Which term describes the device that reduces speed and increases torque?

• A. Pillow Block Bearing
• B. Sprocket
• C. Lubrication
• D. Gear Reducer

Answer: (D)

A gear reducer is the device that reduces speed and increases torque. It works by using gears of different sizes that mesh together: the smaller gear (pinion) drives the larger gear, causing the output shaft to turn more slowly but with greater torque. The amount of speed reduction is set by the gear ratio—the higher the ratio, the more the speed drops and the more the torque increases, minus some losses from efficiency. This setup is used when the motor’s speed is too high for the load or when more torque is needed at a lower speed.

Pillow block bearings are simply supports for a shaft and don’t change speed or torque. A sprocket can alter speed and torque when used with a chain drive, but it’s part of a drive system rather than a single device whose main function is to reduce speed and boost torque. Lubrication reduces friction and wear, not speed or torque.