• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.101-105
• /
• 2004

The traction drive have a high power transmission efficiency and small size, a light weight, a low noise. So it is expected that alternative drive part of engine. Because it is necessary stillness that essential condition of drive part used moving tool in a room, it has many-sided in field of application. This traction drive is better suitable than other speed reducer as drive part of electric wheelchair. Also it is sufficiently necessary capacity of existing advanced product as apply traction drive to electric wheelchair.

• Proceedings of the KSR Conference
• /
• 2002.10a
• /
• pp.434-439
• /
• 2002

The researches on the direct drive system, which directly transfers axle load of the traction motor to wheels, have been developed as a next generation drive system in Japan and Europe. As a result of excluding couplings and gear units, the direct drive system has advantages on the bogie mount space to be smaller sized, lower noisy, more efficient and less weighted than the conventional drive system - indirect drive system. Since the simplification of the direct drive system design depends on the design of the traction motors, the researches on the direct drive system with focusing on the traction motors get started. The advantages/disadvantages of direct drive system, types, structures, cooling systems and interfaces of the traction motors are presented on this paper. Furthermore, the development of other countries on the electric equipments of the next generation railway vehicles are discussed and the necessity ＆ requirement for developing new concepts of traction motors are assured.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2001.06a
• /
• pp.360-366
• /
• 2001

This paper show the designing, manufacturing and performance test procedure of a high speed, fixed ratio planetary roller type traction drive as a speed reducer. The arrangement and size design for sun roller, planetary rollers and ring roller are carried out and a proper pre-load mechanism are adopted. To improve transmitting power capacity and endurance limit, nitro-carburized bearing steel and a synthetic traction oil are used. The manufactured and assembled traction drive operated successfully under unloaded conditions. Further tests for various load and speed conditions are executing now to improve the performance of the traction drive.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.3
• /
• pp.35-40
• /
• 1997

The traction drive has advantages of having high efficiency and transmitting the power without blacklash. However, when high ratio of speed reduction is desired, excessively large size is required. In this study, a new type of traction drive is invented, designed and manufactured so that stable speed reduction mech- anisms are available by adopting a cross roller type drive. It has a simple structure, but produces high speed reduction ratio. Power loss is observed, and also, driving torque and torque transfer efficiency are calculated. Pre-loads are needed in order that the traction drive transfers power without slipping, and the spacer is enlarged due to the pre-loading. After all, the key point of pre-load mechanism is that the spacer's diameter becomes larger as pre-loads are applied.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.688-694
• /
• 2009

As a drive system for next generation train, we have been making research and development of a direct drive traction motor system without the conventional reduction gear. This traction motor is expected to have many advantages such as low noise, reduced maintenance, and energy saving. Due to the demand for high-output motors in the limited space between the wheels, open-ventilating traction motors with gear box have been widely used for many years. However, a conventional open-ventilating traction motor is necessary periodical disassembly to remove the accumulated dust from open-air ventilation. Reducing this burden, as well as increasing energy efficiency and reducing noise, would benefit the next generation of traction motors. To address these needs, KRRI have been developing a fully enclosed type direct drive motor(DDM) with high-efficiency permanent magnet for the next generation train.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.55 no.2
• /
• pp.62-66
• /
• 2006

This thesis focuses on the design of control schemes for highly efficient BLDC motor drive applications using drives with output capacity of 1Hp. The control system was designed and implemented on a PIC micro-controller and applied to an electric vehicle as a viable replacement to the existing a high phase induction motor that is currently being used for these low cost, small traction drive applications. This paper for the brushless drive research has shown the optimization of the drive system for improved drive design and switching techniques that can improve the entire drive system efficiency for electric vehicle both large and small traction applications using sinusoidal PWM techniques for synthesizing the AC waveforms needed to control these traction drives. In addition, Numerical simulation was conducted to evaluate the performance of designed BLDC Motor using MotorPro simulator.

• International Journal of Railway
• /
• v.5 no.1
• /
• pp.38-47
• /
• 2012

At present among the most important problems in the field of traction systems of railway vehicles are the following: 1) the minimization of the mass-and-overall dimensions of the drive systems; 2) the increase of the drive systems reliability and obtaining their higher fault-tolerance abilities; 3) the minimization of the motion speed pulsations and its oscillations, etc. The results of the researches received by the authors of this paper show that the use of the multiphase (i.e. having the number of phases more than four) inverter-fed induction motors in these traction systems is the most effective way of solving the above mentioned problems. In this case the motion speed oscillations can be decreased only by the increase of the drive phase number without any change in the inverter control algorithm. In addition, the application of some non-traditional control methods in the multiphase asynchronous traction drive system of a railway vehicle allows to decrease the mass-and-overall dimensions of the system and to improve its reliability and some other technical-and economic characteristics.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.11 no.4
• /
• pp.378-384
• /
• 2006

In this paper, the design and performance analysis of switched reluctance motor(SRM) according to the design parameters are researched for a traction drive. The parameters which are sensitive to the performance are examined and selected to have good performances. For the high performance of traction drive, some effective guide lines to have a good performance motor are suggested. The prototype machine is constructed to compare with the simulated and tested for the comparison of design results.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.48 no.11
• /
• pp.646-654
• /
• 1999

This paper deals with PWM patterns for harmonic reduction in inverter fed traction motors and the gear changing techniques for the variable speed drive of traction motor. GTOs are used as switching device of inverter because traction motor is a large load. To derive PWM rattern which can minimize the harmonics with the limited switching frequency, the output current and torque characteristic of SPWM and SHE PWM was analyzed. GTO inverter used for traction motor drive includes harmonics in the output current and torque by the limitation of switching frequency. However, the hybrid PWM method that adopt SPWM in the range of low frequency and SHE PWM in upper frequency range can achieve less harmonic characteristics in GTO inverters. If the traction motor is driven in variable speed by the proposed PWM pattern, 7 times of gear changing is needed. At the instant of the mode change, magnetic flux and torque may be altered and the large current flow. To reduce such an undesirable transient behavior, it is also presented the technique for the gear changing of inverter fed traction motor drive operated with the hybrid PWM. The results are verified by simulations and experiments.

• Journal of the korean Society of Automotive Engineers
• /
• v.14 no.1
• /
• pp.38-46
• /
• 1992

An optimal design technique for minimum power loss in Kopp Ball Variator Continuously Variable Transmission is developed. Kinematic analysis of traction drive contact is performed to find spin for Kopp Ball Variator, and traction force and torque are calculated from mathem atical model of traction drive contact. The objective function for optimal design is total power loss including contact loss and bearing losses. The design contraints are derived from energy balance for input and output power. The formulated optimal design problem is implemented to a non-linear programming algorithm to find minimum power loss. The performance of optimal ly designed Kopp Ball Variator shows that efficiency is increased about 5-10% compare to a commercial unit.