What are two types of reduction gears commonly used in auxiliary turbines?

The correct choice identifies worm and helical gears as the two types of reduction gears commonly used in auxiliary turbines. Worm gears are advantageous in applications requiring a high reduction ratio in a compact size, allowing for shaft arrangements that do not require significant space. They also facilitate smooth operation and minimize backlash.

Helical gears, on the other hand, are known for their efficient power transmission due to their inclined teeth, which engage more gradually than straight-cut gears. This gradual engagement reduces noise and vibration, making them ideal for applications where smooth operation is crucial.

Combining these two types of gears allows for versatile design in auxiliary turbine systems, accommodating the necessary torque and speed changes while ensuring durability and reliability. The synergy of worm and helical gears delivers an effective solution for reducing rotational speed and increasing torque, critical in turbine operation.