Power-Saving Solutions for Pre-Compensated Load-Sensing Systems on Mobile Machines

2021 ◽  
Vol 64 (5) ◽  
pp. 1435-1448
Author(s):  
Xin Tian ◽  
Patrick Stump ◽  
Andrea Vacca ◽  
Stefano Fiorati ◽  
Francesco Pintore
Keyword(s):  
Energy Efficiency ◽  
Hydraulic System ◽  
Power Saving ◽  
Control Valve ◽  
Cost Effective ◽  
Fluid Power ◽  
Flow Control Valve ◽  
List Type ◽  
Load Sensing ◽  
Agricultural Tractors

HighlightsTwo methods (VPM and HVM) are proposed to improve the hydraulic system efficiency of agricultural tractors.VPM and HVM both target reducing the power loss at the flow control valve of the hydraulic system.The solutions are presented conceptually and then numerically modeled, and VPM is tested on an actual tractor.Results show that the VPM solution achieves 6.7% power saving, while HVM achieves 15.6% power saving.Abstract. Load sensing (LS) is a dominant fluid power actuation technology in mobile machines, particularly in construction and agriculture. It has the advantage of guaranteeing good controllability in systems with multiple actuators while promoting higher energy efficiency. Several variants of LS systems have been proposed over the years, and research on cost-effective methods to further increase their efficiency is still of interest for original equipment manufacturers (OEMs) and the fluid power community. This article presents two solution, referred to as variable pump margin (VPM) and hybrid variable margin (HVM), suitable to improve the energy efficiency in pre-compensated LS systems such as those used in agricultural tractors. Both methods allow either downsizing the control valves or reducing the power consumption over the working range. Compared to a standard LS system, the VPM solution lowers the pump pressure using an electronic proportional pressure-reducing valve (ep-PRV), while the HVM solution uses a second ep-PRV in the compensator’s pilot line to further minimize the pressure differential across the LS valve. Simulation and experimental results show that, among the main working conditions, the VPM solution on average achieved 6.7% power saving over the standard LS system, while the model predicted an average improvement of 15.6% for the HVM solution. Keywords: Efficiency, Experiments, Hydraulic, Load sensing, Modeling, Pump.

Research Regarding Pressure Compensated Flow Control Valves

2015 ◽  
Vol 809-810 ◽  
pp. 992-997
Author(s):  
Irina Tiţa ◽  
Irina Mardare
Keyword(s):  
Power Systems ◽  
Flow Control ◽  
Hydraulic System ◽  
Block Diagram ◽  
Control Valve ◽  
Operating Conditions ◽  
Flow Control Valve ◽  
Constant Flow ◽  
Working Pressure ◽  
Displacement Pump

In fluid power systems, flow control may be done either with variable displacement pump or using variable orifice. In this paper is considered the second method for flow control. In a hydraulic system, working pressure is frequently variable and therefore the use of the method does not provide constant flow rates in all operating conditions. In order to keep a constant flow, if this is important in a certain case, the flow control must be accomplished using a pressure compensated flow control valve. In this paper are analyzed possible structural diagrams, mathematical model, block diagram and functional diagram for this kind of equipment. The influence of the spring compression is analyzed also. The diagrams proposed in the paper will be used for the study of a hydraulic system designated for applications with strict flow control. It will represent an important research instrument for such cases.

Dynamic Characteristics of an Oil Hydraulic Constant Speed Drive

1968 ◽  
Vol 183 (1) ◽  
pp. 683-694 ◽  
Author(s):  
A. J. Healey ◽  
J. D. Stringer
Keyword(s):  
Dynamic Response ◽  
Machine Tool ◽  
Special Reference ◽  
Dynamic Characteristics ◽  
Hydraulic System ◽  
Control Valve ◽  
Analogue Computer ◽  
Flow Control Valve ◽  
Stick Slip ◽  
Speed Regulation

