Alamarin Jet AJ 160, Operation And Maintenance Manual

Page: 9 / 40

9 Operation and Maintenance Manual
Version 1.5 Version 1.5
1. The Jet Propulsion Unit
Alamarin-jet water jet propulsion unit is a single stage axial flow pump, which produces
a high volume flow rate and thrust with high efficiency.
The operation of the unit is based on increasing the water flow rate in the nozzle. The
change in the flow rate creates a reacting force in the direction of the flow, which thrusts
the boat forward. By changing the direction of the jet, it is possible to steer the boat in
the desired direction.
Main Parts (figure 1-1):
The intake duct (A), whose
function is to lead the water from
outside the boat to the intake
side of the impeller with as little
loss as possible and an even
distribution of velocity.
The impeller (B), which is
rotated by the driving motor
through direct drive, increases
the water’s flow rate.
The nozzle converts the pressure
energy produced by the impeller
to motion energy.
The steering device (C) is used
to change the direction of the jet
flow coming out of the nozzle,
which creates the force needed
for turning.
The controlling device (D)
Lowering the reversing deflector
causes the boat to reverse. The
direction of the jet flow changes
obliquely forward under the
boat, which is when the thrust
is directed forward and down.
The reversing deflector is also
used for stopping the boat. See
section: Steering and Controlling,
page 10
Figure 1-1
B
A
D
C