scholarly journals Investigations of the micro surface shape for the gear-shaft/journal-bearing interface in water hydraulic internal gear pumps

2017 ◽  
Vol 9 (11) ◽  
pp. 168781401774257
Author(s):  
Hua Zhou ◽  
Ruilong Du ◽  
Anhuan Xie ◽  
Huayong Yang
Keyword(s):  
Journal Bearing ◽  
Surface Shape ◽  
Gear Pumps ◽  
Water Hydraulic ◽  
Internal Gear ◽  
Shaft Journal

Numerical analysis of the lubricating gap between the gear shaft and the journal bearing in water hydraulic internal gear pumps

2017 ◽  
Vol 232 (12) ◽  
pp. 2297-2314 ◽  
Author(s):  
Ruilong Du ◽  
Yinglong Chen ◽  
Hua Zhou
Keyword(s):  
Journal Bearing ◽  
Radial Force ◽  
Gear Pump ◽  
Film Pressure ◽  
Proposed Model ◽  
Gear Pumps ◽  
Water Hydraulic ◽  
Film Characteristics ◽  
Internal Gear ◽  
Shaft Journal

Water hydraulics has drawn considerable attention in recent years for its environmental friendliness. This paper presents a numerical model for analysing the lubricating gap between the gear shaft and the journal bearing in water hydraulic internal gear pumps. The model consists of two parts: the gear part that addresses the radial force on the gear shaft and the film part that addresses the film characteristics of the gear shaft/journal bearing interface. The radial force is obtained by summing the fluid pressure around the gear circumference and the meshing force of the gear pair. The film characteristics are analysed by an elastohydrodynamic model that involves the evaluation of the film geometry, the film pressure, and the elastic deformation of the gear shaft/journal bearing interface. The radial force evaluated by the gear part is balanced by the film pressure evaluated by the film part. The gear part is validated by experiments on an oil internal gear pump from the aspect of the outlet pressure ripple, and the film part is validated by comparison with the results from other research groups. The proposed model allows the evaluation of radial micro-motion as well as the eccentric positions of the gear shaft. In addition, the influence of film deformation is further discussed, suggesting that the maximum film deformation should be maintained under 1.3 times the minimum film height. The proposed model can be used as a tool for design optimization of the water-lubricated journal bearing in water hydraulic internal gear pumps.

scholarly journals Design, Manufacture and Performance of Internal Gear Pumps : 1st Report, Non-Involute Type Pumps for Easy Manufacture

1983 ◽  
Vol 26 (217) ◽  
pp. 1253-1260
Author(s):  
Akira ISHIBASHI ◽  
Shigeru HOYASHITA ◽  
Jinichi IZUNO
Keyword(s):  
Gear Pumps ◽  
And Performance ◽  
Internal Gear

Internal gear pumps – your second choice for thin liquids

World Pumps ◽  
2005 ◽  
Vol 2005 (469) ◽  
pp. 32-37
Author(s):  
John H. Hall
Keyword(s):  
Gear Pumps ◽  
Thin Liquids ◽  
Internal Gear

Experimental and numerical study of the influence of loading direction on the lubrication and cooling of self-circulating oil bearing system applied in internal gear pumps

2017 ◽  
Vol 232 (4) ◽  
pp. 415-426 ◽  
Author(s):  
Jintao Mo ◽  
Chaohua Gu ◽  
Xiaohong Pan ◽  
Shuiying Zheng ◽  
Guangyao Ying
Keyword(s):  
Numerical Study ◽  
Model Development ◽  
Variable Loading ◽  
Loading Direction ◽  
Oil Flow ◽  
Gear Pumps ◽  
Heavy Loads ◽  
Internal Gear ◽  
Hole Axis ◽  
Bearing System

