Contact Analysis of the ZN type Worm Gear and the ZK type Worm with a non-ninety-degree crossing angle

• Main Author: 廖健雄
• Other Authors: Chung-Biau Tsay
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/u6ksd6

碩士 === 國立交通大學 === 機械工程系所 === 92 === Tooth undercutting may occur for conventional gear sets with a small number of teeth, especially for a single stage gear-set with a high reduction gear ratio. Nevertheless, worm gear sets can conquer this issue which spur and helical gear sets could not provide. Worm gear sets are transmission mechanism of high contact ratios. Increasing the contact ratio of a worm gear set not only improve position precision and stability, but also increase load capacity of the worm gear set, which enables it to apply to some particular environments. In this research, the worm gear set with a non-ninety-degree crossing angle not only increase the contact ratio but also obtain different properties by changing the crossing angle of a worm gear set. In this research, the mathematical models for the ZN type worm gear and the ZK type worm are developed based on the theory of gearing and the technique of computer aided design. According to the developed mathematical models and the tooth contact analysis technique, contact situations of a worm gear set, including kinematic error, instantaneous contact teeth, average contact ratio, contact ratio and contact ellipse are investigated. Besides, the influence of different design parameter and different crossing angle on the contact situation of a worm gear set are also studied. Furthermore, contact situation and contact ellipse of a worm gear set under ideal and error assembly conditions are investigated.