Unlike wheeled vehicles, tracked armored vehicles require a highly developed transmission technology since the transmission has to not only shift gears but also steer and brake the heavy ground weapon system precisely. Even though weapons systems including the K00 Infantry Fighting Vehicle (IFV) have recently been developed with domestic technology, it is true that many core parts in the systems are still being imported. In this paper localization process of the accumulator which is one of the most important hydraulic parts in the K00 transmission is introduced. In order to determine design variables such as operating pressure we analyzed torque characteristics of the transmission and calculated spring constant by disassembling the original accumulator. And tests such as durability, safety, etc. were conducted to assure the validation of the development. We expect that the process of reverse engineering we adopted will be helpful to localize similar hydraulic parts.

As hydraulic power has big dynamic fluid force and fast response, fluid power system is used in a wide variety of applications from precision control systems to heavy industrial systems. There are many hydraulic components in hydraulic power systems. Among them, accumulator has several functions such as pressure regulating and storing pressured fluids and it also can relieve the power of hydraulic pump. So, in many hydraulic systems, accumulators are used in proper positions. This thesis develops hydraulic systems which contain exciting damper, accumulator and some other hydraulic components. An external excitation is given to the hydraulic damper to simulate the system pressures and flow-rates. From these simulation data, required hydraulic power can be calculated and a proper size of the accumulator can be designed. The hydraulic system with the designed accumulator is restructured to calculate the overall required system power. Finally, analysing the difference between the hydraulic systems without an accumulator and the hydraulic systems with the suggested accumulator, it is investigated that how effective the accumulator is to save the system power.

More recently, unsteady flow in small-diameter pipes plays a major role in liquid propellantrocket systems, hydraulic and pneumatic control system, and elsewhere. And it has shown that line dynamics can have a marked effect on the hydraulic system characteristics. In this paper, transfer function of hydraulic lines with an accumulator and an outlet orifice is' developed and compared with experimental data from frequency response tests at various airvolume(V.) and the location of accumulator(ld1t), so that their performance may be correctly and easily predicted and the design of the systems incorporating them improved. The obtained results are as follows: 1. The dynamic response of hydraulic lines may be analyzed more accurately by use of the viscous term(22) in unsteady laminar flow. 2. There was good agreement between the theoretical and experimental results of this investigation, and hydraulic systems with liines included an accumulator can be analyzed more accurately by use of the pressure transfer function given by eq. (16). 3. For the mitigation of surge in hydraulic lines, it is more effective that the location ofaccumulator is close to the pipe outlet side. 4. According to the gas volume of accumulator is increased(the sealing pressure is close tomean line pressure), the damping effect of pressure wave is improved.