Posts

New Interface Torque Transducer Selection Guide

Interface produces content to help our customers in choosing the right force measurement products for their exact application requirements. From our Force Measurement 101 Series to the weekly Interface IQ posts, our focus is in building a repository of support resources that meet the needs of test and measurement professionals across all types of industries.

Our new Interface Torque Transducer Selection Guide helps to quickly evaluate the range of Interface’s torque transducer models based on whether you need a reaction (static) or rotary (dynamic) style. The guide assists in selecting best torque sensor based on features and capabilities, such as bearingless, contactless, compact, miniature, force and torque, overload protected, wireless, and USB output options.

Interface’s new web resource covers several types of torque sensors including flange mount, shaft type, square drive, hex drive, and couplings. If you’ve read our blog Choosing the Right Torque Transducer, which would also be a good place to start, you will understand how important it is to choose the right product, options and accessories for the job.

A torque sensor selection guide is typically used by engineers or technicians who need to choose a torque sensor for a specific application. Here are four easy steps to follow when using the Interface Torque Transducer Selection Guide:

  1. Determine the requirements of your application: Before selecting a torque sensor, you need to understand the specific requirements of your application. This includes the torque range you need to measure, the type of torque reaction versus rotary, shaft or mounting of the components you will be measuring, the environment in which the sensor will be used, and any other relevant factors related to the type of device you choose.
  2. Choose the type of torque sensor: There are several types of torque sensors available, including reaction or rotary, shaft or flange, shaft style, floating or fixed, and bearings or bearingless. The selection guide provides information about the features of each type, so you can choose the one that is best suited for your use case.
  3. Consider the accuracy and resolution: These both are key factors to consider, especially if you need to make precise measurements. The selection torque guide helps deliver specification details for each torque sensor, so you can choose the one that meets your requirements.
  4. Evaluate the physical characteristics: The physical characteristics of the torque transducer includes the size and shape of the sensor, the mounting options, and any distinctive features such as temperature compensation or overload protection.

By following these steps and using the information provided in the Interface Torque Transducer Selection Guide, it is easier to choose a sensor that is well-suited for your application and provides accurate and reliable measurements you require.

The Interface Torque Transducer Selection Guide helps to define the right product, as well as provide supplemental help and answers to frequently asked questions, including:

  • What is a torque transducer?
  • Reaction versus Rotary?
  • Shaft versus Flange?
  • Floating versus Fixed?
  • Bearings versus Bearingless?
  • Dual Range
  • RPM Considerations
  • Accuracy and Resolution
  • Coupling Types

Unsure of where to start? Check out Torque Transducers 101 or Recap of New Twist on Torque including the complete webinar below. In addition to our standard products, Interface has a custom solutions group that can collaborate with you to customize torque transducers, instrumentation, and complete measurement systems to fit your exact needs.  Contact Interface’s torque expert application engineers if you need assistance or require a quote.

ADDITIONAL RESOURCES

 

Miniature Torque Transducers 101

Choosing the Right Torque Transducer

A Comparison of Torque Measurement Systems White Paper

Torque Measurement Primer

Aircraft Yoke Torque Measurement

Fuel Pump Optimization & Rotary Torque

CPG Dental Handpiece Torque Check

Torque-Transducer-Brochure

Choosing the Right Torque Transducer

Interface offers an extensive line of torque transducer models in different designs and capacities to fit all types of torque measurement testing requirements.  The first thing to understand when choosing the right torque transducer is how an actual torque transducer works in order to then determine the best type, style, model, mounting, capacity and special features for your requirements.

A torque transducer, like a load cell, consists of a metal spring element, or flexure. Strain gages are applied to the flexure in a Wheatstone bridge configuration. Torque applied to the sensor causes bending or shear strain in the gaged area, generating an output voltage signal proportional to torque.

To assist you in choosing the right torque transducer, get a copy of our Torque Measurement Primer for reference in your selection process.

Reaction or Rotary Type

There are also two different types of torque transducers: reaction and rotary. A reaction, also known as static, torque transducer measures torque without rotating, while a rotary torque transducer rotates as part of the system. A rotary sensor, also sometimes called dynamic torque, is merely a reaction sensor that is allowed to rotate. Normally, a reaction style sensor has a cable attached to it for supplying excitation voltage to the strain gage bridge and for output of the mV/V signal. Spinning of these sensors is prevented by the attached cable. To get around the issue of the attached cable, a variety of methods have been used for rotary sensors Some of those methods include slip rings, rotary transformers, rotating electronics, rotating digital electronics and radio telemetry.

Shaft or Flange Style

Torque transducers typically come in one of two major mechanical configurations, shaft or flange style. Shafts can be either smooth or keyed with keyed shafts coming in either single or double-keyed versions. Flange style sensors are typically shorter than shaft style, and have pilots on their flange faces as a centering feature.

