comparing cat and komatsu dozer undercarriage!

[junior]

what do you say which form is better in big dozers, the triangle cat or linear komatsu and others. which one is superior, why cat is producing the triangle form, does is have a better traction or anything else? thanks.

[farm_boy]

One word as to why Caterpillar uses a high drive set up.....MARKETING

Back in the day when Cat introduced the high drive it was perported that it isolated the final drive from the shock loads from the push beams, thus increasing the final drive reliability. They also claimed that it moved the final drive up and out of the mud and muck and protects the final drive seals.

This was true at the time in that most manufacturers mounted the push beams to the final drive. Cat opted to radically change their machine and relocate the final drive up high. While doing this did isolate the final drive it created other negative issues that are inherent to a high drive set up. Other manufacturers accomplished the same thing by mounting the push beams to the track frame instead of the final drive housing without the negative impact of the high drive set up. These other manufacturers also found that you can protect the final drive seals from debris without physically raising the entire housing out of the way.

IMO Caterpillar has realized that the high drive is not the end all be all for a track configuration. The biggest testiment to that is the new D6K low drive hydrostatic machine that replaces a high drive T/C powershift D5N.

As you can tell.....I am not a high drive fan. I am sure that there are just as many "+" things someone can think up as I can "-" things. I simply feel that Caterpillar is too far down the road of the "signature" high drive to admit that it isn't the best solution in order to turn back.

[CascadeScaper]

I've been told that the high drive system does add significant traction forces, especially in ripping operations. Just what I've heard, but if you think of the geometry, that drive has more leverage and has a mechanical advantage. Kinda like if you're using a block and pulley, the more pullies you add, the more leverage you have. Makes sense I think.

[biggixxerjim]

I've been told that the high drive system does add significant traction forces, especially in ripping operations. Just what I've heard, but if you think of the geometry, that drive has more leverage and has a mechanical advantage. Kinda like if you're using a block and pulley, the more pullies you add, the more leverage you have. Makes sense I think.

hmmm. point well considered....

[Ford LT-9000]

I have meantioned this before can't remember if it was on this site. Anyhow one of the gravel mines tried Komatsu dozers they were good for a little while but they went back to Cat the Komatsus wore out quicker. I remember them getting them shipped undercarriage parts on a regular basis


One thing Cat knows how to build is a dozer over at the pit they use D8s with tiller steer high drive models. The loggers use the old 1970 model D8s the tracks on them are nice and droopy.

[Wulf]

I've been told that the high drive system does add significant traction forces, especially in ripping operations. Just what I've heard, but if you think of the geometry, that drive has more leverage and has a mechanical advantage. Kinda like if you're using a block and pulley, the more pullies you add, the more leverage you have. Makes sense I think.

Who told you that Cascade Scraper because in my experience a D375 or D475 will outrip an equivalent D10 or D11.

You see the enthusiasm on this board when Tigerrotor posted the return of a conventional D6? What's that all about?

[Tigerotor77W]

Who told you that Cascade Scraper because in my experience a D375 or D475 will outrip an equivalent D10 or D11.

My understanding is that the high-drive will out-push, not out-rip, an oval-track machine. There's actually a huge (well, rather large) thread on another forum that is based on D475 vs. D11.

I've copied and pasted some of the discussion here.

"The triangle drive system was developed to eliminate this track frame counter rotation/tractive effort problem. The triangle drive no longer had the sprocket/final drive centerline and track frame pivot shaft inline with each other. By properly positioning the track frame pivot shaft alignment below the final drive they could counter effect the track frames rotation on the pivot shaft. The higher the tension on the track chain the more leverage was created to literally keep the track frame parallel with the contacting surface. This moment effect kept the entire length of the track against the ground. A research engineer named Bob Purcell proved this theory to Cat’s Management and in doing so got funding to start the development of what eventually became the D10. Incorporated with bogie rollers this triangular drive system is the primary reason that the high drives have superior tractive capabilities and will out push anything in their given weight class. This design also allowed the engineers to place the trunion ball center line directly inline with the pivot shaft. This also helped eliminate the track frame loading and unloading problems ,which were present on the old dozers.

