• Journal of Advanced Marine Engineering and Technology
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• v.34 no.1
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• pp.195-201
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• 2010

In this paper, a cooling system of high-power propulsion motor with Energy Saving System(ESS) is described. Normally, the cooling system for ship consists of fresh water pump, sea water pump, 3-way valve and cooler. In the cooling system, F.W(Fresh Water) and S.W(Sea Water) pump is operated on rated rpm, and the 3-way valve is controlled for preventing over-cooling. So, the consumption power of pump's motor is changed according to a sea water temperature. In the proposed cooling system, F.W. pump and S.W pump is controlled by inverter, and it is can be reduced the consumption power. Also, it is proved with simulation.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.61-67
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• 2012

The in-wheel motor used in green car was designed and constructed for an electric direct-drive traction system. It is difficult to connect cooling water piping because the in-wheel motor is located within the wheel structure. In the air cooling structure for the in-wheel motor, a outer surface on the housing is provided with cooling grooves to increase the heat transfer area. In this study, we carried out the analysis on the fluid flow and thermal characteristics of the in-wheel motor under the effects of motor speed and heat generation. In order to check the problem of heat release, the analysis has been performed using conjugate heat transfer (conduction and convection). As a result, flow fields and temperature distribution inside the in-wheel motor were obtained for base speed condition (1250 rpm) and maximum speed condition (5000 rpm). Also, the thermo-flow characteristics analysis of in-wheel motor for vehicles was performed in consideration of ram air effect. Therefore, we checked the feasibility of the air cooling for the housing geometry having cooling grooves and investigated the cooling performance enhancement.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.29-34
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• 2014

Cooling the in-wheel motor in electric vehicles is critical to its performance and durability. In this study, thermal flow analysis was conducted by evaluating the thermal performance of two conventional cooling models for in-wheel motors under the continuous rating base speed condition. For conventional model #1, in which cooling oil was stagnant in the lower end of the motor, the maximum temperature of the coil was $221.7^{\circ}C$; for conventional model #2, in which cooling oil was circulated through the exit and entrance of the housing and jig, the maximum temperature of the coil was $155.4^{\circ}C$. Therefore, both models proved unsuitable for in-wheel motors since the motor control specifications limited the maximum temperature to $150^{\circ}C$.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.2
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• pp.33-40
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• 1997

Recently, there are an increasing needs for high speed rotating spindle which is an important mechanical ele- ment for a high efficiency machine tool in order to shorten machining time and cut production costs. The heat gen- eration is the most important problem in the motor integrated spindle. In this study, the effects of temperature distribution and thermal behavior according to the oil-air lubrication and cooling conditions are investigate theo- retically and experimentally on the motor-integrated spindle under unloading condition. The experimental spin- dle system is composed with the angular contact steel ball bearings, oil-air lubrication, air or oil jacket cooling system. To analyze the thermal behavior and cooling characteristics for the motor integrated spindle, the analysis using the finite element method is carried out. The analytical results are compared with the experimental results.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.72-80
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• 2013

For the proper cooling of in-wheel motor, the cooling channel should have the characteristics which are low pressure drop and adequate cooling oil supply to motor part. In this study, the flow performance of cooling channel for in-wheel motor was evaluated and the shape of the channel was optimized. First, the pressure drop and flow distribution characteristics of the initial channel model were evaluated using numerical analysis. Also, by the result of analysis and design modification, 4 design parameters of the channel were selected. Second, using the Taguchi optimal method, the cooling channel was optimized. In the method, nine models with different levels of the design parameters were generated and the flow characteristics of each models was estimated. Base on the result, the main effect of the design parameters was founded and optimized model was obtained. For the optimized model, the pressure drop and oil flow rate were about 0.196 bar and 0.207 L/min, respectively. The pressure drop decreased by about 0.3 bar and the oil flow rate to the motor part increased by about 0.2 L/min compared to the initial model.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.5
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• pp.376-383
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• 2012

Owing to rapid development of power device and inverters, most of submarines adopt an eletric propulsion system. Although PMPM(Permanent Magnet Propulsion Motor) propulsion system has relatively higher power, energy conversion efficiency and smaller volume than engine propulsion system, it also produces large amount of heat due to current flowing inside motor coils and change of magnetic field induced by iron core. The produced heat in stator and inverter largely affects motor efficiency and bearing lubrication and causes thermal aging while the system is on operation. So, we analyze the existing cooling system and submarine ESS (Energy Saving System) cooling system whose power consumption is reduced. HILS(Hardware In the Loop System) technique is used for the modelling of the submarine cooling system. To confirm the ESS cooling system characteristic, HILS is simulated using LabVIEW with hardware. As a result, the ESS cooling system has the characteristic of better temperature stability and less power consumption than the existing one.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.59-64
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• 2014

Integrated Starter Generator (ISG) system improves the fuel economy of hybrid electric vehicles by using idle stop and go function, and regenerative braking system. To obtain the high performance and durability of ISG motor under continuously high load condition, the motor needs to properly design the cooling system (cooling fan and cooling structure). In this study, we suggested the enhanced design by modifying the thermal design of the ISG motor and then analyzed the improvement of the cooling performance under high-speed condition and generating mode by CFD simulation. The temperatures at the coil and the magnet of the enhanced model were decreased by about $4^{\circ}C$ and $6^{\circ}C$, respectively, compared to those of the conventional model. Therefore, we verified the cooling performance enhancement of the novel thermal design in the case of core loss increment due to the higher speed condition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.239-243
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• 1997

The heat generation is the most important problem in the motor integrated spindle. Double cooling jacket in necessary to reduce the thermal displacement and to get the stable temperature disribution for the housing. In this study, the effects of temperature distribution and thermal displacement for the spindle system according to the variation of cooling oil flow rate are investigated experimentally on the motor-integrated spindle with double cooling jacket system. The experimental spindel system is composed with the angular contact steel ball bearings, oil-air lubrication, air or oil jacket cooling system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.449-450
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• 2006

Development of a feed drive system with high speed, positioning accuracy and thrust has been an important issue in modern automation systems and machine tools. Linear motors can be used as an efficient system to achieve such technical demands. By eliminating mechanical transmission mechanisms such as ball screw or rack-pinion, much higher speeds and greater acceleration can be achieved without backlash or excessive friction. However, an important disadvantage of linear motor system is its high power loss and heating up of motor and neighboring machine components on operation. For the application of the linear motors to precision machine tools an effective cooling method and thermal optimizing measures are required. In this paper presents an investigation into a thermal behavior of linear motor cooling plate. FVM employed to analyze the thermal behavior of the linear motor cooling plate, using the ANSYS-CFX.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3032-3036
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• 2011

Cooling type of traction motor for EMU in domestic is mostly an open type. Its system is a cooling air entered through air inlet cool down a traction motor and an hot air by traction motor get out air outlet. It is easy to cool it down but hard to maintain it. To improve an ability of maintenance, a total enclosed type traction motor is already developed and used in abroad, not an opne type. So we developed a total enclosed type traction motor which will be used in domestic and abroad EMU. We tried to reduce a weight and a size compared with the abroad one. In contrast with open type traction motors which cool off inside of motors, total enclosed motors cool down by cooling exterior frame of motors. In this case, cooling fins or air fan blowing to the exterior of motors are applied. The total enclosed type traction motor developed by us have two housing to block the foreign substance into inner of a motor and have two cooling fan to easy to reduce a heat happened at a coil. In this paper, design of a cooling structure of the total enclosed traction motor developed twice and performance verification through test will be discussed.