Design and Testing of Novel Hydraulic Pump/Motors to Improve the Efficiency of Agricultural Equipment

2017 ◽  
Vol 60 (6) ◽  
pp. 1809-1817
Author(s):  
Farid Breidi ◽  
Jordan Garrity ◽  
John Lumkes

Abstract. Hydraulic systems are prevalent in agricultural machinery and equipment and can be found transmitting power for vehicle drive wheels, powering attachments, and controlling motion (booms, steering, load height, etc.). Agricultural applications of fluid power have advanced in terms of capability and efficiency, but opportunities remain for significant improvements in efficiency, noise reduction, and reliability. The average system-level hydraulic efficiency of current mobile agricultural machines is only 21.1%. Because nearly all hydraulic systems use pumps to convert engine power to fluid power, improving the efficiency of the pumps (and motors when used as actuators) significantly impacts the system efficiency. This work examines the impact of using more efficient digital pump/motors to improve the overall efficiency of agricultural equipment, such as tractors, harvesters, planters, fertilizers, sprayers, and attachments. Maintaining higher pump/motor efficiency throughout the operating range is the central principal for the energy savings. Currently used variable-displacement pumps have low efficiencies at low displacement levels due to constant losses that do not scale with the power produced. Digital pump/motors minimize these inefficiencies because energy losses scale more closely with the power produced. Experimental results indicate an average efficiency of 85% when operating at 20% to 100% displacement. This efficiency is 15% to 20% higher on average than with current variable-displacement axial piston pumps. This study demonstrates that achieving this improvement in the efficiency of the pump/motors used in tractors and harvesters alone would conservatively save $61.7 million worth of energy annually for end users in the U.S. agricultural sector. Keywords: Agricultural equipment, Digital hydraulics, Efficiency improvement, Hydraulic pump/motor.

2014 ◽  
Vol 60 (Special Issue) ◽  
pp. S37-S43 ◽  
Author(s):  
I. Janoško ◽  
T. Polonec ◽  
S. Lindák

In environmental terms, hydraulic fluids used in the hydraulic system of municipal vehicles represent problems related to a potential leakage from the system into the environment and the subsequent contamination of groundwater and soil. More environment-friendly way is to use green hydraulic fluids that are biodegradable in accidents. This paper aims to investigate the possibilities of biodegradable oil application and its adaptation in the hydraulic systems of municipal vehicles by monitoring the impact of the bio-oil Mobil EAL 46 ESSO on the performance parameters as flow, efficiency, durability, etc. Hydraulic pump revolutions were measured using a non-contact sensor based on the principle of magnetic induction change. Method of tightness monitoring was used to achieve results for functionality and wear of the hydraulic system. During 600 h of the test period no significant deterioration of performance parameters was detected. Results are useful for companies involved in waste collection.


Author(s):  
Farid Breidi ◽  
Tyler Helmus ◽  
Michael Holland ◽  
John Lumkes

High speed valves have an important role in many existing fluid power systems and are an enabler for many proposed digital hydraulic systems. One method commonly used to improve the dynamic performance of on-off valves involves modifying the electrical input signal to the solenoids to reduce the inductive lag and eddy current decay. This research examined two commercially available direct actuated and pilot-stage actuated cartridge poppet valves and the role of peak-and-hold voltage and reverse current input profiles on opening and closing switching times. A test stand was built to characterize the performance of these valves. The valves were placed between two high frequency pressure transducers and the pressure differential across the valves was recorded, allowing the calculation of transition and delay time. The peak and reverse voltage duration was tested over a range of zero to ten milliseconds and an optimum response was found at a peak duration of six to eight milliseconds. Peak voltages ranged from 50 to 55 volts, followed by a holding voltage of 12 volts. Reverse current profiles were used to turn off the valves with a maximum peak current of three amps. The reverse current was used to increase the decay rate of eddy currents thus improving the turning off performance of the valves. Commercial valves that had a range of 33 to 55 millisecond turn-on response without input signal modification; these same valves had response times reduced to a range of seven to nine milliseconds after applying the peak and hold method. The turn-off time was reduced from 130 milliseconds to a range of 16 to 50 milliseconds after adding reverse current inputs. This improvement in valve performance can lead to siginificant energy savings due to reduction of transition losses and can widen the useful application of the valves.


