The Analysis of Torsion Vibration to Engine Crankshaft Breaking

• Main Authors: Po-Tsun Lin, 林柏村
• Other Authors: Jang-Ping Wang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/17449245144093881264

碩士 === 國立臺灣海洋大學 === 輪機工程系 === 99 === This research paper is focused on the discussions of crankshaft design about the effects to the range of torsion vibration in a diesel engine. This paper used the software named ANSYS workbench to calculate the natural frequencies by different fillet angle sizes at crank corner and discuss the effects based on the frequencies of rotation directions. This paper used the diesel engine typed LIBERTY-12 as a sample. The range of engine’s rating speeds is adopted to investigate the effects to the crankshaft when the fillet angle sizes at crank corner are changed. The purpose of this study is to improve the calculate method proposed by Holzar table method and can be set as a reference data for the other researchers studied in calculating such problems. In this study, three fillet angle sizes are adopted such as 0.1inch (2.54 mm), 0.15inch (3.81 mm) and 0.2 inch (5.08 mm). The frequencies are calculated for all of the fillet angle sizes. It is found that the frequency slightly increases and the maximum stress decreases with the increase of fillet angle sizes at the crank corner. It can be ascribed to the increase of material on the fillet area that gets higher stiffness. The results also show that the values of natural frequency are not coincided with the literature data. Therefore, a correction by frequency response simulation is fulfilled at rating speed. Finally, it is found that the solutions show much close to the results for the three fillet sizes by the simulation of natural frequency and frequency response.