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The torque required to overcome viscous resistance of a collar bearing is (where R1 andR2 = External and internal radius of collar)
(μπ²N/60t) × (R₁ - R₂)
(μπ²N/60t) × (R₁² - R₂²)
(μπ²N/60t) × (R₁³ - R₂³)
(μπ²N/60t) × (R₁⁴ - R₂⁴)