Anatomy Of A Fuel Pump

[keflaman]

Sorting through all the junk, er...failed components I wondered what I could possibly use them for. Take for example, fuel pumps. I have three of them laying on the table in front of me. They're complete and utter...JUNK.
No bono.
No bueno.
Nein gut.
Still, they have to be of some use, but how?
Ah, a learning moment!
Gently pry the edges from around the bottom of the pump case...


Pop off the suction end of the pump. Notice the "snail" design built into the suction "cap"? I believe that aids in creating a swirling motion? Centrifugal pickup?


I'm not exactly sure what you call the black plastic "fan" I'm holding, or what it does, but the center is slotted to fit over the armature shaft...


Gerotor pump...


Now let's see what else lies within the case; peel it back like a sardine can...


Opposite view of the gerotor pump...


Armature and field casing of the electric motor...


The commutator is worn about 0.015" and probably the source of all the racket coming from the pump before it failed...


A view of the brushes which have plenty of life left in them. At the 12 O'clock position is the discharge port with ball check valve. This valve prevents fuel from draining back into the tank and keeps pressure in the system after shutdown...


And here it is completely laid out...


References:

-http://www.pumpschool.com/principles/gerotor.asp#Overview

[DesktopDave]

Excellent use of a dead pump...if all else fails, at least it can be educational. I think they call that "wisdom," LOL.

Is 'impeller' the word you're looking for?

[keflaman]

Excellent use of a dead pump...if all else fails, at least it can be educational. I think they call that "wisdom," LOL.

Is 'impeller' the word you're looking for?

I was a little surprised to find that fuel runs right through an electric motor!

Impeller makes sense and does more to explain how the pump operates.

[DesktopDave]

I'm assured that a pressure pump won't run for long without the cooling effect of the fuel. I also suspect that the commutator is actually sparking while fuel flows through it. Liquid gasoline is surprisingly resistant to ignition.

[thebrelon]

spark + fuel but no oxygen I guess;

[colin86325]

It's fun to take stuff apart, isn't it? 

[keflaman]

It sure helps me understand things better. I'm a mechanic...my brains are in my thumbs!