Calculation of the actuator system in swash plate axial piston machines by a coupled multibody and TEHL simulation

2021 ◽  
pp. 135065012110340
Author(s):  
Markus Kroneis ◽  
René Scheerer ◽  
Lars Bobach ◽  
Dirk Bartel
Keyword(s):  
Three Dimensional ◽  
Euler Method ◽  
Simplified Model ◽  
Multibody Simulation ◽  
Piston Cylinder ◽  
Swash Plate ◽  
Simulation Based ◽  
Actuator System ◽  
Axial Piston ◽  
Tribological Contact

This paper presents a method for coupling a multibody simulation for the actuator system in axial piston machines in combination with a transient, three-dimensional, thermal elastohydrodynamic contact calculation. For the tribological investigation, the oscillating piston/cylinder contact is focused, whereby a simplified model of the actuator system simulates the loads. The developed method allows the integration of a complex tribological contact simulation under mixed friction conditions into a dynamic multibody simulation based on the Newton–Euler method. It is discussed how the accuracy of the results and the calculation time can be improved by the procedure.

Validation of a coupled multibody and TEHL simulation by a piston/cylinder component test rig

2022 ◽  
pp. 135065012110732
Author(s):  
Markus Kroneis ◽  
René Scheerer ◽  
Lars Bobach ◽  
Dirk Bartel
Keyword(s):  
Three Dimensional ◽  
Original System ◽  
Test Rig ◽  
Control Chamber ◽  
Piston Cylinder ◽  
Component Test ◽  
Simulation Based ◽  
Measurement Results ◽  
New Type ◽  
Actuator System

A tribological highly stressed contact in the actuating system of axial piston machines is located between the control piston and the control chamber. This paper presents a new type of component test rig for measuring the frictional force and the gap heights between piston and cylinder. For this purpose, the original system is reduced to the actuator system, whereby the real kinematics and the loading forces are maintained. The axial movement of the control piston and the pressure in the control chamber can be configured individually. The measurement results of different parameter variations are compared with the results of the simulation. The simulation based on a coupled multibody and TEHL simulation with a transient, three-dimensional, thermal elastohydrodynamic contact calculation.

A Path Toward Effective Piston/Cylinder Interface Scaling Approach

2017 ◽  
Author(s):  
L. Shang ◽  
M. Ivantysynova
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Design Parameters ◽  
Simulation Tool ◽  
Scaling Method ◽  
Plate Interface ◽  
Piston Cylinder ◽  
Swash Plate ◽  
Solid Part

Scaling three main lubricating interfaces (piston/cylinder interface, cylinder block/valve plate interface, and slipper/swash plate interface) of swash plate type axial piston machine while remaining the pump performance is a rewarding but challenging task. Instead of designing a new unit for the desired displacement, scaling a well-designed existing unit to the desired size requires much less computational and experimental cost. However, scaling all the components linearly is far from enough to remain the original sized unit’s performance due to the unscalable fluid properties and material properties. This paper proposes a novel scaling method for the piston/cylinder interface which is able to achieve the baseline performance at some of the operating conditions, and closing the gap between the scaled unit performance and the baseline performance at the rest of the operating conditions. The authors use a special in-house developed simulation tool to study the design parameters of the piston/cylinder interface impacts on the performance in terms of leakage flow rate, and the energy dissipation. This in-house developed tool is able to model the lubricating fluid film behavior considering the complex fluid and structure interaction, the macro and micro motion of the piston, the three-dimensional fluid heat-transfer, the three-dimensional solid part heat-transfer, and the solid part deformation due to both the pressure and the thermal load. This paper includes a brief introduction of the simulation tool, the results of the design parameters investigation, the proposed scaling method, and the simulation results comparison between the baseline unit and the scaled unit using the proposed method.

scholarly journals A New Approach for Modeling Mixed Lubricated Piston-Cylinder Pairs of Variable Lengths in Swash-Plate Axial Piston Pumps

