Worm Gear ABC

What is the Worm Gear?
When it comes to the worm gear, it is usually the worm drive system that people refer to. A worm drive consists of a worm and a worm wheel. The worm is a gear that comes in the form of a threaded shaft (a screw). The worm wheel on the other hand resembles the helical gear, except the teeth are slightly curved or angled to better fit the worm thread. Unlike most gear sets that the gears share the same rotational axis, the worm drive changes the rotational axis by 90 degrees. In other words, the axis of the worm is perpendicular to that of the wheel. Based on this structure, there are several developments into the types and designs of the worm drive.

Worm Gear Starts
The thread and the tooth design determine the use and performance of the worm drive. The worm thread is also called the start. There are variations in terms of the start number. The start number of the worm is usually one, two, or three.That said, there are also worms with more than three starts. The start number affects the transmission speed and reduction ratio of the drive. For example, a single-start worm only has one thread and when it rotates 360 degrees (a full turn), it advances one wheel tooth. The two-start worm has two threads and advances two teeth at a full turn. The reduction ratio of the worm drive is the tooth number divided by the start number. Let’s say a worm drive is composed of a two-start worm and a 36-tooth wheel. The reduction ratio is 18:1.

Why Using the Worm Gear?
There are three main reasons why people adopt the worm drive system into the gearbox or other mechanical devices. Simply put, the worm gear can change the rotational direction, increase the torque, and reduce the transmission speed. This system is efficient because of its simple structure. The reduction ratio is controlled solely by the tooth and thread number. With fewer components in the system, the size of the drive is compact and suitable for installation in confined working environments.

Aside from the efficiency and simple working principle, the worm gear is advantageous when the low-to-non-noise operation is required. Also, since the meshing processing of the worm and wheel involves both rolling and sliding, the friction generated during the process makes the drive direction irreversible; the wheel cannot drive the worm. This mechanism is called self-locking and is preferable in quite a number of applications. However, using the multiple-start worm influences the self-locking characteristic of the system.

Limits
Since friction (hence heat) is an inevitable element in the worm gear operation, lubrication is necessary for heavy-duty applications. Using the correct lubricant for the worm drive can control the heat level, reduce friction, maintain efficiency, and prolong the overall service life of the unit. Depending on the application of the drive and the type of worm and wheel, the system needs different types of lubricant, and we will talk about the lubrication and the material of the worm gear in another article. Now let’s read on to learn more about its applications.

Applications
The common applications of the worm drive include gear reducers, lifts, elevators, conveyor belts, gate controls, and guitars, to just name a few. The tuning pegs on the guitar’s headstock is a standard application of the worm gear. By turning the peg, the screw tightens or loosens the string to tune the guitar. Gate and door control is a gear drive application that involves the motor. The motor controls the direction of the worm to open or close the door. The other common application is the gear reducer. Gear reducers are the transmission device for motors in industrial settings. They are highly effective at adjusting the speed and torque to the desired level. Chun Yeh Gear Co. is an expert in gearbox design and worm gear manufacturing. Contact us right now to learn more about Chun Yeh’s services.

Worm Gear ABC

What is the Worm Gear?
When it comes to the worm gear, it is usually the worm drive system that people refer to. A worm drive consists of a worm and a worm wheel. The worm is a gear that comes in the form of a threaded shaft (a screw). The worm wheel on the other hand resembles the helical gear, except the teeth are slightly curved or angled to better fit the worm thread. Unlike most gear sets that the gears share the same rotational axis, the worm drive changes the rotational axis by 90 degrees. In other words, the axis of the worm is perpendicular to that of the wheel. Based on this structure, there are several developments into the types and designs of the worm drive.

Worm Gear Starts
The thread and the tooth design determine the use and performance of the worm drive. The worm thread is also called the start. There are variations in terms of the start number. The start number of the worm is usually one, two, or three.That said, there are also worms with more than three starts. The start number affects the transmission speed and reduction ratio of the drive. For example, a single-start worm only has one thread and when it rotates 360 degrees (a full turn), it advances one wheel tooth. The two-start worm has two threads and advances two teeth at a full turn. The reduction ratio of the worm drive is the tooth number divided by the start number. Let’s say a worm drive is composed of a two-start worm and a 36-tooth wheel. The reduction ratio is 18:1.

Why Using the Worm Gear?
There are three main reasons why people adopt the worm drive system into the gearbox or other mechanical devices. Simply put, the worm gear can change the rotational direction, increase the torque, and reduce the transmission speed. This system is efficient because of its simple structure. The reduction ratio is controlled solely by the tooth and thread number. With fewer components in the system, the size of the drive is compact and suitable for installation in confined working environments.

Aside from the efficiency and simple working principle, the worm gear is advantageous when the low-to-non-noise operation is required. Also, since the meshing processing of the worm and wheel involves both rolling and sliding, the friction generated during the process makes the drive direction irreversible; the wheel cannot drive the worm. This mechanism is called self-locking and is preferable in quite a number of applications. However, using the multiple-start worm influences the self-locking characteristic of the system.

Limits
Since friction (hence heat) is an inevitable element in the worm gear operation, lubrication is necessary for heavy-duty applications. Using the correct lubricant for the worm drive can control the heat level, reduce friction, maintain efficiency, and prolong the overall service life of the unit. Depending on the application of the drive and the type of worm and wheel, the system needs different types of lubricant, and we will talk about the lubrication and the material of the worm gear in another article. Now let’s read on to learn more about its applications.

Applications
The common applications of the worm drive include gear reducers, lifts, elevators, conveyor belts, gate controls, and guitars, to just name a few. The tuning pegs on the guitar’s headstock is a standard application of the worm gear. By turning the peg, the screw tightens or loosens the string to tune the guitar. Gate and door control is a gear drive application that involves the motor. The motor controls the direction of the worm to open or close the door. The other common application is the gear reducer. Gear reducers are the transmission device for motors in industrial settings. They are highly effective at adjusting the speed and torque to the desired level. Chun Yeh Gear Co. is an expert in gearbox design and worm gear manufacturing. Contact us right now to learn more about Chun Yeh’s services.

2022-03-23