EPS(Electric Power Steeing) has been a popular system in the automotive industry since 2000 after the technology and safety was validated. The Korean Refrigerated Carts like Hankook Yogurt Coco was developed for the first time in the world. However this carts system and other small tranporting carts has no EPS. Thus the drivers of carts needed a EPS to avoid the burden when steeing a big weighted cart with 750Kgf as many women drivers complain the pain on their shoulders. This paper describes the application of EPS on Korean refrigerated carts with simulation results and experimental data shows the improvement of steering efforts.

In the power steering systems used for automobiles, because of its small size and low noise, a balanced type hydraulic vane pump is mainly used as a power source. Therefore it is requested to research on the lubrication characteristics of a oil hydraulic vane pump which is the key part to improve its performance. The performance of a oil hydraulic vane pump is influenced by the lubrication characteristics of the critical sliding components. Thus, lubrication characteristics between the shaft and the journal bearing have to be researched for the design and the performance improvement of a oil hydraulic vane pump. Therefore, in this paper, it is theoretically investigated that the lubrication characteristics between the shaft and the journal bearing of a balanced type oil hydraulic vane pump for power steering systems. The results demonstrate that lubrication characteristics are significantly influenced by the clearance between the shaft and the journal bearing.

The purpose of this study is to design and control position and torque based on the steering controller of power tiller simulator developed by the National Institute of Agricultural Sciences. The tiller simulator selects sensors and motors to detect the motion of the mechanism required for steering, and controls the tiller's steering controller through the PID control method and the PWM control method which can control simultaneously the position and torque. Simulation tests are carried out under various conditions to verify the efficiency of the proposed controller. The power tiller training simulator can be used as a means to prevent agricultural machinery accidents caused by human factors. Through the simulator, the driver can experience a variety of tasks without any risk of collision, the results of his actions, and learn the cause and effect concepts, which can be used for safety education and accident experience.

In commercial vehicles. the pulsation noise when the power steering operating is the major item to make the complain for users. If this noise have related to vibration characteristics in steering system's parts or assembly, it makes the problem in vehicle quality. Recently, the users demand the high quality in commercial vehicles, and we must identified the relevance between the pulsation noise and the vibration characteristics. After the identification, we can design the power steering system for satisfaction the user’s needs. Finally, the identification of relevance in pulsation noise for analysing the vibration characteristics will be suggested advanced power steering system.

Most of the commercial vehicle steering system is hydraulic. In this system, Breakage and leakage of oil tank is the cause of serious problems to inhibiting the vehicle direction control of the driver. In this paper, FSI(Fluid-Structure Interaction) analysis was performed considering the sloshing of oil in the tank for structural safety evaluation of the power steering oil tank. Additionally, vibration analysis of simple and fast evaluation method was performed by assuming the fluid to mass. As a result, sloshing analysis of oil in the tank was confirmed from the FSI vibration analysis, and it could get the distribution of the flow pressure 8.2kPa～-5.5kPa. Second, stress change of the FSI vibration analysis results was greater in the 33.6MPa to 0.25MPa during the transitional period 2cycle, then it showed a stable result. Third, maximum stress of FSI vibration analysis considering sloshing of the oil was 2.22MPa. maximum stress of vibration analysis assuming the fluid to mass was 4.50MPa and 103% higher than the FSI vibration analysis, but the oil tank was safely evaluate structurally safety factor 14.1. Finally, without the FSI vibration analysis by applying a weight of 0.5 to the result of vibration analysis assumes fluid to mass, it could be obtained results similar to FSI vibration analysis.

Most of the commercial vehicle steering system is hydraulic. In this system, Breakage and leakage of oil tank is the cause of serious problems to inhibiting the vehicle direction control of the driver. In this paper, FSI(Fluid-Structure Interaction) analysis was performed considering the sloshing of oil in the tank for structural safety evaluation of the power steering oil tank. Additionally, vibration analysis of simple and fast evaluation method was performed by assuming the fluid to mass. As a result, sloshing analysis of oil in the tank was confirmed from the FSI vibration analysis, and it could get the distribution of the flow pressure 8.2kPa～-5.5kPa. Second, stress change of the FSI vibration analysis results was greater in the 33.6MPa to 0.25MPa during the transitional period 2cycle, then it showed a stable result. Third, maximum stress of FSI vibration analysis considering sloshing of the oil was 2.22MPa. maximum stress of vibration analysis assuming the fluid to mass was 4.50MPa and 103% higher than the FSI vibration analysis, but the oil tank was safely evaluate structurally safety factor 14.1. Finally, without the FSI vibration analysis by applying a weight of 0.5 to the result of vibration analysis assumes fluid to mass, it could be obtained results similar to FSI vibration analysis.