2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Michael Ikechukwu Elikwu ◽  
Uzoma Samuel Ede ◽  
Anthony C. Igbokwe

Agricultural production/activities in Nigeria over the past years have largely remained primitive, resulting in very low productivity due to inadequate application of modern technology. There have also been daunting challenges of access to long-term capital needed to employ modern farming equipment, inadequate inputs and storage facilities, weak agricultural extension and out-dated sectoral infrastructure, all resulting to years of low agricultural productivity. Hence, this study investigates the impact of agricultural equipment financing on increased productivity in the Agricultural sector in Nigeria. The study employs the archival and documentary research design which involves secondary data collection. 16 years data on total annual financial expenditure on agricultural equipment and data for agricultural output and export earnings from 2000 to 2015 (16 years) form the population of the study. Data on cumulative annual expenditure on agricultural equipment financing (AEF), an aggregate of technological advancement in mechanized farming (TMF) and agricultural productivity (AP), were employed. The findings reveal that agricultural equipment financing has a significant impact on technological advancement of mechanized farming and that there is a significant relationship between technological advancement of mechanized farming and production output. The study therefore recommends that efforts should be made by agricultural intervention agencies and financial institutions to increase credit financing for agricultural equipment, which is a sustainable measure towards revolutionizing and industrialisation of the economy through technological advancement in the sector.


Author(s):  
Mengtang M. Li ◽  
Ryan Foss ◽  
Kim A. Stelson ◽  
James D. Van de Ven ◽  
Eric J. Barth

High power density and good controllability are the most appealing characteristics that make hydraulic systems the best choice for many applications. Current state of the art hydraulic variable displacement pumps show high efficiency at high displacement while they have poor efficiencies at low displacement. This paper proposes a novel alternating flow (AF) variable displacement hydraulic pump to 1) eliminate metering losses by acting as a high-bandwidth pump for displacement control, 2) achieve high efficiency across a wide range of operating conditions and displacements, and 3) allow multiple units to be easily common-shaft mounted for a compact multi-actuator displacement control system from a single prime-mover. A dynamic model using first principles describes the cylinder pressure, flows between pairs of cylinders, and net inlet and outlet flows as a function of the pump’s phase shift angle. The model captures hydraulic check valve dynamics, the effective bulk modulus, leakage flows, and viscous friction. Piston kinematics and dynamics are discussed and energy loss models are presented and used to guide the design for a first prototype of the AF hydraulic pump. The paper presents simulation results from the model that offer an initial evaluation of this novel pump concept and potential applications.


2016 ◽  
Author(s):  
◽  
Julie Kay Wisch

This project developed the inlet metering system. An inlet metering system represents a new option in hydraulic pump design. Traditional pressure controlled hydraulic pumps rely on either swashplate displacement (for variable displacement pumps) or bleed off valves (for fixed displacement pumps). Variable displacement pumps require mechanically complex parts which are expensive to machine and prone to break down. Bleed off valves represent a significant loss in system efficiency. In contrast, the inlet metering system is able to make use of a fixed displacement pump (which is relatively inexpensive and mechanically robust) and a two-way spool valve. This dissertation goes through the process of designing the valve and pump dimensions, presents a theoretical dynamic analysis, studies the control law associated with this pump, and examines the energy requirements associated with inlet metering system operation. A prototype of the design was constructed and experimental data was used to validate the efficiency analysis. The major finding associated with this work was that the inlet metering system can be designed to display a first order pressure response. This means that when the inlet metering system is operated, the actual pressure in the system will never exceed the desired pressure. In contrast, traditional hydraulic systems will display up to 60% pressure overshoot, meaning the systems must be designed to handle pressures significantly greater than operating pressures. Additionally it was found that the inlet metering system is more efficient than using a bleed off valve, but less efficient than using a variable displacement pump.


