A torque sensor, torque transducer or torque meter is actually a device for computing and recording the torque on a rotating system, including an engine, crankshaft, gearbox, transmission, rotor, a bicycle crank or torque sensor. Static torque is relatively simple to measure. Dynamic torque, on the other hand, can be difficult to measure, since it generally requires transfer of some impact (electric, hydraulic or magnetic) through the shaft being measured to a static system.
A good way to accomplish this is always to condition the shaft or a member connected to the shaft with a number of permanent magnetic domains. The magnetic characteristics of those domains can vary according to the applied torque, and thus could be measured using non-contact sensors. Such magnetoelastic torque sensors are typically used 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 method to power the strain gauge bridge is important, as well as a means to get the signal through the rotating shaft. This is often accomplished using slip rings, wireless telemetry, or rotary transformers. Newer kinds of torque transducers add conditioning electronics as well as an A/D converter for the rotating shaft. Stator electronics then browse the digital signals and convert those signals to some high-level analog output signal, like /-10VDC.
A much more recent development is the use of SAW devices linked to the shaft and remotely interrogated. The strain 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 use in volume will be in the automotive field as, of May 2009, Schott announced it possesses a SAW sensor package viable for in vehicle uses.
An additional way to multi axis 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 them. This technique is used inside the Allison T56 turboprop engine.
Finally, (as described in the abstract for people Patent 5257535), in the event the mechanical system involves a right angle gearbox, then your axial reaction force gone through by the inputting shaft/pinion may be linked to the torque experienced by the output shaft(s). The axial input stress must first be calibrated from the output torque. The input stress could be nanzqz measured via strain gauge measurement in the input pinion bearing housing. The output torque is easily measured using a static torque meter.
The torque sensor can function such as a mechanical fuse and is a vital component to obtain accurate measurements. However, improper setting up the torque sensor can harm the device permanently, costing time and money. Hence, the torque sensor must be properly installed to make certain better performance and longevity.
The performance and longevity of the load cell along with its reading accuracy will be affected by the appearance of the driveline. The shaft becomes unstable at the critical speed of the driveline to result in torsional vibration, which can damage the torque sensor. It is actually essential to direct the strain to an exact point for accurate torque measurement. This time is typically the weakest reason for the sensor structure. Hence, the torque sensor is purposely designed to be among the weaker aspects of the driveline.