Wheel and axle

A simple machine in which a larger wheel turns a smaller axle, transmitting rotation while trading applied force for distance or speed.

Mechanical advantage: The ratio of a machine’s output force to its input force. The wheel-to-axle radius ratio sets this machine’s ideal force multiplication.
Lever: A rigid bar that pivots around a fulcrum to transmit or multiply force. A wheel and axle can be understood as a continuous rotating lever.
Winch: A rotating drum or spool used to wind in or pay out a rope or cable. A crank wheel turns a smaller drum axle to lift or pull loads.
Wheel: A circular object that rotates around an axis, enabling rolling or transmitting motion. The wheel is the larger rotating component in the named machine.
Torque: The rotational effect of a force, equal to force multiplied by its perpendicular lever arm. Input and output torques balance in an ideal wheel and axle.
Axis of rotation: The line around which a body rotates. The wheel and axle share an axis that constrains their rotation.
Steering wheel: A hand-operated wheel that controls the direction of a vehicle’s steering mechanism. Its large radius lets a driver apply steering torque with manageable force.
Axle: A shaft that supports a rotating wheel or transmits rotational motion. The axle is the smaller central component around which the wheel turns.
Rotational motion: Motion in which an object turns around an axis. The wheel and axle transmit rotation around their shared axis.
Radius: The distance from a circle’s center to its circumference. The wheel and axle radii determine their relative travel and force.

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London EyeRelated: The London Eye’s rim rotates around a central axle held by its support structure.