scholarly journals Review of cylinder block/valve plate interface in axial piston pumps: Theoretical models, experimental investigations, and optimal design

2021 ◽  
Vol 34 (1) ◽  
pp. 111-134
Author(s):  
Jiang'ao ZHAO ◽  
Yongling FU ◽  
Jiming MA ◽  
Jian FU ◽  
Qun CHAO ◽  
...  
Keyword(s):  
Optimal Design ◽  
Theoretical Models ◽  
Valve Plate ◽  
Cylinder Block ◽  
Experimental Investigations ◽  
Plate Interface ◽  
Axial Piston Pumps ◽  
Axial Piston

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.

Experimental Investigation of the Cylinder Block Movement in an Axial Piston Machine

2015 ◽  
Author(s):  
Stephan Wegner ◽  
Stefan Gels ◽  
Dal Sik Jang ◽  
Hubertus Murrenhoff
Keyword(s):  
Viscous Friction ◽  
Friction Torque ◽  
Operating Conditions ◽  
Valve Plate ◽  
Measuring System ◽  
Cylinder Block ◽  
Experimental Investigations ◽  
German Research Foundation ◽  
Block Movement ◽  
Axial Piston

The greatest share of hydromechanic and volumetric losses in axial piston machines are produced within the tribological interfaces piston / cylinder, cylinder block / valve plate and slipper / swash plate. Hydrostatic and hydrodynamic effects are used to minimise the sum of solid friction, viscous friction and throttle losses. Other tribological interfaces have minor influence on efficiency losses in most operating points in machines of this type. This paper focuses on experimental investigations with the objective to acquire further knowledge on the cylinder block / valve plate contact. The investigations are part of a project funded by the German Research Foundation in which experimental and simulative investigations are combined to identify the effects influencing this tribological interface. The experiments focus on the multi-directional movement of the cylinder block and the friction torque within the contact. Therefore a test rig was built, capable of measuring the cylinder block movement in all degrees of freedom and the friction torque between both parts. A sensor system is built around a standard rotary group of an axial piston pump with a spherical cylinder block / valve plate contact. The pump functionality is maintained and measurements under standard operating conditions up to 30 MPa are possible. Procedures of the design process and descriptions of the measuring system are presented, followed by results of the cylinder block movement measurement, comparing the behavior under different pressure levels and speeds.

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.

Experimental Verification of Slipper Spinning Motion in Axial Piston Pumps

2017 ◽  
Author(s):  
Qun Chao ◽  
Junhui Zhang ◽  
Qiannan Wang ◽  
Bing Xu ◽  
Yuan Chen
Keyword(s):  
Experimental Verification ◽  
Experimental Investigations ◽  
Test Rig ◽  
Plate Interface ◽  
Pump Operation ◽  
Axial Piston Pumps ◽  
Swash Plate ◽  
Lubrication Characteristics ◽  
Spinning Speed ◽  
Axial Piston

As one of the micro motions of slipper in axial piston pumps, the slipper spinning motion has a significant effect on the lubrication characteristics of slipper/swash plate interface. However, no experimental investigations on the slipper spin were available in previous studies. The aim of this work is to design a novel test rig to measure the slipper spinning speed. A detailed description of this test rig will be given followed by a sample result of the slipper spinning motion. Also, a simulation model considering the slipper spin will be developed to investigate the effects of the spinning motion on the slipper performance. It can be concluded that the slipper spinning motion does exist during pump operation, which is helpful to prevent the slipper from further tilting motion.

An Approach to Visualize Lifetime Limiting Factors in the Cylinder Block/Valve Plate Gap in Axial Piston Pumps

2017 ◽  
Author(s):  
Roman Ivantysyn ◽  
Ahmed Shorbagy ◽  
Jürgen Weber
Keyword(s):  
State Of The Art ◽  
Operating Conditions ◽  
Valve Plate ◽  
Limiting Factors ◽  
Cylinder Block ◽  
Axial Piston Pumps ◽  
First Results ◽  
Gap Height ◽  
Axial Piston ◽  
External Loads

The lifetime of axial piston pumps is depending on the application and it’s overall robustness to external loads, but even in ideal conditions pumps will fail eventually. The analytics to this problem are known to pump manufacturers. Bearing and shaft calculations paired with FEM models are invaluable tools, however the main questions remain with the rotating kit – cylinder block, pistons, and slippers. If properly designed these parts should theoretically outlast the finite lifetime parts, such as roller bearings due to their hydrostatic and hydrodynamic bearings. In reality however failures still occur due to fatigue or other factors such as contamination or wear. This paper describes an approach for the thermal analysis of the cylinder block / valve plate sealing interface. Using a state of the art test rig the temperature distribution, instantaneous gap height as well as particle wear have been analyzed across the entire operating range of an axial piston pump at the block / valve plate sealing interface. Simulations are done with cooperation of Purdue University by using their developed gap simulation model called Caspar FSTI. These simulations along with the measurements are used to locate potential lifetime reducing operating conditions and analyze them. The first results of the thermal behavior of this interface will be presented in this paper.

scholarly journals A new dynamic seven-stage model for thickness prediction of the film between valve plate and cylinder block in axial piston pumps

2016 ◽  
Vol 8 (9) ◽  
pp. 168781401667144 ◽  
Author(s):  
Chao Zhang ◽  
Shaokang Huang ◽  
Jun Du ◽  
Xingjian Wang ◽  
Shaoping Wang ◽  
...  
Keyword(s):  
Valve Plate ◽  
Cylinder Block ◽  
Stage Model ◽  
Axial Piston Pumps ◽  
Thickness Prediction ◽  
Axial Piston

A partial lubrication model between valve plate and cylinder block in axial piston pumps

2015 ◽  
Vol 229 (17) ◽  
pp. 3201-3217 ◽  
Author(s):  
Lei Han ◽  
Shaoping Wang ◽  
Chao Zhang
Keyword(s):  
Film Thickness ◽  
Reynolds Equation ◽  
Multiple Scales ◽  
Valve Plate ◽  
Cylinder Block ◽  
Height Distribution ◽  
Axial Piston Pumps ◽  
Surface Profiles ◽  
Axial Piston ◽  
Lubrication Conditions

Axial piston hydraulic pumps are commonly used in aircraft, which makes analysis of their lubrication conditions of significant importance. Oil film between valve plate and cylinder block plays an most important role in pump lubrication. This paper proposes a partial lubrication model of the contact surfaces between valve plate and cylinder block in axial piston pumps for predicting film thickness. The asperity curvature at multiple scales and height distribution are obtained by analyzing actual contact surface profiles, then the separating pressure of asperities is estimated by the Hertz theory and the fluid separating pressure is calculated by Reynolds equation. Experimental results indicate that this model can predict film thickness accurately.

“Transparent Pump”: An Approach to Visualize Lifetime Limiting Factors in Axial Piston Pumps

2016 ◽  
Author(s):  
Roman Ivantysyn ◽  
Jürgen Weber
Keyword(s):  
Pressure Sensors ◽  
Transitional Zone ◽  
Operating Conditions ◽  
Valve Plate ◽  
Limiting Factors ◽  
Cylinder Block ◽  
Axial Piston Pumps ◽  
Critical Areas ◽  
First Results ◽  
Axial Piston

The lifetime of axial piston pumps is depending on the application and it’s overall robustness to external loads, but even in ideal conditions pumps will fail eventually. The analytics to this problem are known to pump manufacturers. Bearing and shaft calculations paired with FEM models are invaluable tools, however the main questions remain with the rotating kit — cylinder block, piston, and slippers. If properly designed these parts should theoretically outlast the finite lifetime parts, such as roller bearings due to their hydrostatic and hydrodynamic bearings. In reality however failures still occur due to fatigue or other factors such as contamination or wear. This paper describes the approach to measure and quantify the physical effects that occur in the lubricating gaps of axial pumps by means of simulation and measurements. Simulations are done with cooperation of Purdue University and the Caspar FSTI tool. These simulations are used to locate potential lifetime affecting areas and analyze them. The analysis includes temperature and pressure distributions in the gap with changing operating conditions and studies of the influence of wear and deformation on the parts that are forming the lubricating gaps. After the most critical areas are located within the simulation environment, gap and temperature sensors are placed right at these critical locations. This is planned at two of the three main lubricating gaps — slipper and swash plate as well as cylinder block and valve plate. In addition pressure sensors are placed within many critical areas of the pump, such as the transitional zone between high pressure and low pressure on the valve plate, as well as in the displacement chamber. The first results for the slipper/swashplate investigation of this approach will be shown in this paper.

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