What is a common effect of adding more reduction stages in a gear train on overall efficiency?

• A. Each stage adds friction losses, reducing overall efficiency
• B. Efficiency increases due to smoother speed transitions
• C. Weight increases, improving efficiency
• D. Maintenance decreases

Answer: (A)

More reduction stages bring in extra friction losses from each gear mesh, bearing, and seal. Every stage adds contact and lubrication losses, so the total energy wasted as heat increases. Even though you can achieve greater overall reduction and possibly smoother torque, the extra losses accumulate, reducing the overall efficiency.

That’s why the best answer is that each stage adds friction losses, reducing overall efficiency. The other ideas aren’t as accurate: smoother speed transitions don’t inherently raise energy efficiency, adding weight typically lowers efficiency due to greater losses and inertia, and more stages don’t automatically reduce maintenance needs.