A STUDY ON THE MATHEMATICAL MODEL OF THE FACE-HOBBED STRAIGHT BEVEL GEAR

• Main Authors: Yi-Hui Lee, 李羿慧
• Other Authors: Yi-Pei Shih
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/72930754958768962051

碩士 === 國立臺灣科技大學 === 機械工程系 === 100 === The face-hobbing method is one of the leading methods for manufacturing spiral gears and hypoid gears. Because it is a continuous-indexing and double flank cutting process, it supports high productivity, precision, and cutting gears with better contact bearing. Since this method generates extended epicycloidal flanks of bevel gears, so it is not suitable for cutting straight bevel gears. In this thesis, a special straight line mechanism of hypocycloidal motion is utilized to fabricate straight bevel gears by setting the radius of a rolling circle equals to half of the radius of a base circle. The mathematical model of a straight bevel gear is developed based on a universal face-hobbing bevel gear generator. This model contains three modules: a face-hobbed cutter, an imaginary generating gear, and the relative motion between an imaginary generating gear and the work gear. The tooth tapering and undercutting conditions of the face-hobbed straight bevel gear are checked, and the contact conditions of the designed gear pairs are investigated by ease-off topography, as well as the TCA. In the thesis, the operating procedure for the tooth topographic measurement of bevel gears by gear measuring center is interpreted, and the nominal data are also generated. A numerical example of the face-hobbed straight bevel gears without a cutter tilt, in the essay, is presented to validate the proposed mathematical model, and then the experiment for measuring straight bevel gears is implemented to validate the nominal data.