Geometric Balance:
Also referred to as "blade matching," this process is the analysis of the configuration of each blade in comparison to each of the other blades. In order to be considered in correct geometric balance, each measured position on the blade should be the same as the identical point on each of the other blades (within tolerance). Due to the number of analysis points available and the fact that the propeller is electronically measured in three dimensions, the Hale MRI is the ideal method of matching propeller blade geometry. Our measuring method records the actual blade pressure surface offsets therefore allowing contour to be measured and displayed.
Mechanical Balance:
An important requirement of all machinery is that the rotation axis coincides with one of the principal axes of inertia of the body. After a wheel (propeller) has been manufactured, modified or repaired, it must be balanced to satisfy the requirement, especially for higher speed vessels. The condition of unbalance of any rotating body may be classified as static or dynamic unbalance.
Static Balance:
This is the mechanical balance of the propeller in the plane of rotation. This can be measured by inserting a special arbor into the bore and placing this assembly onto a stand wherein the rotation of the propeller is in the vertical plane and the arbor rests upon bearings. Because the propeller is allowed to freely rotate, the heavier blade(s) will rotate to the downward position. Weight is either added or removed until the propeller will remain static in any rotational position.
A propeller may be in perfect static balance and still not be in a balanced state when rotating at high speeds.
Dynamic Unbalance:
A "couple" or "twisting" force in two separate planes, they cause a rocking motion fore and aft -or- side to side. A propeller that is true (geometrically) can be out of balanced and will cause mechanical vibrations and a decrease in bearing life and efficiency due to the unnecessary forces. The only scientific manner in which to accurately measure and therefore correct dynamic unbalance is through the use of true multi-plane dynamic balance analyzer.
At Propulsion, we include dynamic balancing at no additional charge.
Also referred to as "blade matching," this process is the analysis of the configuration of each blade in comparison to each of the other blades. In order to be considered in correct geometric balance, each measured position on the blade should be the same as the identical point on each of the other blades (within tolerance). Due to the number of analysis points available and the fact that the propeller is electronically measured in three dimensions, the Hale MRI is the ideal method of matching propeller blade geometry. Our measuring method records the actual blade pressure surface offsets therefore allowing contour to be measured and displayed.
Mechanical Balance:
An important requirement of all machinery is that the rotation axis coincides with one of the principal axes of inertia of the body. After a wheel (propeller) has been manufactured, modified or repaired, it must be balanced to satisfy the requirement, especially for higher speed vessels. The condition of unbalance of any rotating body may be classified as static or dynamic unbalance.
Static Balance:
This is the mechanical balance of the propeller in the plane of rotation. This can be measured by inserting a special arbor into the bore and placing this assembly onto a stand wherein the rotation of the propeller is in the vertical plane and the arbor rests upon bearings. Because the propeller is allowed to freely rotate, the heavier blade(s) will rotate to the downward position. Weight is either added or removed until the propeller will remain static in any rotational position.
A propeller may be in perfect static balance and still not be in a balanced state when rotating at high speeds.
Dynamic Unbalance:
A "couple" or "twisting" force in two separate planes, they cause a rocking motion fore and aft -or- side to side. A propeller that is true (geometrically) can be out of balanced and will cause mechanical vibrations and a decrease in bearing life and efficiency due to the unnecessary forces. The only scientific manner in which to accurately measure and therefore correct dynamic unbalance is through the use of true multi-plane dynamic balance analyzer.
