Bushed vs Bearing S/G end cap
 

Bushed versus Bearing support on the rear end cap of an S/G generator

I'm doing a rebuild of an S/G motor and the rear end cap on the unit is a bushed support. Is there any reason to seek out a replacement end cap with a bearing support? Given the tractor may only get 100 - 150 hours a year use, is it worth changing the style of the end cap or just redoing the bushing (which appears to be OK).

Is it normal for the bushing to have a "hole" in the side ? to wick oil onto the armature shaft ??

thanks

I would think there is almost no side load on the end cap end of a S/G.

A bushing would be better than a bearing in a no load situation, IMHO. :bigthink:

Is there area enough for a needle bearing - will reduce drag.

You cannot simply swap out the end caps. The armatures are different lengths, so you might as well switch out the entire S/G. I think the bushing gets plenty of loading by the torque placed upon the armature by the belt tension. In any case they do wear out, and more quickly than the bearing. Regarding the bushing cap, yes, that structure you see molded on contains a wick/weep hole system that is supposed to oil the rear shaft.

I suspect that the duty cycle of these things are so low (compared to say, an automotive application) that it wouldn't matter in any practical sense.

John

What does that have to do with this? The bearing is always reacting the belt tension, and the armature is always turning in the bearing when the engine is on, no different than a car or anything else.

I think he means the tractors aren't designed to run like a car. As in every day all day and hours upon hours at a time at sometimes much higher rpm. Even though I'm sure some of us prolly run our machines more then their vehicles.

Besides....
 

Tractor: Typically constant RPM, very low electrical load, no other accy's on belt path.

Car: Constantly changing RPM, much higher electrical load, higher ambient temps, and I suspect, higher belt tension because of A/C compressor, PS pump, water pump, etc.

But hey , I'm just a lowly electronics engineer.... :biggrin2:

John

The next obvious question is, has anyone successfully reloaded their oil wick system with fresh oil? I believe that reservoir would have to run dry at some point.

anyone ever take off the welch plug to see if there is a pad underneath?

http://i1228.photobucket.com/albums/...r/e31bc9e4.jpg

I was thinking about your question regarding reloading the oil reservoir. Maybe a small hole at the top of the welch plug and fill with oil thru a syringe and needle - then a dab of silicone to seal the hole ?

thanks for the clarification on the different armature lengths for the different end cap styles :Bowdown2:

Sounds like a good solution. There's not much room in there for much of anything else. While I'm a firm believer in oil and lubricants, aren't "oilite" or impregnated bronze bushings advertised as self lubricating? The oil wick would indicate these aren't .

Pop out the original oilite bushing - mike the Od and shaft Od stop at a large hardware store and pick up a replacement. If you can not find or order one from MSC send me the measurements and I will turn one up for you. Saturate the felt with fresh TUBINE OIL and good to go for 20 years.
http://www.reidsupply.com/products/b...eeve-bearings/

Never mind what I said there. :bash2:
Now that I see the outside of the end cap bracket has another welch plug (much smaller) where I imagine an oil cup could be fitted. The casting from the smaller welch plug appears to lead down into the oil reservoir area, not directly to the side of the bushing as I first thought. :bash2: