An Investigation of the Impact of Micro Surface on the Cylinder Block/Valve Plate Interface Performance

2014 ◽  
Author(s):  
Rene Chacon ◽  
Monika Ivantysynova
Keyword(s):  
Primary Source ◽  
Valve Plate ◽  
Cylinder Block ◽  
Plate Interface ◽  
Design Elements ◽  
Positive Displacement ◽  
Swash Plate ◽  
Surface Shaping ◽  
Fluid Film Thickness ◽  
The Impact

Lubricating gaps are the primary source of energy dissipation in axial piston machines of swash plate-type. One of these lubricating gaps is designated as the cylinder block/valve plate interface, and is one of the most critical design elements for this type of positive displacement machine. In the past, extensive work has been done at Maha Fluid Power Research Center both to model this interface and to study the effects of micro-surface shaping on the valve plate. This paper presents a more in-depth investigation into optimizing valve plate micro-surface shaping (both by altering the number and amplitude of waves) in order to achieve a fluid film thickness that compromises between leakage and torque loss, minimizes power loss in the cylinder block/valve plate interface, and maximizes machine efficiency.

Advanced Virtual Prototyping of Axial Piston Machines

2016 ◽  
Author(s):  
Rene Chacon ◽  
Monika Ivantysynova
Keyword(s):  
Numerical Models ◽  
Virtual Prototyping ◽  
Valve Plate ◽  
Cylinder Block ◽  
Plate Interface ◽  
Design And Optimization ◽  
Swash Plate ◽  
Axial Piston Machine ◽  
Axial Piston ◽  
Plate Type

This paper explains how a combination of advanced multidomain numerical models can be employed to design an axial piston machine of swash plate type within a virtual prototyping environment. Examples for the design and optimization of the cylinder block/valve plate interface are presented.

scholarly journals Analysis on micro-motion of cylinder block based on elasto-hydrodynamic lubrication

2019 ◽  
Vol 72 (5) ◽  
pp. 645-650 ◽  
Author(s):  
Jihai Jiang ◽  
Wei-Peng Yan ◽  
Ge-Qiang Li
Keyword(s):  
Numerical Model ◽  
Hydrodynamic Lubrication ◽  
Valve Plate ◽  
Cylinder Block ◽  
Asperity Contact ◽  
Plate Interface ◽  
Content Type ◽  
Micro Motion ◽  
Belt Width ◽  
Discharge Pressure

Purpose The purpose of this paper is to analyze the micro-motion of the cylinder block. Design/methodology/approach Based on the elasto-hydrodynamic lubrication, a numerical model for the cylinder block/valve plate interface is proposed, with consideration of the elastic deformations, the pressure-viscosity effect and asperity contacts. The influence-function method is applied to calculating the actual deformations of the cylinder block and the valve plate. The asperity contact model simplified from Greenwood assumption is introduced into the numerical model. Furthermore, the relationship between the micro-motion and the operating condition, the sealing belt width is discussed, respectively. Findings The results show an increase in the discharge pressure causes the tilt state and the vibrating motion getting worse, which can be eased by improving the rotational speed, the sealing belt width and the ratio of external and internal sealing belt width. Originality/value The proposed research can provide a theoretical reference for the optimizing design of cylinder block/valve plate pair.

scholarly journals Tribological Properties of Cylinder Block/Valve Plate Interface of Axial Piston Pump on the Tribometer

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Jiahai Huang ◽  
Zhenhua Dou ◽  
Zhenglei Wang ◽  
Long Quan ◽  
Linkai Niu
Keyword(s):  
Heat Treatment ◽  
Contact Pressure ◽  
Tribological Properties ◽  
Optimization Design ◽  
Valve Plate ◽  
Piston Pump ◽  
Cylinder Block ◽  
Axial Piston Pump ◽  
Plate Interface ◽  
Axial Piston

AbstractThe tribological properties of cylinder block/valve plate is an important consideration in the design of axial piston pump. The effect of materials and heat treatment on friction and wear properties has been studied in depth. Engineering experiences show that the speed and load also affect the tribological properties, but these have not been systematically analyzed. The purpose of this paper is to evaluate the tribological properties of the commonly used materials (CuPb15Sn5 and 38CrMoAl/42CrMo) for cylinder block/valve plate with different heat treatment and contact pressure at different speed. During the test, tribometer is used to simulate the contact pattern between the valve plate/cylinder block in axial piston pump, the friction coefficient, wear rate and surface topography are analyzed to evaluate the tribological properties of different types of friction samples at different speed. Results indicate that: (1) contact surface of the samples at 1800 r/min is more prone to adhesive wear than those at 500 r/min; (2) in the terms of wear resistance, quench-tempered and nitrided 38CrMoAl (38CrMoAl QTN for short) is better than quench-tempered and nitrided 42CrMo, although they are all commonly used materials in the axial piston pump; (3) 2.5 MPa is the critical contact pressure of the interface between valve plate made of 38CrMoAl QTN and cylinder block made of CuPb15Sn5 on the tribometer, which implies the pressure bearing area at the bottom of the cylinder block should be carefully designed; (4) the valve plate/cylinder block made of 38CrMoAl QTN/CuPb15Sn5 exhibits good tribological properties in a real axial piston pump. This research is useful for the failure analysis and structural optimization design of the valve plates/cylinder block.

