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| STATIC BALANCE OF PROPELLERS | |
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Due to the fact that marine propellers are turning bodies, the final step of the manufacture process is a static balance depending on RPMs of operation. |
From the desktop
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This process requires to identify the weight amount and the area where material needs to be removed to compensate the unbalance, allowing to improve quality and performance by reducing vibration.
Every propeller has a fabrication standard, and ISO 484 is the norm that rules static balance of all our propellers, which has different sections about how to perform this procedure, being the main variant the propeller diameter. Basically this norm defines the maximum unbalance permitted.
For example, according to the standard of propellers larger than 2.50 mts, section ISO 484/1, the maximum permissible balancing mass (in kilograms) at the tip of the propeller blade is defined by:
Where:
P = is the maximum permissible mass in kilograms.
m = is the mass of propeller in kilograms.
R = is the radius of blade tip in meters.
n = is the designed revolutions per minute of the propeller.
C and K = are factors depending on class given in the following table:
CLASS S
I
II
III
C
15
25
40
75
K
0.0005
0.001
0.001
0.001
Static balance verification
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