Working in rock all the time we get regular occurences of scratches on D9 & D10 dozer blade tilt cylinder rods caused by rocks falling over the top of the blade spill guard. One good gouge on the chrome of the rod and that's it - head seals gone. Sick and tired of constantly changing cylinders - also the cost of the repair because the rod has to be replaced or re-chromed at the same time as installing a seal kit ........ I'm not in a position to fire the operators responsible (much though I'd like to personally shoot them ...!!) so I have to come up with something to address this issue. I can recall seeing protective concertina-type "sleeves" to go over cylinder rods but now I need some I can't find any information about them. The cylinders only have a stroke of about 12" so it wouldn't need much material to protect the rod. Anyone have any ideas of something available on-line..?
Grapple tilt cylinders on a lot of log skidders have a 3-sided steel channels that pin on with the rod-end pin, and lay on pieces of steel welded on to the cylinder. When the cylinder is retracted they cover all of the cylinder, and when it is extended, it is just long enough to rest on its slides on the cylinder. They'd be quick and easy to fab up with some AR-450.
Good suggestion Mitch. The problem is that the cylinder on the dozers does not move in a straight line all the time because of the blade tilt facility. Your idea would be fine so long as the blade was level, but as soon as it was tilted to one side or the other the channel would jump off the top of the block welded to the cylinder.
I am trying to picture what you are describing here. In my memory the tilt cylinders are mounted to the push arms. If this is the case then how is it possible for them to move in anything other than a straight line? I suggest that you look at Cats backhoe stabilzer cylinder gaurds. You may be able to modify them to suit your application (not sure if the cylinder diameter is big enough on the stabilizers), and they may even bolt right on if you fab a mount on the dozer. At the very least you could fabricate something based on that design. I'm surprised that Cat does not offer a guard. I doubt you are the only one who has this issue.
The channel goes down over the sides of the cylinder, and hangs a little below the cylinder on both sides. A lot of them have a strap welded across under the cylinder, to keep it from flying up. You, I guess, would need a loose mounting on the pin, since the pin doesn't stay perpendicular to the rod.
If the blades had a single tilt RH cylinder with an adjustable bar on the LH side you would be pretty much correct. However these ones are twin tilt cylinder setups. If you go from full left tilt to full right tilt on the blade (which is a hell of an angle believe me) the guards welded on the back side of the blade directly above the tilt cylinder rod pin go from approximately 30 degrees one side of vertical to 30 degrees the other side. The tilt cylinder rod end pins have ball joints in them so that they can cope with the angle change. Hence anything mechanically connected (even loosely as you suggest) to the rod-end pin of the tilt cylinder like the suggestions above would move the same way. They would move so far that eventually they'd fall off the side of the tilt cylinder barrel even though they were pinned to the rod end of the cylinder. That's why I was initially thinking something like a concertina fitted right over the rod and fastened at the rod end pin which at least is somewhat protected by the guard mounted on the back side of the blade.
The only thing like that I've seen is a company that made sleeves from heavy fabric, but I think big rocks would cut them. I was thinking of a single tilt cylinder. What if you welded a mount for the channel just behind the ball end on the rod?
Basically what I'm up against is the scratches on the chrome. I don't mind the protection getting cut TBH so long as it protected the chrome and was easy to replace. Welding something to the rod is probably a no-no, however attractive an idea it might seem on the face of it. The issue would be that whenever a cylinder was disassembled if it was necessary replace a rod we'd have difficulty getting Reman Core Credit from Cat if the scratched rod went back with signs of welding on it.
Ok, I send my rods out for rechroming, not cat reman. Here is a few people who make the fabric ones. http://www.google.com/search?hl=en&safe=off&rls=com.microsoft%3A*%3AIE-Address&rlz=1I7ACGW_en&q=cylinder+rod+protectors&btnG=Search&oq=cylinder+rod+protectors&aq=f&aqi=g-l1&aql=f&gs_sm=s&gs_upl=56375l59485l0l9l8l0l1l1l0l2343l3546l3-2.0.1.9-1l4
What about a bolt-together collar around the rod, just below the end. Do you have room between the ball end and the gland seal?
I have had the same problem, and we built a shield that was I think 3/4" plate welded to the side of the dozer blade, and it projected back to about the mid point of the barrel of the tilt cylinder. Then another plate came back from the rear of the blade over the top, so essentially you had half of a box. On the D-9L each side was about 3 feet square or so. Ours is single tilt, so not as much range of motion, but I am pretty sure it would work with a twin tilt as well, just some more time in the set up to make sure it has clearance. It will rub on the head of the cylinder, and being unsupported at the rear, it sometimes gets bent far enough out of whack it needs cut and rewelded, but it is far cheaper than the constant rework of the rods. We cut a hole in the front end to be able to remove the upper tilt cylinder pin. This is the only picture I could find that shows it. Though it is at a distance, I think you can get the idea.
Let me see if I can post a couple of pictures to show what I'm up against. The first one is with the cylinder fully retraced, the 2nd with it fully extended. The line made by the wiper seal when the cylinder is fully retracted is clearly visible on the rod in the 2nd photo and you can see just a few scratches in this area, compared to dozens in the area I'm not in the least worried about.
Yair...this has been a problem since the first tilt ram was fitted back in?? As some one else has said, it's wonder Cat hasn't addressed the issue. I have seen blades with a horizontal plate and triangulation welded above the ram. JDOFMEMI's setup is better as it stops the gooleys getting in there as you get in down the slot...and Nige, how much seat time you got man? It's a bit unreasonable to blame operators for this sort of damage don't you reckon? A bit of lateral thinking and it's a pretty easy fix.
