The Linear Guideway Property Measurement System Design and Testing of Linear Guideway

• Main Authors: Keng-Hao Hsu, 許耿豪
• Other Authors: Dein Shaw
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/52254945771758756905

碩士 === 國立清華大學 === 動力機械工程學系 === 94 === 　　A linear rolling ball guideway is a key component of many high speed machines. It can achieve high positioning accuracy (μm order) and reduce the friction force effectively. However, due to the point contact between the rolling balls and the rail, the rigidity of a linear rolling ball guideway is lower than that of a sliding guideway. Also, the contact stress is higher in a linear rolling ball guideway. 　　The purpose of this study was to design and setup a multiple linear guideway property measurement system which could measure the deformation, friction force and vibration of the linear guideways (in this study, the preload of the linear guideway was considered as very light or medium level). The variations of the deformation, friction force and vibration with different break-in distance were obtained in this research. Measuring the fore-mentioned characteristics via only one measurement system took the following advantages: (1) the same set of driver and mechanism could be used for measuring each characteristic; (2) the required space was smaller than that of measuring each characteristic using a lot of equipments, and (3) to avoid troubles when assembling the linear guideway in different measurement systems. 　　In this study, the theoretical model of vertical deformation of the circular contacted linear ball guideway was developed by both the geometry relationship and Hertz theory. In addition, the ball passage vibration of linear guideways with different interferences was calculated. 　　The experimental results showed that the stiffness of the medium preload linear guideway is higher than that of the very light preload one. It was also showed that the stiffness of the guideways increases slightly after the guideways are properly broken in. The friction force of linear guideway is not only associated with preload but also with driven velocity. With the appropriate break-in period, the friction force decreases slightly. However, the friction force of the guideway with 40 to 80 km break-in distance was found higher than that of the guideway with 0 to 20km break-in distance. The vibration spectra are affected by the velocity and preloads. As the velocity increased, the amplitude and the frequency of the main peak in spectra are also higher. At the same driven velocity, the frequency of the main peak of the medium preload linear guideway is higher than that of the very light preload one.