Drive Systems; Rotary Drive Unit - Raymarine Autohelm 5000 User Manual

1.2 DRIVE SYSTEMS

Mechanical steering systems may be driven by
either a rotary or linear drive unit. Some steering
systems are fitted with an autopilot drive shaft,
and in such cases the choice of a rotary drive
system is straightforward. In general, if a drive
shaft exists and lost motion does not exceed
2% of total rudder movement, the rotary drive
unit becomes the most economic choice. In all
other cases the linear drive unit will provide the
simplest installation since it may be connected
directly to a tiller link on the rudder stock. Total
independence of the mechanical steering
linkage also allows the linear drive unit to be
used to power steer the vessel in the event of
steering linkage failure, and this is an important
safety feature. In addition, minimisation of
working parts improves the overall efficiency of
the rudder drive system and reduces lost
motion to an absolute minimum.
All vessels with hydraulic steering systems
will require a hydraulic drive unit.
2 Holes: 12Smm (0.5") diameter

1.2.1 ROTARY DRIVE UNIT

The output shaft is driven by a continuously
rated servo motor via an efficient reduction
gearbox. The gearbox is dry lubricated to permit
operation in any attitude. A fail safe friction
clutch within the gear train engages
automatically when the autopilot is switched to
Duty and will disengage instantly even under
extreme load when the autopilot is switched
to Set.
Supply voltage
Peak output torque
Maximum shaft speed
Power consumption (typical
average)
Suitable for vessels up to
r - - - -
12 volts
rpm
1 S-3 amps
40ft. LOA (12m)
i