How about slipping a large diameter heavy duty coil spring over it? It could be attached to the cylinder and blade at the ends with brackets so when it was closed it wouldn't scratch the rod. Maybe an accordian like hose or tube (radiator?) could be slipped inside the spring? Just brainstorming here.
Seat time. I started on a D8 2U with a donkey engine and a string blade. That enough for you...? What you don't see in the photos is the height of the rock guard on the back of the blade that we've modified to make it EVEN higher than standard to try to stop rocks falling over the back .......... my current location has no previous history of mining or even heavy earthmoving. Therefore the company is having to train people who have never run this type of equipment before to be "operators". See my dilemma now ..? Actually what I'm thinking now is a version of the extended guard welded on the back of the blade as suggested above by JDOFMEMI, but instead attached to the cylinder. Effectively to prevent rod seal failures what I need is protection for about a 6" length of the rod that actually goes past the wiper seal when the cylinder is fully retracted. So what I'm thinking is a piece of thick-walled pipe maybe 9" or so long and about the same diameter as the outside diameter of the cylinder barrel, cut in half lengthways so make a semi-circle. I'll make a base plate out of 3/4" profiled to fit around the head bolts and be bolted to the head using 3 of the 6 bolts. Might need a couple of internal ribs as well for strength. Bolt all that to the head of the cylinder (I'll need longer bolts) and I will have a semi-circular tube that covers over the top of the rod, not long enough to hit the rod eye when the cylinder is retracted, but almost. If I leave it open at the bottom and make the pipe large enough of an I/D any small stuff that gets in that area will naturally fall out. Judging by the depth of the scratches I would say it's big lumps causing the problem, not small material. Any thoughts/suggestions on that idea..?
my thoughts exactly!!
Also an idea to consider.
This will sound far out but may spark some other ideas. Weld a pin joint directly above the one on the blade with appropriate heavy duty gussets. Weld or bolt a heavy pipe "guide" on the tilt cylinder. Stick an old rod in these mounts & they will be parallel & work in unison. Now the "dummy" rod on top will take the blows.
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Sounds like a plan to me. You might want to make it 18" or so long, so that it extends back down the barrel longer than it sticks out over the rod. Then put a band around the barrel at the back, that way if a huge chunk lands on the end, it won't bend down. Good Luck, and thanks for the interesting discussion, Mitch
Working on a "cigarete packet" sketch to give to the welders as we speak. Availability of materials should not be a problem, I just need to find some pipe the correct diameter with a thick enough wall.
Yair...Nige. 2U with a string blade and donkey start? Fair enough point taken. I reckon the heavy wall tube idea could work. HOWEVER. There is a possibility that out there somewhere is scientificaly designed gooley of the correct dimensions that some manages to lodge in between the pipe and the rod for a few strokes. Just a thought. Your split pipe idea though jogged the memory bank and I seem to remember a tractor with a piece of heavy (say) sixteen inch tube split and welded to the back of the blade and gusseted onto the hungry board that you have already fitted. I have spent a lot of time devising gaurds and shielding to keep sticks out of tractors (and operators) vital bits and some times there are unintended consiquences to what seems a good idea. Interesting thread. Cheers
Good point. Honestly up to a point I'm glad that we just work in rock and so I don't have to cope with the difficulties of pioneering, etc. I'd be ecstatic if the idea I've had worked first time out, but I'm enough of a realist to accept it if it doesn't and try something else. TBH I'm not discounting ANY of the suggestions that people have come up with so far. The for the "split pipe" idea I'm only going to use half of it, the bottom will be totally open. Hopefully the goolies (not heard that word for a while) will fall out of the bottom. I will make sure to let people know how this goes and post pictures of whatever we finally come up with that works.
We'd like to see the ideas that don't work too!
What about a section of old truck tyre or something similar bolted to the blade end and long enough to slide up and down the hyd cyl as it moves, conveyor belt could be a possibility. Cheers RDG.
We have topcon gps on 2 of are 8T's and we keep breaking poles because of rocks coming up and over, we going to order a few rock guards and do some fabricating and see how that works, those poles are $2000 a pop and we have 400 acres that has to be toped with 2ft of shot rock.
Vapor300 If the operator is not savvy enough to keep the rocks out of the GPS poles, I would send them packing. There is no excuse for that. On the guarding issue, I would stay away from the spring idea. It would allow smallish rocks to get in when axpanded, then when compressed, trap them in there to have their way with the rod untill the spring opened enough or they were ground up (against the "protected" cylinder rod) enough to fall out. Likewise with the pipe idea, or even the half pipe. If your protection is very close to the cylinder, it serves as a trap to hold rock against what you are trying to protect. That is why the guard in my picture is well away from the cylinder. It protects the rod from the big ones, and does not leave much of a way to trap a small or mid sized one in there. It still gets some rock stuck, but USUALLY not where it is against the rod. I have worked rock and quarrying for many years, and if there was an easy way to protect that rod, I an pretty sure Cat would have it fitted by now, or if not them, then some of the bigger mining customers. Most of the obvious looking "protection" ideas end up doing more harm than good.
I thoughts exactly. If you can't keep rocks off the GPS poles you aren't much of operator. How do they treat the rest of the machine?