Torque Limiters

General Guide & Overview

Torque limiters are essential devices that provide torque overload protection for machinery, safeguarding against potential damage to machine components. These devices play a crucial role, especially in systems operating at low speeds, where excess torque can cause significant harm.

While electronic current limitation of the motor can control torque overload in some cases, mechanical torque limiters offer a higher level of sensitivity and accuracy, ensuring optimal protection. But how do torque limiters work, and what exactly are they?

A torque limiter is a type of device that allows for the control and limitation of torque transmitted between the drive and the load. When the torque exceeds the pre-set limit, the torque limiter intervenes to prevent any further transmission of torque, thereby protecting the machinery from potential damage.

There are two primary types of torque limiters: disconnect type and slip type. Disconnect torque limiters physically separate the drive and load, effectively stopping the torque transmission. In contrast, slip type torque limiters allow the drive shaft to slip when the torque exceeds the preset limit.

Torque limiters come in various types, each offering specific advantages and applications. Some common types include friction torque limiters, shear pin torque limiters, ball detent torque limiters, magnetic torque limiters, adjustable torque limiters, and mechanical torque limiters.

Friction torque limiters are mounted on the shaft and can transmit torque through roller chains, belts, and gears. Shear pin torque limiters utilize shear pins that break when the torque exceeds the set limit, preventing further torque transmission. Ball detent torque limiters use rollers or balls that slip when an overload occurs. Magnetic torque limiters use permanent magnets to disconnect the drive and load. Adjustable torque limiters allow users to adjust the torque setting according to their specific needs. Mechanical torque limiters, on the other hand, are widely used and offer a reliable and cost-effective solution for torque overload protection.

The benefits of torque limiters are significant. They help protect workers by preventing excessive torque that can lead to accidents and injuries. Torque limiters also provide a grace period for equipment malfunction, allowing workers to shut down the machinery before further damage occurs. While there may be some minor drawbacks, such as approximate limiter settings and the need for manual shutdown, the advantages far outweigh these limitations.

For optimal performance and protection, it is crucial to set the torque limiter at the appropriate value. This ensures that the torque limiter effectively controls and limits the torque transmitted, offering optimal protection for both workers and equipment.

Types of Torque Limiters

When it comes to torque overload protection, there is a wide range of torque limiters available on the market. Each type of torque limiter offers its own set of advantages and is designed for specific applications. Understanding the different types can help you choose the right torque limiter for your needs.

Friction Torque Limiters

Friction torque limiters are mounted directly on the shaft and can effectively transmit torque through roller chains, belts, and gears. They rely on the friction generated between mating surfaces to limit torque. These torque limiters are suitable for applications where precise and reliable torque control is required.

Shear Pin Torque Limiters

Shear pin torque limiters are designed with shear pins that are intended to break when the torque exceeds the preset limit. These torque limiters offer a simple and cost-effective solution for overload protection. When a shear pin breaks, it indicates that a torque overload has occurred, allowing maintenance personnel to readily identify and address the issue.

Ball Detent Torque Limiters

Ball detent torque limiters work by utilizing rollers or balls that rest in mirror-image detents. When an overload occurs, the balls or rollers slip, allowing the drive shaft to decouple from the load. This slip mechanism provides immediate and reliable torque limiting. Ball detent torque limiters are often used in applications where quick disengagement is essential for protecting machinery and components.

Magnetic Torque Limiters

Magnetic torque limiters utilize permanent magnets to disconnect the drive and load when an overload occurs. The magnetic force is calibrated to a specific torque level, providing accurate and instantaneous torque limiting. These torque limiters are commonly used in applications where precision and fast response times are critical.

Adjustable Torque Limiters

Adjustable torque limiters allow users to fine-tune the torque setting according to their specific requirements. This flexibility makes them ideal for applications that may have varying torque limits or need to accommodate changes in operating conditions. Adjustable torque limiters offer versatility and ease of adjustment, ensuring optimal performance and protection.

Mechanical Torque Limiters

Mechanical torque limiters are widely utilized in various industries and offer a reliable and cost-effective solution for torque overload protection. They are designed to disengage or slip when the torque exceeds the set limit, safeguarding machinery and preventing potential damage. Mechanical torque limiters are known for their robustness and durability, making them a popular choice for many applications.

Benefits of Torque Limiters

Torque limiters provide significant advantages when it comes to worker safety and protecting equipment. Their primary function is to prevent excessive torque, which plays a crucial role in safeguarding workers from accidents and potential injuries. By limiting the torque transmitted through machinery, torque limiters help create a safer working environment.

One of the key benefits of torque limiters is that they offer a grace period for equipment malfunction. When an overload occurs, the torque limiter activates, providing workers with valuable time to shut down the machinery before further damage can occur. This feature not only protects the equipment but also prevents high-risk situations, ensuring the well-being of workers.

While there may be some minor disadvantages, such as approximate limiter settings and the need for workers to manually shut down the equipment, the advantages of torque limiters far outweigh these drawbacks. Torque limiter couplings, in particular, are highly efficient in protecting both workers and equipment. These couplings, integrated with torque limiters, provide an additional layer of protection by disconnecting the drive and load when the torque exceeds the preset limit.

To ensure optimal performance and protection, it is crucial to set the torque limiter at the appropriate value. This requires a careful assessment of the specific requirements and operating conditions of the machinery. By correctly configuring the torque limiter settings, workers can benefit from enhanced safety, while equipment can enjoy prolonged lifespan and reduced downtime due to torque-related damages.