Smooth shafts offer some advantages over their keyed counterparts, including more uniform introduction of the torque into the measuring shaft, ease of assembly and disassembly and zero backlash. A coupling designed for use with smooth shafts will have some method of clam ping to the shaft. This is commonly accomplished with split collars or shrink-disk style hubs. Shrink-disk style hubs usually include features to aid in their removal from the shaft.

Hubs for keyed shafts are simpler than those for smooth shafts and cost less but can suffer from wear due to backlash, especially in reciprocating applications. To prevent backlash, the hub must be installed on the keyed shaft with an interference fit, which is usually accomplished by either heating the hub before installation or pressing the hub onto the shaft.

Fixed or Floating Mount

There are also two main methods of mounting rotary torque transducers, fixed or floating. Fixed mount applies only to sensors with bearings and involves attaching the sensor housing to a fixed support. In floating installations the sensor is supported only by its drive and load side connections, which are typically single-flex style couplings. A flexible strap keeps the torque transducer housing from rotating. By definition, bearingless sensors are always floating mount.

Fixed mounting requires that the sensor housing have a means to attach it to the support. Sometimes the mount is an option on the sensor and sometimes the foot or pedestal mount is built as part of the sensor. The simplest fixed mount design sensors include a flat machined surface on the housing with threaded mounting holes. In fixed mount installations, double flex couplings must be used.

Capacity

Once you have determined the type, style and mount, how do you choose the right transducer for your project? One of the primary considerations is selecting the right capacity. On one hand, if you choose too large a range, the accuracy and resolution may not be enough for the application. On the other hand, if you choose too small a size, the sensor may be damaged due to overload, which is an expensive mistake. No manufacturer wants you to overload the sensor.

To select the proper size, first determine the amount of torque you want to measure. This can be easy or hard, depending on your application. An easy example would be a fastener torque application, where a certain amount of torque is to be applied to a fastener. A more difficult application might be trying to figure out how much torque is required for a new design wind turbine.

This is just a brief overview, there are many other variables to consider when choosing a torque transducer. To get a full rundown, check out our white paper Torque Measurement Primer. And as always, give us a call to speak directly with our applications engineers to learn more at 480-948-5555.

With more than 36,000 product SKUs in Interface’s extensive catalog, it can be a daunting task choosing the sensors that fit your exact needs. Fortunately, we’re here to work you through it! There is an abundance of content, including product brochures, white papers, case studies and application notes, for easy comparing of different product types and categories . These resources, as well as our model product datasheets with specifications can help navigate the options and along with common solutions by industry.

Our application engineers are just a phone call away and can help you determine the off-the-shelf products or custom solutions needed for your specific application. To learn more about our torque transducer selection, you can also visit www.interfaceforce.com/product-category/torque-transducers/.

ADDITIONAL RESOURCES

New Twist on Torque Webinar

AxialTQ

Latest Spin on AxialTQ

A Comparison of Torque Measurement Systems White Paper

Rover Wheel Torque Monitoring

Aircraft Yoke Torque Measurement

Insights in Torque Testing Featured in Quality Magazine

Torque Measurement for Electric Vehicles

 

Recap of Latest Spin on AxialTQ Webinar

Interface recently hosted a new webinar in our ForceLeaders series that highlighted the revolutionary AxialTQ product.  The event reviewed the bearingless wireless rotary torque transducer design and detailed component specifications, why test engineers prefer the AxialTQ, and use cases for this precision measurement system.

If you were not able to attend the Latest Spin on AxialTQ event, you can watch the entire recording online here.

The revolutionary AxialTQ was first introduced in 2018. The design originated from the popular HRDT product that utilized a rotor stator gap design as a single component. After hundreds of users, we started the product engineering exercise to see how we could advance the soon-to-retire HRDT and evolve it into something that would perfectly fit current market conditions.

As technologies were changing testing protocols and requirements, such as for electric motors, alternative energy hardware, space vehicles and industrial machine automation, we wanted to add new functionality. Jay Bradley and the Interface engineering team began the process by looking at DIN size optimization, shorter stators, additional coupling options, advanced software configurations and simple “drop-in” replacement parts with a modular design.

After thousands of design hours and testing, Interface released the AxialTQ. The specialized product is a unique combination of accuracy, reliability and ease of use that redefines the standard torque measurement device in terms of function and durability.

Engineers prefer the new AxialTQ because of the time-proven sensing element with longer active area providing greater measurement sensitivity while being less vulnerable to shock loads.  The high-resolution digital electronics are state-of-the art. Uniquely, the large gap design up to 6 mm axial and 12 mm radial minimizes contact damage which is important at high-speed testing. It has 120-degree partial loop antenna on the stator to make installation easier.

