Presentation on theme: "FMECA & Reliability Analysis of an Elastomeric Rotating Scissor Bearing of Helicopter Jacques Virasak RPI DSES-6070 HV5 Statistical Methods for Reliability."— Presentation transcript:
1FMECA & Reliability Analysis of an Elastomeric Rotating Scissor Bearing of Helicopter Jacques VirasakRPI DSES-6070 HV5 Statistical Methods for Reliability Engineering Spring 20083/31/2008
2ObjectivesTo perform both FMECA and reliability analyses on a typical helicopter main rotor scissor bearing assembly.To evaluate the response of the scissor bearing to failures occurring in any of its components with respect to aircraft and personnel safety as well as scissor bearing operational efficiency.To perform Failure Mode, Effects and Criticality Analysis (FMECA) in accordance with MIL-STD-1629A to address the qualitative safety requirements identified in the requirement specification.To analyze the reliability of the elastomeric shim package of the scissor bearing based on both Sikorsky and US government experiences with laminated elastomeric and metallic shim packaged production parts.To demonstrate the application of diverse techniques learned throughout the current reliability analysis classes.
3If An Rotating Scissor Bearing (RSB) Fails… The loss of relative motion between the rotating scissors and the rotating swashplate will result in loss of the controllability of the main rotor, increase rotor vibration, and decrease response to control input.The loss of load transmission from the rotating scissor to the rotating swashplate will create an unbalanced rotor and increase rotor vibration.
4What Is An Elastomeric RSB? Outer MemberInner MemberMetallic ShimsandElastomeric ShimsZBushingsSleeveK1K2K5K6K10K11ForceForce
5Failure Mode, Effects and Criticality Analysis (FMECA) OuterMemberInnerMemberMetallicShimsElastomericShims
6RAPTOR vs. TheoryThe discrepancy is RAPTOR run driven
9ConclusionsElastomeric RSB is an on-condition replacement and non-repairable part.FMECA was used to ensure the save usage of the elastomeric RSB.Diverse reliability analytical tool and techniques were successfully used to analyze the elastomeric RSB.