• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2001.11a
• /
• pp.151-158
• /
• 2001

This paper presents a method for evaluating the lubrication characteristics between the plunger and cylinder in a radial type plunger pump. A numerical analysis is carried out in order to obtain the pressure distribution and acting forces between the plunger and cylinder. The pressure distribution is also measured experimentally by using pressure transducer through the cam type test machine. The experimental pressure distribution result is compared with the numerical result which is estimated by the computer simulation. In conclusion, the acting forces to the plunger are expressed for the operating conditions such as clearance, supply pressure, rotation speed and viscosity of oil.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.486-489
• /
• 2003

To reduce lateral force of traditional plunger type piston in the swash plate type hydraulic piston pumps and motors, we have proposed rod type piston with ball joint on both ends. We have studied the theoretical reaction force on two types of piston moving in the cylinder block bore. and made an experiment for the resistance force measurement on a reciprocating motion of plunger and rod type piston, changing the test condition such as swash plate angel and supply oil pressure and so on. As a result. a rod type piston has more smaller resistance force, about 29%. than a plunger type one.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.840-843
• /
• 2003

The Paper presents theoretical and experimental investigation of plunger type water hydraulic pump (plunger pump). An analysis of Crank shaft for plunger pump is carried out. With this results, the optimal dimensions of plunger pump are determined. And performance test results about slide resistance, hydraulic leak test, efficiency-pressure. and flow-speed and flow-pressure are presented.

• Journal of the Korean Society for Precision Engineering
• /
• v.10 no.3
• /
• pp.125-132
• /
• 1993

On this study, magnetic force versus input currents is analyzed by modeling taper plunger type proportional electromagnet of ISC valve using the permernce method. And, the reliabiliy of simulation is verified by comparing the experimental values with the calaulate magnetic force. From the result of this study, it is found that the taper angles at plunger and core, the length of air gap between plunger and yoke are the prumary factors in designing taper plunget type proportional electromagnet. Magnetic force is decreased as a whole according to increasing the air gap between pluger and yoke, and vise versa. But, the magnetic force is not proportional to current, when the air gap is very small. In case of decreasing the taper angle of pluger, the stroke range of plunger where magnetic force is proportional to current becomes farther from core.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.10a
• /
• pp.311-312
• /
• 2006

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.3
• /
• pp.126-133
• /
• 2008

The main objective of the present study is to achieve linear temperature distribution of cooling surface of plunger. K type thermocouples are attached at the surface of plunger to measure temperature. Nozzle and insulating material are inserted in the pin hole of the plunger for this study. Cooling water flow enters at one nozzle and leaves at three nozzles. Flow through nozzle can be activated in the pin hole, temperature of hot point around hole is decreased. Meanwhile, insulating material blocks off heat transfer, temperature of cold point around hole is increased. By combination of nozzle and insulation, heat transfer of hole is controlled effectively, as result its, temperature of plunger surface shows linear temperature distribution.

• Journal of the Korean Society for Precision Engineering
• /
• v.11 no.6
• /
• pp.127-135
• /
• 1994

This paper is concerned about a high speed electromagnet of Pressure control solenoid valve. Solenoid valve is controlled by means of Pulse width modulation. The magnetostatic field problem on a solenoid is numerically solved by the 2-D axisymmetric finite element method. And permeance method is adopted for analysing the static and dynamic property of solenoid part theoretically. In addition, in this study, experiments on solenoid part were performed in order to measure the magnetic force and plunger displacement. The numerical results coincided with the experimental results. As a result, the magnetic force has the linear relation with displacement of plunger and the primary factors on the performance of PWM type high speed electromagnet are coil resistance, plunger mass, and the length of air gap between plunger and core.

• Journal of Aerospace System Engineering
• /
• v.15 no.3
• /
• pp.87-92
• /
• 2021

In this study, a numerical approach was utilized to observe the phenomena in the ground combustion test of a gas generator for a ducted rocket with a plunger-type flow control device. The design factors were also identified through the analysis. It was observed that the pressure increase without the adhesion of the combustion product at the discharge pipe was quite similar to the analysis assuming a cone-shaped erosive burning effect. The pressure increase in most cases was similar to the analysis results when assuming the change in discharge pipe area due to the adhesion of combustion products. Moreover, it was also established that for a given grain shape and discharge flow area, the effect of the adhesion of combustion products has a significant effect on the combustion chamber pressure for cases over n=0.45.

• Journal of Aerospace System Engineering
• /
• v.15 no.3
• /
• pp.79-86
• /
• 2021

For a preliminary study on a thrust-throttleable Variable Flow Ducted Rocket, a gas generator and flow control valve were developed, and ground combustion tests were performed. The gas generator and flow control valve operated at the required performance level for parameters, such as heat-resistance, combustion-time, pressure, and temperature. The combustion characteristics of a fuel-rich solid propellant mixed with Boron/MgAl/AP, etc., were also analyzed. A Plunger-type flow control valve was designed to control the discharge flow area, and it was confirmed that the flow control valve was able to control the combustion gas flow rate and pressure. However, due to the reduction of the discharge flow area caused by adhesion of combustion products, the combustion pressure continuously increased. The analysis of the pressure increase is covered in Part 2 of this paper.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.2 no.1
• /
• pp.26-32
• /
• 1997

In this paper, numerical analysis of dynamic characteristics for the plunger-type solenoid was used for a high speed solenoid valve with fast switching is discussed. The theoretic analysis of the electromagnetic field including eddy currents in the solenoid is studied by using permeance. The optimum value of design parameters which are a mass and an area of the plunger, a source voltage, a elastic modulus of the spring, a stroke, a number of turns, are obtained by the results of the investigation on effect of a parameter on others. And dynamic characteristics of acting solenoid that is the variation of magnetic force, displacement, solenoid current are investigated.