A mechanical assembly where a smaller input gear drives a larger output gear, resulting in a gear ratio greater than 1:1. This arrangement sacrifices rotational speed at the output shaft in exchange for a proportional increase in rotational force. They are essential in heavy machinery where high-speed electric motors must drive massive, slow-moving loads.
Heard on the job
The conveyor belt uses a massive reduction drive to step the motor speed down to ten RPM.
Also heard as
- Speed reducer
- Gear reducer
Related terms
Gear ratio
The number of teeth on the driven gear divided by those on the driver, setting speed reduction and torque gain.
Bull gear
Shop name for the biggest gear in a drive train, usually the slow, heavy output gear.
Overdrive
A gear arrangement where the output shaft spins faster than the input shaft.