Kamrul Ahsan Posted December 19, 2020 Share Posted December 19, 2020 Hellow friends and brothers i just wanted to know what are the reasons behind the generator shaft bearing(only front) failure in C-130B ac with T56-A-7B engine. Quote Link to comment Share on other sites More sharing options...
munirabbasi Posted December 19, 2020 Share Posted December 19, 2020 3 hours ago, Kamrul Ahsan said: Hellow friends and brothers i just wanted to know what are the reasons behind the generator shaft bearing(only front) failure in C-130B ac with T56-A-7B engine. Due to ENG RGB vibration.install GEN DISC System and Bearing failure system. Best Regards Munir Abbasi Home of Hercules Pakistan Quote Link to comment Share on other sites More sharing options...
Kamrul Ahsan Posted December 19, 2020 Author Share Posted December 19, 2020 Sir what are the reasons and indications available for this type of problem? How to determine RGB vibration? How can i check if some other thing causing failure of generator bearing? Quote Link to comment Share on other sites More sharing options...
munirabbasi Posted December 20, 2020 Share Posted December 20, 2020 17 hours ago, Kamrul Ahsan said: Sir what are the reasons and indications available for this type of problem? How to determine RGB vibration? How can i check if some other thing causing failure of generator bearing? My 30 year experience say. that front bearing housing clearance more/or play between GEN end plate bearing housing and bearing. Change the GEN end plate. all GENs End PLATE should be checked during phase inspection/ISO inspection 2. Greasing must be carried out after three years elapsed time if your using ball bearing of USAF standard. Best Regards Munir Abbasi Home Hercules Pakistan Quote Link to comment Share on other sites More sharing options...
Kamrul Ahsan Posted December 20, 2020 Author Share Posted December 20, 2020 Sir i was the student of urs in a Type maintenance course in pakistan.. hope you remember. Sir apart from generator, what else i can check for such kind of failure. Like you said RGB vibration. Though i am not clear how to check the RGB vibration. Quote Link to comment Share on other sites More sharing options...
munirabbasi Posted December 21, 2020 Share Posted December 21, 2020 6 hours ago, Kamrul Ahsan said: Sir i was the student of urs in a Type maintenance course in Pakistan.. hope you remember. Sir apart from generator, what else i can check for such kind of failure. Like you said RGB vibration. Though i am not clear how to check the RGB vibration. Dear Normal large scale vibration is display RPM IND thru tachometer generator. but a device is installed on ENGINE RGB to display vibration of Engine /RGB parameters on Engine digital display unit ie EIDS. Best Regards Munir Abbasi Home of Hercules Pakistan Quote Link to comment Share on other sites More sharing options...
Kamrul Ahsan Posted December 22, 2020 Author Share Posted December 22, 2020 Sometimes Generator voltage travels from 120 to 125V, again comes back to 120V after 15-20minutes of flying. It is not fluctuations but slow travelling. Is there anything to worry about? Frequency always remains same, that is 400cps. Quote Link to comment Share on other sites More sharing options...
munirabbasi Posted December 22, 2020 Share Posted December 22, 2020 3 hours ago, Kamrul Ahsan said: Sometimes Generator voltage travels from 120 to 125V, again comes back to 120V after 15-20minutes of flying. It is not fluctuations but slow travelling. Is there anything to worry about? Frequency always remains same, that is 400cps. Kamrul Ahsan Sahib. Type of GEN brushless or brush type? All ENG GEN? No load condition of GEN Voltage may exceed to 125 V until the voltage is regulated by VR , normally it does not happened.Your defect belong to malfunctioning of VR or Excitation generator poles.check the voltage "A "point (PMG) VR terminal block 1 it should be 108 volts AC (GE GEN) if Bendex type 30 V DC . If westinghouse GEN (Brush type) It has No PMG. than "F" point to A to-A of VR (TB-1) 3.75 to 7.5 Vlots (GE), Bendex 30 Volt. If brush type (Westinghouse) check boost XFMRs are mounted F.S 245. Best Regards Munir Abbasi Home Of Hercules Pakistan Quote Link to comment Share on other sites More sharing options...
Kamrul Ahsan Posted December 24, 2020 Author Share Posted December 24, 2020 On 12/20/2020 at 7:39 AM, munirabbasi said: My 30 year experience say. that front bearing housing clearance more/or play between GEN end plate bearing housing and bearing. Change the GEN end plate. all GENs End PLATE should be checked during phase inspection/ISO inspection 2. Greasing must be carried out after three years elapsed time if your using ball bearing of USAF standard. Best Regards Munir Abbasi Home Hercules Pakistan Sir can you give me any manual reference regarding greasing of those bearing. I think we missed this part. Quote Link to comment Share on other sites More sharing options...
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