Possible de-alignment of flywheel at Arbtrak190?

[Soeren]

Hello,

 

after the summer pause we just started to use our Arbtrak 190 on some groundcare in the forrect when after a half day session I noticed a strange sound coming from the motor compartment; a little bit like something would touch metal hardly from time to time. Opening the compartment and also the chipper box, I noticed three things:
 

• The two outer discs had significant defects. So I suppose somewhat like a stone got fed together with the wood and brushes.  Not sure if this is related, just want to mention it. The discs had been just recently turned, so I assume it really happened in our recent works.
• Three wings of the 400mm fan at the flywheel had some smaller breakouts, two very little, one maybe like a one-pound coin. I also noticed they would just so touch the left (left as looking from the front part of the motor) part of the fan housing. That's the obvious reason why some little parts came off. The wings do not touch on the right side, so there is some kind of mis-alignment of the flywheel system I suppose. (foto 1 + 2)
• Most interesting, see foto 3: I measured the distance of the square box (not sure how this named), that holds the flywheel axle to the left and right side of the housing and it's the same here: The distance to the left is slightly smaller then to the right.
  Please note the foto is not perfectly made centered to the axle, so it does not look symetrically. But the difference left to right space is barely noticable with the eye, I haven't measured but I suppose its somwhere in the range of <2mm.

 

So for me it looks like the fixing for the flywheel is slightly out of alignment. Can this really be caused by stone or something getting into the feed? The fixing looks so massive and it seems not to be moving by the 1/100 of a milimeter that I'm quite astounded on this problem. Especially the two M10 bolts to the left and right of this "holding box" look like they are super-fixed and not moving at all. Is this a common or rare problem?

 

I suppose we need to reposition the flywheel, is this correct? We have all the tools for that but I suppose that's a delicate work anyhow, so any hints on this work would be appreciated.

 

 

Thanks a lot,
Soeren

[monkeybusiness]

I suspect the bearing has failed - if you slacken the belts and put a bar under the rotor shaft you will probably see movement.

[GA Groundcare]

1) Have you got photos of the cutter discs? You can usually tell the difference between blade-anvil contact and debris damage.

2) I wouldn't overly worry about the small amount of damage on the orange fan blades. 

3) Your flywheel alignment adjustment on the front bearing is up, down, left and right. The gap down each side of the bearing may not be identical. When setting up a flywheel you are looking for a good rotation with no tight spots, no creaking from the rear self aligning bearing and a 2mm blade gap. Getting these three key points correct may give an uneven gap down the side of the bearing.

4) Slacken your drive belts and get a bar under the flywheel, check for play up and down plus end to end.

If there is play then either the bearings are worn or the front bearing has been turning on the main shaft. If the latter then you will need a reconditioned exchange flywheel and the updated NTN front bearing setup.

[Soeren]

@monkeybusiness: Bingo, exactly as you described. The motor shaft moves slightly, maybe 1~2 mm. @Jase hutch: Would this be enough description to provide spart part numbers?

Edited December 18, 2023 by Soeren

[Soeren]

24 minutes ago, GA Groundcare said:

1) Have you got photos of the cutter discs? You can usually tell the difference between blade-anvil contact and debris damage.

 

Hi, looks like our last postings crossed. So here is a foto of one cutter disc. The inside disc looks normal, also the second outside disc has only very little signs of wear. Never had such huge impacts before.

What do you mean by "end to end movement"? I checked up/down, very little, same as left/right. And in fact at a certain position I can hear a slight creaking.

I measured also the current misalignement, the fan blades have zero to the left and 5mm to the right. So after the repair that should yield the 2.5mm on each side then again.

 

[GA Groundcare]

We carry all the flywheel bearings in stock should you wish to order.

[Mike Hill]

2 hours ago, Soeren said:

Hi, looks like our last postings crossed. So here is a foto of one cutter disc. The inside disc looks normal, also the second outside disc has only very little signs of wear. Never had such huge impacts before.

What do you mean by "end to end movement"? I checked up/down, very little, same as left/right. And in fact at a certain position I can hear a slight creaking.

I measured also the current misalignement, the fan blades have zero to the left and 5mm to the right. So after the repair that should yield the 2.5mm on each side then again.

 

Honestly that thing is so lightly built that it's probably warped during normal use or was welded up a bit "skew whiff".

 

Looks like it's eaten some stones or gravel,dosnt look too serious to me.

 

The "end to end" movement means forward and aft on the shaft,taillights to tow hitch if you like.

 

I would purge the bearings with grease and spin the rotor by hand with the belts off. The noises you described sound like dry bearings.

 

If you do replace the bearings consider welding a 10mm plate behind the current bearing mount and setting that bearing back on the shaft. That mounting point is total shite imho 

 

 

[Jase hutch]

Never had an issue with the front bearing mounting before.....

[Soeren]

3 hours ago, GA Groundcare said:

We carry all the flywheel bearings in stock should you wish to order.

Sounds great, will send you an PM 👍

[swinny]

4 hours ago, Soeren said:

Hi, looks like our last postings crossed. So here is a foto of one cutter disc. The inside disc looks normal, also the second outside disc has only very little signs of wear. Never had such huge impacts before.

What do you mean by "end to end movement"? I checked up/down, very little, same as left/right. And in fact at a certain position I can hear a slight creaking.

I measured also the current misalignement, the fan blades have zero to the left and 5mm to the right. So after the repair that should yield the 2.5mm on each side then again.

 

****************  me. I thought I had some animals work for  me before but that's the 2023 award for worst chipper disc surely.

 

Not surprised bearings are shot