Definition of idle wheel in English:

idle wheel

noun

  • An intermediate wheel between two geared wheels, especially when its purpose is to allow them to rotate in the same direction.

    • ‘A bearing is adjacent to the idle wheel.’
    • ‘On the arbor of the wheel of 57 is a pinion of 16, driving a wheel of 70, on whose arbor is a pinion of 8 driving an idle wheel of 40.’