Vermeer BC620 Bearing Problem

[rcw3586]

Hi Folks,
It's been a while since I posted here because my machine has been so reliable. But I need expert advice once again - so here I am!
This 6" chipper with 1200 hours on it would not take any grease into the rear disk bearing last week. I could not see any problem so I did a small job with it. I stopped when the chipper started to make a very bad noise and I saw a spark fly out of the disk housing.

Opening the disk cover, I found that the entire disk assembly had shifted forward in the housing such that the edge of the paddles were now hitting the bolts that hold the front cover guide in place. This is about 1/2 inch forward of its normal location. I unbolted the bearing mounting plates and took the disk out. I found that the rear bearing had slid forward in its mounting cup (welded into the rear mounting plate). The tiny grease holes in the outer race no longer lined up with the machined grease groove in the cup. I was unable to remove the bearing from the disk shaft even after removing the set screws from the retaining collar. No amount of lubrication and force would cause that to budge. It did appear to be correctly positioned on the shaft though. Using a great deal of patience, a 6' pry bar and lots of shims I eventually worked the bearing (while still on the shaft) all the way out of its mounting cup to see what the problem was.
I didn't see any retaining rings, clips or anything that would keep that bearing from sliding out. It seems to be a press fit in the cup so I heated the cup/plate to about 200F and persuaded it back onto the bearing with a 5lb hammer. It's all is back in alignment now but I wonder what to do to keep this from happening again? It seems natural that the force of the feeder against the disk would work that bearing out.
Thanks for any ideas or similar experiences.

Roger

 

[Bigus Termitius]

Hi Folks,
It's been a while since I posted here because my machine has been so reliable. But I need expert advice once again - so here I am!
This 6" chipper with 1200 hours on it would not take any grease into the rear disk bearing last week. I could not see any problem so I did a small job with it. I stopped when the chipper started to make a very bad noise and I saw a spark fly out of the disk housing.

Opening the disk cover, I found that the entire disk assembly had shifted forward in the housing such that the edge of the paddles were now hitting the bolts that hold the front cover guide in place. This is about 1/2 inch forward of its normal location. I unbolted the bearing mounting plates and took the disk out. I found that the rear bearing had slid forward in its mounting cup (welded into the rear mounting plate). The tiny grease holes in the outer race no longer lined up with the machined grease groove in the cup. I was unable to remove the bearing from the disk shaft even after removing the set screws from the retaining collar. No amount of lubrication and force would cause that to budge. It did appear to be correctly positioned on the shaft though. Using a great deal of patience, a 6' pry bar and lots of shims I eventually worked the bearing (while still on the shaft) all the way out of its mounting cup to see what the problem was.
I didn't see any retaining rings, clips or anything that would keep that bearing from sliding out. It seems to be a press fit in the cup so I heated the cup/plate to about 200F and persuaded it back onto the bearing with a 5lb hammer. It's all is back in alignment now but I wonder what to do to keep this from happening again? It seems natural that the force of the feeder against the disk would work that bearing out.
Thanks for any ideas or similar experiences.

Roger

Getting a brush bandit would keep that from happening again.

 

[troythetreeman]

Getting a brush bandit would keep that from happening again.

you guys are so helpful sometimes... heh
but hes right, sortta, im not a big vermeer fan either
morbark makes a nice machine too
but bias aside
get a parts list, see if theres a part in there youre missing or something, if there isnt, and this happens again, possibly you can have some sort of sleeve machined to do the job

 

[gorman]

you can tack a weld bead on that shaft to prevent it from sliding around. I did that on my grinder.

 

[Bigus Termitius]

you guys are so helpful sometimes... heh
but hes right, sortta, im not a big vermeer fan either
morbark makes a nice machine too
but bias aside
get a parts list, see if theres a part in there youre missing or something, if there isnt, and this happens again, possibly you can have some sort of sleeve machined to do the job

what ever do you mean, my advice here will save you thousands at the versmeer stealer in the long run...

 

[rcw3586]

you can tack a weld bead on that shaft to prevent it from sliding around.

I think I mentioned that the bearing is in the correct place on the shaft. It does not slide around. The outer race is working its way out of it's mounting hole.

I do have the exploded parts diagram for the chipper but unfortunately that area has been changed since the manual was published. It mentions that but does not show what the old/new parts are. I don't think anything is missing. I don't know if my configuration is older or newer than the manual. Here is that page from the manual which is far different from my actual unit.

 

[troythetreeman]

isnt the race tapered against the bearing?

 

[rcw3586]

isnt the race tapered against the bearing?

The bearing does not come apart. One can't see inside. It's semi-sealed. I suspect it is a ball bearing as there is no way to pre-load it like a wheel bearing. Refer to the photos.