Oil Pump Question

[Marvel]

Is the OP6 driven scavenge gear supposed to be a press fit on the OP4 driven spindle? If its not what locates the OP4 driven spindle axially and whats to stop the drive peg in the driven spindle rubbing on the OP8 intermediate plate or worse catching on the notch where the drive peg passes through it.

 

[davidd]

If you could point out your concerns by citing the items on the Factory drawing it would be more productive.

The OP31 is the gear driving the oil pump. It is a slip fit on the flywheel main shaft and keyed to the main shaft. The OP31 fits through the bearing bronze sleeve (the hole is not shown) and engages the gear teeth cut into the oil pump. Thus, the main shaft turns the oil pump.

The reciprocating action is supplied by screwing OP36 into the case and allowing the peg on its end to direct the motion by entering the machined slot in the oil pump worm that provides the back and forth pumping motion. OP31 is happy to rotate the pump while the pump is sliding back and forth as the gear teeth on the pump are wide enough to accommodate the motion. The oil pump turns in the bronze sleeve and needs no support other than from the cases.

David

 

[bmetcalf]

Pre war category!

 

[Robert Watson]

Note to DavidD Definitely prewar oil pump. It's been a few years since I put one together, and not sure I have enough left over parts to remind myself what's what. I 'm sure some one with more recent exposure will be able to answer.

 

[greg brillus]

The gears are not a press fit on the shaft, and they are driven by the small pin you mention......I think the pin is supposed to be a tight fit in the shaft, but can be loose from wear in service.

 

[Marvel]

Thanks David for your detailed reply. Unfortunately I was referring to the part numbers for the superior pre-war oil pump ;-)

Thanks Greg. That's what I was looking for. I still can't see what locates the driven spindle axially unless its the E51 idler gear shaft which seems a bit vague.

 

[roy the mechanic]

Most of your questions are answered in a book called back to A.

 

[Marvel]

Not this one though.

 

[greg brillus]

The spindle is driven from a spade drive in the center of the large idler.......This drives the female spindle of the oil pump, this is located by a sleeve bush in the main body of the oil pump itself, and this comes away when the oil pump is removed from the front of the engine. The spindle that the large idler rotates on has a small flange with three (3) machine screws that lock the spindle to the hub of the gear.

 

[davidd]

Sorry for the confusion! I kept checking the question, but not the category!

David.