Simulation Study on Load-Sensing Hydraulic Drawing System of Coal Mining Machine

2010 ◽  
Vol 37-38 ◽  
pp. 1195-1198
Author(s):  
Tian Hao Peng ◽  
Mei Sheng Yang ◽  
Xiao Song Hao ◽  
Jia Dong Liu

A new hydraulic drawing system of coal mining machine is proposed in this paper. The variable plunger pump adopted in the hydraulic drawing system of coal mining machine is replaced by load-sensing variable displacement pump. The working principle and energy-saving of the new system are introduced. The performance of the new system is obtained by the simulation study using AMESim.

2020 ◽  
Vol 197 ◽  
pp. 07010
Author(s):  
Paolo Casoli ◽  
Barbara Zardin ◽  
Salvatore Ardizio ◽  
Massimo Borghi ◽  
Francesco Pintore ◽  
...  

Increasing interest in reducing pollutant emissions and fuel consumption of off-road vehicles has led to research alternative systems that aim to reduce the power dissipations of the hydraulic circuits. This work presents the advantages of few alternative solutions for a hydraulic high-pressure circuit of a medium-size tractor. The standard high-pressure circuit is a typical multiusers load sensing system that uses a single variable displacement pump to feed: steering, trailer brake, rear remotes, hitch and suspension. The alternative architectures have been simulated and compared in terms of mechanical energy consumption. In particular, the steering has been separated from the circuit, it has been actuated by means of a dedicated pump moved by an electric motor, in this way the priority valve could be removed and losses due the pressure compensators are reduced. A further architecture based on the insertion of the LS signal conditioner was studied. The results show that relevant energy saving can be achieved with the new alternative architectures; the physical prototyping of the most promising solutions will be realized as the next step of the project.


Author(s):  
Niall Caldwell

The paper describes the work done by the author (1) from 1999 to 2006 to develop the Digital Displacement Pump (DDP) and Pump/Motor (DDPM) and demonstrate the feasibility of off-highway vehicle applications. The link between DDPM capacity and the solenoid valve performance was identified. Magnetic geometry was improved by parametric FEA, then time-domain behavior was improved with a hybrid FEA/lumped-parameter model. Software improvements allowed variable speed and bidirectional operation, enabling the demonstration of the first Digital Displacement Transmission (DDT) systems on a vehicle, one featuring a load-sensing DDP and secondary control by DDPM displacement, and one featuring primary control by DDP displacement and a conventional axial motor. A time-domain simulation was created of the primary-controlled vehicle, which yielded good comparison to experimental results. The deterministic nature of the DDP lends itself to model-based system design methods, which have since been used to develop larger commercial systems. The first detailed analysis of DDP efficiency characteristics revealed profound differences to conventional variable displacement pumps, including exceptional part-load efficiency and the dominant effect of fluid compressibility. A peak overall efficiency of 97% was recorded for a DDP after analysis of loss sources prompted design improvement.


2010 ◽  
Vol 44-47 ◽  
pp. 1380-1386
Author(s):  
Bi Zhong Xia ◽  
Ping Fa Feng ◽  
Hua Yong Yang

Based on introduction of the basic configuration, working features of hydraulic drive system of the cutter head in a shield machine, the internal structure of the bidirectional variable displacement pump, BVDP, as the kernel element in the above hydraulic system, is depicted and compared with the ordinary variable plunger pump. Then the working principle and process of hydraulic pilot operated servo displacement adjustment about the BVDP are discussed in detail, and then the mathematical models and its transfer functions of the positive and negative displacement adjustments are established respectively. Also, the relationships between the primary performance indices such as stability condition, positioning stiffness, steady-state error, as well as initial control pressure and system parameters are analysis and concluded.


2013 ◽  
Vol 765-767 ◽  
pp. 171-175 ◽  
Author(s):  
Xiao Hua Zeng ◽  
Hui He ◽  
Zhen Ping Zhou ◽  
Sheng Li ◽  
Xiang Hua Li ◽  
...  