This patent is extremely well written and there is no way around it. Had the goal been to just isolate the final drive then Caterpillar could have simply raised the finals the same way Komatsu did. Komatsu raised it enough so that it wasn’t carrying the rear weight of the dozer. It’s interesting to note that Euclid had isolated the final drives and gone to a forward pivot shaft design way back in the fifties, long before anyone else. It is also interesting to note that the two engineers Russ Williams & John Carroll who developed the Euclid dozers with isolated final drives were both former Caterpillar Engineers. Williams and Carroll knew full well the downfalls of the old combined centerline system, which was still in use on all of Caterpillars dozers at that time.

You are correct about the three points of rotation in the track chain and this was really the only unforeseen down fall of the high drive system and still is missed by many to this day. The three points of rotation while in tension was the main driving force for the development of the SALT chains. Komatsu published a document at one time, which explained this in great detail."

I don't agree that the high-drive is a huge branding game for Cat, but I do believe that in certain environments, high-drive wins. I think Cat has realized that it's not for everyone, all the time, and the D6K is one admission of that. It'll be interesting to see whether they continue the trend.

[Lashlander]

I have to wonder if price was a factor in the decision to bring back a low track six. A lot of contractors won't pay the extra for a high track in a smaller machine. That prices them out of a whole market.
I don't buy the fact that after 30 years of dominating the market that they figured out the high drive was a flop. I think the buyers would have let them know that years before now. Sure there are a lot of people who don't like them, especially salesman of other brands. I've got around 15,000 hrs seat time on large dozers and I'll take a Cat over any other anyday.

[Ford LT-9000]

For gravel mines the high track machines work good I aways been told washed and processed aggregate is more abbrasive on the machine than pushing regular dirt. The one D8 spends allot of time pushing up piles usually they replace the tracks every 6 months to a year. Then again the machine is running 20 hours a day 5 days a week.

[Opie]

Cat has a new design out for the track links and the undercarrage, this new design is on my 6R XW. The new link design lets the track to be taken apart anywhere in the track, and the front and rear idlers ride inside the links on the pins, and the pis roll inside the links so that the contact area is different each time of contact to the idlers. I gettin high speed net Thursday and will try to get some pics up, i cant figure out how to get them posted! I know some of u probably seen this design but i just thought id through this in here!

[wrenchbender]

Cat has a new design out for the track links and the undercarrage, this new design is on my 6R XW. The new link design lets the track to be taken apart anywhere in the track, and the front and rear idlers ride inside the links on the pins, and the pis roll inside the links so that the contact area is different each time of contact to the idlers. I gettin high speed net Thursday and will try to get some pics up, i cant figure out how to get them posted! I know some of u probably seen this design but i just thought id through this in here!

Can't wait to see the pics this sounds like a dream come true for mechanics. Just bust it anywhere no more raising the machine turning one track holding the other so they break evenly with the front or rear.This will really be great on disabled machines in need of final drive repairs and the such.

[JBL]

Well I think the alligator clamps were a better setup but won't work with the system one undercarriage due to the rotating bushings. You can take the new track apart anywhere but it requires a track press to get the pin out.

[Tigerotor77W]

Cat has a new design out for the track links and the undercarrage, this new design is on my 6R XW. The new link design lets the track to be taken apart anywhere in the track, and the front and rear idlers ride inside the links on the pins, and the pis roll inside the links so that the contact area is different each time of contact to the idlers. I gettin high speed net Thursday and will try to get some pics up, i cant figure out how to get them posted! I know some of u probably seen this design but i just thought id through this in here!


This is System One undercarriage -- it's been offered as an option for a little bit now, but it's becoming standard feature on more and more products.

[Opie]

Yeah i knew its been offered for awhile, just wanted to let the fellas know about it that havent seen it! I gotta tell ya our mechanics love the system one! Havent had one problem.

[Tigerotor77W]

No, no, it's all good -- I think it's awesome, too.

