Before revision: An idler-wheel drive is a system used to transmit the rotation of the main shaft of a motor to anotherrotating device, for example is wheel which serves only to transmit rotation from one shaft to another, in applications where it is undesirable to connect them directly.
After revision: An idler-wheel is wheel which serves only to transmit rotation from one shaft to another, in applications where it is undesirable to connect them directly.