What is a worm gearbox?

Before understanding what is worm gearbox, we will first know what is a gearbox. A Gearbox is a mechanical system used to transmit the mechanical power of a motor in an automobile or in any dynamic machine. Gearbox is used to change output speed or torque of a motor as per requirement.

Worm gears are an old style of gear, and a model of one of the six easy machines. Generally, a worm gear is a screw butted up against what looks as if a trendy spur tools with barely angled and curved teeth.

Worm gears and helical gears are the two main types of gears that are widely used in several Industrial applications. Conventionally one would go for a helical gearbox design over a worm gearbox. But advances in the worm gearbox design has not only closed the efficiency gap but has also given worm gearboxes a competitive edge over helical gearbox.

A worm gearbox is a type of gearbox in which the driving component is a shaft with a spiral thread. The threaded shaft meshes or engages with a toothed wheel and advance the teeth of the wheel. The spiral threaded shaft and the toothed wheel are also called the worm screw and worm wheel, respectively. The worm gearbox is sometimes referred to as the worm drive. In worm gearbox, the spiral threaded shaft (worm screw) and the toothed wheel (worm wheel) are oriented in non-parallel and non-intersecting manner, at 90° to each other.

The worm gear transfers the motion in 90 degrees because it changes the rotational movement by 90 degrees. Because of the position of the worm screw on the worm wheel, the plane of movement also changes.