Driver Thrust Bearing

This forum is dedicated to the Live Steam Hobbyist Community.

Moderators: cbrew, Harold_V

Post Reply
daves1459
Posts: 213
Joined: Mon Jun 07, 2010 7:58 pm

Driver Thrust Bearing

Post by daves1459 » Sun Jan 16, 2022 4:45 pm

Last winter 2020/2021 I dropped the drivers of my Disney 4-4-0 to replace the original cast bronze journal boxes with steel boxes and guided needle roller bearings, two bearing per journal. I added harden sleeves on the axles in the journal area and cylindrical ground them to size. During last summer's steaming the loco accumulated 26 miles as indicated on the riding car odometer. During the last steam up I noticed a distinct squeak coming from the right rear driver. This winter 2021/2022 I again dropped the rear driver and found disturbing damage. First was the obvious lack of oil on the outer journal needle bearing. Second, and more disturbing was the thrust bearing wear. The journal box and thrust washer are both made of 12L14 steel. The washer is trapped between the driver and a shoulder on the axle so speed difference between the washer and journal is 100%. Upon inspection there was oil on the thrust faces but wear into the journal box thrust face was .014". The left rear journal had .007" wear. There was no similar wear on the old bronze journal boxes after many years of operation. Fixing the low oil problem is easy. So here is my dilemma: Is the wear simply a matter of incompatible materials and what should the fix be? Hopefully the expertise out there can give me some direction. Can I solve the wear issue by changing the thrust washer from 12L14 steel to bearing bronze and make it a separate loose floating washer? Should the washer be Oillite impregnated bronze. Or should the solid washer be replaced with a caged needle roller thrust bearing with hardened races, there is enough room. There is not enough room to convert to ball bearings.

Dave
Attachments
DSC02699.JPG
DSC02740.JPG

User avatar
Bill Shields
Posts: 7747
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: Driver Thrust Bearing

Post by Bill Shields » Sun Jan 16, 2022 5:12 pm

bronze would be a better choice.

Olilte....probably not since it has a propensity to crack.

a loose, floating washer is generally a good idea...
Too many things going on to bother listing them.

User avatar
Chris Hollands
Posts: 488
Joined: Thu Mar 26, 2009 8:38 am
Location: Vancouver ,Canada

Re: Driver Thrust Bearing

Post by Chris Hollands » Sun Jan 16, 2022 5:28 pm

Some form of plastic is another option - ask a plastic supplier for options to suit the application .
There is self lubricating versions as well - Teflon impregnated and so on .
INA /DU bearings is another option in thrust washers .
Lots of options to choose from .

RET
Posts: 937
Joined: Wed Jun 07, 2006 8:36 am
Location: Toronto, Canada

Re: Driver Thrust Bearing

Post by RET » Sun Jan 16, 2022 5:56 pm

Hi daves1459,

You might also try something different. They used to use grease fittings on automotive front suspensions and our locomotives also run in a dirty environment, so a similar setup would make sense. Drill a hole in the end of the axle with a cross hole in the middle of the bearing so when you use a grease gun to force the grease in, it goes to the center of the bearing. I have done this with Dart and I'm doing the same thing with Jeannie Deans. Both locomotives are still under construction, so I don't have running time on them but the concept makes perfect sense. When you force in the new grease, it will also force any dirt out of the bearing. With that setup, I would expect such a bearing design to last almost forever.

I use a machined 8-32 NC capscrew in the tapped hole in the end of the axle as a plug and when I want to relubricate the bearing, I remove the plug and screw in an adapter with a grease fitting on one end to grease the bearing and then replace the 8-32 plug in the end of the axle until the next time. With this setup, I would expect to only have to lubricate the bearing once or twice a year.

Richard Trounce.

User avatar
Marty_Knox
Posts: 1615
Joined: Thu Jan 09, 2003 6:50 pm
Location: Michigan, USA

Re: Driver Thrust Bearing

Post by Marty_Knox » Sun Jan 16, 2022 6:08 pm

Full size they are called hub liners. As a student engineer I was taught to poke the spout of the oil can between the spokes and dribble oil down the back of the wheel to keep the hub liners lubricated.

User avatar
Bill Shields
Posts: 7747
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: Driver Thrust Bearing

Post by Bill Shields » Sun Jan 16, 2022 6:18 pm

I am all in on the lube up the center trick which I have been using for decades. I also cut radial grooves in the thrust discs so that they can allow lube up on the face.
Too many things going on to bother listing them.

User avatar
Greg_Lewis
Posts: 2454
Joined: Wed Jan 15, 2003 2:44 pm
Location: Fresno, CA

Re: Driver Thrust Bearing

Post by Greg_Lewis » Sun Jan 16, 2022 9:26 pm

As I understand it, you have a thrust washer and a journal box both made of steel, and they are wearing against each other. I've been taught not to use the same material for both parts in such friction bearing situations. A bronze washer as Bill suggests would solve that, and Chris suggests plastic. There is an oil-impregnated polyethylene that might be a good choice if you don't want to use bronze.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.

User avatar
Bill Shields
Posts: 7747
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: Driver Thrust Bearing

Post by Bill Shields » Sun Jan 16, 2022 9:58 pm

It is a dirty area..think carefully of the material choice.

Cast iron would not be out of place either
Too many things going on to bother listing them.

Rwilliams
Posts: 1007
Joined: Thu Dec 22, 2005 2:45 pm
Location: Central California

Re: Driver Thrust Bearing

Post by Rwilliams » Sun Jan 16, 2022 10:24 pm

Over ten years ago we elected to use some Delrin AF to make hub liners for a full size steamer at the museum where I work. Of course there were the usual naysayers who complained that this is not the way we have always done it. A few more, cognizant of modern industrial materials decided that there was no reward without a little risk. So far the Delrin AF hub liners have worked out perfectly and we would use them again. Getting ready to use more Delrin AF in other areas of the locomotive as needs arise.

For your hub liner situation, Delrin AF might be the easy answer.

User avatar
NP317
Posts: 3523
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon

Re: Driver Thrust Bearing

Post by NP317 » Sun Jan 16, 2022 10:45 pm

With driver axle boxes next to the firebox, there is a temperature caution to consider with the bearings.
I've seen the ball bearing on an Allen Mogul driver fail next to the firebox due to over firing and flames licking out on the to axle box.
So plastic bearings might not work for long in that situation.
RussN

Harold_V
Posts: 19351
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Driver Thrust Bearing

Post by Harold_V » Mon Jan 17, 2022 4:33 am

I fully agree with the comment about not running similar alloys on each other. That's a sure recipe for failure. Beyond that, I can't imagine a scenario where I'd use 12L14 for a bearing (or thrust washer) of any description.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

User avatar
Greg_Lewis
Posts: 2454
Joined: Wed Jan 15, 2003 2:44 pm
Location: Fresno, CA

Re: Driver Thrust Bearing

Post by Greg_Lewis » Mon Jan 17, 2022 10:35 am

While a bearing plastic is an interesting idea, as I think about this, replacing the thrust washer is such a chore that I'd think bronze would be the best choice. And as Russ says, the firebox heat wouldn't be good for the plastic.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.

Post Reply