, whatever. It's a natural reaction to the effort it requires to propel the vehicle. First thing that happens is the pinion tries to climb the ring gear, which in turn lightens the front of the vehicle. That's why dragsters do wheelies. It's also why my buggy will tip over backwards if this torque is wrongly applied. I've saw buggies destroy their suspension without moving because the torque applied and traction attained was greater than the strength of the suspension setup.

Unlike you Larry, I will not proclaim that you are "wrong" as you have done to me. We might even be agreeing, just using different terminology. But I am not "wrong".

That easy explanation is wrong and is adhered to by many because it offers an attractive analogy. I didnt say you originated it. Im not blaming you for it. I blame tthe person that originated it -- lost, but still causing trouble by thwarting valid analysis. ... Im just showing that it is a mistake in resolving forces. Im sorry that you feel compelled to declare yourself not wrong.
larry

SPYDERLK · Apr 20, 2014

Egon said:
Nope; never harp!:thumbsup:

But I do watch wrong perspective's. And try and give reasonable explanations.:thumbsup:

Reasonable can be correct, or not. Factual physical science is never unreasonable. Historically tho it has caused people who insist on it a lot of trouble.

msmith1wa · Apr 20, 2014

Some other examples of a vehicles that has a ring gears that rotate in the opposite direction of most rear drive vehicles are the old VW buses that have the swing axle rear suspension, Mercedes Unimog and the Hummer. I am sure there are others but that is three. All of these have a gear attached to the wheel end of the axle that drives a gear on a stub axle attached to the wheel. So again using the concept of the pinion gear climbing the ring gear, then these setups would be pushing the Ring gear down and vehicles would not be able to do a wheelie. When I was a kid back in the 70's my family was in a dune buggy club several of the club members, including my dad's buggy used the VW set up I mentioned earlier and all of them could do wheelies.

I think what is confusing people is converting the rotational force (torque) from the tire to a linear force being resisted by the object being pulled and the effects of the height the pulling force has on how the vehicle will react. It's been a long time since I took statics.

ovrszd · Apr 20, 2014

Okay, I give. You guys win.

I'll stick with my previous opinion, it's fairies that cause the front to lift. It appears that my pinions are the only ones climbing the ring gear. So it's gotta be fairies.

Egon · Apr 20, 2014

CalG said:
and what if the object hitched to is not immovable?

Then it does move. However if the consolidated tractor?? Has a lower forward speed than designated engine RPM and gear selection while the tires have a no spin grip show and explain to us what happens??:thumbsup:

A simple force diagram would help!

Egon · Apr 20, 2014

ovrszd said:
Okay, I give. You guys win.

I'll stick with my previous opinion, it's fairies that cause the front to lift. It appears that my pinions are the only ones climbing the ring gear. So it's gotta be fairies.

You gotta watch out for the Wee Folk. Afore you know it they will have you partaking of their Magic Brew and all you will see is two flat front tires from overload and your tractor sitting in a big hole it dug when turning the front end under.

And they'll convince you that the tractor your squished under is really sitting upright and all is good.

vtsnowedin · Apr 20, 2014

msmith1wa said:
Some other examples of a vehicles that has a ring gears that rotate in the opposite direction of most rear drive vehicles are the old VW buses that have the swing axle rear suspension, Mercedes Unimog and the Hummer. I am sure there are others but that is three. All of these have a gear attached to the wheel end of the axle that drives a gear on a stub axle attached to the wheel. So again using the concept of the pinion gear climbing the ring gear, then these setups would be pushing the Ring gear down and vehicles would not be able to do a wheelie. When I was a kid back in the 70's my family was in a dune buggy club several of the club members, including my dad's buggy used the VW set up I mentioned earlier and all of them could do wheelies.

I think what is confusing people is converting the rotational force (torque) from the tire to a linear force being resisted by the object being pulled and the effects of the height the pulling force has on how the vehicle will react. It's been a long time since I took statics.

This has become quite silly. Any setup of driveshaft to rear axle will be set up to rotate the wheels forward when power is applied in a forward gear. Moving the pinion from the front to the back of the ring gear would only mean the drive shaft rotation direction was reversed not that the torque was now applied downward. And pinions don't climb up a ring gear as much as they walk around the circle. Stop the circle and the walk goes faster. Like walking up the down escalator and having them shut off the power. And last but not least is the weld the axle to the housing theory. That would amount to applying a very good parking brake and you would stall the engine, nothing more.

CalG · Apr 20, 2014

Pesky fairies!

Look what they did to this guy!

http://www.cdc.gov/niosh/face/images/04IA011a.jpg

SPYDERLK · Apr 20, 2014

vtsnowedin said:
And last but not least is the weld the axle to the housing theory. That would amount to applying a very good parking brake and you would stall the engine, nothing more.

Right. no wheelie. Zero tendency to tip. You keep the force from output to ground and you have all forces consolidated in the tractor. That tractor is as stable as if it is off. Interact outsde the tractor and you have to be careful in dealing with output and load forces to ensure stability. External interaction is where its at. Tip is a rotation at the tire-ground interface unless the tire is truly frozen in place.
larry