What is a worm drive gearbox and how does it work?
Tags: gearbox, motor
Published: 2024-01-18 01:25:46

Worm Drive Gearbox is also called [Worm Gearbox](https://www.omc-stepperonline.com/worm-gearbox) or Worm Gear Reducer. As its name suggests, a worm drive gearbox is a box that contains worm gears. It is also often referred to as a worm gear reducer, and these terms essentially refer to the same thing. A worm drive gearbox functions like any gear system in that it can increase torque and decrease speed between a drive device such as a motor and a load.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/x3n4w6vieepsodp5j9w8.jpg)
Worm gears are found in industrial applications, heavy equipment, and even consumer applications. While their efficiency is relatively low, they can provide very high reduction ratios and they are self-locking in many situations.

**
What is a worm gear?**

A worm gear consists of a worm and a worm wheel (or simply "the wheel"), whose shafts are oriented non-parallel, non-intersecting, and at 90 degrees to each other. The worm is similar to a screw with a V-thread, while the gear is similar to a spur gear. The worm is usually the driving part, and the thread of the worm drives the teeth of the gear.


**Construction and characteristics of worm gears**

The engagement of the worm and worm wheel is a mixture of sliding and rolling actions, but the sliding contact predominates at high reduction ratios. This sliding action causes friction and heat generation, which limits the efficiency of the worm gear to 30% to 50%. The worm and worm wheel are made of different metals to minimize friction and the resulting heat. For instance, worm gears may be made of hardened steel and worm wheels of bronze or aluminum.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/70op5dponluxtcw1b999.jpg)
Though sliding contact reduces efficiency, it provides very quiet operation. In addition, the use of different metals for the worm and worm wheel also contributes to quiet operation. These enable the worm gear to be used where noise needs to be kept to a minimum, such as in elevators. Furthermore, the use of softer materials for worm wheels means that it can absorb shock loads, such as those encountered in heavy equipment or crushers.

The main benefit of worm gears is that they provide high reduction ratios and corresponding high torque multipliers. They can be used as speed reducers in low to medium speed applications. Additionally, because their reduction ratios are determined solely by the number of teeth in the worm wheel, they are more compact than other types of gears. Like fine-pitch lead screws, worm gears are generally self-locking, which makes them the preferred choice for lifting and hoisting applications.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/hef625csrw4qbyvtjkx7.jpg)

**How do worm gears work?**

A [stepper motor](https://www.omc-stepperonline.com) exerts rotational energy to the worm. The worm circulates against the worm wheel and the screw face pushes against the worm wheel through the teeth. The worm wheel is pushed against the force.