You may not have heard of torque and speed sensor, but after seeing its name, you should probably know what it does. Speed is related to frequency. Sensors are used to sense something. Together, they measure the speed of something, that is, the frequency of a machine. Bian Xiao also learned about the torque speed sensor. In fact, it measures the speed and power of some power machines such as various engines and compressors under certain conditions. Let's first look at the working principle of the torque and speed sensor.

The torque sensor is mainly composed of a torsion shaft, a magnetic detector, a rotating drum and a shell. The magnetic detector includes two pairs of internal and external gears, permanent magnet steel and induction coil. External gears are installed at both ends of the measuring section of the torsion shaft; The inner gear drum is opposite to the outer gear, and permanent magnet steel is installed in the drum beside the inner gear. Permanent magnet steel and internal and external gears form an annular closed magnetic circuit, and induction coils are fixed in two end covers of the shell. Driven by the driving motor, the internal gear rotates with the drum.

The internal and external gears are both modified gears, which are not meshed. The tooth top six is determined by the working air gap. When the tooth tips of internal and external gears are opposite, the air gap is the narrowest, and when the tooth tips are opposite to the tooth grooves, the air gap is the widest. When the internal and external gears rotate relative to each other, the tooth tops and tooth grooves are alternately paired. When the internal and external gears rotate one tooth position relatively, the working air gap changes periodically, and the reluctance and flux of the magnetic circuit also change periodically. So as to induce a voltage signal which is approximately sine wave in the coil, and the change of the instantaneous value of the signal voltage is consistent with the change of the relative position of the internal and external gears. If the gear projections of the two sets of detectors coincide, the phase difference of the two sets of voltage signals is zero. During installation, the projections of the two internal gears are coincident. The two external gears on the torsion shaft are installed by moving half a tooth. Therefore, the two voltage signals have a phase difference of half a period, that is, the initial phase difference is α 0 = 180. If the gear is 120 teeth, the indexing angle is 3, and the phase difference is180, then the corresponding external gear is staggered 1.5.

When the torsion shaft is subjected to torque, the torsion angle β is generated, and the dislocation angle of the two external gears becomes1.5β.. The phase difference angle of the two voltage signals correspondingly becomes α =120× (1.5β) =180120β. The twist angle is proportional to the torque, so the change of twist angle is proportional to the torque, that is, the change of phase difference angle △α = α-α 0 =120β k =120K 1+0m = km, where k1is the proportional coefficient of phase difference angle and torque, and k =/kloc. Let the measured cross section diameter of the torsion shaft be D, the length be L, and the shear elastic modulus of the torsion shaft material be G, then K 1=32L/πdG.

Two voltage signals of the sensor are input into the TR- 1 torque and speed power measuring instrument, and the voltage signals are amplified, shaped, detected, converted into counting pulses, and then counted and displayed, so that the measurement results of torque and speed can be directly read out. Due to the adoption of magnetoelectric conversion, phase difference principle and digital display torque and speed measurement method, stable, reliable, fast and sensitive high-precision measurement can be carried out.