The utility model has the advantages of simple structure, convenient manufacture and high contact rigidity. However, the sliding guide of the transmission has the characteristics of high friction resistance, fast wear, large difference in static and dynamic friction coefficients, and easy "crawling" at low speeds. Therefore, plastic sliding guide rails have been widely used in CNC machine tools. Compared with other guide rails, plastic guide rails have a small friction coefficient, a small difference between dynamic and static friction coefficients, which can prevent low-speed crawling; good chemical stability, good vibration resistance, and good self-lubricating; simple structure and technology, low cost, and CNC machine tools The plastic guide rails used mainly include glued plastic guide rails and plastic coated guide rails.
Pasting the plastic guide rail is to paste a layer of plastic guide rail soft tape on the moving guide rail, usually used together with the cast iron guide rail or the quenched guide rail on the support guide rail. The plastic guiding soft belt is a composite material made of polytetrafluoroethylene as the matrix, alloy powder, oxide and other fillers. Because the material is soft, the bearing capacity is low, the dimensional stability is poor, and it is easily scratched by hard objects, and good sealing and protective measures are required. Plastic guide rails of various thicknesses, specifications, lengths and widths can be cut and fixed by pasting.
Coated rails are plastic rails formed by plastic coating or injection molding between the moving rails and the supporting rails. The plastic coating material is based on epoxy resin and molybdenum disulfide, added with plasticizer, mixed into a liquid or paste two-component plastic coating, and the curing agent is the other component of the epoxy-type wear-resistant coating . After adjusting the gap between the guide rails, the two groups of materials are mixed in a certain proportion and applied to the surface of the movable guide rail to solidify the surface of the plastic guide rail. The utility model has good workability, no shrinkage after curing, stable size, good friction performance and good wear resistance. Its compressive strength is higher than that of PTFE guided soft belt. It is often used for difficult-to-use guiding soft belts on heavy machine tools and complex mating surfaces.
Plastic rails are usually used on the moving rails of rail pairs. There are two types of metal rails that match the plastic rails: cast iron and steel inlays, forming cast iron plastic rail pairs or steel inlaid plastic rail pairs.