"wheel and axle." YourDictionary, n.d. Web. 14 September 2018. <http://www.yourdictionary.com/wheel-and-axle>.
wheel and axle. (n.d.). Retrieved September 14th, 2018, from http://www.yourdictionary.com/wheel-and-axle
wheel and axle
A simple machine consisting of an axle to which a wheel is fastened so that torque applied to the wheel winds a rope or chain onto the axle, yielding a mechanical advantage equal to the ratio of the diameter of the wheel to that of the axle.