The ratio of driven to driving tooth counts, which equals the ratio of input to output speed. A 3:1 reducer turns the output at one-third input speed and multiplies torque by close to three, less friction losses. Multi-stage drives multiply the stage ratios together, and idlers in between have no effect on the overall ratio.
Gear ratio is 41 over 11, so 3.73, and it's a hunting tooth set, no timing marks to line up.
Also heard as
- ratio
- reduction
- tooth ratio
Related terms
Pinion
The smaller of two meshing gears, usually the driver in a speed reducer.
Idler
A gear placed between a driver and a driven gear to change direction or span distance, without changing ratio.
Hunting tooth
A tooth combination with no common factor, so every pinion tooth eventually meets every gear tooth.
Planetary gear set
A compact gear arrangement of a central sun, orbiting planets on a carrier and an outer ring gear.