Effect of groove shape in ball parts on tribological properties under high contact pressure

• Main Authors: Ming-Yuan Chiu, 丘明遠
• Other Authors: Jeng-Haur Horng
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/4d6525

碩士 === 國立虎尾科技大學 === 機械與機電工程研究所 === 103 === The article discusses orbit movement of the single ball in different groove shape and contact angle. Meanwhile, it designs a innovative experiment machine for the single ball, where the experiment on different initial contact angle(Gothic, V type, trapezoid type) under high contact pressure can be operated, on the condition of different orbit groove shape, which is supposed to be one of the development direction of Heavy-Duty Ball Screw, All-Electric Injection Molding Machine and Ball Bearings. The experiment result shows that in the case of fixed axial load and rotation speed, contact pressure changes with initial contact angle, axial load and contact angle. Gothic groove shape loads in same axial, rotation speed increases; Gothic groove shape loads in same rotation speed, contact angle and offset increase. Contact angle increasing leads to normal load increasing, so friction coefficient increases accordingly. If contact pressure increasing, friction coefficient and contact pressure can be reduced effectively and transmission efficiency can be increased by Gothic groove shape increasing groove shape factor properly and reducing initial contact angle. Trapezoid type and V type load in same axial, rotation speed increases; they load in same rotation speed, contact angle and offset increase, which lead to normal load and contact pressure increase. The only difference from Gothic groove shape is that Trapezoid type and V type increase initial contact angle, which can reduce friction coefficient. In the case of high load and rotation speed, the experiment result shows, when Gothic groove shape factor is 0.55, initial contact angle is 45°, friction coefficient is lower that with 0.52 Trapezoid type and V type. In addition, in the case of high load and low rotation speed, when initial contact angle of V type is 55°, friction coefficient is the lowest compared to that on other conditions.