![]() Komatsu published a document at one time, which explained this in great detail." The three points of rotation while in tension was the main driving force for the development of the SALT chains. 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. 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. 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. ![]() 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. Komatsu raised it enough so that it wasn’t carrying the rear weight of the dozer. Had the goal been to just isolate the final drive then Caterpillar could have simply raised the finals the same way Komatsu did. This patent is extremely well written and there is no way around it. This also helped eliminate the track frame loading and unloading problems ,which were present on the old dozers. This design also allowed the engineers to place the trunion ball center line directly inline with the pivot shaft. 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. 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. This moment effect kept the entire length of the track against the ground. The higher the tension on the track chain the more leverage was created to literally keep the track frame parallel with the contacting surface. 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 triangle drive no longer had the sprocket/final drive centerline and track frame pivot shaft inline with each other. "The triangle drive system was developed to eliminate this track frame counter rotation/tractive effort problem. I've copied and pasted some of the discussion here. There's actually a huge (well, rather large) thread on another forum that is based on D475 vs. My understanding is that the high-drive will out-push, not out-rip, an oval-track machine. 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. I am sure that there are just as many "+" things someone can think up as I can "-" things. The biggest testiment to that is the new D6K low drive hydrostatic machine that replaces a high drive T/C powershift D5N.Īs you can tell.I am not a high drive fan. IMO Caterpillar has realized that the high drive is not the end all be all for a track configuration. 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. 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. While doing this did isolate the final drive it created other negative issues that are inherent to a high drive set up. Cat opted to radically change their machine and relocate the final drive up high. This was true at the time in that most manufacturers mounted the push beams to the final drive. They also claimed that it moved the final drive up and out of the mud and muck and protects the final drive seals. MARKETINGīack 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. One word as to why Caterpillar uses a high drive set up.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |