Rotary torque sensors can measure the torque generated by rotating objects during operation. It provides key data for system control, fault diagnosis and performance optimization.
When you understand the definition, working principle and classification of rotary torque sensors. It will help us better use them to improve the performance and safety of equipment.
What is a Rotary Torque Sensor?
Rotary torque sensor, also known as rotary torque transducer. It is a sensor used to measure the torque generated by rotating objects during operation. These sensors enable us to accurately control the performance of rotating mechanical equipment. It converts mechanical quantities into electrical signals.
Rotary torque sensors can be divided into different types. Different types of rotary torque sensors have different characteristics.
Features:
1. Strain-type rotary torque sensor:
Features: high precision and high reliability.
Application: demanding industrial environment.
2. Magnetoelectric rotary torque sensor:
Features: non-contact measurement, high output voltage.
Application: high-speed rotation and harsh environment.
3. Photoelectric Rotational Torque Sensor:
Features: fast response speed, strong anti-electromagnetic interference ability.
Application: high-speed rotation and harsh environment.
4. Non-contact Rotational Torque Sensor:
Features: high safety and convenience.
Application: occasions where mechanical wear needs to be avoided.
How do You Measure Rotational Torque?
The measurement principle of rotational torque is based on the definition of torque. Torque equals force multiplied by the lever arm. In the measurement of rotating shaft torque. The point of force is usually on the shaft, so the lever arm is the shaft radius.
It can be achieved by measuring the product of the force acting on the shaft and the lever arm.
Methods for measuring rotating shaft torque
1. Direct measurement method
The direct measurement method is a method of directly measuring torque by using a sensor. Commonly used sensors are strain sensors, capacitive sensors and electromagnetic sensors. Strain sensors are one of the main methods for measuring rotating shaft torque. They transmit force to the elastic body, form strain on the elastic body. And then convert it into an electrical signal for measurement.
Capacitive sensors measure torque by measuring the change in capacitance generated on the rotating shaft. Electromagnetic sensors use the principle of electromagnetic induction. It measures torque by measuring the torque that causes the induced current.
2. Indirect measurement method
It is a method of inferring torque by measuring the influence of the torque of the rotating shaft on other parameters. Commonly used methods are the speed method and the power method. The speed method infers torque by measuring the change in the speed of the rotating shaft. Calculates torque by the slope of the torque-speed curve. The power method calculates torque by measuring the difference between input power and output power.
3. Numerical simulation method
It is a method of predicting the torque of the rotating shaft through computer simulation. It requires the establishment of a numerical model based on the structure and load conditions of the rotating shaft. The calculation of the torque distribution by finite element analysis. It can predict the torque change of the rotating shaft under different working conditions. It is used for optimization design and fault diagnosis.
What is the Difference Between Rotary Torque Sensors and Reaction Torque Sensors?
Reaction torque sensors and rotation torque sensors are two completely different devices. Many people still can’t tell the difference between them. The following is a relevant introduction.
1. Reaction Torque Sensor
The reaction torque is the rotational force or torque. It is applied by the rotating part to the stationary part of the equipment. When the rotating part transmits or absorbs power. If the load source remains rigid while the drive source attempts to rotate. Torque is detected. Reaction torque sensors are limited. Because the housing is fixed to the sensor element. They cannot rotate 360 degrees without tangling the cable.
These sensors are often used to measure torque for back-and-forth stirring motions. Since these sensors do not use bearings, slip rings, or any other rotating elements. They are very cost-effective to install and use.
2. Rotary Torque Sensors
Rotary torque sensors are similar to reaction torque sensors in design and application. Except that the torque sensor is mounted in a straight line on the device being measured.
Since the shaft of the torque sensor rotates 360 degrees. These sensors must be able to transmit the signal from the rotating element to the stationary surface. You can achieve this by using slip rings, rotary transformers, or telemetry.
How does a Rotary Torque Sensor Work?
Different rotary torque sensors have different working principles. Here is an introduction to some of the principles.
Strain gauge torque sensor:
The strain gauge torque sensor is the most widely used one at present. Its working principle is based on the resistance change of metal strain gauges. When the object being measured is twisted. The strain gauge deforms and the resistance value changes. Converted into an electrical signal output through the Wheatstone bridge circuit.
Application scenarios: laboratory testing, motor performance testing, automotive transmission system monitoring, etc.
Magnetoelectric torque sensor:
Based on the principle of electromagnetic induction. Magnetoelastic torque sensor uses the change in magnetic permeability of ferromagnetic materials. When the shaft is subjected to torque. Its surface magnetic properties change. The torque value is calculated by detecting the change in the magnetic field.
