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 Miniature Load Cell. Static torque is comparatively simple to measure. Dynamic torque, on the other hand, is difficult to measure, as it generally requires transfer of some effect (electric, hydraulic or magnetic) from the shaft being measured to a static system.
One way to do this is always to condition the shaft or perhaps a member linked to the shaft with a number of permanent magnetic domains. The magnetic characteristics of those domains will be different in accordance with the applied torque, and so can be measured using non-contact sensors. Such magnetoelastic torque sensors are generally used 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 method, a way to power the strain gauge bridge is necessary, and also a way 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 plus an A/D converter for 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 much more recent development is the use of SAW devices attached to the shaft and remotely interrogated. The force on these tiny devices as the shaft flexes may be read remotely and output without resorting to attached electronics on the shaft. The probable first use within volume are usually in the automotive field as, of May 2009, Schott announced it possesses a SAW sensor package viable for in vehicle uses.
Another way to measure Torque Sensor is by means of twist angle measurement or phase shift measurement, whereby the angle of twist caused by applied torque is measured by utilizing two angular position sensors and measuring the phase angle between the two. This method is utilized within the Allison T56 turboprop engine.
Finally, (as described in the abstract for US Patent 5257535), if the mechanical system involves a right angle gearbox, then this axial reaction force experienced by the inputting shaft/pinion can be associated with the torque experienced 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 in the input pinion bearing housing. The output torque is definitely measured using a static torque meter.
The torque sensor can function like a mechanical fuse and is also an important component to obtain accurate measurements. However, improper installing 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 of the Multi Axis Load Cell and its reading accuracy will likely be afflicted with the design from 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 really is necessary to direct the strain for an exact point for accurate torque measurement. This point is usually the weakest reason for the sensor structure. Hence, the torque sensor is purposely created to be one from the weaker elements of the driveline.