An assembly of two or more gears working together to transmit torque and rotational motion. By combining different sizes of gears, the train alters the speed, torque and direction of the power flow. They can be simple arrangements with one gear per shaft or complex compound trains and epicyclic systems used in heavy machinery.
Heard on the job
We need to calculate the overall ratio of the entire gear train to spec the right electric motor.
Also heard as
- Drive train
- Gear set
Related terms
Gear ratio
The number of teeth on the driven gear divided by those on the driver, setting speed reduction and torque gain.
Planetary gear set
A compact gear arrangement of a central sun, orbiting planets on a carrier and an outer ring gear.
Idler
A gear placed between a driver and a driven gear to change direction or span distance, without changing ratio.