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 Compression Load Cell. Static torque is fairly very easy to measure. Dynamic torque, alternatively, 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 achieve this is always to condition the shaft or even a member attached to the shaft with a series of permanent magnetic domains. The magnetic characteristics of those domains will vary according to the applied torque, and therefore could 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. Using this method, a way to power the strain gauge bridge is important, in addition to a means to receive the signal from the rotating shaft. This is often accomplished using slip rings, wireless telemetry, or rotary transformers. Newer types of torque transducers add conditioning electronics plus an A/D converter for the rotating shaft. Stator electronics then read the digital signals and convert those signals to your high-level analog output signal, like /-10VDC.
A more recent development is using 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 making use of attached electronics on the shaft. The probable first use within volume will be in the automotive field as, of May 2009, Schott announced it features a SAW sensor package viable for in vehicle uses.
A different way to measure Torque Sensor is through 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 them. This method is used in the Allison T56 turboprop engine.
Finally, (as described within the abstract for US Patent 5257535), in the event the mechanical system involves a right angle gearbox, then the axial reaction force experienced by the inputting shaft/pinion can be associated with the torque gone through by the output shaft(s). The axial input stress must first be calibrated against the output torque. The input stress can be simply measured wbtbtc strain gauge measurement in the input pinion bearing housing. The output torque is definitely measured employing a static torque meter.
The torque sensor can function such as a mechanical fuse and is an important component to get accurate measurements. However, improper setting up the torque sensor can harm the device permanently, costing money and time. Hence, the torque sensor has to be properly installed to make certain better performance and longevity.
The performance and longevity in the Multi Axis Load Cell and its reading accuracy will likely be affected by the design in the driveline. The shaft becomes unstable at the critical speed from the driveline and causes torsional vibration, which can damage the torque sensor. It is actually necessary to direct the strain with an exact point for accurate torque measurement. This point is typically the weakest point of the sensor structure. Hence, the torque sensor is purposely made to be one in the weaker components of the driveline.