회전기계용 비접촉식 토크 측정법 성능 평가

Evaluations on Performances of a Non-Contact Torque Measurement Technique for Rotatory Machinery

Abstract

Gas compressors are mostly driven by motors. It is important to measure the power of motors to evaluate their power efficiency, because the mechanical loads of gas compressors are always varied. In order to measure the power given to the driving motors, the torque should be measured. Manufacturers of compressors usually use the torque data to calculate the compressors qualities such as power consumption, efficiencies and failures. In general, measurements for the shaft torque of the compressors have been based upon contact types, strain gauges. In the cases of larger compressors, the contact type of strain gauges have several disadvantages such as large size and high cost. In this study, a relatively inexpensive and simple torque sensing technique that is not restricted to shaft diameter is introduced using visualization technique. Particle image velocimetry (PIV) has been adopted to complete non-contact torques measurements for rotating motors. In order to compare the performance of the newly constructed torque measurement technique, torque measurement by a transducer based on MEMS technology has been performed simultaneously during experiments.

Fig. 1. Torsional angle diagram

Fig. 2. Relation of ring radius

Fig. 3. Measurement system schematic

Fig. 4. Photo of the measurement system

Fig. 5. Random pattern (left camera image, right camera image)

Fig. 7. Power comparison for load 1

Fig. 8. Power comparison for load 2

Fig. 6. Images taken at each torsional angle

Table 1. Torque measured by torque transducer and by PIV method for load 1

Table 2. Torque measured by torque transducer and by PIV method for load 2