Hydraulic Drive - Raymarine Autohelm ST7000 Installation Instructions Manual

The mounting bracket should be bolted to a
substantial frame number. Always over engineer
to ensure reliability and maintenance of correct
alignment.
Installation
The pushrod ball end must be attached to the tiller
arm using the fixing bolt supplied with its flange
positioned between the ball end and the tiller arm
(Fig. 19). It is vitally important that the lock
washer supplied is used and that the nut is fully
tightened.
The mounting bracket should be attached with
four stainless steel M10 bolts with locknuts or lock
washers.
Having installed the drive unit turn the steering
wheel from hardover to hardover and check that:-
• no part of the drive unit fouls the vessels'
structure.
• the mechanical limit stop on the vessels'
steering system is reached before the
actuator reaches its mechanical limit.
• angular movement of the ball end fitting is less
that 5 deg.
2.2.3 Hydraulic Drive Units
General Guide-lines
The hydraulic drive unit should be mounted clear
of spray and the possibility of immersion in water.
It should be located as near as possible to the
hydraulic steering cylinder. It is important to bolt
the hydraulic drive unit securely to a substantial
member to avoid any possibility of vibration that
could damage the inter-connecting p@pework.
There are three basic types of hydraulic steering
system, these are illustrated in Fig. 20. Typical
connection points for the drive unit are shown in
each case. In all cases it is strongly
recommended that the steering gear manufacturer
be consulted.
Minimisation of hydraulic fluid loss during
connection of the drive unit will help to reduce the
time and effort required later to bleed the system
of trapped air. Absolute cleanliness is essential
since even the smallest particle of foreign matter
could interfere with the correct function of
precision check valves in the steering system.
19