There are two kinds of rolling guides: one is rolling and the other is sliding. Now the design principle of the last unit between the slider and the slide rail: sliding friction becomes rolling friction. Introduction, principle, comparison, applicable occasions, structural forms, classification of ball guide rail, roller guide rail and needle roller guide rail. The final unit design between the slider and the slide rail makes the linear slide rail bear loads in all directions at the same time, which is patented reflux. The principle of rolling guide is to place rolling elements such as balls, rollers and needle rollers between the guide surfaces, so that the sliding friction between the guide surfaces becomes rolling friction. Comparative advantage: 1, high sensitivity, small difference between dynamic friction coefficient and static friction coefficient, so the movement is stable and crawling is not easy to occur at low speed. 2. The positioning accuracy is high, the repeated positioning accuracy can reach 0.2 micron .. 3, the friction resistance is small, the movement is light, the wear is small, and the accuracy retention is good. Disadvantages: the rolling guide rail has poor seismic performance and high protection requirements. Applicable occasions Rolling guide rails are especially suitable for occasions where the working parts of machine tools require uniform movement, sensitive action and high positioning accuracy. Structural form: the ball guide rail takes the ball as the rolling body, which has good motion sensitivity and high positioning; However, its bearing capacity and stiffness are small, so it is generally necessary to improve the bearing capacity and stiffness by pre-tightening. In order to avoid the loss of precision caused by pressing out pits on the guide rail, hardened steel is generally used to manufacture the guide rail surface. Ball guide rail is suitable for CNC machine tools with small moving parts and small cutting force. The bearing capacity and rigidity of roller guide rail are greater than that of ball guide rail, but the requirements for installation are also high. Improper installation will cause deviation and sideslip, accelerate the wear of guide rail and reduce accuracy. At present, CNC machine tools, especially heavy-duty CNC machine tools, generally use roller guides. Needle roller guide The needle roller of needle roller guide is longer than the roller with the same diameter. Needle roller guide rail is characterized by small volume and compact structure. In order to improve the motion accuracy of the worktable, the dimensions of needle rollers should be grouped according to their diameters. Needle roller guide rail is suitable for machine tools with limited guide rail size. Other classification of rolling guide rails According to whether they are preloaded or not, rolling guide rails can be divided into two categories: preloaded and non-preloaded. The advantage of preloading is to improve the rigidity of the guide rail, which is suitable for the guide rail with large overturning moment and vertical direction. This kind of guide rail is usually used in the coordinate axis of CNC machine tools. Non-pretensioned rolling guide rail is often used in conveying mechanisms such as manipulator and tool magazine of CNC machine tools. Supplement: CNC machine tools also generally use rolling guide rail support blocks, which have been made into standard parts, characterized by high rigidity, large bearing capacity and convenient disassembly, and can be directly installed on moving parts with any stroke length.