The development history of torque sensors is roughly as follows: optical-mechanical deformation type, electromagnetic induction type, phase difference type, and strain type. In 1856, Thomson discovered the phenomenon that the resistance of metal wires changes under the action of mechanical strain, which laid the foundation for the development of resistance strain gauges. In 1938, Lucci and Simmons created paper-based resistance strain gauges. Since then, electrical strain gauges have developed rapidly and are widely used in the engineering field, and resistance strain gauges are also a better choice for torque measurement.
?
Strain gauge torque transducers can use the measured physical quantity to produce elastic deformation on the elastic element, so the elastic deformation can be converted into a change in resistance through the strain gauge, so as to measure the torque value. Reliable self-power supply and signal transmission technology in the rotating state are the main issues that still need to be studied for this type of torque sensor.
?
In 1982, researchers such as Sasada of Kyushu University in Fukuoka, Japan, developed a new type of magnetic head torque sensor, which used the plasma method to spray a magnetostrictive layer on the surface of the rotating shaft, which can make the whole test device compact.
?
In 1984, Sasada et al. proposed an improved scheme by using triangular or parallelogram magnetic sheets with specific shapes of magnetic field anisotropy in order to obtain a wide dynamic range and good linearity.
?
In 1986, Sasada et al. studied the use of the magnetostrictive inverse effect of amorphous thin strip to detect torque, the specific way is to paste amorphous thin strip on the surface of a circular axis, and its pasting direction is at an angle of 45 degrees to the circular axis, and finally based on this method, the solenoid torque sensor was successfully developed.
?
In 1992, in order to improve the problem of “angle dependence”, Wang Rong et al. developed a reverse magnetostrictive torque sensor by pasting a special soft magnetic alloy thin strip on the surface of the rotating shaft.
?
In 2011, Wen Xiqin, Li Jiming and others from Huaihai Institute of Technology studied a new type of torque sensor with magnetoelastic effect, which has small air gap disturbance and low hysteresis, and can meet the requirements of electric power steering system.
?
The MR encoder torque transducer developed by Hitachi is a typical representative of the angular torque transducer, which works by installing a rotating shaft between the measured specimens, and an MR encoder is installed at each end of the rotating shaft, and the angle at each end of the rotating shaft can be calculated separately from the two-phase sinusoidal output of each encoder, and then the torque is calculated by the intersection of the two angles. In 2005, the Institute of Remote Testing and Control Technology of Chongqing Institute of Technology developed a screw differential transformer-type torque sensor, when the elastic shaft is subjected to torque, the shaft will produce a certain torque angle, and then output it in the form of induced electromotive force through the internal armature action.
?
In 2010, Huaihai Institute of Technology and Jiangsu Institute of Marine Resources Development jointly developed a magnetoelectric torque sensor with non-contact measurement method. In 2014, Zhao Hao, Ding Lijun and others designed a new type of torque sensor based on the principle of electromagnetic induction.
?
In recent years, some new torque sensors have been developed and developed, including optical fiber torque sensors, wireless surface acoustic wave torque sensors, magnetic sensitive torque sensors, laser Doppler torque sensors, laser diffractive torque sensors, etc. For example, the American Virginia Simmons Aircraft Company has developed a fiber-optic torque sensor based on optical fiber technology in order to test the torque of the turbine engine of the aircraft. Researchers from the Key Laboratory of Optoelectronic Technology and Systems of Chongqing University have proposed a new type of flat plate piezoelectric four-dimensional force/torque sensor, and Dalian University of Technology, together with Changchun Institute of Optics, Fine Mechanics and Physics, has developed a preloaded Stewart structure six-dimensional force/torque sensor with offload measurement function.
?
For any questions such as product consultation, product customization, agency, technical inquiry, quotation, etc., please contact Xingyi Hotline: 400-600-4496!
?
