• Journal of Power Electronics
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• v.9 no.3
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• pp.491-498
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• 2009

The hydraulic-oil pump is widely used for building machinery, brake systems of vehicles and automatic control systems due to its high dynamic force and smooth linear force control performance. This paper presents a novel direct instantaneous pressure control of the hydraulic pump system with SRM drive. The proposed hydraulic pump system embeds the pressure controller and direct instantaneous torque controller. Due to the proportional relationship between pump pressure and torque, pressure can be controlled by the motor torque directly. The proposed direct torque controller can reduce inherent torque ripple of SRM, and develop a smooth torque, which can increase the stability of the hydraulic pump. The proposed hydraulic pump system has also fast step response and load response. The proposed hydraulic pump system is verified by computer simulation and experimental results.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.150-151
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• 2007

In hydraulic oil pump system, pressure has a linear relationship with output torque of motor. Torque control of pump drive can easily output stable pressure, and it can retain required pressure at minimum speed to save power consumption. Switched reluctance motor(SRM) has many advantages such as low cost and low inertia. It can generate high torque at low speed. But inherent high torque ripple of SRM influences performance of pressure control in hydraulic oil system. This paper presents direct instantaneous torque control(DITC) of hydraulic oil pump system. DITC method can reduce inherent torque ripple of SRM, and output smoothing torque to load. So the proposed hydraulic oil pump system can support smooth pressure and fast dynamic power supply to the hydraulic pump system. At last the proposed hydraulic oil pump system is verified by computer simulation and experimental results.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.1181-1190
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• 2023

Hydraulic performance and flow resistance tests were performed to confirm the main parameters of the hydraulic instrumentation that can affect the pump performance of the reactor coolant pump. The flow resistance test offers important experimental data, which are necessary to predict the behavior of the primary coolant when the circulation of the reactor coolant pump is stopped. Moreover, the shape of the hydraulic section of the pump, which was considered in the test, was prepared to compare the mixed-flow- and axial-flow-type models, the difference in the number of blades of the impeller and diffuser, the difference in the shape of the impeller blade and its thickness, and the effect of coating at the suction bell. Additionally, five models of the hydraulic part were manufactured for the experiments. In this study, the differences in performance owing to the design factors were confirmed through the experimental results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.282-285
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• 1997

The torque efficiency of oil hydraulic pump is an important factor for it's performance characteristics. A study on the performance test method of oil hydraulic pump is based on test standard, but there is to be desired an study for double or tandem type oil hydraulic piston pump. So in this study present a test method on the tandem pump for torque efficiency and analysis method of the results.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.4
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• pp.148-154
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• 2000

In this study, the static and the dynamic characteristics of the load-sensitive hydraulic pump control systems of a hydraulic excavator were analyzed using the developed analysis tool. The results were compared with the experimental ones. To improve the static performance of the system, the system parameter effects on the controllable region and the pump pressure variation were studied. The parameters enhancing dynamic characteristics were also considered.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.211-216
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• 2015

Large hydraulic excavator weighted 90 tons used the several pumps installed in parallel to use the hydraulic pump driving gearbox to improve fuel consumption by improving the energy efficiency of the hydraulic system. Gearbox connected to hydraulic pump supply the mechanical output to the high pressure and low pressure pump to be supplied by torque and rotation, which are the mechanical power, through a input shaft connected to large size engine of the excavator. So, gearbox connected to hydraulic pump is same as main artery in the human body and is required long life because it operates the hydraulic pump continuously during operating the engine. This study had used oil contamination analysis method to check the wear characteristics of the gearbox and frequency response characteristic analysis method to check the failure of the teeth failures of gearbox, while the test equipment adopted by the electrical feedback method to reduce the energy consumption was operating for the life assessment, in which the required power was 600 kW input power.

• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.4
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• pp.1-7
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• 2006

A water hydraulic pump is likely to have serious problems of high leakage, friction and low energy efficiency. A water hydraulic pump has commonly a fixed displacement type and its outlet flow is adjusted by controlling rotation speed of the pump, which can be implemented by using an electric inverter. This study aims to investigate energy efficiency of the water hydraulic pump system which is driven by an electric inverter. The study is based on the experimental results. The pump which is used in the study shows relatively good efficiency and low leakage, low friction as well. The reasons for the good performance of pump is also investigated.

• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.45-49
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• 2000

Vibration and noise problem in a hydraulic system became one of very important factors in evaluating the performance of a hydraulic system. It is known that vibration and noise in a hydraulic system is directly related to flow pulsation in the hydraulic pump in the system. This study investigated a modeling and simulation technique for pulsating flow in a swash plate type axial piston pump. The key design factors of the pump related to flow pulsation phenomenon of the pump are the physical parameters for notches on the valve plate of the pump. By the numerical analysis, effects of the physical parameters of the notch on the flow pulsation was elucidated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.585-588
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• 1995

In this study, the analysis of the static and dynamic characteristics of the load-sensitive hydraulic pump control system used in the hydraulic excavator was performed by hydraulic circuit ananlysis program. Thess results was verified by the experimental data of the hydraulic excavtor system. The responses on effective parameters of system at the controllable region and the pressure variation of the pump used in hydraulic excavator system was studied to enhance the static performace of the system. the parameter enhance dynamic sharacteristics was considerd.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.408-416
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• 2002

Hydraulic performance of the pump with an inducer was predicted by 3-D Navier-stokes calculation. The evaluated pump was the single-stage centrifugal pump with a separated inducer to pressurize fuel (LCH4) in Turbo-pump system with a specific speed (Ns) of approximately 0.3[rad/s, m3/s, J/kg] and a suction specific speed(s) of 15[rad/s, m3/s, J/kg]. That conventional pump was designed with the combination of 1-D theory and empirical correlation. In this study, preliminary design to select key parameters such as inlet flow coefficient was reviewed by investigating sets of the known design methods to achieve appropriate suction performance, and the performance of newly designed inducer and impeller was compared with the old one, using CFD method. The numerical results showed that the hydraulic efficiency of the new pump was predicted $5.5\%$ higher than that of the conventional one, through design parameter re-selection, configuration improvement and blade loading control