Reduction Gears - Westerbeke ATOMIC 4 Operation And Maintenance Manual

a ser ies of fr ict ion discs , alternate
ones held in the reverse gear drum
and on the tailshaft clutch carrier.
This group of discs can be clamped
together by a pressure plate oper-
ated by three toggle arms attached
to clutch adjustment plate. These
toggles are moved by the yoke and
collar assembly on the tailshaft.
In the forward position the entire
drum and clutch assembly rotates
wi th the crankshaft. When in neutral
and in the reverse posit ion the for-
ward clutch plates are free to turn
with respect to each other.
(4) The reverse clutch consists of
a brake band around the drum with
an operating mechanism for clamping
the band to the drum. The band is
supported and rotation prevented by
the band feet which zest on the
support flanges in the reverse gear
housing. When the operating lever
is moved to the rear, the band clamp-
ing toggle levers pull the open ends
of the band together, clamping the
band. tightly around the drum. This
prevents rotation of the drum and
the planet pinions or idle pinions.
This causes the tailshaft to be
rotated in the opposite direction
to the crankshaft. The arrangement
of forward and reverse clutches
prevents both being actuated at the
same time.
(5) When the operating lever is
placed in the center position the
drum and forward clutch plates are
free to turn and no power is trans-
mitted from the engine to the pro-
peller shaft.
c.Paragon Hydraulic Reversing Gears
(1) The Paragon hydraulic reversing
gear is basically a hydraulically
operated multiple disc clutch in
combination with a hydraulically
operated planetary reversing gear
train. The unit is self-contained
and independent of the engine oil
system.
(2) Power for the operation of the
-42-
reversing gears is provided by the
transmission oil pump mounted in-
side the reversing gear case and
driven continuously by the engine
while the engine- is running. From
the oil pump the oil under'pressure
is delivered to the pressure relief
valve and control valve.
(3)
The operation of the system is
controlled by a control valve mounted
on the top cover. Moving the lever
determines whether the actuating oil
is delivered to the forward or re-
verse mechanism.
(4)
The forward clutch is engaged by
moving the shifting lever to the
forward position. This operates the
control valve so that it in turn
directs the pressure oil from the
pump to the forward piston in its
cylinder. The forward piston squeezes
the forward multiple disc clutch
and so turns the propeller shaft in
the proper direction to move the
boat ahead.
(5)
The reverse band is similarly
engaged by moving the shift ing lever
to the reverse position. This
operates the control valve so that
it in turn directs the pressure oil
from the pump to the reverse piston
in its cylinder. The reverse posi-
tion clamps the brake band on the
planetary gear train and so turns
the propeller shaft in the reverse
direction, thus moving the boat
astern.
(6)
Neutral, or center position,
of the control lever prevents any
pressure oil from entering either
the forward or reverse cylinders.
In addition the control valve opens
drains in both cylinders so that
any oil in either cylinder is drained
out and the pistons completely re-
tract disengaging both forward and
reverse drives.
7.
REDUCTION GEARS
Some models of UNIVERSAL engines
are equipped with reduction gears