| Modern manufacturing require machine with high-speed and high-accuracy. Linear motion ball guide has a good performance of compact, responsive, bearing and the advantages of simple installation, as a supporting components in the processing center, NC machine tools industry was used more and more widely. The performance, accuracy and life of domestic product has certain gap with the same type of overseas product.Analyzing preloading on performance of the linear motion ball guideway, has a great significance. the main contents of this paper is theoretical analysis, simulation and experimental validation and integration on performance of slider stiffness, ball movement, load distribution, accuracy average under preloading. It can be divided into five aspects as following:1. according to structural characteristics and channel contact of linear motion ball guideway with Hertz contact theory and the theory of elasticity built up the model of elasticity distortion of balls in the slide under preloading. This paper analyzes the ball contacts state with Hertz theory combining structural characteristic . and on this basis further analyze the slide offset.2. according to the theory of rolling bearings, establishing the movement model of bearing areas and reverse areas of linear motion ball guideway .Conclude the mathematical model of effective rolling and ineffective sliding model. Study on the ratio of effective rolling and ineffective sliding.3. it is believed that imposing preloading will reduce the affording ability of linear motion ball guideway. But preloading and work load imposed manner is not the same. Through finite element simulation software can draw conclusions, Preloading can improve load distribution of torque and thrust , reducing of the maximum load. Increasing the number of bearing balls. under thrust, at the time, the ball will increase the load, but can effectively increase the number of bearing balls. And also studying on the way of avoiding failure preloading.4. the preloading has great effect on ball stiffness, sports and load distribution , also has a great effect on accuracy, through theoretical analysis ,as the preloading increasing, the accuracy to be enhanced. Borrowing sthers experimental data to verify the theoretical analysis is correct. Introducting the Weibull distribution of three parameters .linear motion guide for life, forecast the life of linear motion ball guideway. |
