A torque sensor, torque transducer or torque meter is a device for measuring and recording the torque on a rotating system, such as an engine, crankshaft, gearbox, transmission, rotor, a bicycle crank or Micro Load Cell. Static torque is fairly very easy to measure. Dynamic torque, on the other hand, is not easy to measure, since it generally requires transfer of some effect (electric, hydraulic or magnetic) from the shaft being measured to a static system.
One way to accomplish this is to condition the shaft or even a member linked to the shaft with several permanent magnetic domains. The magnetic characteristics of such domains can vary in accordance with the applied torque, and therefore can be measured using non-contact sensors. Such magnetoelastic torque sensors are generally utilized for in-vehicle applications on racecars, automobiles, aircraft, and hovercraft.
Commonly, torque sensors or torque transducers use strain gauges applied to a rotating shaft or axle. With this particular method, a method to power the strain gauge bridge is important, as well as a methods to have the signal through the rotating shaft. This could be accomplished using slip rings, wireless telemetry, or rotary transformers. Newer varieties of torque transducers add conditioning electronics as well as an A/D converter towards the rotating shaft. Stator electronics then look at the digital signals and convert those signals to your high-level analog output signal, like /-10VDC.
A far more recent development is using SAW devices connected to the shaft and remotely interrogated. The stress on these tiny devices as the shaft flexes may be read remotely and output without the need for attached electronics on the shaft. The probable first utilization in volume are usually in the automotive field as, of May 2009, Schott announced it features a SAW sensor package viable for in vehicle uses.
An additional way to measure Torque Transducer is by means of twist angle measurement or phase shift measurement, whereby the angle of twist caused by applied torque is measured by making use of two angular position sensors and measuring the phase angle between them. This procedure can be used within the Allison T56 turboprop engine.
Finally, (as described in the abstract for US Patent 5257535), in the event the mechanical system involves a right angle gearbox, then your axial reaction force felt by the inputting shaft/pinion may be associated with the torque experienced by the output shaft(s). The axial input stress must first be calibrated up against the output torque. The input stress can be simply measured wbtbtc strain gauge measurement of the input pinion bearing housing. The output torque is readily measured using a static torque meter.
The torque sensor can function like a mechanical fuse and is an important component to obtain accurate measurements. However, improper installation of the torque sensor can damage the device permanently, costing money and time. Hence, the torque sensor must be properly installed to ensure better performance and longevity.
The performance and longevity in the Multi Axis Load Cell and its reading accuracy is going to be impacted by the design of the driveline. The shaft becomes unstable in the critical speed from the driveline to result in torsional vibration, which can damage the torque sensor. It is essential to direct the strain for an exact point for accurate torque measurement. This aspect is typically the weakest point of the sensor structure. Hence, the torque sensor is purposely designed to be one of the weaker elements of the driveline.