PC4000 Slew ring change.

[Chris5500]

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

 

[Chris5500]

And some more...

 

[Ross]

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.

 

[w2bstoned]

In that last picture, are they machining the surface? Cutting it down?

 

[JDOFMEMI]

That is some process.

I like the machine grinding the surface flat.

 

[special tool]

Gotta say...

Some of those guys be lookin' mighty cute in those short-shorts.
Is that a nair commercial?

 

[Chris5500]

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.

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.

In that last picture, are they machining the surface? Cutting it down?

Yep, they sure are machining it, was out by +0.12-0.18mm.

That is some process.

I like the machine grinding the surface flat.

Cost around $40,000 AU for the process.

Here's some more of the one Gav did, different procedure altogether.

 

[Chris5500]

And some more...

 

[Bigstevex4]

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.

 

[lybearing]

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 .

 

[michel]

does it take lots of time to change a slewing ring for this huge machine?

 

[LACHAU]

Hi Chris5500, Could you tell me why the boom cylinders have been installed in reverse direction?

 

[hammerman]

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?

 

[LACHAU]

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??

 

[hammerman]

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...

 

[alco]

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.

 

[hammerman]

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.

 

[MitchSA]

Awesome pics!! Whats the turn around time on a job like this?

 

[alco]

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.

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.

 

[RandyT]

How many hours on the machine before this was done? Data I have found so far suggests 40000-50000hrs.