Characteristics and Working Principle of Torque Sensors

2024-06-04

The emergence of the torque sensor itself should be used in all walks of life in a short time and become an indispensable variety in the sensor series.

 

1. The characteristics of torque sensor:

1. Can measure both static torque, can also measure rotary torque, can measure both static torque, can also measure dynamic torque.

2. High detection accuracy, good stability; Prevent interference;

3. Small size, light weight, diverse installation structure, easy to install and use. Continuous measurement of positive and negative torques without repeating 0.

4. No conductive ring and other wear parts, can be high-speed long time running.

5. The sensor output high level frequency signal can be directly sent to the computer for processing.

6. Measuring the strength of the elastomer can withstand high overload.

 

2. The torque sensor measurement principle:

The special torsion strain gauge is attached to the measured elastic shaft as a strain glue to form a strain bridge and supply power to the strain bridge. The electrical signal of torsion of the elastic shaft can be measured. After amplifying this deformation signal, it undergoes pressure/frequency conversion and becomes a frequency signal proportional to the torsion reaction. The energy input and signal output of the system are handled by two sets of special annular transformers with a gap, thus providing contactless energy and signal transmission.

 

3. The torque sensor principle structure:

The basic torque sensor-variable bridge is formed by attaching a special torsion measuring sheet to a special elastic shaft. Fixed on the shaft: (1) the secondary coil of the energy ring transformer, (2) the primary coil of the signal ring transformer, (3) the axis printed circuit, and the circuit board including the rectifier stable power supply, the instrument amplifier circuit, the V/F conversion circuit and the signal output circuit.

 

4. Working process of torque sensor:

The sensor is supplied with a 15V power supply, a crystal oscillator on the magnetic circuit generates a 400Hz square wave, and an AC magnetoelectric power supply is generated through the TDA2030 power amplifier. The energy loop transformer T1 is transferred from the stationary primary coil to the rotating secondary coil. Results The AC power supply obtained 5V DC power supply through the rectifier filter circuit on the shaft. The power supply is used as a working power supply for the operational amplifier AD822. A high precision power supply consisting of a reference power supply AD589 and a dual operational discharge AD822 generates a 4.5V DC power supply. The power supply is used as a working power supply for bridging power supplies, amplifiers, and V/F converters.

 

When the elastic shaft is twisted, the MV-class deformation signal detected on the deformation bridge is amplified by the instrument amplifier AD620 to a strong signal of 1.5v 1v, and then converted into a frequency signal by the V/F converter LM131. Through the signal ring transformer T2, it is possible to pass from the rotating primary coil to the stationary secondary coil, and then through the signal processing circuit filter of the sensor housing, shaping, obtaining a frequency signal proportional to the torque received by the elastic bearing, because the rotating transformer is in motion, zero between the static rings. With a gap of only a few millimeters, part of the sensor shaft is sealed inside the metal housing, forming an effective shield, and therefore has a strong anti-interference ability.

 

RELATED NEWS