Theory of Machine
Crowning on pulleys helps

In increasing velocity ratio
Increase belt and pulley life
In decreasing the slip of the belt
For automatic adjustment of belt position so that belt runs centrally

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Theory of Machine
The frictional torque transmitted in a flat collar bearing, considering uniform wear, is (where r₁ and r₂ = External and internal radii of collar respectively)

(2/3) μ W [(r₁³ - r₂³)/(r₁² - r₂²)]
(2/3) μ W (r₁ + r₂)
(1/2) μ W [(r₁³ - r₂³)/(r₁² - r₂²)]
(1/2) μ W (r₁ + r₂)

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