Experimental study of non-involute free-form gear dynamics under varying operating conditions

Abstract

The non-involute Free-Form-Gear (FFG) has been recently developed to mitigate the involute gear drawbacks. Previous studies have shown that sliding velocity, meshing efficiency, filet, and contact stresses are enhanced in comparison to the standard involute gear pair. However, the dynamic behavior in terms of noise and vibration of the newly developed gear drive has not been evaluated yet. So in this paper, an assessment of the dynamic behavior of the proposed FFG is established. The assessment is conducted by directly measuring the gearbox’s vibration, noise, and oil temperature at various loads and speeds. The tests have been conducted on special case studies in which extreme meshing conditions are present. The behavior of the proposed FFG is then compared to that of standard involute gear under the same operating conditions. The results have shown that the FFG pair may produce higher vibration levels than the involute gear at no load condition by 34%, but the vibration levels can be improved by 6% under load. The modified addendum versions of the FFG drive, on the other hand, can operate with lower vibration levels by 28% and 23% for no load and loading conditions, respectively. In addition, the suggested FFG pair has reduced the gearbox’s oil temperature in comparison to the involute gear pair. It has been concluded that under specific conditions, the FFG can operate with lower vibration and noise levels than the involute gear under the same operating conditions.