Steyer Motors 4 Cylinders, Руководство по установке

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Z001007/0_4_September 2007 Page ENGINE INSTALLATION-15
ENGINE INSTALLATION INSTALLATION INSTRUCTION
5.15.8. Space between Propeller and Boat
5.15.9. Sediments
When removing sediments from the hull, pay special attention to the propeller. Salt water in particular, but also
sediments and vegetation cause additional resistance, and thus a smaller efficiency resulting in a lower speed.
In general, lower propeller speeds bring about higher efficiency and less vibrations compared to high speeds.
5.15.10. Choice of Propeller
There are a couple of coarse rules:
In general, for a "water displacer" a 3-blade propeller with Fa/F of approx. 0,51 will be sufficient. More or larger
blades do not make sense.
For semi-gliders we generally recommend 3- or 4-blade propellers with Fa/F of 0,54 to 0,74. For gliding boats,
4-blade propellers with Fa/F of 0,54 to 0,74 may be considered.
Most propellers are made of bronze, but propellers made of metal or aluminum are also available.
Various propellers with examples of application:
The maximum propeller diameter results from the shape
of the hull. The illustration shows a displacer but even for
a glider the conditions are similar. The most important
size A , the space between propeller and hull, should be at
least 2" (50 mm) resp. 10 % of the propeller diameter
(noise, malicious vibrations). Size B should be approx. 30
% of size D. C = 3/4" (20 mm) more than the propeller hub
length in order to avoid a dismantling of the oar in case
of a propeller change.
X = space propeller - stem bearing 1" (25 mm)
ill. 5/18
3-blade
high-speed propeller
ill. 5/19
3-blade propeller
for commerical use
ill. 5/20
3-blade propeller
to be applied in regions
with strong alga and algae
vegetation
ill. 5/17