Stability of the Internal Gear Motor and Pump: Single-Valued and Interval Analysis Technique

Abstract

The dynamic behavior of the internal gear motor and pump is significantly influenced by the stiffness and damping characteristics of the oil lubricating film. This study addresses the stability problem of the internal gear motor and pump. The single-valued analysis is firstly used to predict the stability of internal gear motor and pump under the effect of the oil film coefficients. However, the oil lubricating film characteristics change according to operating conditions. Moreover, the internal ring gear and housing parameters are known with a certain tolerance interval owing to the manufacturing inaccuracy and poor assembly process. Consequently, the geometric parameters of the internal gear motor and pump are given as a range of values rather than single.valued quantities. This leads to significantly changes in dynamic behavior as well as stability of the internal gear motor and pump. Therefore, the interval analysis technique must be used to analyze the stability of the internal gear motor and pump. The numerical simulation is performed to prove the applicability and importance of this method. With this approach, it allows designers to evaluate the stability of internal gear motor and pump as well as analyze the effect of geometric and operating parameters on stability status of the internal gear motor and pump at the early design stage. This is the basic to expand the stable operating area for internal gear motor and pump.