Following are the specification described for the new proposed method of Balancing of Turbine Rotor.
1. Background of Invention:
The times taken for balancing of turbine rotor were exorbitantly high, tedious and time taking process. Further in industrial engine the blade swab/changing procedure to adjust the opposite weight is quite tedious and rotor needs to be taken out from balancing m/c as the number of iteration in present method were more and the overall cycle time of balancing was more. This prompted to think in the line of time reduction by process change to facilitate faster turnaround of engine efforts.
2. Summary of Invention:
New process introduced gives the less hindrance to airflow as the flow is taking place in favorable pressure gradient where turbine is rotated on the balancing machine. This favorable pressure gradient flow maintains less fluctuation on support pedestal of rotor.
3. Objectives of the Invention:
1. To achieve the required turbine rotor balancing within the specified limits by reducing unbalance.
2. To reduce balancing time and overall engine assembly time.
4. Detailed Description of Invention:
In three stages turbine blades are assembled in turbine disc by dovetail slot and lock pin arrangement. For interchanging the blades for weight adjustment during balancing of turbine rotor, it is not possible to remove the blades from the disc on the machine bed and every time rotor will have to be removed from balancing m/c to turnover fixture and entire blade needs to be removed for putting the blades in new position as the number of iteration of blade interchange increases the time taken to complete the balancing of the rotor increases significantly. In the existing method rotor is rotated on balancing machine opposite to actual direction of rotor in engine. In this situation turbine is working like a pump and due to overhung configuration the

air flow creates buffeting effect on rotor support pedestal of balancing machine causing fluctuation in the reading and delays in converging of unbalance and hence increasing the number of iteration required to minimize the unbalance increases, resulting in increased cycle time. New method ensures airflow on the machine in favorable pressure gradient hence the airflow buffeting on the pedestal rotor support is less and allows convergence of unbalance faster, resulting in less number of iteration to achieve the desired unbalance residue limit. Further due to fast convergence of unbalance consequently less number of iteration we could reach much below the specified max permitted residual unbalance limit of turbine rotor.
Hence proposed method of balancing (in the direction of actual rotation in engine) yielding significant improvement in terms of reduction of number of iteration and overall balancing cycle time of turbine rotor by 50%. Thereby meeting the Quality standards and also meeting the needs of customer by delivering the engines in time.

Claims: We claim:
1. A new approach to minimize the number of iteration in balancing of turbine rotor and consequently reducing the cycle time of balancing.
2. Claim at 1 will be helpful in reduction of overall overhaul cycle time of the engine.