A torque sensor, torque transducer or torque meter is actually a device for computing and recording the torque on a rotating system, like an engine, crankshaft, gearbox, transmission, rotor, a bicycle crank or torque transducer. Static torque is relatively very easy to measure. Dynamic torque, on the contrary, is difficult to measure, as it generally requires transfer of some impact (electric, hydraulic or magnetic) from the shaft being measured to a static system.
One way to achieve this would be to condition the shaft or even a member attached to the shaft with a series of permanent magnetic domains. The magnetic characteristics of such domains will vary in accordance with the applied torque, and so may be measured using non-contact sensors. Such magnetoelastic torque sensors are usually utilized for in-vehicle applications on racecars, automobiles, aircraft, and hovercraft.
Commonly, torque sensors or torque transducers use strain gauges put on a rotating shaft or axle. With this particular method, a means to power the strain gauge bridge is necessary, as well as a way to have the signal from your rotating shaft. This is often accomplished using slip rings, wireless telemetry, or rotary transformers. Newer varieties of torque transducers add conditioning electronics plus an A/D converter for the rotating shaft. Stator electronics then look at the digital signals and convert those signals to some high-level analog output signal, including /-10VDC.
A far more recent development is the use of SAW devices attached to the shaft and remotely interrogated. The stress on these tiny devices because the shaft flexes may be read remotely and output without resorting to attached electronics on the shaft. The probable first utilization in volume are usually in the automotive field as, of May 2009, Schott announced it has a SAW sensor package viable for in vehicle uses.
A different way to triaxial load cell is by means of twist angle measurement or phase shift measurement, whereby the angle of twist resulting from applied torque is measured by making use of two angular position sensors and measuring the phase angle between the two. This procedure is utilized inside the Allison T56 turboprop engine.
Finally, (as described within the abstract for people Patent 5257535), in the event the mechanical system involves the right angle gearbox, then this axial reaction force experienced by the inputting shaft/pinion could 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 may be nanzqz measured via strain gauge measurement from the input pinion bearing housing. The output torque is definitely measured using a static torque meter.
The torque sensor can function just like a mechanical fuse and is also an important component to get accurate measurements. However, improper installing of the torque sensor can damage the device permanently, costing time and money. Hence, the torque sensor needs to be properly installed to make sure better performance and longevity.
The performance and longevity in the miniature load cell as well as its reading accuracy is going to be impacted by the appearance of the driveline. The shaft becomes unstable in the critical speed of the driveline to result in torsional vibration, which can damage the torque sensor. It is essential to direct the strain to an exact point for accurate torque measurement. This aspect is normally the weakest reason for the sensor structure. Hence, the torque sensor is purposely designed to be one of many weaker components of the driveline.