Experimental and analytical studies are made of an oil hydraulic system which uses a pressure compensated flow control valve for speed regulation. The study concerns dynamic response with special reference to the effects on the system of the sudden application of a retarding force to the mass it is moving. Equations of a typical ‘meter-out’ type of system are first developed and solved. The consequent predictions are then compared with experimental results from an apparatus which simulated a machine tool application. The advantages of incorporating a restrictor in the inlet (supply) line are then examined both experimentally and analytically using an analogue computer. The results show that the mathematical models give satisfactory predictions of the maximum changes of velocity and pressure occurring during the transients. The restrictor reduced the magnitudes of these transient changes and also eliminated ‘stick-slip’ oscillations at low speed. It is concluded that the methods of analysis outlined in this paper could be used to advantage in the design of practical systems.

Dynamic analysis of a hydro-motor drive system using priority valve

2018 ◽  
Vol 233 (3) ◽  
pp. 508-525 ◽  
Author(s):  
Sujit Kumar ◽  
K Dasgupta ◽  
SK Ghoshal ◽  
J Das
Keyword(s):  
Hydraulic System ◽  
System Modeling ◽  
Dynamic Performance ◽  
Control Valve ◽  
Drive System ◽  
Motor Drive ◽  
Flow Control Valve ◽  
Mining Equipment ◽  
Design And Optimization ◽  
Motor Drive System

The priority valve is considered to be one of the critical parts of the hydraulic system used in mining equipment. This article analyzes the dynamic performance of a hydro-motor drive system using priority valve through system modeling and simulation. A typical hydraulic system of a mining equipment is considered for the analysis, where a stable source of flow is supplied to two hydro-motors through priority flow divider valve. Bondgraph simulation technique is used for the modeling of the complete system, which is validated experimentally. The influences of some key parameters on the transient response of the system have been studied through simulation. The work presented in this article forms the basis idea for the design and optimization of the priority flow control valve for a given application.

Modeling and Stability of a Hydraulic Load-Sensing Pump With Investigation of a Hard Nonlinearity in the Pump Displacement Control System

2014 ◽  
Author(s):  
Zachary D. Wagner ◽  
Roger Fales
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
Flow Control ◽  
Control Valve ◽  
Pressure Control ◽  
Flow Control Valve ◽  
Pump System ◽  
Load Sensing ◽  
Pressure Control System ◽  
The Stability

Certain types of Load-sensing (LS) pumps utilize a hydro-mechanical control system designed to regulate the pressure difference, or margin pressure, between the inlet and outlet of a flow control valve. With a constant margin pressure, predictable flow control can be achieved by controlling the orifice area of the flow control valve. In this work, the stability of the pressure control system will be investigated. A combination of linear analysis and nonlinear analysis is employed to assess the stability of a particular LS pump system. Among many nonlinearities present in the hydro-mechanical system, of particular interest is the saturation inherent in the actuator that is used to displace the pump swash plate and the saturation within the 3-way spool valve that permits flow to reach the actuator. This saturation nonlinearity has been isolated from the rest of the system to enable stability analysis. Analysis of model characteristics is used to make conclusions about the stability of the system consisting of interconnected linear and nonlinear portions. The stability analysis is compared to results obtained through a simulation study using a nonlinear model based on first principles.

scholarly journals ANALYSIS OF A LOAD SENSING HYDRAULIC FLOW CONTROL VALVE

1996 ◽  
Vol 1996 (3) ◽  
pp. 307-312 ◽  
Author(s):  
Rathindranath MAITI ◽  
Sandip PAN ◽  
Debasis BERA
Keyword(s):  
Flow Control ◽  
Control Valve ◽  
Flow Control Valve ◽  
Hydraulic Flow ◽  
Load Sensing

Analysis of Power Distribution in the Hydraulic Remote System of Agricultural Tractors Through Modelling and Simulations

2019 ◽  
Author(s):  
Xin Tian ◽  
Josias Cruz Gomez ◽  
Andrea Vacca ◽  
Stefano Fiorati ◽  
Francesco Pintore
Keyword(s):  
Power Distribution ◽  
Experimental Tests ◽  
Cost Effective ◽  
Operating Conditions ◽  
Future Research ◽  
Hydraulic Control ◽  
Load Sensing ◽  
Agricultural Applications ◽  
Remote System ◽  
Agricultural Tractors

