Commissioning of a Large-Scale Bevel Gear Test Rig

Abstract

Bevel gear standards regarding manufacturing techniques and dimensioning are fairly traditional. Staying in development progress requires for introducing new technologies. Commercializing new products that are manufactured beyond the standards requires intensive testing that verifies the reliability of used materials and techniques to the customers and classification societies. However, verification process demands for a bevel gear test machine to be built. To realize this scheme, a large-scale, full power bevel gear test rig and its monitoring system were designed by experts of mechanical, hydraulic and automation engineering. The rig design utilizes a principle of circulating power and it has four gear sets, two of which are test gear sets. The monitoring systems includes a variety of parameters such as running speed, torque of main shafts, oil and bearing temperatures, oil flow rates, vibration and oil particle count. The aim of this study was to commission the designed bevel gear test rig and its monitoring system and to demonstrate a complete test procedure for test gears. In theoretical part, basic principles of bevel gears and their failure types were shortly introduced, monitoring methods and related sensors and transducers were reviewed, and the test rig design was presented. In applied part, commissioning of the rig and planned test procedure are described with conclusions. The test rig was assembled and the measurement and monitoring systems were installed to the rig. Functionalities for majority of mechanics and monitoring systems were verified. The wireless torque monitoring system was calibrated, and it was noticed that the readings were close to theoretical values. The gears were loaded with intended fatigue test loadings and loadings can be kept stable with the closed loop control system. Good thermal stability of the rig with reasonable temperatures was achieved with full loading. In final operational tests, test rig was operated successfully in manual control and its noise level was experienced to be moderate. Vibration levels were measured on a range of running speeds. Measurement methods included accelerometers and torque measurement system. Resonances were observed on certain running speeds which should be avoided. At highest designed running speed of 1500 rpm, the vibration levels were faint so the rig assorts well for this running speed. A potential test procedure for fatigue tests was defined with a run-in loading scheme. Operating parameters and alarm limits were also defined. With minor leading actions the automated fatigue tests may really begin.