A torque sensor, torque transducer or torque meter is a device for computing 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 very easy to measure. Dynamic torque, on the contrary, is difficult to measure, because it generally requires transfer of some impact (electric, hydraulic or magnetic) from the shaft being measured to a static system.
One method to accomplish this is to condition the shaft or a member attached to the shaft with a series of permanent magnetic domains. The magnetic characteristics of those domains will vary based on the applied torque, and thus can 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 placed on a rotating shaft or axle. Using this method, a means to power the strain gauge bridge is important, and also a methods to have the signal from your rotating shaft. This could be accomplished using slip rings, wireless telemetry, or rotary transformers. Newer varieties of torque transducers add conditioning electronics and 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, including /-10VDC.
A more recent development is the usage of SAW devices attached 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 on the shaft. The probable first use in volume are usually in the automotive field as, of May 2009, Schott announced it features a SAW sensor package viable for in vehicle uses.
Another way to 3 axis load cell is by way 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 technique can be used within the Allison T56 turboprop engine.
Finally, (as described within the abstract for all of us Patent 5257535), if the mechanical system involves a right angle gearbox, then your axial reaction force felt by the inputting shaft/pinion may 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 may be nanzqz measured via 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 just like a mechanical fuse and it is an important component to obtain accurate measurements. However, improper installing of the torque sensor can damage 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 in the load cell and its reading accuracy is going to be affected by the design of the driveline. The shaft becomes unstable in the critical speed in the driveline and results in torsional vibration, which can harm the torque sensor. It really is essential to direct the strain to an exact point for accurate torque measurement. This point is typically the weakest reason for the sensor structure. Hence, the torque sensor is purposely made to be one of the weaker aspects of the driveline.