PPT Slide

Gear Basics

Rolling Cylinders

1. 2 cylinders contact and roll against each other

2. Velocity where they contact MUST be equal (if there is no slip)

3. Velocity on the circumference of cylinders = rotational speed of cylinder x radius

v = w1 x r1 = w2 x r2

4. From this equation one can derive:

w2 = w1 x (r1 /r2)

5. Since Pin = Pout (assume 100% efficient)

T1 x w1 = T2 x w2

Contact with no slip

r2

r1

w1

w2

v

Cylinder 1

Cylinder 2

Direction of rotation

Velocity at contact point

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