Specialized design features of AxialTQ make it a great fit for test and production applications.

  • Crash-proof design for maximum reliability
  • Industry-leading gap to prevent damage to rotor stator at full speed
  • Simultaneous analog and digital outputs, enables real-time control and data collection
  • Interchangeable stators and output modules minimize parts inventory
  • Versatile design and wide range of configurations to match any application
  • Hardware is self-configuring
  • New advanced software with added features and logging capabilities
  • Rotor and stator coils designed using printed circuit boards for durability

The AxialTQ rotor sensing element and electronics are the heart of the system. It has a rugged design for all types of torque measurement applications.  It comes in 8 torque capacities. The status assembly matches to the rotor DIN size and is interchangeable with equipment DIN size rotor assemblies, increasing usability.  The USB digital output module has galvanic isolation on all outputs and has standard IP65 ingress protection.  It enables real-time control and accurate data collection.

Keith Skidmore shared several use cases during the presentation, including engine dynamometers, motor test stands and other automotive production line applications.

The AxialTQ is designed for testing anything that spins. It’s ideal in testing and production of hydraulic motors, EVs, helicopters, aircraft, and drones, along with windmills and industrial fans.  It’s great for testing forklifts, off-road and utility vehicles as wells as tractors and watercraft.  AxialTQ is also generally used for measuring torque on industrial motor assemblies, pumps, appliances, braking systems, and motor vehicle accessories.

Watch the entire webinar below to hear Keith and Jay share tips, specifications, frequently asked questions and how to get the most out of your torque measurement applications.

Learn more about AxialTQ here.

Couplings 101

One of the biggest challenges in the force measurement is dealing with misaligned loads. Misaligned loads can result in bad data and damaged test equipment. Therefore, it’s important to understand the affect these types of loading conditions can have on a force test and know of the ways to fix or account for it.

For every force test, there is typically a piece of equipment designed to deal with misaligned loads. Whether it’s simply applying the force device properly or if misaligned loads are unavoidable, using the right tools to reject misaligned load. Learning more about couplings is a great place start in knowing how to this power tool is designed to deal with misaligned loads in torque testing.

Couplings are a critical component to be used alongside torque transducer that ensures the isolation of torque loads. A coupling is a mechanical element that connects two shafts together to accurately transmit the power from the drive side to the driven side while absorbing the mounting error of misalignment of the two shafts. Essentially, they allow and compensate for misalignment in a torque test. It is one of the topics we discuss in our online webinar, New Twist on Torque.

For instance, if two shafts are coupled together and the center shafts aren’t aligned, measuring torque without a coupling may ruin the test, affecting the longevity of the parts and the performance of the measurement. With a coupling, the shafts don’t have to be perfectly aligned in length and can still provide an accurate torque test.

There are two main categories of couplings used in force measurement and the biggest difference in the two is the degree of freedom needed for the application. The categories are single-jointed and double-jointed. A single-jointed coupling allows for angular and axial misalignment, while double-jointed coupling allow for an additional radial misalignment. For floating mount installations, Interface recommend single-flex disk couplings. For fixed mount installations, double-flex disk couplings are required.

Couplings should be used in all applications and the selection of the coupling type is based on the speed of the application. For higher speed applications, Interface recommends a high-quality coupling with a flexible, yet sturdy construction made from premium metals.

Interface offers a wide variety of torque transducers and can provide couplings off the shelf or in a custom solution when necessary. One of our most popular torque solutions, which includes a coupling, is the Interface Model T1 Torque Coupling Rotary Torque Transducer. This solution integrates torque measurement with a robust double flex coupling.  The coupling and sensor are completely hollow, allowing the shortest possible distance between the coupled shaft ends. On-board digital electronics provide a ±5V output, low-noise signal. Powered by 12-28V DC, the strain gage based T1 Torque Coupling offers precision rotary torque measurement in a bearing-less, contact-free design. Covering ranges from 50 to 1000 Nm (443 to 8.85K lbf-in), the T1 ships with factory bored hubs to mate precisely with the customer’s shaft ends.  Both smooth and keyed shaft style hubs are available.

Examples of a torque solutions using a coupling in the field can be found in our application notes section of the website. We’ve provided an example of one such application below.

Fuel Pump Optimization – Rotary Torque

A nationally renowned race team was using a flow bench to measure fuel pump performance. They wanted to determine if they could reduce the power consump­tion of the pump by further analyzing the precise torque it produced. An Interface Model T25 High Speed Rotary Torque Transducer was integrated into the pump drive to directly measure the torque required to spin the pump. Interface Shaft Style Torque Transducer Couplings we’re also used to marry the shafts to the T25. Using this data collected from the T25 in conjunction with the pressure and volume measurements of the fuel flow, the race team was able to characterize fuel pump performance versus drive line torque, and then minimize the required drive power while maintaining the needed pressure and flow for efficient fuel delivery.