Abstract Agricultural tractors make massive use of hydraulic control technology. Being fuel consumption a big concern for agricultural applications, tractors typically use the latest state-of-the-art technology to allow efficient fluid power actuation. Nevertheless, the quantification of the energy loss within the hydraulic system of such applications represents an important step to drive the development of the current technology with cost-effective solutions. In this paper, the load sensing (LS) circuit that typically equips of the hydraulic remotes is taken as reference. A simulation model has been developed within the Amesim software with the aim of accurately predict the operation of the system including the energy flow from the hydraulic supply to the hydraulic user. The paper particularly details the models of the LS pump and the hydraulic remote valves. Within the research, experimental tests on a reference tractor were designed and executed to allow the model validation. The comparison between the experimental results and the simulation data shows the validity of the model. Furthermore, the model allows highlighting the energy losses in the different components of the system as well as identifying the most favorable operating conditions of the system with respect to energy efficiency. The model can be used in support of future research aimed at formulating a more efficient solution for the hydraulic circuit of agricultural tractors.

Analysis of a priority flow control valve with hydraulic system simulation model

2016 ◽  
Vol 39 (5) ◽  
pp. 1597-1605 ◽  
Author(s):  
Gokhan Coskun ◽  
Turgay Kolcuoglu ◽  
Taner Dogramacı ◽  
Anil Can Turkmen ◽  
Cenk Celik ◽  
...  
Keyword(s):  
Flow Control ◽  
Simulation Model ◽  
Hydraulic System ◽  
System Simulation ◽  
Control Valve ◽  
Flow Control Valve ◽  
A Priority ◽  
Hydraulic System Simulation

The Effect of Different Designs on Performance of a Fluid Power Control System

2014 ◽  
Author(s):  
Tahany W. Sadak ◽  
Ahmed Fouly
Keyword(s):  
Hydraulic System ◽  
Dynamic Performance ◽  
Time Lag ◽  
Control Valve ◽  
Operating Conditions ◽  
Flow Control Valve ◽  
Hydraulic Systems ◽  
Supply Pressure ◽  
High Speeds ◽  
Hydraulic Servo

Hydraulic systems are characterized by their ability to import large forces at high speeds and are used in many industrial motion systems, also, in applications where good dynamic performance is important. This research concentrates on static and dynamic performance of a linear hydraulic system under different operating conditions in case of connecting an Electro Hydraulic Servo Valve (EHSV) and a Proportional Directional Flow Control Valve (PDFCV). High technology is used for measuring and recording the experimental results which achieves accurate evaluations. Experiments have been conducted in case of no-load and under load 5560 N. Supply pressure has been changed from 10 up to 50 bar. Effect of pressure and load variation on hydraulic system performance has been studied. It is concluded that increasing the load decreases the bandwidth frequency, but increasing the supply pressure increases the bandwidth frequency. Comparing the time lag of the system considering connecting the (EHSV) with that in case of connecting (PDFCV), it’s observed that in the present investigation the time lag improves by about 86.4% in case of free-load and by about 95.3% in case of system loaded.

Energy-saving strategies on power hydraulic system: An overview

2020 ◽  
pp. 095965182093162
Author(s):  
Anil C Mahato ◽  
Sanjoy K Ghoshal
Keyword(s):  
Energy Efficiency ◽  
Power System ◽  
Energy Saving ◽  
Energy Efficient ◽  
Hydraulic System ◽  
Fluid Power ◽  
Clear Understanding ◽  
Loss Reduction ◽  
Tabular Form ◽  
Fluid Power System

Different strategies for improving the energy efficiency of a power hydraulic system have been reviewed in this article. The energy-saving scheme is classified into three categories: S ystem design, Improving components or product functions and Loss reduction. The sub-categories of energy-saving strategies are discussed briefly. Also, different energy-saving potentials of power hydraulic system are presented in tabular form for clear understanding on the chronological development toward energy-efficient fluid power system.

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