Multi-collar thrust bearing — the frictional torque transmitted by a multi-collared shaft compared with a single-collared shaft (for the same total axial load and mean radius) is:

Introduction / Context: Thrust bearings transmit axial loads through collar faces. Designers sometimes split a single collar into multiple collars to reduce pressure and heat. A common exam point asks whether total frictional torque changes under the same overall axial load.

Given Data / Assumptions:

• Total axial load on the shaft = W (fixed).
• Uniform pressure or uniform wear theory may be used for mean radius R_m.
• Coulomb friction with coefficient μ, and n identical collars share load.

Concept / Approach: For one collar, torque T = μ W R_m. For n collars sharing the same total load W, each collar carries W/n. The torque per collar is μ (W/n) R_m, and the total torque becomes n × μ (W/n) R_m = μ W R_m — the same as the single-collar case, provided R_m is unchanged.

Step-by-Step Solution:

Verification / Alternative check: If instead each collar saw the full W (not load-sharing), torque would scale with n, but that is not how multi-collar bearings are designed.

Why Other Options Are Wrong:
Wrong — suggests torque changes despite equal total load and mean radius, which contradicts the load-sharing derivation.

Common Pitfalls: Forgetting that the stated W is the total axial load; confusing uniform pressure vs wear (which affects R_m slightly but not the equality under equal R_m).

Final Answer: Right.