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 fairly 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 method to make this happen is to condition the shaft or a member attached to the shaft with a number of permanent magnetic domains. The magnetic characteristics of such domains will vary in accordance with the applied torque, and therefore can be measured using non-contact sensors. Such magnetoelastic torque sensors are generally employed 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. With this particular method, a way to power the strain gauge bridge is important, in addition to a methods 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 to the rotating shaft. Stator electronics then browse the digital signals and convert those signals to some high-level analog output signal, including /-10VDC.
A far more recent development is using SAW devices linked to the shaft and remotely interrogated. The strain on these tiny devices because the shaft flexes can be read remotely and output without the need for attached electronics on the shaft. The probable first utilization 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.
Another way to multi axis load cell is by way of twist angle measurement or phase shift measurement, whereby the angle of twist as a result of applied torque is measured by using two angular position sensors and measuring the phase angle between them. This technique can be used in the Allison T56 turboprop engine.
Finally, (as described within the abstract for all of us Patent 5257535), in the event the mechanical system involves the right angle gearbox, then the axial reaction force felt by the inputting shaft/pinion can be related to the torque felt by the output shaft(s). The axial input stress must first be calibrated against the output torque. The input stress may 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 it is a vital component to get accurate measurements. However, improper installation of the torque sensor can harm the device permanently, costing money and time. Hence, the torque sensor needs to be properly installed to make certain better performance and longevity.
The performance and longevity of the miniature load cell as well as its reading accuracy will be impacted by the design of the driveline. The shaft becomes unstable at the critical speed of the driveline and results in torsional vibration, which can damage the torque sensor. It really is necessary to direct the strain with an exact point for accurate torque measurement. This aspect is normally the weakest point of the sensor structure. Hence, the torque sensor is purposely created to be one of the weaker components of the driveline.