Publicité
Les langues disponibles
Les langues disponibles
ULTRAFLEX
1 PRODUCT DESCRIPTION
1.1 Hydraulic steering system operation
All ULTRAFLEX hydraulic steering systems are designed in conformity with UNI-EN-ISO 10592 and A.B.Y.C. P21
regulations. All ULTRAFLEX steering systems can operate at temperatures between -18°C (0°F) and +77°C (+170°F).
All the components are made for the marine environment, using materials and working processes which
offer long life and safety under the most extreme conditions. A hydraulic steering system consists of a
steering pump, a cylinder tied to the rudder or to the outboard or
sterndrive engine and the connecting hoses (see picture). Under normal
operating conditions, a turn of the steering wheel will pump the oil,
which flows in through the hoses to the cylinder, according to the turn
direction. With the consequent cylinder movement the oil will flow to the
pump through the hoses and at the same time moves the engine or the
helm which are connected to the cylinder. The pumps are equipped
with a valve, which prevents outgoing fluid from returning along the
same hose. It also allows the operation of the steering systems with two
or more steering stations. The cylinders are double acting and may be
balanced or unbalanced. In the unbalanced cylinders the two chambers
have different volumes and so they need a different number of turns of
the steering wheel and a different rotation effort. The balanced cylinders
have same number of steering wheel turns in order to move the helm
from the center to the end stroke in the two opposite directions. A well
balanced steering system needs a correct choice of the pump for the
cylinder. ULTRAFLEX produces different pump models, which have different capacity (cm
steering wheel turn) and for each type of installation. While choosing the pump it is important to consider
the cylinder volume. The number of starboard and port turns is determined by the ratio between the cylinder
volume and the pump capacity.
Example: if the pump has a capacity of 28 cm
formula looks like this: 120/28=4,2. Accordingly, the steering wheel will turn 4,2 times before the cylinder will
completely turn from one side to the other. In case of installations with double cylinders connected in
parallel the cylinder volume must be added. Applications with less than 4 turns are not recommended, as
they need a higher effort, also applications with more than 8 turns are also not recommended, as the
response of the boat to steer is slowly. The maximum operating pressure is 7,0MPa (70 bar) (1000 PSI).
1.2 Warnings for the product correct use
DANGER
Do not modify the steering cylinder in any way to fit it to your application, otherwise the cylinder will no
longer operate in safety and it will endanger the boat and the occupants.
WARNING
All ULTRAFLEX steering systems must not be installed on boats equipped with engines whose maximum
horsepower is higher than the horsepower rating approved by boat manufacturer.
WARNING
The UP56-UP68 pump must not be installed on race boats.
WARNING
The UP56-UP68 pump is provided with (external) pressure relief valve (see picture above) that must be
placed absolutely between pump and cylinder as shown in the paragraph 3.5.
[1,7cu.in.] and the cylinder has a volume of 120 cm
3
PUMP FOR HYDRAULIC SYSTEMS
Installation and Maintenance Manual
pump
l
l
l
l
pressure relief valve
of oil moved each
3
page 7
-
hydraulic hose
l
cylinder
helm
[7,3cu.in.], the
3
of 75
Publicité