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5836
Author(s):  
Bo Zhao ◽  
Xinqing Hu ◽  
Haifeng Li ◽  
Yonghui Liu ◽  
Baocheng Zhang ◽  
...  
Keyword(s):  
Multibody Dynamics ◽  
Tilt Angle ◽  
Piston Pump ◽  
Dynamics Model ◽  
Axial Piston Pumps ◽  
Piston Cylinder ◽  
Cylinder Length ◽  
Swash Plate ◽  
Axial Piston ◽  
Multibody Dynamics Model

The swash-plate axial piston pump is one of the most widely used pumps due to its simplicity and compactness in structure. In such a pump, the piston-cylinder system plays a crucial role, with its lubrication characteristics greatly affecting the overall pumping performance. A new numerical approach is proposed in this study for modeling mixed lubricated piston-cylinder interfaces of variable lengths in swash-plate axial piston pumps in the framework of multibody dynamics. The approach couples the hydrodynamic mixed lubrication model of the piston-cylinder interface with the multibody dynamics model of the piston pump. The lubrication model is established with a transient average Reynolds equation considering asperity contacts and is solved with the finite element method to derive the hydrodynamic forces of the lubricated pair, while the multibody dynamics model is established with Lagrangian formalism by considering hydrodynamic forces as external forces. Results for piston-cylinder interfaces of variable lengths in swash-plate axial piston pumps are presented, and the impacts of cylinder length and the tilt angle of the swash plate on the tribological performances of the interface are discussed. The results indicate that increasing the cylinder length can improve the stability and wear resistance of the piston, but it can exacerbate the frictional power loss. Moreover, although enlarging the tilt angle of the swash plate can effectively increase pump displacement, it can easily lead to serious friction, wear, and leakage problems. Consequently, the tilt angle of the swash plate should be carefully selected in practical applications.

scholarly journals Virtual Prototyping of Axial Piston Machines: Numerical Method and Experimental Validation

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1674 ◽  
Author(s):  
Rene Chacon ◽  
Monika Ivantysynova
Keyword(s):  
Numerical Models ◽  
Optimization Procedure ◽  
Cylinder Block ◽  
Plate Interface ◽  
Piston Cylinder ◽  
Swash Plate ◽  
Physical Prototype ◽  
First Time ◽  
Axial Piston ◽  
Plate Type

This article presents a novel methodology to design swash plate type axial piston machines based on computationally based approach. The methodology focuses on the design of the main lubricating interfaces present in a swash plate type unit: the cylinder block/valve plate, the piston/cylinder, and the slipper/swash plate interface. These interfaces determine the behavior of the machine in term of energy efficiency and durability. The proposed method couples for the first time the numerical models developed at the authors’ research center for each separated tribological interface in a single optimization framework. The paper details the optimization procedure, the geometry, and material considered for each part. A physical prototype was also built and tested from the optimal results found from the numerical model. Tests were performed at the authors’ lab, confirming the validity of the proposed method.

Kinematic Structure of Mechanisms for Fixed and Variable-Stroke Axial-Piston Reciprocating Machines

1984 ◽  
Vol 106 (3) ◽  
pp. 355-364 ◽  
Author(s):  
F. Freudenstein ◽  
E. R. Maki
Keyword(s):  
Three Dimensional ◽  
Structure And Function ◽  
Degree Of Freedom ◽  
Kinematic Structure ◽  
Reciprocating Motion ◽  
Double Frequency ◽  
Swash Plate ◽  
And Function ◽  
Axial Piston

The creation of mechanisms according to the separation of kinematic structure and function has been carried out for a class of three-dimensional mechanisms suitable for conversion between rotary and reciprocating motion in axial engines, pumps and compressors. The structural and kinematic classification of such mechanisms has been established and a suitable search specification formulated with its aid. The resulting search has yielded fifty linkage configurations which have been determined to be possible candidates for such motions. These have four links, one degree-of-freedom and incorporate rotary, sliding, cylindrical, ball, and plane joints. Eleven of these linkages show sufficient promise to be considered for additional evaluation. Several of the linkages have a double-frequency motion of the floating link which would be suitable for a swash-plate drive. These linkages appear to be particularly promising because the double-frequency motion would reduce the stroke and swash-plate speed by one-half compared to a conventional swash-plate drive of the same displacement.

