• Transactions of The Korea Fluid Power Systems Society
• /
• v.6 no.1
• /
• pp.10-16
• /
• 2009

Automatic power transmission systems consisted of a torque converter and several planetary gear sets, clutches and brakes are controlled by a hydraulic shift control circuit and an electronic transmission control unit. The hydraulic circuit serves for the operation of the torque converter and lubrication oil supply of the transmission system as well as for the actuation of clutches for the automatic gear shift. The complicated hydraulic control circuit constructed by many spools, solenoids, orifices and flow passages are integrated into one small valve block and it is powered by one hydraulic pump. In this paper, a test equipment was developed to measure the oil consumption of each component at various wide operating conditions. Test data about 730 sets acquired from five test items are analyzed and discussed on the oil capacity of the circuit.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.15 no.2
• /
• pp.46-50
• /
• 2016

When rotating the clutch drum in the power take-off (PTO) gear box of an armored recovery vehicle, lots of inner oil is drained through the adapter by centrifugal force. Therefore, a lack of lubrication is caused by inner oil loss, and the bearing is damaged by overheating. This study, therefore, aims to design an oil-controlling adapter by using shape alteration to prevent oil loss. Both the original and improved adapters were tested at 1,800rpm by using an operational test machine. When applying the original adapter to the gear box, the bearing was damaged by overheating, which was caused by the lack of lubrication. When applying the improved oil-controlling adapter, on the other hand, it prevented the loss of inner oil. Applying the improved adapter is expected to prevent the overheating caused by lack of lubrication.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.10a
• /
• pp.670-671
• /
• 2016

AMT(Automated Manual Transmission) is manual transmission that can shift gear automatically by actuator. AMT is applied many commercial vehicles, for easy to operate and high fuel efficiency. 12-Steps AMT that is applied heavy duty commercial vehicle determine gear shifting point by using shifting map and auto shifting logic like other common auto transmissions. But shifting 1-step like common auto transmissions makes shifting crush, clutch abrasion, decrease fuel efficiency problems. In this paper, it deals with design of shifting map and auto shifting logic for 12-step AMT and result of performance test.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.774-780
• /
• 2021

The auxiliary power unit (APU) of a rotorcraft starts the engine during operation/flying. The APU is composed of a gas turbine engine type. The starting principle of the component is that the electric start motor generates the power required for starting by rotating the shaft. In this study, quality improvement was performed by applying an over-running clutch (ORC) between the APU and the starter motor to secure the operability of the starter motor of the APU mounted on the rotorcraft. The starter motor has the main role of starting the APU, but during operation, it is rotated without load by the rotational force of the APU gear shaft, resulting in friction at the brush. This phenomenon causes abrasion of the brush of the starter motor. Consequently, when the APU operation time increases, the brush life decreases, and the operability of the APU is affected. In this study, an ORC that separates the interlocking between the start motor brush abrasion and the APU operation time was applied to improve the operability/durability of the APU starter motor. The effect was verified through a test, and the technical feasibility of the design change was analyzed.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.7 no.9
• /
• pp.75-81
• /
• 1999

In this paper, the details of electronically controlled CVT is described , which Kia Motor company recently developed in prototype form for hybrid passenger car. This transmission has two input shafts, one for engine and the other for traction motor. The shaft for traction motor is located at rear side which is extended from primary pulley shaft and connected to traction motor through adapter gear box. Adopting two input system, various driving mode is available such as motor alone driving in hybrid vehicle application. As far as electrohydraulic system concerned , this transmission uses two bleed type variable force solenoids for line pressure and ratio control, and one on-off solenoid for clutch control. Another feature for this transmission is that oil pump for transmission is separate from CVT for supplying oil pressure even at vehicle standstill.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.313-317
• /
• 2005

Precision motor dynamometer is requiring for nano positioning control performance recently. Particularly, linear motor is using rapidly and the dynamometer needs is increasing. In this study, a precision control dynamometer is designed using MR (Magnetic Rheological) damper. The ultra precision motor system including the driver and controller is tested using the MR damper dynamometer. This dynamometer is able to measure torque for rotary motor or traction force with linear positioning accuracy for linear motor system.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.10
• /
• pp.935-945
• /
• 2014

This paper presents a new road generative system that employs a pad of preventive overspeed or tollgate. The system consists of pad, shaft, torsional damper, oneway-clutch, gear system, and electricity generator components. When the car driven through the road generation system, it occurred to surplus energy in the DC power. In order to maximize the power of electricity energy harvester, the simulation software is developed. It is used to determine parametric dimension for optimal design with the theoretically calculated results from the simulation software. The transient responses at the conditions of low and high vehicle speed are compared with the calculated results as torque, impact force, power, out energy etc. Consequently, before design a road generation system, the analysis of simulation results shows that the proposed concept and system has efficiency and confidence.

• Journal of Power System Engineering
• /
• v.6 no.2
• /
• pp.73-81
• /
• 2002

In this study, electronically controlled automatic transmission adopted on a subcompact model in the market was modelled, and the driving performances of the transmission were simulated with the models. Kinetic and dynamic models of working components are established. The driving simulation program is developed with those models, and the various driving conditions are analyzed. With the results, the dynamic behaviour of the engine and the automatic transmission is easily understood. Especially, the transient performances of torque converter and clutches are deeply analyzed. Skipping the vehicle road test by using this analyzing tool, we can expect the cost down and the reduction of the development period of automatic transmission.

• Proceedings of the KIEE Conference
• /
• 1998.11b
• /
• pp.487-489
• /
• 1998

To evaluate vehicle performances and driving behavior of a vehicle, it is necessary to acquisit and analyze vehicle data during the vehicle driving, which affect fuel economy and emissions. An in-vehicle data acquisition system, which is called Mode Survey System(MOSS), is designed and developed to analyze the traffic and driving patterns of the vehicle. MOSS is a stand-alone system based on the 68HC11 MCU. MOSS logs various data relating to powertrain and vehicle driving such as vehicle speed, engine RPM, gear position, brake, clutch, fuel consumption, and others. The driving patterns are dependent on the driver's habit and the road and traffic conditions, these driving patterns would be able to make a official driving mode to be used in emission, fuel efficiency, shift survey, catalyst durability, and other tests using the analyzed driving patterns.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.13 no.6
• /
• pp.99-104
• /
• 2005

The CARB in USA has demanded OBD functions that detect any deterioration of performance of OTS as well as a simple defect of OTS which can affect emission to meet the reinforced emission regulation. In this paper, OTS plausibility monitoring functions to meet the demand from CARB are discussed. The output from OTS is used for the diagnostics of the torque converter clutch stuck and the gear ratio synchronous error. It is possible to diagnose the abnormality of OTS function by considering the oil temperature characteristics which changes according to the driving status of vehicles. In result, the OBD regulations of the CARB can be satisfied obligating car manufacturer to detect any problems in OTS functions which can affect emissions.