Bf 109 variable pitch gearbox

[mkloby]

Very nice pic. Shows the clean installation of the powerplant.

[wrbrd]

Thanx for all that information, however it's not the correct variable pitch system used on a Bf 109E.
Due to a cannon running through the prop shaft the VDM company designed an electric variable pitch prop for the Bf 109. It could not use a hydromatic propeller for this reason. The pitch mechanism consisted of a planetary gear setup installed around the propeller shaft and activated by an electric motor. It was a manually controlled prop until somewhere around 1940 where they did incorporate an automatic or governing feature.
What I need to know is how did this planetary system work?
Thanx!

[mkloby]

Originally Posted by wrbrd

Thanx for all that information, however it's not the correct variable pitch system used on a Bf 109E.
Due to a cannon running through the crankshaft the VDM company designed an electric variable pitch prop for the Bf 109. It could not use a hydromatic propeller for this reason. The pitch mechanism consisted of a planetary gear setup installed around the propeller shaft and activated by an electric motor. It was a manually controlled prop until somewhere around 1940 where they did incorporate an automatic or governing feature.
What I need to know is how did this planetary system work?
Thanx!

Sorry buddy... I don't know a damn thing about that!

[FLYBOYJ]

Originally Posted by wrbrd

Thanx for all that information, however it's not the correct variable pitch system used on a Bf 109E.
Due to a cannon running through the crankshaft the VDM company designed an electric variable pitch prop for the Bf 109. It could not use a hydromatic propeller for this reason. The pitch system mechanism consisted of a planetary gear installed around the propeller shaft and activated by an electric motor. It was a manually controlled prop until somewhere around 1940 where they did incorporate an automatic or governing feature.
What I need to know is how did this planetary system worked?
Thanx!

Again, I think semantics are getting in the way here - a planetary gear is used to reduce turning ratios within a gear box. Prop hubs don't have planetary gears, in the case of electric propeller there should be an electric solenoid geared to the end of the prop shank which changes propeller pitch.

Here is a Curtiss Electric propeller used on the P-39. I believe the set up would be very close to the bf 109E.

Now full feathering propellers did have a gear box in the front portion of the hub which housed an electric motor. This is where you might be thinking planetary gears and gearbox...



I know I have a Bf 109E hub cutaway somewhere and again I think it's operation is very similar to the set up shown for the P-39.

[wrbrd]

The curtiss prop is a totally different system altogether. The gearbox used on the Bf 109 uses a planetary system to change the sun gear to which it drives the gears on the prop hub and by way of worm gears turns the blades.
In the gearbox are planet gears, sun gear and what have you. At the back end of this gearbox is an input gear driven by an electric motor which in turn (this is what I'm trying to find out) drives the forward gear which operates the blades. I need to know the set up of the gearing so this blade change can be accomplished.

[FLYBOYJ]

Originally Posted by wrbrd

The curtiss prop is a totally different system altogether. The gearbox used on the Bf 109 uses a planetary system to change the sun gear to which it drives the gears on the prop hub and by way of worm gears turns the blades.
In the gearbox are planet gears, sun gear and what have you. At the back end of this gearbox is an input gear driven by an electric motor which in turn (this is what I'm trying to find out) drives the forward gear which operates the blades. I need to know the set up of the gearing so this blade change can be accomplished.

Ok - I misunderstood you, it seems you know how the system works, you're looking for specifics. In our tech library we have a Bf 109 tech manual (I don't know if it says much about the propeller. I know in most electric propellers the electric motor will drive a geared slider or piston which in turn is geared to the bottom of the propeller shank, which changes pitch. I don't think there was anything really unique in the 109E bot I have read BoB reports where Luftwaffe pilots did have troubles with the propeller.

[wrbrd]

Thanx for those who tried to help. I was just given the info I was looking for. Here is the website if your interested. I'm not sure how I missed it.

http://www.enginehistory.org/Convent...20Electric.pdf

[mkloby]

Originally Posted by wrbrd

Thanx for those who tried to help. I was just given the info I was looking for. Here is the website if your interested. I'm not sure how I missed it.

http://www.enginehistory.org/Convent...20Electric.pdf

excellent. Thanks - that's interesting... seems very awkward and heavy...

[FLYBOYJ]

Very cool - In actuality there are similarities to the Curtiss Electric Prop. On the Curtiss you have soliniods doing the work of the gear box on the front end of the engine.