Weight distribution /fuel savings

[slowzuki]

Well, I read through the technology thread and typed a reply but something went wrong when I went to post. When I refreshed the little reply button is greyed out. So here is my reply.

Ok, I read through most of this. I'm another mechanical engineer, and am one of those guys with a pile of projects behind and in the shop.

I will talk about modern ie 4wd tractors.

The ultimate point of this debate as far as I can see is lower fuel consumption. The tractor pulling an implement only has a few variables:

The force and therefore the fuel used to pull the plow is fixed. And assume there is no relative speed change from the front to rear axle.

Given an ideal slip rate for a particular soil, and the load/rim pull/slip info for a tire in that soil, there will be an ideal split of load on the front and rear axles and a minimum tractor weight to achieve this under steady state plowing conditions.

This would be the minimum fuel consumption. Weight unbalanced front to rear or too little total weight results in to much slip and increased fuel consumption.

Too much weight and the slip drops as soil compaction increases and the fuel consuption increases.


Farmers and manufacturers play this game already with GPS and ground radar to choose ideal ballasting.

Movable ballast can't change the total weight, but could only adjust the front rear balance. During the day, how much could this possibly save in fuel? 0.25% is conditions of soil change? Someone could study this in an intrumented tractor of conventional design and do an analysis, it could prove valuable, maybe not.

3 point hitches already provide sensing of loads which reacts to prevent large changes in front / rear weight distribution.

Ken

 

[nomad]

</font><font color="blue" class="small">( Well, I read through the technology thread and typed a reply but something went wrong when I went to post. When I refreshed the little reply button is greyed out. )</font>

I just came back and realized that that thread was closed(?). I've been trying to stay in the topic although a few people have attempted to make it off the subject. These a few people talking off the subject could only be considered as a minority comparing with a silent majority. After giving a brief info on techniques by my last two post, I was planning to connect them to the original subject; i.e. the technology in farm machinery field. Closing a thread because only a very few people talked bad in it shouldn't have been done in My Opinion if it was closed because a few people wanted it to be done, however. Anyways..

After all, I can add only a few words here;
Rather than the weight distribution, the force acting distribution is important and changing the application center of total net force even a little bit may lead some important results if the force flow through the tractor+attachment is nonlinear.

 

[MossRoad]

Don't you think the major manufacturers study this stuff all the time? I mean, heck... if an Ag manufacturer could state that their machine will do what everbody else's machines will do for the same price, AND do it with less fuel consumption, they'd have a great marketing tool. I've never shopped for Ag equipment, but I bet there is all kinds of litterature on this on the Ag sites.

 

[HayDR]

Because of the New EPA standards the fuel consumption is similar on most diesel engines of similar size. To have an engine to be declared a Green Engine many of the companies have the same head and injection designs. CAT, Cummings, Perkins, FIAT, ETC paid for approval and many of the smaller companies did not have the time or technology to comply with the standards. So these smaller companies purchased Perkins heads and CAT injection technology.

 

[slowzuki]

I'm gonna stay away from the engine discussion and stick to the weight or I suppose more technically correct force distribution with respect to fuel consumption.

We still will reach a minimum weight that will move a particular implement as ideal tire slip rates.

Improved tires for conditions can reduce the weight needed. The problem is that the weight only increases fuel consumption due to the increased soil compaction and resistance to the turning tire.

More to come when I'm not at work

 

[rambler]

I've always though ballisting a tractor set up the best weight for the soil, tire, and load conditions. More weight or less weight, put at the right part of the tractor.

It seems like nomad wants to only move the weight from front to rear or rear to front to balance the tractor.

That seems like a very small part of the issue. You need to add or subtract weight, not just move it?

Now, if you go from loading up 2000# round bales with a loader on your tractor, take the loader off & pull a small grain drill in the afternoon, and then put a chisel plow on & go chisel plowing in the evening, sure it will help to move weight from way back rear, to middle, to somewhat forward.

But it would help a lot more to have a lot of weight behind the rear wheels, to no weight at all, to about 1/2 the weight near the front axle in this example.

Isn't that the point of good weight distribution for a pulling unit like a tractor? Not just shifting the weight, but changing the amount of weight.

--->Paul

 

[Slamfire]

I don't know about weight distribution, but I know you can make a considerable savings with the correct air pressure in the tires. Of course that ain't very high tech. /forums/images/graemlins/tongue.gif