Couplings are an integral part of any torque test project. To learn more about couplings and their application in a wide variety of projects, reach out to Interface at 480-948-5555 or contact us here. We can suggest a combination of off-the-shelf transducers, couplings and data acquisition devices or work with you to develop a custom solution necessary for your goals.

ADDITIONAL READING: TORQUE TRANSDUCERS 101

Source: Keith Skidmore

Driving Force in Automotive Applications

Among the most highly regulated industries in the world, automotive is up there with the likes of medical and defense. Every component and system needs to be thoroughly tested and deliberately analyzed to ensure that the final product is safe for the driver, other vehicles and pedestrians. Any mistakes or failures can cause catastrophic damage and put lives at risk.

There are hundreds of thousands of different tests that car parts and software go through before they are approved for the road. Among them is force measurement testing. Force and torque tests are integral to the structural and mechanical design and build of the car. Gathering data on the build quality and safety of materials and components found within cars, trucks and more is done through a wide variety of different force measurement testing.

Interface has been a partner to the automotive industry for more than 50 years, from the major OEMs to smaller parts manufacturers and test labs. We build force and torque sensors and acquisition devices designed to provide automotive engineers and manufacturers with high-quality data to monitor and confirm the design and in-action processes of a wide variety of vehicles.

Force testing applications for the automotive industry involve everything from structural, engine, brake, seat belt and suspension tests, all the way down to individual lug nut torque testing.

Recently, Interface has also been supplying solutions to those in the growing electrical vehicle (EV) market. EV cars and other motor vehicles present a wide variety of unique challenges for engine torque and battery technology testing.

As an example of some of the products we offer to the industry, we are highlighting Interface expertise in different automotive applications. This will include specific examples of work we’ve done for our customers recently or in the past.

BRAKE PEDAL TESTING

One of the largest areas of automotive test and measurement we are involved in is brake pedal testing. Our customers need to ensure that applying certain amounts of force to the brake will slow and stop the vehicle as intended.

In this application note, Interface supplied our customer with a BPL-300-C Brake Pedal Load Cell, which was installed on the brake pedal. As the user depressed the brake pedal, force data was transmitted by our BTS-AM-1 Bluetooth Low Energy (BLE) Strain Bridge Transmitter Module to the BTS Toolkit Mobile App and displayed on a mobile device. This allowed our customer to view and graph the data in real-time.

Read the application note for Brake Pedal Testing here.

EV BATTERY TESTING

In the EV market, one of the most integral pieces of technology is the battery used to run every piece of hardware and software in the car. One of the critical tests that’s performed on EV batteries in compression testing. As an EV battery is charged and stores more electrons, it swells. If the packaging that houses the batteries is not intelligently designed to compensate for this swelling, you could have a major problem.

For this challenge, Interface can supply the popular WMC Miniature Load Cell. The load cell will measure compression force as a battery goes through charge cycles on a test stand to determine the force given off as the battery swells. This allows our customers to design the proper packaging for the batteries.

Read more about Interface’s role in the The Future of Automotive is Electric.

SUSPENSION TESTING

A personal favorite of the Interface team is a suspension test we performed on a race car. As you can imagine, race car components need to be finely tuned for optimal performance. The suspension is one of the most significant factors in the tuning process.

Using an Interface Model 1200 Standard Load Cell, we were able to measure simulated motions of a racetrack including bumps, banks and other track conditions. This allowed the customer to gather highly accurate (0.04%) measurements of loads applied to individual suspension points. This type of suspension testing technology can also be performed on a regular commercial automobile, but the race car example is much more fun!

View the race car suspension testing application here.

MOTOR TESTING

In this motor test stand application, it was used in the quality control lab of a major automotive manufacturing customer that needed to test, record and audit the torque produced by a new motor design under start load.

Interface supplied a Model AxialTQ Rotary Torque Transducer that connected between the motor and the differential, on the drive shaft, which could measure and record these torque values. Based on the data collected using the AxialTQ, AxialTQ Output Module, and customer laptop, the test engineer was able to make recommendations to optimize the amount of torque created by the new motor design.

You can read more about the AxialTQ in this post.  

The wide variety of applications for automotive force testing that Interface has been involved in is significant. We have many published application notes beyond those highlighted, including Seat Testing, Engine Head Bolt Tightening and one for an Engine Dynamometer (dyno for short) use case. The examples listed above just scratch the surface.

Interface is a preferred partner to the automotive industry.  To review some of the automotive application notes we have published, please check out our website at /solutions/automotive-vehicle/. You can also give us a call to learn more about the various solutions we offer for customers in the automotive industry at 480-948-5555.