In the past many gas turbines, including Frame 5, 6, and 7 machines, incorporated a Jaw Clutch to engage the gas turbine starting drive. This required a control system and actuators to engage the Jaw Clutch, and this could only be done when the gas turbine was at rest.
The SSS Clutch, directly interchangeable with the Jaw Clutch, engages the instant the starter speed tries to overtake that of the gas turbine whether the gas turbine is rotating or stationary. It will also automatically disengage at the instant the gas turbine speeds up relative to the starter. An SSS Clutch gives you reduced re-start time and automatic operation.
The SSS Pinion Clutch is a mechanical turning gear designed to meet the requirements of a turbine plant where a shaft-end is not available, and an in-line turning gear drive and an SSS Clutch cannot be fitted.
The SSS Pinion Clutch engages axially on helical splines, disengages automatically due to reverse torque, has a mechanical phasing mechanism to ensure gear teeth are in alignment before engaging, is easy to install and maintain, and is fail safe. An SSS Control unit can be supplied to allow engagement during the rundown of the turbine or the turbine can be allowed to come to rest before engaging the Pinion Clutch and re-accelerating the shaft to turning gear speed.
SSS Clutches can be used to engage/disengage auxiliary drives to run electric motors or generators up to speed so that they can be connected to the grid.
Synchronizing packages/SSS Clutches are used both for synchronous machines and large induction motors where the in-rush current of starting a motor direct-on-line would be unacceptable. Clutches can be stand alone or encased to allow one starter drive to be shared between different machines, incorporate a thrust bearing to position the generator rotor after it has been disconnected from the axial bearing in the turbine, and incorporate a turning gear.
SSS Clutches provide automatic connection/disconnection of slow speed turning drives providing both high torque capacity and high overrunning speed capability. When the main machine is operating, the pawls of the SSS Clutch retract to ensure that there is no contact between the input and output sides of the clutch.
SSS Clutches are offered in a range of standard low cost clutches for mounting on a free shaft end as well as many other customer requirements. When no shaft end is available, SSS Pinion Clutches can be used and are mounted in a mid-shaft position.