Analysis of continuous-contact helical gear pumps through numerical modeling and experimental validation. (1st September 2018)

• Record Type: Journal Article
• Authors: Zhao, Xinran; Vacca, Andrea
• Is Part Of: Mechanical systems and signal processing. Volume 109(2018)
• Page Start: 352
• Page End: 378
• Publication Date: 2018-09-01
• Subjects: External gear pumps -- Helical gear pumps -- Continuous-contact gear pumps -- Kinematic flow ripple -- Pump modeling -- Pump noise -- Experimental validation; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2018.02.043
• Languages: English
• ISSNs: 0888-3270

Abstract

Highlights: Description of the gear profile requirement for continuous-contact helical gear pumps (CCHGP). The derivation of the kinematic flowrate for CCHGP is derived. A proof for CCHGP cancellation of kinematic flow ripple is provided. A fluid dynamic simulation model for CCHGP is presented and validated against experiments. The simulation results provide a justification for pressure ripple generation in CCHGP. Abstract: External gear pumps are one of the most commonly used types of positive displacement machines in high pressure hydraulic control systems, fuel-injection and fuel transport systems. Despite many merits of the traditional external gear pump design with involute teeth, the significant flow non-uniformity intrinsic of such design is considered to be a detrimental aspect, since it causes undesired noise emissions and mechanical vibrations. A disruptive concept of continuous-contact helical gear pumps (CCHGP) was proposed and successfully commercialized in the recent past. Such concept was proven to have clear advantages in terms of noise emissions. However, a clear interpretation of the displacing action and the transient features of the delivery flow was never addressed in past literature. This paper addresses this gap by first discussing the family of gear profiles suitable for implementing the CCHGP design. Subsequently, an analysis on the kinematic flow ripple is given, showing how such design concept can reduce or even eliminate the kinematic flow pulsations. The paper also presents a numerical approach for modelling the operation of CCHGPs, starting from the modeling of the geometric features necessary for a fluid dynamic analysis based on a lumped parameter approach. For model validation purposes, a commercial CCHGP was tested at the authors' research center, and the simulation results were compared against the experiments, to show the level of accuracy of the model, as well as it potentials for future design studies.