I was going to post photos of the KMG (Komatsu Mining Germany) factory where the PC3000, 4000, 5500 and 8000's are made. Apart from Komatsu and Demag machines, the factory started its life as a Nazi war factory during WW2. Anyway, I've lost the photo's and while searching I came across these which I'd like to share with you because not many (if any at all) have been exposed to such maintenance activities and for some people these will be quite interesting. Title says it all really... For those of you who saw the ones that Gav posted on DHS a while back of the 5500 slew ring change (will post photos if requested) you will notice that it’s a completely different procedure. Reason being is that this machine is part of a marked contract and as per the Komatsu slew ring procedure the bearing mounting surface must be measured (and machined if required) and has to be within 0.4mm (0.015inch) in order for KMG to warrant the new slew ring, as it happens this particular one was out by +0.12-0.18mm and had to be remachined. As the 5500 was not part of a marked contract it was the owner’s decision to take a chance and fit it without measuring or machining (correct me if I’m wrong Gav!) Feel free to ask any questions you may have... hopefully some technical ones
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Nice set of Pictures Chris ... Done slew rings on big hydros in the past ... Pretty decent set up ... Is that a triple Bearing set up? Funny they still havent mounted the Slew gear inboard.
In that last picture, are they machining the surface? Cutting it down?
That is some process. I like the machine grinding the surface flat.
Gotta say... Some of those guys be lookin' mighty cute in those short-shorts. Is that a nair commercial?
Yeah it’s a triple bearing swing circle. The first job I got as an apprentice was to degrease and clean the bearings from an H 655S slew ring so the German's could inspect the damage and take photographs. I also had to cut it into quarters for transport back to the factory. Quite a big job first up considering it weighs 16 tonne. Yep, they sure are machining it, was out by +0.12-0.18mm. Cost around $40,000 AU for the process. Here's some more of the one Gav did, different procedure altogether.
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Those big red jacks are cool as hell! if you have the equipment to work on that big stuff sure makes it easy. tring to crib that big stuff is a pain.
impressed . Cost around $40,000 AU for the process. maybe the new slewing bearing for the PC4000 is only USD 10,000 and less . we are an expert in manufacturing slewing bearing .
does it take lots of time to change a slewing ring for this huge machine?
Hi Chris5500, Could you tell me why the boom cylinders have been installed in reverse direction?
The cilinders work the same in both directions, the designer-contructor has some explanation sure.It´s like the bike´s suspension, currently are all inverted, why?
Hi Hammerman. Yes, I know the cylinders have operated the same inboth directions. I have wondered why they's been installed in forward direction with small and med. size machine and reverse direction with large size machine??
I don´t know why,that´s the question...
The cylinders are mounted like this for several reasons. Probably the biggest two reasons are to simplify and reduce the hydraulic hose runs. And to stop dust and debris from gathering around the seals on the hydraulic cylinders where they could potentially do damage.
My thought,it´s more easy and cheaper changing the seal of the cylinder than repairing the cylinder´s rod or chrome by a knock.
Awesome pics!! Whats the turn around time on a job like this?
Well, there are a couple of ways to look at that differently. For starters, there should never be contact with the cylinders to begin with, but if there was, having the rod damaged would be the easier fix. If the barrel of the cylinder took the hit, the barrel would deform inside, which would be a cause of damage to the piston as it passed the deformation. That in turn causes the metal shaved from the piston to be spread throughout the whole hydraulic system, contaminating everything. In that situation, the whole cylinder has to be changed out and the system flushed. Besides that, debris rubbing against the rod will do more than just damage the seals, it will also score the rod over time.
How many hours on the machine before this was done? Data I have found so far suggests 40000-50000hrs.
The 5500 had no where near those hours, 20000 range for that one. The 5500 got machined also Chris. Say g,day to your old man for me hey? Hang on a sec, am i admitting i worked on Komatsus?...!!!!
When the seals leak it runs down the chrome to lube it mounting them like this also gains room and vision around the carbody, a benefit moreso with face shovels where space limited, just how the designed roll
And if you know Komatsu diggers with there old Demag technology when it comes to hyd cylinders you are right, those 5500 at Roach when i was there had to have the seal packings reshimmed once a month easy and replaced every 3 or so, what a dinosaur that set up is. With the regularity that we did them we welded a big piece of mesh at the top of the stick so you had a platform to stand on to do the reshim.
Exactly Gav those chevron seals suck! reshimmed and replaced them more times than I care to remember!
I've line bored the swing box bores on plenty of Liebherr 994's and they also had the hoist rams "upside down" The 996 was the same I believe The machining on the slew mount is nice. I've seen them done with single point machining but not with a milling head.
Have a EX5500 with 34000hr so far, trying to forecast an overhaul frequency.
Hitachi should have centerline files that give estimates on life achieved with major components, like any OEM they will be conservative and it is then up to you to have a very good understanding of many of the facets of your operation in order to make sound judgements on when to do the components. Application, Useage and Maintenance all play key roles in life being achieved or exceeded and you have to have a good handle on them to push things out further.
Randy do you measure the swing bearing deflection every 1000hrs? This is recommended so then you can plot a trend of wear. You should see a steady increase in wear over time, when you see a big increase in wear, time to start planning for a swing bearing change. Some people call it the "bathtub effect". Imagine drawing a line from the centre of bathtub floor, to the top of the bathtub. Looking at the tub side on, there would be a small, steady increase up, then when it gets to the end, it rises rapidly. This same principle can be used to monitor wear.
OEM recommendation is 40000-50000 but history on other machines indicates around 32000 but we are past that. Swing Bearing Freeplay is measured every 3000hrs, I'm yet to receive this historical data.
Michel I am part of the team that did that change out and I think back then it 5 days, I am glad to say with advances in the procedures we now have completed over 75 slew ring changes since then and average downtime of the machine is 28 hours. Let me know if you would like to see some pics
I Sure would!
hi pakkajackas we have a couple of 5500s that are getting close to the hours for a slew ring c/o are you able to quote for this ta
Hi Blue leader, do you need pricing on the slew ring? We provide reman units as well as new and we currenlty have repair and replacement programs with Peabody and Alpha in the U.S.
Can you please send these pictures to me? [email protected] .