Energy-saving design of variable-displacement bi-directional pump-controlled electrohydraulic system

2020 ◽  
pp. 095965182097389
Author(s):  
Samir Kumar Hati ◽  
Nimai Pada Mandal ◽  
Dipankar Sanyal
Keyword(s):  
Energy Saving ◽  
Absolute Error ◽  
Fast Response ◽  
Maximum Energy ◽  
Radial Clearance ◽  
Simulation Based Design ◽  
Simulation Based ◽  
Displacement Pump ◽  
Variable Displacement ◽  
Axial Piston

Losses in control valves drag down the average overall efficiency of electrohydraulic systems to only about 22% from nearly 75% for standard pump-motor sets. For achieving higher energy efficiency in slower systems, direct pump control replacing fast-response valve control is being put in place through variable-speed motors. Despite the promise of a quicker response, displacement control of pumps has seen slower progress for exhibiting undesired oscillation with respect to the demand in some situations. Hence, a mechatronic simulation-based design is taken up here for a variable-displacement pump–controlled system directly feeding a double-acting single-rod cylinder. The most significant innovation centers on designing an axial-piston pump with an electrohydraulic compensator for bi-directional swashing. An accumulator is conceived to handle the flow difference in the two sides across the load piston. A solenoid-driven sequence valve with P control is proposed for charging the accumulator along with setting its initial gas pressure by a feedforward design. Simple proportional–integral–derivative control of the compensator valve is considered in this exploratory study. Appropriate setting of the gains and critical sizing of the compensator has been obtained through a detailed parametric study aiming low integral absolute error. A notable finding of the simulation is the achievement of the concurrent minimum integral absolute error of 3.8 mm s and the maximum energy saving of 516 kJ with respect to a fixed-displacement pump. This is predicted for the combination of the circumferential port width of 2 mm for the compensator valve and the radial clearance of 40 µm between each compensator cylinder and the paired piston.

scholarly journals Effect of buried depth on thermal performance of a vertical U-tube underground heat exchanger

Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 327-330
Author(s):  
Li Yang ◽  
Bo Zhang ◽  
Jiří Jaromír Klemeš ◽  
Jie Liu ◽  
Meiyu Song ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Simplified Model ◽  
Two Dimensional ◽  
Construction Sites ◽  
Full Size ◽  
Unit Depth ◽  
Research Show

Abstract Many researchers numerically investigated U-tube underground heat exchanger using a two-dimensional simplified pipe. However, a simplified model results in large errors compared to the data from construction sites. This research is carried out using a three-dimensional full-size model. A model validation is conducted by comparing with experimental data in summer. This article investigates the effects of fluid velocity and buried depth on the heat exchange rate in a vertical U-tube underground heat exchanger based on fluid–structure coupled simulations. Compared with the results at a flow rate of 0.4 m/s, the results of this research show that the heat transfer per buried depth at 1.0 m/s increases by 123.34%. With the increase of the buried depth from 80 to 140 m, the heat transfer per unit depth decreases by 9.72%.

Forklift Hydraulic System Simulation Based on ADAMS

2012 ◽  
Vol 424-425 ◽  
pp. 598-602 ◽  
Author(s):  
You Min Wang ◽  
Chun Zhao ◽  
Jian Hua Zhang
Keyword(s):  
Hydraulic System ◽  
Production Cost ◽  
Control Function ◽  
Three Dimensional ◽  
Improve Design ◽  
Kinematics Simulation ◽  
Simulation Based ◽  
Motion Speed ◽  
Work Size ◽  
Control Functional

In order to improve design performance, shorten development cycles, reduce production cost, we design and research the forklift hydraulic system, developed forklift hydraulic system diagram. Forklift virtual prototype’s 3-D solid modeling is designed by Pro / E three-dimensional software, and imported into the ADAMS environment. Add constraints and drivers exert the control function separately to the tilting cylinder and lifting cylinder, carry on the kinematics simulation. Through the analysis to the compound motion actuation control functional arrangement、the compound motion speed graph、the gate’s tilt angle graph、the tilting cylinder stress graph and the lifting cylinder stress graph, he simulation result indicated: each cylinder design is reasonable, the movement without interference，the reasonable work scope satisfied to the work size request

Sign in / Sign up

Export Citation Format

Share Document