2001 ◽  
Vol 28 (3) ◽  
pp. 306-319 ◽  
Author(s):  
Karen Webb ◽  
Penelope Hawe ◽  
Michelle Noort

A case study is presented that describes the 10-year evolution of a local intersectoral project aimed at improving components of a community’s food system as an approach to improving nutrition. Aspects of innovation and good contemporary practice in collaborating for health promotion are illustrated. Key initiators of the project were a university public health department, a community health service, and a local government authority. Players brought into the process included the agricultural sector and food retailers. Several strategies have contributed to the success and institutionalization of the project. These include a specific focus on organizational development and capacity building among the key intersectoral partners and the use of formative evaluation methods to hasten the natural phases of collaborative problem solving. The project achieved many policy- and system-level changes. The impact on food consumption patterns is still to be evaluated.


Author(s):  
Haink C. Tu ◽  
Michael B. Rannow ◽  
Meng Wang ◽  
Perry Y. Li ◽  
Thomas R. Chase ◽  
...  

The application of switched mode control to hydraulic systems has the potential of decreasing component complexity, size, and cost. This is accomplished by enabling variable pump or motor functionality using a single on/off valve paired with a compact, inexpensive fixed displacement machine. A 4-way tandem rotary on/off valve is presented in this paper that extends a novel rotary valve concept (experimentally validated for pump applications) to hydraulic pump/motors. The pump/valve system is referred to as a Virtually Variable Displacement Pump/Motor (VVDPM) since the effective displacement of the system is variable and not the physical displacement of the pump itself. This paper investigates the design and efficiency of the proposed rotary valve when utilizing the VVDPM on a light weight power-split hydraulic hybrid passenger vehicle that is driven over a standard federal drive cycle. Simulated VVDPM efficiency maps are presented for motoring and pumping and the cycle efficiency of an optimized VVDPM is compared to that of a typical bent axis unit. Vehicle fuel economy is also explored through simulation.


2017 ◽  
Vol 1 (1) ◽  
Author(s):  
La Ode Jabuddin ◽  
Ayub M Padangaran ◽  
Azhar Bafadal Bafadal

This study aims to: (1) Knowing the dynamics of fiscal policy and the performance of the agricultural sector, (2) Analyze the factors that influence fiscal policy and the performance                   of the agricultural sector, and (3) Analyzing the impact of fiscal policy on the performance of the agricultural sector. The data used in this study were pooled 2005-2013 data in the aggregate. Econometric model the impact of fiscal policy on the performance of the agricultural sector is built in the form of simultaneous equations, consisting of 7 equations with 25 total variables in the model, 7 endogenous variables, 12 exogenous variables, and 6 variables lag. The model is estimated by 2SLS method SYSLIN procedures and historical simulation with SIMNLIN procedure.The results showed that: (1) The development of fiscal policy in Southeast Sulawesi from year to year tends to increase, (2) The performance of the agricultural sector from the aspect of GDP has decreased, from the aspect of labor is still consistent, in terms of investment to grow positively, and assign roles which means to decrease the number of poor people, (3) factors affecting fiscal policy is local revenues, equalization funds, other revenues, as well as the lag fiscal policy, (4) the factors that affect the performance of the agricultural sector from the aspect GDP is labor, direct expenditure and GDP lag; from the aspect of labor is the total labor force, investment, land area, direct expenditure, as well as the lag of labor; from the aspect of investment is influenced by GDP per capita, land area, interest rates and investment lag; as well as from the aspect of poor people, are affected by population, investments, direct expenditure and poverty lag, (5). Fiscal policy impact on the agricultural sector GDP increase, a decrease in the number of poor, declining agricultural laborers, and a decrease in the amount of investment in the agricultural sector.Keywords: Fiscal policy, the performance of the agricultural sector, the simultaneous equations