Application scenarios: industrial automation, energy field, aerospace.
Photoelectric torque sensor:
A photoelectric torque sensor measures the torsion angle of the shaft through an optical encoder or laser interferometer. Using the photoelectric effect or fiber optic sensing technology. It measures the transmission or reflection characteristics of light on the rotating parts.
Application scenarios: precision instrument calibration, micro motor testing, aerospace equipment.
Wireless torque sensor
With the development of the Internet of Things (IoT) technology. Wireless torque sensors have gradually become popular. It uses wireless transmission technology (such as Bluetooth, ZigBee or LoRa) . It is suitable for rotating parts or occasions where wiring is difficult.
Application scenarios: wind turbine main shaft monitoring. automotive test bench. and smart factory equipment.
Rotary Torque Sensor Applications
Rotary torque sensor plays a very important role in instrument measurement. It is mainly used in the following aspects.
Aerospace field:
It is used to measure the torque of the engine drive shaft. Help engineers evaluate the performance and efficiency of the engine.
In the flight control system of the aircraft. it measures the driving torque of the control surface. Accurately control the attitude and flight direction of the aircraft.
Automobile manufacturing field:
It plays an important role in the detection of the processing process of automobile engines, diesel engines, steering gears and other components. It can also be used for transient torque testing of automobile engines. Provide a key basis for the optimization and control of the engine.
Industrial automation production line:
In the manufacturing production line of high-end electronic equipment. Real-time monitoring of torque fluctuations during the operation of the equipment. Ensure product quality and production efficiency.
Energy field:
In wind turbines and hydropower generators, it is used to monitor torque changes in real time. So as to evaluate and control the operating status of the equipment.
Medical device field:
In the joints of the robotic arm of the surgical robot, it can accurately sense the operating force. Enable doctors to accurately control the movement of the robotic arm during remote operation.
At the same time, in some rehabilitation training equipment. It is used to measure the user’s limb movement torque. To achieve personalized rehabilitation training.
Transportation field:
In the traction system of the train and the propulsion system of the ship. It is used to measure the torque of the drive shaft. Monitoring the traction power of the train and the power output of the ship. It helps to improve transportation efficiency and safety.
Metrology and detection field:
Used to establish torque measurement standards. Provide accurate standard torque values for the calibration. Verification of other torque measurement equipment.
Material mechanical properties test:
Measure the torque and torsion angle of the material in the torsion test. Obtain the mechanical properties parameters of the material.
How to Select the Right Rotary Torque Sensor?
When selecting a dynamic torque sensor, the following factors need to be considered:
- Measurement range: Select the appropriate measurement range according to the actual application requirements.
- Accuracy level: Select the appropriate accuracy level according to the measurement accuracy requirements.
- Response speed: Select the appropriate response speed according to the dynamic measurement requirements.
- Installation method: Select the appropriate installation method according to the installation space and conditions.
- Environmental adaptability: Select the appropriate protection level and material according to the use environment. such as temperature, dirt and electromagnetic interference.
- Dynamic considerations: Select products based on rotational effects, critical speeds, and external loads.
- Physical requirements: Select products based on the size and installation restrictions of the torque sensor.
- Signal output: Common 10±5kHz (amplitude 5V), 0-5V, 0-10V, 4-20MA, RS485, RS232, CAN, etc.
- Budget and cost: Choose the right product based on your budget.
Rotary Torque Sensors Calibration
The calibration of rotary torque sensors is not just a simple calibration. The influence of environmental factors must also be considered. Such as temperature and humidity
The calibration methods are mainly divided into static calibration and dynamic calibration.
Static Calibration:
It measures the output value of the sensor by applying a known torque without rotating the sensor. Compare it with the theoretical value. Adjust the zero point, sensitivity, linearity and other parameters of the sensor.
Dynamic Calibration；
It is to calibrate the dynamic response characteristics of the sensor. by simulating actual working conditions under the actual working state of the sensor.
What is the Function of a Torque Sensor?
- Measure torque
- Monitor equipment status
- Adjust parameters
- Improve production efficiency
- Market research and development
Rotary Torque Sensor Price
The price is affected by many factors. such as application field, technology type, and brand awareness. The price ranges from a few hundred to tens of thousands of yuan.
Sino-Inst is a professional supplier of rotary torque sensors. Our rotary torque sensors are very cost-effective. Please contact us for a quote.
This article introduces the relevant knowledge of rotary torque sensors. The measurement of torque is a very complex issue. Inaccurate torque measurement can cause great problems.
Sino-Inst’s rotary torque sensors support customization. If you have trouble measuring torque. Please consult us immediately. Sino-Inst will provide you with professional answers.
