Direction: A gear set has a pinion with 20 teeth and a gear with 40 teeth. The pinion runs at 30 rev/s and transmits a power of 20 kW. The teeth are on the 20° full-depth system and have a module of 5 mm. The length of the line of action is 19 mm.
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The contact ratio of the contacting tooth is
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- 1.21
- 1.25
- 1.29
- 1.33
Correct Option: C
| Arc of contact (AOC) = | = 20.21 mm | cos 20° |
| Circular pitch = | = π m = π × 5 = 5πmm | z |
| Contact ratio = | = | = 1.29 | Circular pitch | 5.π |
