Page 42 – Is a Clutch Necessary?
In
a car, yes.
A
special starting gear, 1st
gear, is needed to overcome static friction
and
clutch/accelerator skills are needed.
But
with a Stirling – and connected to a propeller?
I
argue “No – not necessary”
I
have been using a 3 cylinder simple beta, atmospheric, for some
years.
It is directly linked to the propeller. No gear box –
no clutch.
Built
by Norris Bomford around 1999, it has been starting nicely ever
since (20 years)
See this
video
for a description of the starting procedure.
Yes, to start a
Stirling engine when it is already connected to a load, it does
require more energy from the engine.
But
with a propeller, the load is proportional to the revs.
When
the engine first starts to run the revs will want to climb, and
the load will rise to match.
The
load is variable and the engine coupled to the propeller is self
regulating.
A
recently built 100cc swept volume pressurised single beta is quite
difficult to manage
when
it starts on the bench. It roars into life and in the first few
seconds is headed for
a
thousand rpm and self destruction. Being attached to a propeller,
in water, could be
very
welcome news.
But
yes, extra power is needed to start an engine under load.
My
argument is that all that is needed is to wait a little longer for
sufficient heat to build up.
Engines
don’t start at 10 rpm. Usually under 100 rpm. So there is
the need for the engine
to
not just start and overcome its own friction, but to overcome the
load of say 75 rpm.
Wait
for the heat to build.
