salve, scusate il disturbo, in rete si leggono mille discussioni, mille forum in cui ognuno esprime la propria opinione ed esperienza, ma onestamente parlando e obiettivamente parlando, per le macchine movimento terra, conviene adottare la classica trasmissione che trasforma , credo, power shift o idrostatico? un operatore mi dice che secondo la sua esperienza il convertitore è la migliore soluzione attuale la macchina movimento terra ha prestazioni e resa migliori. Da esperti cosa potete aggiungere grazie scusate per il disagio. The Hydrostatic Revolution: How crawler dozers became infinitely more versatile when stripped of their gears Once known as one of the more difficult earthmoving machines to master, the crawler dozer, with the right technology, has become one of the easiest to run. The difference? In just 10 years, hydrostatic transmissions have come to dominate dozers in the under-130 horsepower class. That combined... www.equipmentworld.com
Trombeur you need to post in English. Thanks
hi, sorry for the inconvenience, on the net you can read a thousand discussions, a thousand forums in which everyone expresses their opinion and experience, but honestly speaking and objectively speaking, for earthmoving machines, it is better to adopt the classic transmission which transforms, I think, power shift or hydrostatic? an operator tells me that according to his experience, the converter is the best current solution, the earthmoving machine has better performance and yield. As experts what can you add thank you sorry for the inconvenience. the computer translates automatically sorry for the misunderstanding,.
Hydrostatic machines, are a pain in the ass. And do not last long… TC with planetary transmissions last ages and are kind of easy fix. Both absorb the rigors of dragging implements… Direct transmissions are not a good suit even when fitted with perma clutches. And do not dampen shock‘s very good for track machines. Nevertheless u have the 3 types still . Today a TC with lock up system will behave as if it was a direct drive, and the clutch packs inside can be off perma system… so almost no energy lost to couple… as they designed to be permanently engaged . The bad thing is this systems need computation power and lot of sensors , which eventually fail, making them hard and costly to repair.
basically you prefer a classic d8 caterpillar instead of a modern Liebherr, right?
Well, if u’re a rich contractor… or a gold mine owner liebhrr is fine.
Both systems have their advantages and disadvantages. In a track loader with more frequent direction changes a hydrostatic machine is roughly 2 1/2 times more productive than a powershift torque converter machine. With proper maintenance hydrostatic can last just as long as powershift TC machines and both are expensive to rebuild. There are a lot of high hour Hydrostat Cat track loaders and other brands of hydrostat crawlers. Some have said if you're using a dozer strictly to pull a scraper a direct drive machine is preferred.
Doing the kind of work I did, hystat was too slow, clutch and brake is fast. Some seem to think since you can have power to the tracks all the time, that it some how is an improvement. I say no. To turn any tracked machine power or rotational speed needs to be either slowed or stopped to affect the turn. I suppose if your making a 200 or so foot radius turn then it maybe nice to have hystat.
Turning with a full blade having power to both tracks can be an advantage. Also turning around in tight quarters or sloppy conditions. They both have their advantages.
I’ve wondered about the use of the new Liebherr high track hystat mining dozer in the mines and if they’re hanging in with the D9/10/11 machines they’re meant to compete with. Maybe this will be the string to get that answer. Any of our fellow HEF members here working in any mining operations with them? Seems to me like Liebherr is popular in Australia, Africa and is making a push to get into South America. I recently saw they’ve released an articulated truck for sale in the USA. Be curious if they’ve translated any of their big truck successes to their new artic truck line. I agree that there are certainly a lot of high gout Cat track loaders that are still kicking around. Ask me how I know… same with the Cat D5G and D6K etc. many of them around still too. Most of John Deere, we’ll I guess all of them since probably the 90’s have been hystat machines. For a while at least, they were good little dozers for finish work. Same situation, list of machines with higher hours still kicking around out there.
Well, in my opinion, its all about power transission and how fast u can shutle or recicle throug the power band... and this also have a lot to do with the machine caracteristics and what type of power transmission is used. As some brands use some really complicated outfits ... hard to repair and f%$# costly in dwn time and parts. Lets take the case of a pure Hydrostatic system, where the engine turns an oil pump and fluid will travel directly throug piping to a drive motor on every track , and change of direction is done throug a directional valve, stop and start is achived by this valve, TQ delivery controlled by a swash plate type pump controled by eng RPM drop or increase... symple system i guess is what is present in 953C´s Liebhr system its not like this, they used a power flow to it and a differential drive motor too, along with gears. It add´s a lot more complexity to the system, it also makes it very competitive, so competitive that they moved it in a 80Ton Dozer, after they gather information and expertise in the 40 to 60 ton dozers. This system is more like a CVT than a pure Hydrostat, being the hydrostat also a part of this system. If u guys know about the Tractor brand FENDT, they are around for 50 years with this type of transmission, and farmers love them, except when the transmission need repair. I also like them but i use JD, not because of colour or manufacture place, its cause of availability, same goes for the dozer i own, could have gone Komatsu or Liebhrr, but i´m a poor business man, and again availability drove me to a CAT Planetary transmission, istead. In a Track Loader with TC with planetary trans makes it too slow, wich is not the case of wheel loader, where nobody questions a TC planetary trans. Nevertheless fiting a track loader with Diferential steering might help in speeding up, but again diferential steering is just a plower flow device that uses also a hydrostat system.
thanks for the clarification, but what about the tracked loaders? I believe that in the world only caterpillar john deere and maybe liebber build them, am I wrong, what is the difference between a bulldozer that pushes and a tracked loader that digs, lifts the load and then transports to unload the resulting material? thanks sorry if I disturbed you thanks
Advantages of hydrostat track loaders was already explained in my 1st response. Used to be more brands of track loaders but a lot of the work is now being done by excavators. Track loaders still have their place though and are very versatile machines.
thanks for the clarifying answer, you never stop learning thanks.