Pitch Change - Outboard - Inboard - Double Row Spherical Tapered Roller Tapered Roller (Timken) (Timken) PD - Pitch Diameter 1.915 5.040 5.860 (in) BD - Ball Diameter 0.460 0.510 0.680 (in) # of Rollers 9 (18) 25 22 Contact Angle (deg) ~23 ~30 ~30 Approximations of Defect Frequencies Race Defect (Hz) 156 226 196 Inner Race Defect 204 274 244 (Hz) Ball Defect (Hz) 178.6 249 219 Cage Fault (Hz) 8.6 9.04 8.9 Sikorsky’s Defect Frequencies Outer Race Defect 140.2 228.1 197.9 (Hz) Inner Race Defect 219.8 271.9 242.1 (Hz) Ball Defect (Hz) 79.2 196.1 170.6 Cage Fault (Hz) 7.83 9.12 9.00 Bearing Defect Frequency Equations developed by Sikorsky: race defect in Hz = (# of balls / 2) * rev/sec* ( 1 ((BD/PD)* cos B)) – Inner race defect in Hz = (# of balls / 2) * rev/sec* ( 1 + ((BD/PD)* cos B))
Pitch Change - Double Row Spherical Outboard - Tapered Roller (Timken) Inboard - Tapered Roller (Timken) PD - Pitch Diameter (in) 1.915 5.040 5.860 BD - Ball Diameter (in) 0.460 0.510 0.680 # of Rollers 9 (18) 25 22 Contact Angle (deg) ~23 ~30 ~30 Approximations of Defect Frequencies Race Defect (Hz) 156 226 196 Inner Race Defect (Hz) 204 274 244 Ball Defect (Hz) 178.6 249 219 Cage Fault (Hz) 8.6 9.04 8.9 Sikorsky’s Defect Frequencies Outer Race Defect (Hz) 140.2 228.1 197.9 Inner Race Defect (Hz) 219.8 271.9 242.1 Ball Defect (Hz) 79.2 196.1 170.6 Cage Fault (Hz) 7.83 9.12 9.00 Bearing Defect Frequency Equations developed by Sikorsky: race defect in Hz = (# of balls / 2) * rev/sec* ( 1 – ((BD/PD)* cos B)) Inner race defect in Hz = (# of balls / 2) * rev/sec* ( 1 + ((BD/PD)* cos B))
team29_report.docx