Experimental Study of Micro Vibration of the Ring Gear in Internal Gear Motor and Pump Under Unstable Working Condition

Abstract

Analysis of micro movement of the ring gear is important for the understanding of dynamic behavior of the internal gear motor and pump. This paper presents the experimental results of micro movement of the ring gear under different working conditions by using the micro displacement sensors. An interesting phenomenon of ring gear is that the backward whirl phenomenon in case of instability has been occurred and observed. Experimental results pointed out that if the internal gear motor and pump operate under stable conditions, the ring gear center has small vibration and it whirls in forwards sense. However, when the internal gear motor and pump runs at unstable working conditions then the vibration amplitude of ring gear reaches much large value and it turns into spinning in backward sense. Due to backward whirl phenomenon, the solid contact between the outer ring gear and inner housing can occur. This is an unwanted phenomenon for internal gear motor and pump during operation.