A smooth transmission is essential for the most enjoyable driving experience. Positioned in the drive line, between the engines and the propellors, the gear shift system makes the difference between an effortless or a jarring gear change. In the larger, shaft-driven 64, 68 and 72 Sports Motor Yachts, 78 Motor Yacht and 645 SUV Riviera motor yachts, their impressive responsiveness is delivered via the QuickShift system manufactured by Twin Disc – a tried and tested system that guarantees the most fluid driving experience possible in large yachts.
This gear shift system is the mechanism by which power is transmitted from the engines to the propellers. In some vessels a gear change comes with a clunk or a shudder, but the patented QuickShift system has been carefully designed for the rapid engagement of gears in both ahead and astern; the shift is barely discernible, and the power is delivered instantly. It also provides superior slow speed control and precision handling. The QuickShift clutch response is 15 times faster and more than 10 times faster to full torque.
The system is known not only for being fast and efficient, but also for its reliability. Twin Disc is unique in that it designs and manufactures all components in-house. The integrated system of transmission, valves, actuators and controls has been precisely engineered to fit and work together. It also means low maintenance. The QuickShift system requires an oil change after its first 50 hours, then the next service interval is at 1,000 hours.
The transmission has a unique clutch, actuation system (responsible for actually moving the system) and electronic controls, which work together to provide the rapid response.
The rapid shift is achieved by making up to 80% of the maximum oil pressure available to 20% of the clutch piston area, where conventional systems are filled at four to five times lower pressure.
The GP Valves
This is the building block of the actuation system. The GP valve combines advanced hydraulics with electronic technology for a constant rate of rise that requires no adjustment. It’s a simple design that is robust, reliable and effective. The electronic system monitors the clutch for overheating (especially handy when idling), disables engagement at low voltage and provides diagnostic and protection capabilities.
Ultimate Propulsion Control with Joystick and Dynamic Positioning System
The Twin Disc Electronic Control System offers fingertip, single-level control of engine and prop speeds between idle and full speeds – even propeller control down to a staggering 50 RPM, or one knot boat speed, for the safest docking imaginable. We’ve all become accustomed to joysticks and DPS, and the QuickShift system doesn’t disappoint here either, with its instant direction and speed; the EJS or Express Joystick System can even pivot on its own axis.
Riviera has partnered with Twin Disc for decades and the synergy between the companies is clear: they both strive to be the best in their categories, have very low tolerance for poor quality materials, a keen eye for great design and they both offer a superior service network worldwide.
For more information visit www.rivieraaustralia.com
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