Grate Rollers

Yanche · By: **Yanche** On: Tue Jul 24, 2007 4:33 pm

In describing his A-A boiler tear down forum member GregL describes worn grate rollers. Forum member Bob responds with post
http://www.nepadigital.com/bb/viewtopic.php?p=10993#10993 suggesting that the AHS boiler improved the design with greaseable grate rollers. Well my AHS S-130 has no obvious way to grease these rollers. The external roller shaft, the part that has a nut on it, has a center hole, but no grease fitting. Should there be a grease fitting? If yes it was obviously left out on my boiler. All four grate rollers are the same, a hole but no grease fitting. The boiler owners manual I received makes no mention of greasing these rollers. Just says to makes sure the rollers move freely.

Eric · By: **Eric** On: Wed Jul 25, 2007 12:37 pm

The bearings on our S130 can be greased from the outside. To do this, you must put a "push-in" type grease fitting in the grate bearing holes. To my knowledge, we have never included greese fittings on our machines (probably because we've never had any real problems even with people who don't ever grease the bearings). These grease fittings are available from any industrial supply house. I checked with Grainger today and they will typically run about $2/piece.

coaledsweat · By: **coaledsweat** On: Wed Jul 25, 2007 1:18 pm

There are also small Zerks that come with 1/4-20 thread available. Most auto parts stores should have both. Personally, I would not use grease in a boiler/stove, I would think a high temperature Neversieze or similar (I am fond of the copper based stuff, it is just prettier) is more appropriate. The temperatures a boiler/stove operates at would consume the grease or have it run out shortly after the application.

WNY · By: **WNY** On: Wed Jul 25, 2007 1:44 pm

How about this?

http://www.schaefferoil.com/286c_grease.html

We use it in some of our High Temp applications...

Yanche · By: **Yanche** On: Wed Jul 25, 2007 1:48 pm

I would agree it doesn't look like there would be a problem. The roller assembly is well built and the roller appears to be hardened steel. The one I've removed was difficult to turn completely but did free up after a couple of tries. It's been in service for four years without a problem. Given what I've observed I suspect some ash dust has gotten in the bearings since they screeched when turned. As the existing grease worked in they quieted down. I'll add grease fittings. Hopefully the grease will act like a seal to keep the ash dust out. IF it all doesn't melt and run out. :-)

Yanche · By: **Yanche** On: Wed Jul 25, 2007 1:59 pm

coaledsweat wrote:The temperatures a boiler/stove operates at would consume the grease or have it run out shortly after the application.

The grate rollers are well shielded from the hottest parts of the boiler. Certainly no hotter than the ash container which is never to hot to touch. I use synthetic high temperature grease on the blower shaft pillow blocks. It doesn't run out and that shaft does get hot. Much hotter than the ash bucket. When I get the grease fitting installed that's the grease I'll try first. Hopefully the roller bearing shaft is not completely hardened and I'll be able to tap it for a grease fitting. I was just able to scratch it with a utility knife so I should be able to tap it.

ktm rider · By: **ktm rider** On: Thu Jul 26, 2007 1:48 am

Yanche wrote:The grate rollers are well shielded from the hottest parts of the boiler. Certainly no hotter than the ash container which is never to hot to touch.

I wouldn't want to try that with tthe AHS multifuel boiler !!! OUCH !!!

Bob · By: **Bob** On: Thu Jul 26, 2007 8:58 am

Yanche wrote:
coaledsweat wrote:The temperatures a boiler/stove operates at would consume the grease or have it run out shortly after the application.
The grate rollers are well shielded from the hottest parts of the boiler. Certainly no hotter than the ash container which is never to hot to touch. I use synthetic high temperature grease on the blower shaft pillow blocks. It doesn't run out and that shaft does get hot. Much hotter than the ash bucket. When I get the grease fitting installed that's the grease I'll try first. Hopefully the roller bearing shaft is not completely hardened and I'll be able to tap it for a grease fitting. I was just able to scratch it with a utility knife so I should be able to tap it.

I was told by Jeff at AHS that a press fit grease fitting can be installed directly in the hole.

Alternatively you can just use a fitting on your existing grease gun that will deliver grease into the hole. The fitting I have is just a steel tube with a rubber cone fit over it. The rubber cone provides sufficient sealing to allow grease to be pumped into the fitting. The bearings apparently have no seals because grease pumps in very easily.

I suspect that you could also use a product like a dry Teflon spray into the existing hole to lubricate the bearing.