Propellers
New Contra-Rotating Propeller System
Hitachi Zosen Corporation, Kawasaki Heavy Industries, Ltd., Mitsui Engineering & Shipbuilding Co., Ltd., NKK Corporation, and Sumitomo Heavy Industries, Ltd. have jointly developed a new contra-rotating propeller (CRP) system.
The new CRP system achieves large fuel cost saving by 13%-15% and reduction in hull vibration and noise, and consequently contributes to the preservation of global environment.
Furthermore, the new CRP system, developed with highly advanced design technology, provides high reliability.
Applying know-how accumulated through extensive experience of towing tank and cavitation tests, optimum propellers are designed.
The best combination of number of blades, diameter, revolution speed and arrangements are chosen considering the fuel consumption rate, vibration and shaft alignments collectively.
Moreover, blade outline, pitch distributions and rake distributions also have the optimum design in reference to the CRP characteristics.
The AHT (Advanced Hydrostatic Taperland) bearing is a new contra-rotating bearing which was developed as a direct result of long technical experience.
The AHT bearing is made up of special tapered land bearing parts and special oil pockets on the shaft surface.
Performance, reliability, and durability were verified by a 10,000 PS full scale model test.
Hydrostatically oil lubricating journal bearing achieves a semi-permanent life. Excellent dynamical lubricating effect in a wide outer/inner shaft revolution range guarantees safety in case of oil pressure loss.
