Torque testing is a test of mechanical properties. Torque can be divided into two categories, static torque or dynamic torque. The method used to measure torque can be further divided into two categories, anti-torque and on-line torque measurements. The type of torque being measured and the existing types of sensors have an important influence on the accuracy of the measured data and the cost of the measurement.
REACTION We generalize to "static", which means that the sensor's measuring elastomer does not participate in relative motion. From the force of understanding, this type of test is to test the relative reaction of the elastomer. Common is the shaft that is fixed at one end and stressed at the other end.
Dynamic Torque Measurement Elastomers generally participate in relative motion (mainly rotation). Because of the relative motion, the overall design requires high requirements for leads, signal processing, and mechanical connections. A shaft-shaft coupling or a flange-flange elastic connector is generally used.
Different dynamic torque test products for signal and energy transmission are divided into the following types:
A. Current collecting ring
This kind of torque sensor is the most original product. It relies on 4-16 or more sets of sterling silver or platinum collecting rings and carbon brushes to transmit signals. The disadvantage is that it cannot withstand high speed due to friction, that is, using air cooling or Liquid cooling (currently Freon has been banned in Western countries). Friction causes signal noise to increase with use. The advantage of a single current collecting loop is that it is difficult to replace other products. The first is its high response speed/data transmission speed, because there is no signal delay or response problem in the analog mode current collector loop. Some high dynamic tests only Can rely on the collector ring.
The principle of this torque sensor is very simple, relying on two toroidal transformer coil sets to achieve the transmission of excitation energy and the transmission of test signals. However, the implementation is not very simple, the manufacturing process is very demanding, and the gap of the toroidal transformer and the matching requirements are very high. Directly causing such sensors is very afraid of vibration, if the collision friction between the two sets of coils will directly damage the sensor. However, the advantage of this method is that the presence of friction can be achieved at a high speed and the response speed is acceptable. The disadvantage is that only one channel can be coupled at present, and the layout multi-channel sensor has no space to place the coil.
At present, two types of products are derived, one is a circular brass antenna RF represented by HBM, which relies on RF signals to transmit signals and energy to a rotating elastomer, and the other is a digital method of LEBOW in the United States, which digitizes test signals. With RF output, a curved antenna is used. These two types are currently the mainstream products of dynamometers and various large torque tests. The digital approach is more flexible and can compress data to increase data transfer rates and can be multi-channel parallel. The disadvantage is that there are still many limitations on the high frequency digital method. Dynamic torque sensor
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