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 rotary torque sensor. Static torque is comparatively easy to measure. Dynamic torque, on the contrary, 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 to condition the shaft or perhaps a member attached 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 therefore could 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 essential, as well as a means to receive the signal through the rotating shaft. This can be accomplished using slip rings, wireless telemetry, or rotary transformers. Newer types of torque transducers add conditioning electronics as well as an A/D converter for the rotating shaft. Stator electronics then look at the digital signals and convert those signals to a high-level analog output signal, such as /-10VDC.
A much more recent development is the usage of SAW devices connected to the shaft and remotely interrogated. The force on these tiny devices since the shaft flexes could be read remotely and output without resorting to attached electronics on the shaft. The probable first use in volume are usually in the automotive field as, of May 2009, Schott announced it possesses a SAW sensor package viable for in vehicle uses.
A different way to 3 axis load cell is through twist angle measurement or phase shift measurement, whereby the angle of twist as a result of applied torque is measured by utilizing two angular position sensors and measuring the phase angle between them. This method is utilized within the Allison T56 turboprop engine.
Finally, (as described within the abstract for people Patent 5257535), when the mechanical system involves a right angle gearbox, then the axial reaction force experienced by the inputting shaft/pinion may be related to the torque gone through by the output shaft(s). The axial input stress must first be calibrated up against the output torque. The input stress could be nanzqz measured via strain gauge measurement in the input pinion bearing housing. The output torque is readily measured utilizing a static torque meter.
The torque sensor can function just like a mechanical fuse and is a key 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 must be properly installed to make sure better performance and longevity.
The performance and longevity of the compression load cell along with its reading accuracy will likely be afflicted with the style of the driveline. The shaft becomes unstable in the critical speed from the driveline and causes torsional vibration, which can harm the torque sensor. It is essential to direct the strain to an exact point for accurate torque measurement. This time is usually the weakest reason for the sensor structure. Hence, the torque sensor is purposely created to be one of the weaker components of the driveline.