Build Issues


Sample Case Studies

The following sample case studies are meant to illustrate typical shop assembly issues for specific engine models that were solved upon the installation of an Axiam Assembly Process. Problem resolution typically takes four-to-six months.

CFM56 HPC Build Time
Problem:  Customer took three days to assemble an HPC rotor within engine manual runout specification due to an average three rebuilds to get one satisfactory rotor.
Solution:  An Axiam Assembly Process required only four hours to build a straight, optimal HPC rotor on the first pass, eliminating multiple rebuilds.

F101/F108/F110 Military Engines Test Cell Rejects/ Excessive Vibration
Problem:  Rotor vibration caused test cell rejects to climb to 22 percent. Multiple rotor builds were needed in order to meet the engine manual runout specifications.
Solution:  Axiam’s Assembly Processes easily achieved the rotor runout specifications on the first build. Test cell rejects due to vibration were eliminated. Vibration levels were reduced by a factor of ten.

PW2037 Test Cell Trim Time/ LPT Balancing Rejects
Problem:  Excessive Trim Time in the test cell and a high reject rate balancing the low rotor.
Solution:  Axiam’s ECR Assembly Processes eliminated the balancing reject problem and the test cell trim time was reduced by 90% saving on fuel consumption costs and improving throughput.

CF34 Vibration, Oil Consumption & Rubbing
Problem:  Customer was experiencing excessive vibration, high oil consumption and blade-tip rubbing.
Solution:  During assembly process development, Axiam found that many of the parts’ high point markings were incorrect. After installation of the ECR Assembly Processes, vibration was reduced to 0.1 mils, blade-tip rubbing disappeared, oil consumption was reduced to acceptable levels, and EGT margins showed marked improvement.

Space Shuttle Rocket Engine Turbo Pumps Vibration
Problem:  Turbo pump vibration was causing rotor bearings to wear out requiring a pump rebuild after each flight.
Solution:  Subsequent to the installation of the Axiam Assembly Processes, the pumps only needed to be rebuilt after the fourth flight.

5000F Industrial Gas Turbine Assembly Time/ Reject Rate
Problem:  Assembly of the 50-ton turbine rotor took three weeks. Once the rotor was assembled, the reject rate due to vibration was 50%.
Solution:  Subsequent to the installation of Axiam’s Rotor Assembly Process, the time of assembly was 16 hours and it was always an optimal build on the first pass. Rejects due to vibration were eliminated.

J52 Military Engine Wing Time, Oil Leakage & Excessive Vibration
Problem:  Bowed engine core builds caused excessive vibration that resulted in premature engine removals, blade rubbing, oil leakage, and engine failures.
Solution:  Subsequent to the installation of Axiam’s ECR Assembly Processes, wing time improved over 500%, vibration was reduced by 78%, oil leakage was stopped, and engine failures were eliminated.