Spinner Question

[JCS]

Anybody know the purpose of those little fan blade-like things on the front of the spinner?

 

[Nonskimmer]

No.
Anyone else?

 

[cheddar cheese]

Pretty decorations
Seriously I dont know either

 

[wmaxt]

Anybody know the purpose of those little fan blade-like things on the front of the spinner?

It was an airflow driven electrical generator for cocpit instruments.

 

[JCS]

Ah ok, that one has been bugging me for a while.

 

[the lancaster kicks ass]

good pic..............

 

[cheddar cheese]

Yeah it is, Ive always like the 189 8)

 

[R Pope]

That " fan-like thingie" is part of the variable-pitch mechanism for the propellers. It uses air resistance to control the RPM by changing the pitch of the blades.

 

[the lancaster kicks ass]

ohhh two contrasting answers...............

 

[Nonskimmer]

Oh! Oh! Let's bet on 'em! I'll take R Pope's answer!

 

[cheddar cheese]

Ok, ill take wmaxt's

 

[evangilder]

R pope is correct. It is a funky setup to control to pitch of the blades based on the air passing over the spinner.

From another message board, "the little spinner in the picture above is mounted on a free-turning bearing and is of a known, fixed pitch. When the aircraft is stopped, the little prop on the front is not spinning, and the propeller is in fine pitch. As the airspeed rises, the little prop starts turning and the pitch begins to get more coarse by means of a cam. There is a design speed for the prop and, as long as you don't exceed design speed and power rating, the unit above results in a more-or-less constant speed propeller without the complexity of a pitch control knob in the cockpit."

Kind of a dynamic pitch control mechanism.

 

[Nonskimmer]

Yay, I win!

 

[cheddar cheese]

You may have won the battle, but you will not win the war

 

[wmaxt]

That " fan-like thingie" is part of the variable-pitch mechanism for the propellers. It uses air resistance to control the RPM by changing the pitch of the blades.

That may be true - for some reason I was thinking about the one on the nose of the 163 rocket plane.

 

[R Pope]

If you look close, you'll see that the hub blades have zero pitch. They drag back when the prop turns, activating the above-mentioned cam arrangement and coarsening the pitch of the prop. Many early constant-speed props used similar setups.

 

[cheddar cheese]

That " fan-like thingie" is part of the variable-pitch mechanism for the propellers. It uses air resistance to control the RPM by changing the pitch of the blades.

That may be true - for some reason I was thinking about the one on the nose of the 163 rocket plane.

Isnt that a small propellor though?

 

[wmaxt]

That " fan-like thingie" is part of the variable-pitch mechanism for the propellers. It uses air resistance to control the RPM by changing the pitch of the blades.

That may be true - for some reason I was thinking about the one on the nose of the 163 rocket plane.

Isnt that a small propellor though?

Yup, many of the early pitch adjusters were just counter weights on the hub. The P-38 had Curtis electric prop controls, they were a problem early on (runaways and flat pitch when an engine was out - not good) until a second generator was installed.

 

[Archangel]

That " fan-like thingie" is part of the variable-pitch mechanism for the propellers. It uses air resistance to control the RPM by changing the pitch of the blades.

one oter thing why he's right, why would anyone put the generator in such a "unsave" position (u know, where it depends on the wind and stuff) while you can connect it directly to the engine, so you can be shure its always turning.
and the me 163 only has that generator in the nose, cuz i has no engine, at least none with turning parts

 

[Karaya_1]

You are both right....on the FW 189 you see the drive of the variable-blade-pitch-mechanism and on the Me 163 you see the propeller of the electrical power generator !