Author(s):  
M. S. Bugaeva ◽  
O. I. Bondarev ◽  
N. N. Mikhailova ◽  
L. G. Gorokhova

Introduction. The impact on the body of such factors of the production environment as coal-rock dust and fluorine compounds leads to certain shift s in strict indicators of homeostasis at the system level. Maintaining the relative constancy of the internal environment of the body is provided by the functional consistency of all organs and systems, the leading of which is the liver. Organ repair plays a crucial role in restoring the structure of genetic material and maintaining normal cell viability. When this mechanism is damaged, the compensatory capabilities of the organ are disrupted, homeostasis is disrupted at the cellular and organizational levels, and the development of the main pathological processes is noted.The aim of the study is to compare the morphological mechanisms of maintaining structural homeostasis of the liver in the dynamics of the impact on the body of coal-rock dust and sodium fluoride.Materials and methods. Experimental studies were conducted on adult white male laboratory rats. Features of morphological mechanisms for maintaining structural homeostasis of the liver in the dynamics of exposure to coal-rock dust and sodium fluoride were studied on experimental models of pneumoconiosis and fluoride intoxication. For histological examination in experimental animals, liver sampling was performed after 1, 3, 6, 9, 12 weeks of the experiment.Results. The specificity of morphological changes in the liver depending on the harmful production factor was revealed. It is shown that chronic exposure to coal-rock dust and sodium fluoride is characterized by the development of similar morphological changes in the liver and its vessels from the predominance of the initial compensatory-adaptive to pronounced violations of the stromal and parenchymal components. Long-term inhalation of coal-rock dust at 1–3 weeks of seeding triggers adaptive mechanisms in the liver in the form of increased functional activity of cells, formation of double-core hepatocytes, activation of immunocompetent cells and endotheliocytes, ensuring the preservation of the parenchyma and the general morphostructure of the organ until the 12th week of the experiment. Exposure to sodium fluoride leads to early disruption of liver compensatory mechanisms and the development of dystrophic changes in the parenchyma with the formation of necrosis foci as early as the 6th week of the experiment.Conclusions. The study of mechanisms for compensating the liver structure in conditions of long-term exposure to coal-rock dust and sodium fluoride, as well as processes that indicate their failure, and the timing of their occurrence, is of theoretical and practical importance for developing recommendations for the timely prevention and correction of pathological conditions developing in employees of the aluminum and coal industry.The authors declare no conflict of interests.


2019 ◽  
Vol 5 (1) ◽  
pp. 18-25
Author(s):  
Isah Funtua Abubakar ◽  
Umar Bambale Ibrahim

This paper attempts to study the Nigerian agriculture industry as a panacea to growth as well as an anchor to the diversification agenda of the present government. To do this, the time series data of the four agriculture subsectors of crop production, livestock, forestry and fishery were analysed as stimulus to the Real GDP from 1981-2016 in order to explicate the individual contributions of the subsectors to the RGDP in order to guide the policy thrust on diversification. Using the Johansen approach to cointegration, all the variables were found to be cointegrated. With the exception of the forestry subsector, all the three subsectors were seen to have impacted on the real GDP at varying degrees during the time under review. The crop production subsector has the highest impact, however, taking size-by-size analysis, the livestock subsector could be of much importance due to its ability to retain its value chain and high investment returns particularly in poultry. Therefore, it is recommended that, the government should intensify efforts to retain the value chain in the crop production subsector, in order to harness its potentials optimally through the encouragement of the establishment of agriculture cottage industries. Secondly, the livestock subsector is found to be the most rapidly growing and commercialized subsector. Therefore, it should be the prime subsector to hinge the diversification agenda naturally. Lastly, the tourism industry which is a source through which the impact of the subsector is channeled to the GDP should be developed, in order to improve the impact of such channel to GDP with the sole objective to resuscitate the forestry subsector.


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