Surface Deformations Enable High Pressure Operation of Axial Piston Pumps

2011 ◽  
Author(s):  
Matteo Pelosi ◽  
Monika Ivantysynova
Keyword(s):  
Film Thickness ◽  
Material Properties ◽  
Fluid Film ◽  
Cylinder Block ◽  
Steel Cylinder ◽  
Elastic Deformations ◽  
Piston Cylinder ◽  
Fluid Film Thickness ◽  
The Impact ◽  
Axial Piston

In this paper, a fully coupled fluid-structure interaction and thermal numerical model developed by the authors is used to demonstrate the impact of surface elastic deformations on the piston/cylinder fluid film thickness and on the overall axial piston pump rotating kit performance. The piston/cylinder interface is one of the most critical lubricating interfaces of axial piston machines. This interface fulfills simultaneously a bearing and sealing function under oscillating load conditions in a purely hydrodynamic regime. It represents one of the main sources of energy dissipation and it is therefore a key design element, determining axial piston machine efficiency. In the past years, the research group of the authors studied the impact of advanced micro surface design and fluid film thickness micro alteration in the piston/cylinder interface through extensive simulations and experiments. However, the numerical models used did not include the influence of surface elastic deformations, heat transfer and therefore material properties on the piston/cylinder interface behavior. Hence, the aim of this paper is to show the alterations on fluid film thickness and on the consequent coupled physical parameters due to the solid boundaries pressure and thermal surface elastic deformations. A simulation study considering two different material properties for the cylinder bores is performed, where a steel cylinder block and a steel cylinder block with brass bushings are separately studied. Piston/cylinder gap pressure field and coupled gap surface elastic deformations due to pressure and thermal loading are shown for the different materials. The impact of the different materials behavior on lubricating interface performance is discussed.

Simulation of the Tribological Contacts in an Axial Piston Machine

2004 ◽  
Author(s):  
Michael Deeken
Keyword(s):  
Valve Plate ◽  
Cylinder Block ◽  
Simulation Tool ◽  
Test Rig ◽  
Research Project ◽  
Standard Unit ◽  
Swash Plate ◽  
Measurement Results ◽  
Axial Piston Machine ◽  
Axial Piston

A research project at the Institute for Fluid Power Drives and Controls (IFAS) sponsored a simulation tool, which was developed to analyze the tribological contacts in an axial piston machine. This paper describes the comparison between simulation and measurement results. The research project defined several objectives. These included extending the program for the tribological contacts, such as slipper/swash plate and cylinder block/valve plate pairings. Furthermore, the results of the simulations were to be verified by means of measurements conducted on the test rig and these were to be performed on a standard unit, if possible. The values to compare simulation and measurement must first be defined in order to meet these objectives.

Tipping the Cylinder Block of an Axial-Piston Swash-Plate Type Hydrostatic Machine

1997 ◽  
Vol 122 (1) ◽  
pp. 216-221 ◽  
Author(s):  
Noah D. Manring
Keyword(s):  
Control Volume ◽  
Pressure Profile ◽  
Mechanical Analysis ◽  
Design Guidelines ◽  
Design Criterion ◽  
Valve Plate ◽  
Cylinder Block ◽  
Swash Plate ◽  
Axial Piston ◽  
Plate Type

Tipping the cylinder block within an axial-piston swash-plate type hydrostatic machine is a phenomenon that results in a momentary and sometimes permanent failure of the machine since the fluid communication between the cylinder block and the valve plate is instantaneously lost. The efforts of this research are to identify the physical contributors of this phenomenon and to specify certain design guidelines that may be used to prevent the failure of cylinder block tipping. This research begins with the mechanical analysis of the machine and presents a tipping criterion based upon the centroidal location of the force reaction between the cylinder block and the valve plate. This analysis is followed by the derivation of the effective pressurized area within a single piston bore and the cylinder block balance is defined based upon this result. Using standard control volume analysis, the pressure within a single piston bore is examined and it is shown that an approximate pressure profile may be used in place of the more complex representation for this same quantity. Based upon the approximate pressure profile a design criterion is presented which ensures that the pressures within the system never cause the cylinder block to tip. Furthermore, if this criterion is satisfied, it is shown that the worst tipping conditions exist when the system pressures are zero and therefore a criterion governing the design of the cylinder block spring is presented based upon the inertial forces that contribute to the tipping failure. [S0022-0434(00)00901-1]

Sign in / Sign up

Export Citation Format

Share Document