What is turbine turning gear?
A jacking gear (also known as a turning gear) is a device placed on the main shaft of an engine or the rotor of a turbine. The jacking gear rotates the shaft or rotor and associated machinery (such as reduction gears and main steam or gas turbines), to ensure uniform cool-down.
What is the function of turning gear in steam turbine?
The turning gear of the steam turbine is an important rotating equipment to ensure that the steam turbine rotor is evenly heated and cooled when the steam turbine unit starts and stops.
What is the turning gear speed?
Turning gears are usually installed on heavy rotors. Turning gear has wide range of speed. For example in SIEMENS design, the turning gear have speed less than 1 RPM, while in other designs, turning gears have the speed around 400 RPM.
Why is turning gears important?
Purposes The major purposes of turning gear operation during turbine startup are: 1. To rollout sbaft hogging or sagging before runup is begun. with an excessively deformed shaft is bound to fail because high vibra- tion would sooner or later fOICe a turbine trip.
Why do we use turning gears?
The turning gear or turning engine is a reversible electric motor which drives a worm gear which can be connected with the toothed flywheel to turn a large diesel. A slow-speed drive is thus provided to enable positioning of the engine parts for overhaul purposes.
What is turning gear interlock?
Turning gear interlock is another important thing that prevents the admission of starting air to the engine cylinders when the turning gear is engaged. If the starting air is admitted with the turning gear engaged, then the turning gear along with the motor will fly off puncturing the bulkhead.
How does a turning gear work?
The turning gear assembly typically consists of an electric motor connected to a set of reduction gears that mesh with a corresponding bull gear attached to the turbine rotor. The electric motor torque is converted to slow-speed rotation of the turbine rotor through a series of gear reductions.
Why gas turbine should come on turning gear following a shutdown?
The purpose of turning gear operation while shutting down the turbine is to prevent rotor hogging. speed has decreased to zero or nearly zero, depending on the station.
Which type of motor is used in turning gear?
reversible electric motor
The turning gear or turning engine is a reversible electric motor which drives a worm gear which can be connected with the toothed flywheel to turn a large diesel. A slow-speed drive is thus provided to enable positioning of the engine parts for overhaul purposes.
What is a turning gear in a turbine?
A jacking gear (also known as a turning gear) is a device placed on the main shaft of an engine or the rotor of a turbine. The jacking gear rotates the shaft or rotor and associated machinery (such as reduction gears and main turbines), to ensure uniform cool-down. The major purposes of turning gear operation during turbine startup are: 1.
What is a jacking gear in a turbine?
The major purposes of turning gear operation during turbine startup A jacking gear (also known as a turning gear) is a device placed on the main shaft of an engine or the rotor of a turbine. The jacking gear rotates the shaft or rotor and associated machinery (such as reduction gears and main turbines), to ensure uniform cool-down.
How long does it take for a turbine generator to shut down?
Usually, the minimum time depends on the duration of the preceding shutdown during which the turbine generator rotor was left stationary, and may reach up to 24 hours.When the turning gear is started up, its motor is energized and the turning gear drive is engaged to the turbine generator rotor.
What happens if the turning gear is not used properly?
• Failure to use the turning gear as required during turbine startup may re sult inrubbing damage during nmup. Very high bearing vibrations may force a turbine 1rip, and even damage the machine. TURNING GEAR OPERATION WHILE SHUTTING DOWN THE TURBINE