Gear Trains

Simple, Compound, & Reverted

Lecture 24

Gearset

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Definition: A pair of gears in mesh.

Smaller is called pinion, larger is called gear.

Mg should be <= about 10:1 per gearset

Internal Set

Mv = + Nin / Nout

External Set

Mv = - Nin / Nout

Simple Gear Trains

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Definition: One gear per shaft or axle

23

4

56

All intermediate

gears are idlers

Compound Gear Trains

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Compound Train Example

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Square root of 180 = 13.42 >10

Cube root of 180 = 5.646 < 10

What are factors of 180?

6 x 6 x 5 = 180

Compound Train Example

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Compound Reverted Gear Trains

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Reverted Train Example

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= 18

Let K = 7 x 4 = 28

Then N2 = 4, N4 = 7