For middle-pressure and high pressure gear pumps, the temperature failure problem of bearings is now of considerable concern due to their heavy loads. A self-circulating oil bearing system has been developed for gear pumps in this paper to solve this problem. A test rig has been designed and built to carry out a series of tests for variable loading directions and rotational speeds. An experimental investigation and numerical model development to predict the behaviour of the self-circulating bearing subjected to different loading directions is described. The experimental and numerical results agree well. It was found that the variation of loading directions has a strong effect on the oil flow rates of the system. The maximum oil flow rate can be achieved when the loading direction is along the hole axis direction and a considerable part of the friction heat can be carried away by the oil. The lubrication of the bearing will also be improved.

scholarly journals Degradation detection for internal gear pumps using pressure reduction time maps

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Kurt Pichler ◽  
Rainer Haas ◽  
Veronika Putz ◽  
Christian Kastl
Keyword(s):  
Operating Time ◽  
Close Relation ◽  
Data Driven ◽  
Pressure Reduction ◽  
Reduction Time ◽  
Novel Approach ◽  
Gear Pumps ◽  
Data Driven Approach ◽  
Pump Pressure ◽  
Internal Gear

In this paper, a novel approach for detecting degradation in internal gear pumps is proposed. In a data-driven approach, pressure reduction time maps (PRTMs) are identified as a useful indicator for degradation detection. A PRTM measures the time for reducing the internal pump pressure from certain levels to any lower level when the pump engine is stopped and the valves are closed. The PRTM can thus be interpreted as an internal leakage indicator of the pump. For simplified evaluation, PRTMs are compressed to a single scalar indicator by computing their volume (PRTMV). When the internal leakage increases due to wear, the pressure in the pump decreases faster (implying a decreased PRTMV). The proposed approach has been developed and tested with data of real internal gear pumps with different operating times. The PRTMV shows a close relation to the operating time of the pump. Moreover, we compare PRTMV with the commonly used and well known approach of observing pressure holding speed (PHS). Especially for medium degradation, PRTMV shows better sensitivity then PHS.

Investigation into the lubricating gap between the ring gear and the case in internal gear pumps

2018 ◽  
Vol 70 (3) ◽  
pp. 454-462
Author(s):  
Ruilong Du ◽  
Yinglong Chen ◽  
Hua Zhou
Keyword(s):  
Simulation Model ◽  
Power Loss ◽  
Radial Clearance ◽  
Hydrodynamic Effect ◽  
Optimized Design ◽  
Ring Gear ◽  
Content Type ◽  
Oil Film ◽  
Gear Pumps ◽  
Internal Gear

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.

Design of Rotor for Internal Gear Pump Using Cycloid and Circular-Arc Curves

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
T. H. Choi ◽  
M. S. Kim ◽  
G. S. Lee ◽  
S. Y. Jung ◽  
J. H. Bae ◽  
...  
Keyword(s):  
Flow Rate ◽  
Superior Performance ◽  
Correction Coefficient ◽  
Gear Pump ◽  
Circular Arc ◽  
Limit Value ◽  
Outer Rotor ◽  
Gear Pumps ◽  
Internal Fluid Flow ◽  
Internal Gear

In the case of internal gear pumps, the eccentricity of the outer rotor, which resembles a circular lobe, must be limited to a certain value in order to avoid the formation of cusps and loops; furthermore, the tip width of the inner rotor, which has a hypocycloid curve and an epicycloid curve, should not be allowed to exceed the limit value. In this study, we suggest that the tip width of the inner rotor be controlled by inserting a circular-arc curve between the hypocycloid and epicycloid curves. We also suggest that the outer rotor be designed using the closed-form equation for the inner rotor and the width correction coefficient. Thus, it is possible to design a gerotor for which there is no upper limit on the eccentricity, as in this case, undercut is prevented and there is no restriction on the tip width. We also develop an automated program for rotor design and calculation of the flow rate and flow rate irregularity. We demonstrate the superior performance of the gerotor developed in this study by analyzing the internal fluid flow using a commercial computational fluid dynamics (CFD)-code.

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