Rotary Cutter Removing roller bearings from Bush Hog pulverizer

chanceu · Apr 12, 2007

I went to a local rental shop to rent a pulverizer. The guy said the one he had was on no shape to be used. After looking at it, he offered to sell it to me cheap. I ended up buying it (Bush Hog PV-600) and a second pulverizer for parts for $100.

I'm no expert, but the Bush Hog seemed to be in pretty good shape except the teeth were missing or bent beyond use. The good news is all the teeth on the second pulverizer where in good shape. In about an hour, I had all the teeth replaced and only twisted off 1 u-bolt.

All in all, I think it was a pretty good deal considering replacement teeth cost $5-6 each and I needed 27. I have no idea what a new pulverizer would cost, but I have to imagine it's considerably more than $100 and the cheapest rental I could find was $35/day.

The only real problem I can see with it is the roller has been installed off center. On one side, the roller shaft sticks through the bearing about a 1/4" and on the other side, it sticks through about 1 1/2". It still works fine, but the roller hits the arm and has worn a groove in it.

I loosened the set screws that hold the shaft in the bearings and hit it a couple times with a 3lb sledge hammer, but it didn't move at all. I can't see any way to get a puller on it so my question is how do I get the bearings off the shaft?

For what little I will use it, I don't want to pay a shop to do it, but I also don't want to continue until I tear it up.

BTDT · Apr 12, 2007

Any pics? Sounds like you got a good deal. Try 16# hammer, something will move.

DieselPower · Apr 12, 2007

Pic's would help. If it is a pressed on bearing on the shaft you need a bearing splitter, T-bar puller with the leg's that attach the bearing splitter to the puller. This setup will pull the bearing off. You can also remove the shaft and press the bearing off in a hydraulic press.

To install a new bearing heat the bearing to about 260-280 degree's F. Get a temperature crayon from your local welding supply store. You can buy the crayons in whatever temp you want, they melt when the metal get's to the temp. When it's hot enough it will just slide on and when it cools it will shrink to a press fit.

You can also press it on on a hydraulic press. Last option to install it is to get a piece of pipe just a little biger than the shaft but smaller than the OD of the inner race and beat it on with a hammer (beat on the pipe that is).

chanceu · Apr 16, 2007

Pics...

BTDT · Apr 22, 2007

After looking at the pics, I would start by torching off the bolts that hold the bearing block in place on both sides. Then (last pic) try driving a chisel-prybar between arm and bearing block. You may have to take a grinder and dress up the end of the shaft, it may be mushroomed, see if you can heat bearing race next to shaft and work it off. If too much effort involved, probably better to just cut bearings off, dress up shaft and install new bearings.

Might be able to grease real good and just use it as is. Does the roller turn at all?

chanceu · Apr 22, 2007

The bolts come off. I've had them all off and they came off pretty easily. I think I'm going to try a bearing splitter before I do anything that'll cause damage.

I'm sure the bearings need to be replaced, but the roller stiller turns without any effort. The biggest reason I want to remove/replace them is that the roller rubs the arm. You can see that the bearings weren't installed at the same place on both sides. If you look at the left top picture, you can see where the roller touches the arm. I don't have a picture of it, but the roller has worn a nice semi-circular groove in the arm.

radman1 · Apr 22, 2007

chanceu said:
The bolts come off. I've had them all off and they came off pretty easily. I think I'm going to try a bearing splitter before I do anything that'll cause damage.

I'm sure the bearings need to be replaced, but the roller stiller turns without any effort. The biggest reason I want to remove/replace them is that the roller rubs the arm. You can see that the bearings weren't installed at the same place on both sides. If you look at the left top picture, you can see where the roller touches the arm. I don't have a picture of it, but the roller has worn a nice semi-circular groove in the arm.

I think you are on the right track. The bearings just need to be slid over or replaced. Looks like they need to move over 3/4" or 1". Heating the bearing and then use a press or pipe over the shaft to move the one bearing inward. The other bearing that needs to move out will be more difficult to get behind. Try to apply the heat to the bearing and not the shaft. Could the bearings be held in place by a set screw or collar with set screw?

chanceu · Apr 22, 2007

There are set screws, but I got those out. I'm going to price new bearings and if they're not too much, I'll just replace them. Otherwise, I'll try to pull the one side out enough so the roller doesn't rub the arm.