Research Article
Vibration Sideband Modulations and Harmonics Separation of a Planetary Helicopter Gearbox with Two Different Configurations
Table 1
Bell 206 gears, speed, and data acquisition parameters.
| Parameter | Value | Reduction ratios |
| Shaft input speed (Hz) | 100 | | Number of stages | 2 | | Number of teeth of the bevel pinion | 19 | First-stage reduction ratio: 3.73 : 1 (71/19) | Number of teeth of the bevel gear | 71 | Number of teeth of the sun gear | 27 | Second-stage reduction ratio: 4.67 : 1 (99/27 +1) | Number of teeth of the planet gear | 35 | Number of teeth of the ring gear | 99 | | | Overall reduction ratio: (1st stage times 2nd stage) 17.45 : 1 | Carrier (arm) output speed (Hz) | 5.73 | | Sampling frequency (Hz) | 51200 | | Length of records | 30 seconds | |
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