any large driving gear among smaller gears.
Origin of bull wheel
An Americanism dating back to 1820–30
Also called bull gear.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for bull wheel
Historical Examples of bull wheel
The big graft in this neck-a woods is political, and the Red Tower gang is only set-a cogs in the bull-wheel.The Wreckers