The objective of this paper is to introduce a newly developed Hydraulic In-wheel Motor Drive System (HIMDS) mainly made up of a variable displacement pump and two motors. The new HIMDS is primarily applied to heavy truck to improve its passing ability when encountering the low-roads. This paper Not only illustrates the structure and working principle of the system, but also gives a detailed description of calculation of the improvement in traction force and climbing capacity of the vehicle after working with HIMDS. The Simulation results show that after using the system, the vehicle traction force was increased by 23%, and the climbing capacity was improved by 30% mostly.


2001 ◽  
Author(s):  
Timo J. Käppi

Abstract In this paper modeling of variable displacement pump system is discussed. The system described is typically used in mobile hydraulic applications. An easy-to-parameterize loss model is presented which is based on the Dorey’s model. The model identification is done semi-empirically with a reduced number of parameters. Two parameters are required to identify the volumetric losses and four to determine the hydromechanical efficiency. The accuracy of the loss model is proven by comparing calculated values between the measured values of a commercial axial piston pump. The relative error in total efficiency is less than 4% over the whole range of variables and thus acceptable. The pump system model presented includes the operation of load sensing regulator and power restrictor. The pump system model also includes the dynamic effect of a load sensing line from the mobile valve to the pump regulator and the first order dynamics of the pump itself. The suggested model is usable in carrying out the system level simulation of mobile hydraulic machine systems. Simple examples demonstrate the application.


Author(s):  
Marco Scopesi ◽  
Andrew Plummer ◽  
Can Du

The subject of this paper is a VPVC (variable pressure valve-controlled) hydraulic actuation system, which is a hydraulic plant with variable supply pressure. The concept is similar to a load sensing system but it is implemented using an electronic controller, instead of a hydraulic one, and the flow is provided using a servo pump, instead of a variable displacement pump. The intention is to maintain a high dynamic response but substantially improve efficiency compared to a conventional system with fixed supply pressure. FPVC (fixed pressure valve-controlled) systems are unable to completely modulate the input energy due to the constant supply pressure. However, since the ability to control the energy flow is usually needed, a proportional valve for each actuator is used to dissipate the extra input energy. This leads to a simple but inefficient way to control, for example, the velocity of a piston. The idea of a VPVC system is that, instead of dissipating energy by throttling flow, it is better to generate less fluid power in the first place: this is achieved by adjusting the speed of the servo pump as well as the spool positions. In this paper, a controller for a VPVC system is presented along with numerical simulations showing a comparison with a fixed pressure system. Up to 70% energy saving is predicted.


Author(s):  
Samir Kumar Hati ◽  
Nimai Pada Mandal ◽  
Dipankar Sanyal

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.


Author(s):  
Akash A. Nair ◽  
Gnanaraj A. Anbu ◽  
Panneer Selvam Rajamanickam ◽  
Gopakumar Kuttikrishnan ◽  
Ramadass Gidugu Ananda

Deep sea mining is mineral retrieval process that takes place on the ocean floor wherein global industries are actively exploring and experimenting of different techniques in this relatively new concept of mining for extracting it economically from depths of 5000–5500 m below the ocean’s surface. National Institute of Ocean Technology (NIOT), India has been working on a mining concept for ∼6000 m water depth where a crawler based mining machine collects, crushes and pumps nodules to the mother ship using a positive displacement pump through a flexible riser (umbilical) system. The umbilical also serve as the weight supporting member for the miner and pump. In this paper, static and dynamic analysis of the umbilical system in steep wave configuration and the miner is carried out using ORCAFLEX for launching and touchdown conditions. Three different materials are considered and the best suitable material for umbilical is selected as the first step based on the tension. Then umbilical with Single Miner System is analyzed for the launching and touchdown conditions. Based on the analysis the optimum number and spacing of buoyancy tanks that will keep the stresses within the allowable limits in the umbilical cable are recommended.


2002 ◽  
Vol 124 (4) ◽  
pp. 613-616 ◽  
Author(s):  
X. Zhang ◽  
S. S. Nair ◽  
N. D. Manring

A robust adaptive pressure control strategy is proposed for a novel indexing variable-displacement pump. In the proposed approach, parametric uncertainties and unmodeled dynamics are identified to the extent possible using a model free learning network and used to decouple the dynamics using physical insights derived from careful reduced order modeling. The swash plate motion control is then carefully designed to provide the desired pressure response characteristics showing improved performance with learning. The proposed control framework and designs are validated using a detailed nonlinear simulation model.


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