Torque Limiter: What Is It and Why Is It Important for Mechanical Equipment?

Applications around the world and in many industries use mechanisms to operate machinery. From harvesting crops and processing food to mining precious ores from the earth, these machines use rotating systems to operate, such as tracks on an excavator or a tractor equipped with a brush hog attachment used to clear a field.

Depending on the machine, the amount of generated torque can be vast depending on the equipment and the task. Therefore, these mechanisms are designed to handle a specific amount of generated torque consistently. However, some unforeseen circumstances may cause the mechanisms to experience higher torque loads that exceed design specifications. In these instances, a torque limiter is used to prevent the machine from overloading.

What is a Torque Limiter?

A torque limiter is a device that limits the amount of torque that mechanisms will experience. It is a device placed somewhere between the drive and the system that is driven. The torque limiter engages when the machine experiences a high torque load that the system cannot handle. 

The torque limiter disconnects (slips) the drive from the driven system. Due to this decoupling, the torque force begins to dissipate as the machine falls back into normal torque load thresholds or completely shuts down. For some torque limiter designs, the device still allows the equipment to function at lower speeds as engineers diagnose the issue to get the equipment running back at total capacity. For other instances, the torque limiter must be manually reset to reengage the drive system. 

There are many types of torque limiter designs. Some standard devices include the following:

  • Shear pin
  • Friction torque limiters
  • Ball detent torque limiters
  • Magnetic torque limiters
  • Hydraulic torque limiters

Why Are Torque Limiters Important?

Torque limiters act as a safety mechanism for equipment. It prevents equipment from experiencing a catastrophic failure that could result in tool breakage or even injuries to workers. The torque limiter is designed to work within milliseconds of detecting high torque loads. As a result, they can prevent damage from gearboxes, shafts, couplings chains, and other mechanisms. 

The location of the torque limiter varies based on which type of equipment it should protect. Multiple torque limiters may be placed between different points along the drive system. You may have a torque limiter between the gearbox and the motor to protect the motor, or the gearbox and the driven system to protect both the motor and the gearbox.

Best practices when deciding on the size and type of torque limiter and its placement will depend on the generated torque load. Typically, the torque load may be placed between mechanisms that are the most expensive to maintain, repair, or replace in the event of a catastrophic failure. In addition, the torque limiter should always be set at a place that generally has a low amount of torque to prevent the device from accidentally tripping on its own. 

When it comes to torque limiters, these devices protect your equipment through their entire lifecycle. As a result, they may prevent unnecessary downtimes, complete equipment failure, and workplace accidents. For more information about torque limiters, contact Kor-Pak.

Posted in Industrial Equipment.