Definition of Worm Gear
Worm gear is a special gear that utilizes a screw-shaped rotor to mesh with one or more meshed gear. The most common type of worm gear is an internal gear and spur gear combination. It is a compact, efficient gear mechanism compared to the traditional gear systems and has a wide range of applications in many industries.
The architecture of a classic worm gear is much different from a classic gear system. The worm gear consists of a cylindrical gear, often referred to as a spur gear or gear wheel, and a worm gear or screw-shaped rotor. The gear wheel has a single or multiple teeth, while the rotor is flat and usually has a helical thread or screw groove embedded into its circumference. The number of teeth or grooves commonly range from a few hundred to several thousands.
The function of the worm gear is to rotate the gear wheel at a certain speed and in a certain direction according to the pitch and outside diameter of the helical thread or spiral groove. There are several advantage to using a worm gear. First, they are space efficient and can be used in tight spaces. Second, they are capable of providing large speed reduction with a single pair of gears. Third, because of their special tooth shape, they are effective in absorbing shock loads. Lastly, they are extremely quiet and have low vibration.
Types of Worm Gears
The worm gears can be divided into three main types: single start, multiple start, and helical type. Single start worm gears are the most common form and feature a single thread on the rotor. This type of worm gear works in much the same way as a single start thread. In other words, the number of turns of the rotor is equal to the number of turns of the helical thread. Multiple start worm gears are similar to single start versions, but feature multiple threads on the rotor. They offer increased speed reduction and torque capability. Helical worm gears feature a helical shape on the rotor instead of a circular threaded shape. The angle and pitch of the helical gears dictate the speed and torque specifications of the gear system.
Applications of Worm Gears
Worm gears are widely used in various applications due to their ability to provide high torque and speed reduction in a small package. They are often used in machinery and equipment requiring slow speed and high torque, such as winches, automobile engines, conveyors, and elevators. They are also used for indexing applications, where precise positioning of components is required. Worm gears are even used in robotics and motion control systems to accurately move machines from position to position.
Conclusion
Worm gears are a special gearing system used in a wide variety of industrial and commercial applications. They are effective in providing speed reduction and shock absorbing capabilities. The three main types of worm gears are single start, multiple start, and helical type. Worm gears are widely used in winches, engines, conveyors, elevators, robotics, and motion control systems.
