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A spur gear has a module of 3 mm, number of teeth 16, a face width of 36 mm and a pressure angle of 20°. It is transmitting a power of 3 kW at 20 rev/s. Taking a velocity factor of 1.5 and a form factor of 0.3, the stress in the gear tooth is about
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- 32 MPa
- 46 MPa
- 58 MPa
- 70 MPa
Correct Option: B
Lewis equation is given as
F = σd Cv bπ ym
F can be calculated as P / ωr ...[ω = 20 × 2π rad /sec]
D = mZ = 3 × 16 = 48mm
Cv = 1.5, b = 36, y = 0.3, m = 3
| ∴ F = | 40π 24 |
| → | σd × 1.5 × 36 × π × 0.3 × 3 | 960 π |
⇒ ωd65 ≅ 65
⇒ nearest stress in gear tooth taking in account some F.O.S., σ = 58
