• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer
  • Advertise
  • Subscribe

Motion Control Tips

Automation • Motion Control • Power Transmission

  • News
    • Industry News
    • Editor Blogs
  • Controls
    • HMIs
    • PC-Based Controllers
    • PLCs + PACs
    • Stand-Alone Controllers
    • Software
  • Drives
    • Servo Drives
    • Stepper Drives
  • Encoders
    • Absolute Encoders
    • Incremental Encoders
    • Rotary Encoders
  • Mechanical
    • Bearings
    • Brakes + Clutches
    • Belt + chain
    • Couplings
    • Gears + Gearing
    • Lubrication
    • Shock + Vibration Mitigation
    • Springs + Rings + Seals
  • Linear
    • Actuators
    • Linear Motors
    • Linear Encoders
  • Motors
    • AC Motors
    • DC Motors
    • Brushless Motors
    • Gearmotors
    • Piezo Motors
    • Servo Motors
    • Stepper Motors
  • Systems
    • Conveyors + linear transport systems
    • Gantries + Stages
    • Rotary Tables
    • Grippers + End Effectors
    • Robotics
  • Networks
    • Connections + Sliprings
    • Fieldbuses
    • I/O
    • Sensors + Vision
  • Resources
    • FAQs
      • Motion Casebook
      • Motion Selection Guides
    • Suppliers
    • Video
You are here: Home / FAQs + basics / What are torque limiters? Technical summary for motion engineers

What are torque limiters? Technical summary for motion engineers

October 6, 2011 By Miles Budimir 3 Comments

Updated November 2018 by Lisa Eitel || Torque limiters protect equipment or loads from excessive torque. In essence, they are used to shut down a machine and dissipate any rotational energy without causing damage to the machine. Often, systems operating at low speeds can develop a large quantity of torque. In the event of a malfunction, this excess torque can damage machine components such as gearing, couplings, and motor or drive shafts. A torque limiter will prevent damage by limiting the amount of torque to some preset level.



Some consider mechanical torque limiters outdated because there are other ways to control torque overload, most notably via electronic current limitation of the motor. While this may work in some cases, as machinery becomes more dynamic, the inertia of moving parts becomes more critical. So, for instance, it’s possible to abruptly decelerate a rotating mass through unintentional blockage or the application of a dynamic braking system at a rate faster than the drive would normally accelerate.

This can create torque overload through the reflected inertia which is completely independent of the electronic system and so can easily exceed the peak torque rating of the motor. While older and bulkier designs may be out of the question, these modern mechanical torque limiters offer a high level of sensitivity and accuracy, with increasingly smaller impact on the size, mass, balance, and power consumption of the drive system.

There are fundamentally two types of torque limiter technologies, the disconnect type and the slip type. Disconnect torque limiters, as the name implies, physically disconnect the drive from the load. Several methods exist for the disconnecting process. The shear pin method actually destroys the pin joining the load with the drive. Another common method is via magnetic disconnection using permanent magnets. The common feature of disconnect type torque limiters is that they permanently separate the drive and driven shaft and require a manual re-engagement.

Slip type torque limiters work by letting the drive shaft run faster than the driven shaft. It effectively “slips” at some preset torque setting and reengages when the torque falls below the limit.

Here’s how the simplest versions work: Rollers (usually balls) are sandwiched between two component halves — and rest in mirror-image detents machined into these halves. Usually springs hold the halves together. The motor-driven side transmits torque to the load half called the thrust or pressure flange, and the whole assembly rotates in unison unless there’s an overload. In such situations, the overload-clutch halves overcome the axial spring force and repel apart. The rollers come free of their detents and roll to continue onward or resettle into the next detent pair when the jam or other overload is removed.


The most important factor in selecting a torque limiter is determining the proper torque rating, which will help determine the proper torque limiter size. Torque limiters are ideally installed as physically close to the point of impact or overload as possible in order to enhance sensitivity.

Torque limiters are often used in conjunction with a proximity sensor to detect the movement of an external ring around the disengaging safety clutch, and then trigger an e-stop condition in the machine. Free wheeling safety clutches will permanently separate the drive and driven shaft hubs of the coupling, requiring a manual re-engagement. This cuts back significantly on potential wear between the two halves of the torque limiter as they ratchet against each other.

Overload clutches (torque limiters) for guaranteed actuator protection

Torque limiters are sometimes called overload clutches. That’s most common when they’re pre-integrated into designs. Case in point: The new Warner Linear B-Track K4x dc-motor-driven ballscrew actuator (which delivers 4,000 lb load capacity) includes a ball-detent overload clutch. The actuators excel where designs can’t use fluid-power cylinders — on solar panels, off-highway equipment, scissor and dump box lifts, and mower and tractor lifts, for example.

Warner Linear rugged B-Track K4x actuators for demanding industrial applications include ball-detent overload clutches.

Its overload clutch setting is at 25% over the actuator’s rated dynamic load.  Main strengths here are simple and accurate disengagement at a preset torque.

You Might Also Like

Filed Under: FAQs + basics, Mechanical PT Tagged With: torque limiter

Reader Interactions

Leave a Reply

You must be logged in to post a comment.

Primary Sidebar

LEARNING CENTER

Design World Learning Center

Motion Control Handbook

“mct
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, tools and strategies for Design Engineering Professionals.

RSS Featured White Papers

  • Robotic Automation is Indispensable for the Logistics Industry’s Continued Growth and Success
  • Reliable Linear Motion For Packaging Machines
  • Polymers Outperform Metals In Precision Gearing

Footer

Motion Control Tips

DESIGN WORLD NETWORK

Design World Online
The Robot Report
Coupling Tips
Linear Motion Tips
Bearing Tips
Fastener Engineering.
Wire and Cable Tips

MOTION CONTROL TIPS

Subscribe to our newsletter
Advertise with us
Contact us
About us

Copyright © 2025 · WTWH Media LLC and its licensors. All rights reserved.
The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media.

Privacy Policy | RSS