Competing Propulsion Systems Surface Drives
Surface Drives Propulsion Systems competing with Top System Surface Drive
Currently, the supercavitating propellers propulsion systems made on the market, which use joint systems called “ball joint”, present structural problems originated from failures of mechanical components.
They take place, above all, as these “ball joint” systems adopt, for the movement in the two shafts, a joint which mechanically does not absorb the torsional strengths transmitted by the propeller and, above all, do not maintain the drive of the constant-velocity motion in comparison with the rotation center of the joint.
All that has caused, in not properly dimensioned applications, several breakages to the joints and to essential parts of the system.
The double universal joint “H” of the systems above mentioned does not absorb the moment generated by the rotation of the propeller and of the shaft inside the stern tube. What keeps the torsion of the drive is the trim cylinder, which, besides its function as trim corrector, supports also the torsion of the whole drive.
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Neutral condition: Rotation center perfectly balanced and constant – velocity. |
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Rotation condition of a cruise along shaft Y: Rotation center decentralized and sloping, no constant-velocity condition. |
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Rotation condition of a cruise along shaft Y and shaft Z: Rotation center decentralized and sloping in two senses, no constant-velocity condition. This configuration results to be the worst functional condition of these systems, in which the energies are not isotropic anymore, and so they produce twisting moments bringing to the breakage of the joint. |
The technology of Top System Drive and its joint:
Surface drive Top System propulsion
The evolution of the ring joint absorbs the totality of the moment generated by the propeller rotation and by the shaft rotation inside the stern tube, transmitting all that to the transom group and so to the upper stern.
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Neutral condition: Rotation center perfectly balanced and constant-velocity. |
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Rotation condition of a cruise along shaft Y: the rotation center keeps on maintaining its position, even though the cruises are sloping, constant-velocity condition. |
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Rotation condition of a cruise along shaft Y and shaft Z: the rotation center keeps on maintaining its position, even though the cruises are sloping, constant-velocity condition. |
