U.S. Navy Experience with SSS (Synchro-Self-Shifting) Clutches

Abstract

This article discusses the experience of the US Navy with Synchro-Self-Shifting (SSS) clutches. The US Navy has nearly 40 years of experience using SSS clutches in main reduction gears of gas-turbine-driven ships and propulsion systems with combinations of gas turbines and diesel engines or electric motors, and in steam-turbine propulsion plants for use with electric motor drives. Over 900 SSS clutches have been installed in 14 different classes of US Navy ships, with some having been in service for over 30 years. SSS clutches have accumulated approximately 15,278,000 hours of operation. Mean Time Between Failures in Hours for US Navy clutch applications is relatively high (271,550 hours) based on the operational hours accumulated and the total number of failures that have occurred. The maintenance and repair strategy used for US Navy SSS clutches is similar to a Performance Based Logistics arrangement, where the Navy maintains a rotatable pool of ready-for-issue clutches, and in the event of a problem or failure, the clutch is changed out with an available spare.

Theoretical and Experimental Study of the Torque Impact and Shaft Response during the Rapid Engaging Process of a Gas Turbine

“…In a COGAG plant, the SSS clutch is a key component for achieving engagement of the gas turbines and changing the torque transmission path in the system. As shown in Figure 1, an SSS clutch is primarily composed of a driving unit, a sliding unit, and a driven unit [6]. It operates according to the principles described next.…”

“…e synchro-self-shifting (SSS) clutch is the key component for achieving reliable engagement and disengagement between a gas turbine and a combined power plant. Hendry introduced the operation and maintenance experience of the SSS clutch on a ship in detail [6][7][8]. e study of the dynamic characteristics of SSS clutches primarily involves either numerical calculation [9,10] or multibody dynamics calculation methods.…”