And post some pics when you get 'em. :)

[Opie]

Im gonna try to get some photos with my new phone, and hopefully i can get them on here Thursday after noon!:thumbsup This dial up is sloooooooooowwwwwww!!!!!!!!!!!!!:bash

[JBL]

I found this real interesting when they talk about operating cost.
http://www.cat.com/cda/layout?m=48863&x=7

[Opie]

I found this real interesting when they talk about operating cost.
http://www.cat.com/cda/layout?m=48863&x=7

Yeah how bout it!!:thumbsup

[Wulf]

Well I think the alligator clamps were a better setup but won't work with the system one undercarriage due to the rotating bushings. You can take the new track apart anywhere but it requires a track press to get the pin out.

Although I haven't seen one a master link is supposed to be available for 'system one'... see last sentence in the description

http://www.cat.com/cda/layout?m=48811&x=7&f=24703

[JBL]

Although I haven't seen one a master link is supposed to be available for 'system one'... see last sentence in the description

http://www.cat.com/cda/layout?m=48811&x=7&f=24703

Yeah they say the clamp style is available but not suggested for high impact conditions. I think I read it under the D6T specs page.

[Tigerotor77W]

JBL, where did you see the D6T literature?

And yes, there is a clamp master link option available. (And not suggested for high-impact environments)

[JBL]

JBL, where did you see the D6T literature?

And yes, there is a clamp master link option available. (And not suggested for high-impact environments)

Cat website

http://www.cat.com/cda/layout?m=37840&x=7

We have system one on our D6R XL. I have to say that is performing very good and is exceptional on slopes. I think there is about 1500 hours on the machine.One thing I have noticed though when you bogged down in heavy mud. The rails want to jump over the teeth on the sprockets. I am assuming that the bushings rotate and it just jumps a tooth. I have had this happen a couple times.

[farm_boy]

JBL, where did you see the D6T literature?


Do you mean this one Tiger??:wink2

[Dozer575]

Hi.

I'm new here this is my first post. Don't have the time now. But just wanted to say. I'm not a fan of the hi track design. I will elaborate later. This is a nice looking site.

[Dozer575]

Farmboy, I agree with you.

Junior, what you need to do is take a tape measure a pencil and paper to your Cat dealer or a job site that has a big Cat high drive dozer.

You need to draw out all the wheels in the configuration that you see in front of you. And then add the dimensions that you measure. Also notice where the main pivot is for the track frame. The next thing to do is get a brochure on that tractor. One of the things you will want to do is find the ratio between the distance from the center of the pivot to the centers of the front and rear idlers. So when you look at what half the tractive effort is on the spec sheet in low gear you know that it is approximatly what is being pulled on that rear idler in a hard push say its a huge rock, and you have 100% traction and the tracks are not slipping. What is happening is not only is this pull on that idler what causes the wear pattern on the rails, it is also pulling down on the final drive assembly, and up on the rear of the track frame which will tend to lift it. You ask so what? Well not only are these stresses on these items, as well as lifting the rear of the track frame and pivots the front part down, which is probably the reason a guy on here mentioned that a conventional oval dozer ripped better, but these stresses also sap horse power. There is that extra wheel to have to turn. There is like a major tug a war going on between that high final and that track frame.
Now look at the oval type drive on the old D9G and H. If there is a blade mounted and you are pushing, all that force is transmitted to the final support bearings and no tug a war pulling down on the final or frame of the tractor or track frame. The sprocket pulls straight on the track, there is no lifting in the rear and no extra wheel to pull the chain over. But with the newer free planetary finals on the ovals there is pulling and stressing the mainframe. With the dimensions and spec sheet you can calculate the amount of lift up and stress where that track chain rail meets the rear idler,
it amounts to way more per unit loading that at anyother roller that the chain makes contact with. This is why the high drives eat track chain at a faster rate than the ovals do. And may brand loyal ones will argue it.
But like farmboy says, Cat sales really pushed how great the hi drive was, but now they are going back to the ovals. I have always wondered why the D3's never became a hi drive. I think cat sees the goof they did, and how Komatsu and John Deer and others are taking away sales. Just like the old cletracs, someday these hidrives will be museum pieces.

[farm_boy]

thanks Dozer.....I beginning to think that I was the only one on this site that didn't think the high drive was "all that".

BTW.....Welcome to HEF. Salute!:drinkup