Geun-Ho Lee

Optimal Design of Wind Turbine Gearbox using Helix Modification

Abstract Planetary gear sets, used commonly in wind turbine gearboxes, should have good load distribution on gears to improve the durability. In this paper, the influences of external loads caused by wind fluctuation on the load distribution on the gear tooth flank are investigated. A state-of-the-art whole system model is developed to analyze the planetary gear set for the WTG. The results of gear mesh misalignment, contact pattern, load distributions are predicted and the gear safety factor is also evaluated. Therefore, the results presented state that if the optimal helix modification is applied, the edge loading of gear tooth ends disappears, contact pattern improves significantly, the face load factor decreases and the gear safety factor increases.

Influence of Flexible Pin for Planets on Service Life of Wind Turbine Gearboxes

An overhung mounted carrier with flexible pins is applied to the planetary gear train of a wind turbine gearbox to investigate the influence of the self-aligning effect by means of the deflection of the planet spindle and the flexible pin on the lifetime of the planet gear for a wind turbine gearbox. To analyze the load distribution of planet gears, both Euler theory and commercial software are employed. By applying an overhung mounted carrier with flexible pins in the wind turbine gearbox, we can improve the misalignment performance, face load factor, and service life of the planet gears. In particular, it was confirmed that a service life of more than 20 years could be realized for wind turbine gearboxes by applying a flexible pin to the overhung mounted carrier.

Development of Analysis Model of Pressure·Flow-controlled Swash Plate Type Pump for Evaluating Feasibility of Design

This study aims to verify the feasibility of design by developing pressure·flow-controlled swash plate type pump with the use of SimulationX, a computer analysis program. Developing analysis model based on design drawing data has a cost-saving effect because it is possible to figure out the effectiveness of design through the work and it never falls into repeated inaccuracies in the production process. Analysis model is developed in the following order. First, the structure of each part such as valve and rotating unit which have dynamic factor is analyzed and the modeling of single component is carried out, reflecting drawing data. Second, the modeling of pump assembly is carried out with the combination of each analysis model and a work is conducted to determine whether the modeling can perform pressure·flow control function according to load condition smoothly based on design intent. At the end of the modeling process, the feasibility of design is verified by showing the parts which are moving as expected mechanism.

Design of a Torque Application Device in Test Rig for a Wind Turbine Gearbox

* Dept. of System Reliability, Korea Institute of Machinery and Materials, ** Construction Equipment Technology RB Revised January 2, 2015; Accepted February 16, 2015)Key Words: Wind Turbine Gearbox(풍력발전기용 증속기), Mechanical Power-circulation Test Rig(기계식 동력순환 시험 장비), Torque Applying Device(토크 인가 장치), Planetary Gearbox(유성기어박스) 초록: 본 연구는 5.5MW 증속기용 기계식 동력순환 시험 장비의 핵심 기능을 하는 토크 인가 장치의 개발 및 검증에 관한 것으로, 설계 및 해석이 수행되었다. 또한, 시험 장비의 각 부품에 대하여 회전각을 측정하여 비틀림 강성을 확인하였다. 시험체를 제외한 시험 장비에 토크를 인가하여 각 부품의 회전각을 측정한 결과 시험 장비의 비틀림 강성은 정방향에서 231.13 kNm/rad으로 나타났으며, 증속기 1대의 비틀림 강성이 1,064,400 kNm/rad보다 큰 경우 정격 토크를 인가할 수 있다. 따라서 시험 장비의 회전각 한계로 인하여 시험체 증속기의 비틀림 강성에 따라 정격 토크 인가 여부가 결정된다. Abstract: This study was conducted to develop and verify a torque application device for use in a mechanical power-circulation test rig for 5.5 MW wind turbine gearboxes. The design and analysis of the torque application device was conducted . In addition, the torsional stiffness of the test rig was calculated using the rotational angle measurements for each of the components. The calculated stiffness of the test rig was 231.13 kN·m/rad for a clockwise torque application . The rated torque can be applied when the stiffness of the gearbox is greater than 1,064,400 kN·m/rad for a clockwise torque application . Because of the limited rotational angle of the test rig, the potential application of the rated torque is determined according to the torsional stiffness of the test gearbox.