There are many causes of interior noise in commercial vehicles. The one of them is power steering noise and this study try to reduce the power steering noise by theoretical consideration. The interior noise was tested for the real truck and analysed the frequency. For reducing the interior noise, the spiral tube was adapted and modified the structure in the steering system. The spiral tube system was analysed and made the formula to calculate the reducing frequency. And the effective frequency for reducing the interior noise was calculated by changing the length of tube. Finally, we found the possibility between thoeretical results and real interior noise by comparing the frequency results. The second, the experimental consideration will be worked in power steering system. Finally, the optimal design result will be suggested for reduce the noise.

This study is making a product for the development of a process worm wheel of making a shape for gear for worm wheel without hobbing manufacturing process. Because of removing a hobbing process, plastic worm wheel for increased productivity and equivalent quality is produced in this molding, As the result, this important process is to manufacture a EPS worm wheel of small and middle stage cars and hybrid vehicle. Especially, the main goal of this study is as follows. The worm wheel design software of electronic power steeringis developed through this study. CAD file of this software is expressed as design notes and design shape of worm gear for manufacturing of worm wheel.

This study is making a product for the development of a process worm wheel of making a shape for gear for worm wheel without hobbing manufacturing process. Because of removing a hobbing process, plastic worm wheel for increased productivity and equivalent quality is produced in this molding. As the result, CAE manufacturing process for a EPS worm wheel of small and middle stage cars and hybrid vehicle is developed. Especially, the considerations for analysis results of worm wheel are as follows. the first, CAE analysis for worm wheel of first stage is considered. the second, CAE analysis for boss is considered. the third, CAE analysis for gear module strength of first stage is considered. Finally, the redesign of product drawings for troubled-considered in first stage try-out is considered in EPS worm wheel.

Steering gear is the part of an automobile that change circular movement of steering wheel to lateral movement of rack to change driving direction. This can be classified with manual and power steering gear. Manual steering gear is operated only with human power while power steering gear use oil pressure support. These days power steering gear is more common to almost of the car. Recently a korean company manufactures a speed sensitive power steering which provide variable steering feel depend on the speed of car. The Broens company of Australia produces and exports the test equipments for the manufacture of power steering valves and assemblies to major vehicle manufactures. Some korean companies imported the test equipments from Australia, thus increasing the cost. The purpose of this study is development of the valve balance test equipment to measure the valve torque of the power steering gear. This study designed and manufactured the valve balance test equipment to take hold of the power steering valve using CAE analysis. In order to evaluate the performance of the developed valve balance test equipment, the R&R tests have been conducted.

Power steering gear is the part of an automobile. That converts circular movement of steering wheel into lateral movement of rack for changing driving direction. Recently power steering gear gets more common. A Korean company manufactures a speed sensitive power steering gear, which provides variable steering feel depending on speed of the car. However, the Broens company in Australia produces and exports the test equipments for manufacturing power steering valves. Some Korean companies import the test equipments from Broens and the maintenance cost gets increasing. The purpose of this study is development of the valve balance tester to measure the valve torque of the power steering gear. This study designed and manufactured a chuck and a jig of the valve balance tester to take hold of the power steering valve using CAE analysis.

With the development of mechatronics technology in the transporter industry, the electric power assisted steering (EPAS) system has many advantages compared to the hydraulic system. Many manufacturers are developing and applying EPAS systems to improve the performance of the transporter. Using the HILS system developed in the paper, an adaptable EPAS system was developed for real transporter. It was installed in a real, KIA Rio, and tested. Results indicated outstanding performance. Therefore, the developed EPAS can be applied via HILS system.