Stihl 028 oiler, how does it work?

[rshaffer3]

Hi,

Long time lurcher but 1st time post.

I'd consider myself very mechanically inclined but this thing makes no sense to me. I see a little pump with a shaft, then a sprocket that spins on the shaft and makes a worm gear turn. How does the oil get to the bar? I see no tubes or channels coming from the pump like on my 034.

Can someone splain this thing?


Incidentially, I just bought a 5100s off the guy on ebay for $320 but I haven't received it yet. Now I've got buyers remorse. Hopefully after a few hours buried into some oak I'll feel better.

 

[thompson1600]

Been a while since I looked at an 028, but I believe the oil came out the back side of the pump and went into a channel inside the case, then came out at the bar area.

 

[CrazyCarl]

oiler

That would be corect.Also the worm gear acts like an auger in a grain elevator.think of the grain as oil. With the close tolerances,it is under a small amount of pressure to ensure the delivery,even past a partial blockage due to saw dust build up

 

[Lakeside53]

If you remove the pump, there are two holes - one from the tank, and the other back from the pump into the casing. There is a hidden passage that transfers oil up to the slot at the top of the studs.

The oil is pumped not with an auger, but with a flat area on the round shaft that rotates between inlet and outlet with a slight oscillation.

 

[rshaffer3]

Thanks guys,

My problem was that there was so much crud up in the bar area that I couldn't see the small hole. After cleaning it out I actually was able to pump some oil just by quickly rotating the cog with my fingers so it seems to be working now.