A torque sensor, torque transducer or torque meter is a device for measuring and recording the torque on a rotating system, including an engine, crankshaft, gearbox, transmission, rotor, a bicycle crank or Miniature Load Cell. Static torque is comparatively very easy to measure. Dynamic torque, on the other hand, can be difficult to measure, because 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 always to condition the shaft or perhaps a member connected to the shaft with a number of permanent magnetic domains. The magnetic characteristics of those domains will be different based on the applied torque, and therefore could 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, in addition to a methods to have the signal from the rotating shaft. This can be accomplished using slip rings, wireless telemetry, or rotary transformers. Newer kinds of torque transducers add conditioning electronics and an A/D converter towards the rotating shaft. Stator electronics then look at the digital signals and convert those signals to a high-level analog output signal, including /-10VDC.
A far more recent development is the usage of SAW devices connected to the shaft and remotely interrogated. The force on these tiny devices as the shaft flexes could be read remotely and output without the need for attached electronics around the shaft. The probable first use 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.
An additional way to measure Rotary Torque Sensor is by way of twist angle measurement or phase shift measurement, whereby the angle of twist as a result of applied torque is measured by using two angular position sensors and measuring the phase angle between the two. This technique is used inside the Allison T56 turboprop engine.
Finally, (as described inside the abstract for US Patent 5257535), in the event the mechanical system involves a right angle gearbox, then the axial reaction force gone through by the inputting shaft/pinion could be associated with the torque gone through by the output shaft(s). The axial input stress must first be calibrated from the output torque. The input stress can be easily measured wbtbtc strain gauge measurement of the input pinion bearing housing. The output torque is readily measured employing a static torque meter.
The torque sensor can function just like a mechanical fuse and is also a vital component to obtain accurate measurements. However, improper installation of the torque sensor can harm the device permanently, costing time and money. Hence, the torque sensor has to be properly installed to make sure better performance and longevity.
The performance and longevity of the Multi Axis Force Sensor along with its reading accuracy will likely be afflicted with the design in the driveline. The shaft becomes unstable in the critical speed in the driveline to result in torsional vibration, which can damage the torque sensor. It really is essential to direct the strain with 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 components of the driveline.