Lister 12/2 Fuel Pump Pushrod/Cam follower Wheel

[mikenash]

that's more like the commentary I was expecting! thanks Mike

The question is does the wheel follow the cam or does it get slapped by the cam? That could change my thinking...

The bearing I've chosen are precision bearings and a bit on the tight side at 5 microns clearance, so designed for more slow speed radial force, which is what I'm expecting this environment is.  They are rated at 180kg, but that force won't be in the same place every time, because the bearing will spin with contact on the cam. Given the precision, top and bottom ball bearings will share the radial loading.

Contact area (ball bearing surface) is smaller than original, however friction should be lower....  I'm in two minds about following the advice on seals... maybe drilling some lubrication holes, the concern is these are low oil areas, which is why the units I have seized in the first place. 

If it doesn't work I'll pull them out and go with the Indian copies.... they're not that hard to get to.

Just got the crank out, so not far from the point I start putting it all back together...

Samo

Good on you, Samo.  You have obviously thought it through carefully

I will watch with interest

Right or wrong, we will all learn something

[Samo]

Hi Amos, my 2 cents worth, drilling holes in the shield very bad idea,    for 30 years I did rebuild water pumps and have dealt with many brgs  and 99% of the time brgs failed because of contamination, and a couple of drops of oil will contaminate the brg.
shielded brgs are designed to operate on there own lubricant, also shielded brgs will let some oil in, so there for I would recommend using rubber shielded brgs. Tony.       

Thanks Tony, I was in two minds about that, open to crankcase oil or not. It is a closed environment and the oil will be kept pretty clean but I expect the manufacturer knows best. As has been pointed out previously not a lot of oil makes it up to the injector cam. I'll leave them sealed.

Samo 

[olNick]

Old post, I know...

In the same boat here, #2 roller is square and beat up since it was not indexed by the adjuster/locknut, it was rotating in the bore. The other roller is ok...

Question on clearance though, I'm getting 10.1 mm ID on both rollers, no seeming wear.
The pins are 9.5mm, or 0.374" on the ends where there is no wear (the part that presses into the follower body). The center of the pin is quite worn...

This gives a clearance of about 0.024", which seems excessive to me. Is this normal?

I would have expected about 3-4 thou clearance, large enough to let oil in there, but not enough to "pound" around there.

Anyone comment, as I will be machining at least one roller. The pins are worn but seem like a standard 3/8 dowel pin

FWIW, here's a pic of said roller