Have you checked for allowable tolerances with stacker suppler?

I feel 34 mm is too high.

Have all the drives are installed?

Uneven numbers of drives can make the stacker to drag at one side. Check with metallurgists & designers for the shaft material quality. ■

There is something untidy about the design if you have 6 drives spread over 4 corners. Would you have bought a 4 x 3 Landcruiser? Or is it a tripod undercarraige?

Can you explain your wheel contact problem in more detail? 34mm out of square is a lot. Can you reduce the figure?

"Machine wheels touches the rail one side while moving farward direction and vice versa." needs a bit more explanation. I imagine you mean the machine skews consistently according to the travel direction.

As stated already the traction must be equal along each rail.

I suspect your situation is the result of unequal traction and/or rail settlement. These would produce high bending moments on the shafts and hence the frequent failures.

Acheson Colloids supply flange lubricators which will cut the noise down but just because the squeal goes doesn't mean the side load has gone as well. South side shafts are suffering more because they must be receiving the greatest camber displacement due to their distance from the centroid of the net traction.

What wear regime have you got on the tripper wheels? ■

Louis is right your track geometry/foundation sounds terribly off. Do you have a licensed surveyor that can measure and check levels of the rails for the stacker or access to a lazer theodolite for measurments of the track geometry?

Is the track foundation on a solid slab from end to end or simply railroad ties and ballast?

What is the railroad gauge british standard, usa standard, narrow guage?

If you have a huge amount of track settlement you will have problems from the widening of the rails from the center line distance and this will cause huge problems.

Find someone to check the tracks geometry first then check each problem one by one after that as it sounds as if the wheel sets are losing and regaining traction and shearing because of the torque generated with out kicking off a circuit breaker or relief valve. ■

How long has this unit been in service?

Is it a linear stacker or a radial stacker?

Has any major work been done on the stacker prior to this problem?

Your drives are no different than a locomotive wheel set in my opinion and if the distance along the tracks are not level, equal, and parallel you will have problems.

It is no wonder you are having problems. How is the roadbed rail system set up? With ties graveled in place? concrete ties supporting each rail with the rail bolted/ anchored in place on the concrete?

Is the rail in question in 39 foot joints or one continous rail with joints strapped together or is each joint welded together?

What is the weight of the rail per foot if known? It will be cast or stamped in the end of a rail joint.

Has the rail ever been cut and reattached due to heat stress expansion or cold shrinkage?

What is used to secure the rail to the bed or what ever is used for a foundation, i.e. tieplates and rail spikes?, rail anchors to allow for linear expansion and contraction?

Are there limit switches or photo-electric targets controlling the movement of the stacker? are they buried or bypassed?

Is the location of the original survey station still accessable if one was used? If not a new one will need to be set in concrete.

If you could post a few pictures of the stacker and the entire set up that would help.

Distances- A to c and B to D should be the same just as the distances for a railroad wheel truck are identical. it sounds as if the main frame structure is badly warped/twisted/stretched.

Are their any broken welds that are visible?

What is the condition of the surface of both rails themselves?

The amount of wear should be equal on the inner edges of the rail sets where the wheel sets contact the rails.

what is the condition of each individual drive wheel, gouged, very worn traction edges?

Rule number one is this: do not forget that only a certain percentage of any wheel on the stacker is in contact with the rail at any time and it is a tiny fraction of the wheels diameter.

Knowing the diameter of the drive wheels would help as well.

lzaharis ■

I have knocked up a sketch in SolidWorks using your dimensions and leaving the track as two driven dimensions.

AC square across the track AC=6951.36 BD=6994.49 43out

BD square across the track AC=6943.54 BD=7002.37 58out

Wheelbases centred provides 23 solutions with the 58mm track discrepancy most prevelant.

Your ideal diagonal is 9898mm over 7000mm rail centres.

If you increase BD to 7054mm your wheel tracks become 6944 & 6952 which becomes acceptable. Your present track difference is probably devouring the side clearances between flanges and rail bulbs. It's still not clear what the nominal 6950mm wheel tracks are doing on a 7000mm rail centre arrangement but these are just raw figures, manipulated as driven sketch dimensions. The indication is that you should increase the shorter wheelbase by about 50mm.

Hopefully you have 2 drives each on A & C and single drives at B & D? ■

Have you checked the reasons for beams cracking?

And I could not find any attachments. ■

But now

2.There are 12nos of boogie wheels out of which 8nos are driven by motor i.e. for every two wheels one motor-gear box.

3.There are four main columns; each column is having two wheels.

(If I could find him; I'm pretty sure my old mathematics teacher would agree with me that your numbers don't match up.)

6.The distance between each column length wise 7500mm

Your observations are somewhat awry. We were told the columns were 7012 & 7004. Now we are told they should be 7500. That's some distortion. After my previous comments backed up by a driven sketch you still haven't given us the actual machine tracks. If you can't be bothered; why should we?

How close to the originals are you replacement legs? About 500mm away if we accept your figures. And somebody is still wondering why they cracked. ■

Is it at all possible the steel supplier short changed you with a poorer grade of steel or smaller thickness.

were the old struts welded with gussets for strength?

What of the cross bracing if any?

In regard to the locomotive wheel sets- who was the manufacturer?The Electromotive Division of general motors? or General Electric? what are voltages-600 volts perhaps? and power for the wheel sets-AC or DC? how is power delivered? trailing cable or insulated third rail?

It sounds as if the steel is thinner/weaker judging by your comments. ■

Greetings and salutations Ramesh Kumar,

It is no wonder you are having troubles!!!!!!!!!!

I am one mad mahoot after seeing this!!!!!!!!!!!!!

First I would see if it would be possibe to remove the wheels and either get new wheel sets for this guage or press the wheels off and turn them around and press them back to fit this guage if possible- the local rail road repair shop is where I would go first!!!

The wheel flanges must be inside the rails for proper adhesion.

You will need to have the rail anchors that are damaged repaired due to the inward pressure of the wheel sets flanges on the outer ball edge of the rail.

The one section of rail in your picture does not look bad but the anchors need attension.

First I would curse at the installer for installing the drive with the flanges on the outboard side-it was only a matter of time before they failed!!!!!!!!!!!!! Apparently they never worked around a railroad engine or rakes of railcars!!!!!!!!!!!!!!!!!

Failing the above:

I would see about having one new single railset and concrete apron installed as this would be the fastest way to solve the problem and still be able to use one of the original rail sets and apron.

After the rail set is installed it will be a matter of moving and jacking the stacker sideways to reset it on the rails- first by returning the stacker to the start or end point and then cut the rails away and reset the stacker on the properly aligned rails.

it is all in the surveying as one new set of rail and anchors should do it- god willing you will have enough of a concrete apron left on one side to anchor the new set and still have adequate strength to hold everything in place.

That said I do not know how much wiggle room you have for the conveyor feeding the stacker- if it is on a concrete apron it may be as simple as sliding the entire conveyor over a bit- and give your surveyor a fit to say the least. ■

If I look at picture 26 I see a double flanged wheel?? ■

Running over DSC040428 indicates that the rails sag locally. OK, I've just run a straightedge over some edges to check the optics of it all. It does look like there is some heavy rail sag though.

I don't fancy getting your cable reel out.

What's the balance situation with the tripper?; a few tonnes of uplift and the adjacent drive might slip. ■

Hi there,

The other authors have probably hit on the most probable issues: frame work, rails etc. Picture DSC04030 took my breath away. Keeping a gear drive free of debris and keeping is lubricated properly is a must if you want a reliable drive system emerge from this. There is so much dirt in the gears that this should be a wonder why gear and drive motor shafts shear.

Clean it up and keep it clean that will be job number one right after starightening your frame and rails system issues out. ■

Mr.Ramesh Kumar,

A) By having closer look of the long travel gearboxes installed ( refer photos from DSC04020.jpg to DSC04024.jpg) I suspect different make of gearboxes are installed.

This I could say that in DSC04022.jpg, I see fabricated gearbox and in DSC04021.jpg, I see cast moulded body gearbox.

If you are having different makes of gearboxes (and it is much possible that their output RPMs are not same), you may end up with long travel drive break downs.

For equipments which are having group drives it is always adviced to replace all the drives together with same make, with same output RPM.

B) What are the photos in DSC04026.jpg & DSC04030.

If there are useless gears, why do not you remove them? They may create additional force on long travel drives.

Please reply for both A & B. ■

There is little point in running crane wheels over bulb rails but you are unfortunately stuck with the scenario. One of the photos does indicate the expected spalling on the rail crown.

Crane wheels are used to give compact drive arrangements which then concentrate the track loadings; which in turn calls for stronger rails.

I suspect there is some uplift from the tripper and suggest you investigate the actual traction condition again. If a drive starts to slip then your alignment is gone. ■

You mean to say that none of the opinions are matching and you need further ideas? ■

If this one isn't knocked on the head it will go on for ever. There's only so much worth saying when there is conflicting dimensioning and no explanation. ■

Yes, we could go on for a while. Looks like we have a combination of issues going on that should be dealt with one-by-one. To round of this picture we kind of forgot to look at the broken shaft(s). Mr. Kumar, could you post a couple of pictures that show the shaft break surfaces? If the shaft broke due to torsion - as the various posts suggest - the surfaces should have failed with a ductile fracture and the shaft pieces should matching 90 degree cones. If the fracture surface is flat and parallel with so called beach marks this may be due to misaligment. ■

I agree with you totally Mr. Weiser I would like to see an end view of both ends of all the broken shafts my self as it it still puzzling if it is one of the the final drive or an itermediate shafts- I dont think we have stepped on that hippo yet have we?

lzaharis ■

Hello,

Some general information, as possibilities, is as below:

1) As stated by you the machine is working since about 8 years, but recently you have problems.

2) It seems you have 4-corner support machine (not converted to 3-point support system).

3) If the machine wheel level is perfect, and rail is not perfect (uneven) then wheel failure will be random.

4) If rail is perfect (as a single plane), but wheel level is imperfect, then diagonally opposite any one set of wheels are likely to have problem.

5) Rail imperfection can arise due to foundation settlement (mild earthquake, water level change, etc.).

6) Wheel level or orientation imperfection can arise due to wheel wear, faulty installation during replacement of wheel or wrong jack-up and structural distortion.

7) Machine skew movement can arise by wheel axle skewness (that is not perpendicular to rail track) which may have arisen during replacement of items, or uneven wear of drive wheels, or drive electrical portion.

8) Drive wheel or its axle failure chances are more because it is subjected to drive torque stresses in addition to radial load stress.

9) Also check drive motor and related electrical.

10) In such cases it is advisable to get suggestions from machine supplier for repair.

Regards,

Ishwar G. Mulani

Author of Book : Engineering Science And Application Design For Belt Conveyors (new print November, 2012)

Author of Book : Belt Feeder Design And Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India.

Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■