Page 36 – The Thrust Bearing
The
propeller shaft is pretty simple.
A
straight shaft supported on two bearings with a propeller at one
end.
The
propeller blades should be equal and when spinning, there should
be no vibration.
Rather
like a flywheel.
And
just like a flywheel, when spun, it should have momentum to spin
for a while.
When
the boat is out of the water, the bearings for the prop should
enable the propeller
shaft
to spin freely.
If
it doesn’t. Engine power is being wasted.
Fix
it.
There
is another issue.
When
the boat is cruising, the propeller is pushing the weight of the
boat through the water.
Courtesy
of Mr Newton’s “action and reaction”, the
propeller shaft is pushed with equal force
into
the boat.
The
propeller shaft bearings are designed to allow freedom of
rotational movement.
They
are not designed to accommodate sideways load. This will create
friction.
Fit
a thrust bearing somewhere along the length of the propeller
shaft.
Keep
the friction down.
Let
the propeller spin freely.
