Investigation into the lubricating gap between the ring gear and the case in internal gear pumps
Abstract
Purpose
The purpose of this paper is to propose a simulation model for studying the lubricating gap between the ring gear and the case in internal gear pumps.
Design/methodology/approach
The pressure distribution of the wedge-shaped oil film between the ring gear and the case is obtained based on the theory of film lubrication using the Reynolds equation implemented with MATLAB. After that, the balance of the ring gear is achieved by the radial micro motion of the ring gear. The power loss due to the leakage and the shear stress is then calculated for optimized design of the radial clearance.
Findings
The hydrodynamic effect and the squeezing effect of the wedge-shaped oil film play a role in the hydrodynamic balance of the ring gear, and they become more intense when the operating speed gets lower and the pressure gets higher. The optimal radial clearance should stay between 20 and 25 µm for the minimum power loss.
Originality/value
The present research provides the first simulation model that treats the oil film between the ring gear and the case as wedge-shaped oil film and explains why the ring gear stays balanced. Furthermore, the simulation model can be regarded as a tool for optimized design of the radial clearance.
Keywords
Citation
Du, R., Chen, Y. and Zhou, H. (2018), "Investigation into the lubricating gap between the ring gear and the case in internal gear pumps", Industrial Lubrication and Tribology, Vol. 70 No. 3, pp. 454-462. https://doi.org/10.1108/ILT-07-2016-0158
Publisher
:Emerald Publishing Limited
Copyright © 2018, Emerald Publishing Limited