(1) Reduce Pressure
Lowering pressure reduces the frictional force per unit area. L'aumento dell'area di contatto e la riduzione del carico possono essere utilizzati per diminuire la pressione. Per esempio, improving the straightness of the guide rail surface and refining surface roughness can increase the actual contact area. Additionally, widening the guide rail surface and extending the length of the moving guide rail can also increase the contact area, but this must be adapted to the stiffness of the supporting structure. Otherwise, excessive deformation after loading, uneven contact, and localized pressure increase may occur, rendering even wider and longer guide rails ineffective. Furthermore, lengthening and widening the guide rail increase technical difficulty; unloading methods can be employed to reduce the guide rail load.
(2) Reduce Friction Coefficient
Replacing sliding friction pairs with rolling friction pairs can significantly reduce friction coefficient and wear, though this is rarely used in stone cutting machines. In sliding pairs, proper selection of lubricating oil can optimize friction performance by modifying the mixed coefficient. Additionally, maintaining clean lubricating oil is crucial as dirty oil can lead to excessive wear. Circulating lubrication ensures sufficient lubricant while providing cooling and flushing. To evenly distribute lubricating oil on the guide rail surface for effective lubrication, grooves can be cut into the guide rail surface. Proper selection of oil viscosity can effectively reduce the friction coefficient. The viscosity of guide rail lubricating oil should be chosen based on working conditions and lubrication methods; for instance, 20# oil can be used for low-load (pressure > 0.1MPa), high-speed, small to medium-sized stone cutting machines feed guide rails; 30# or 40# oil can be used for medium-load (pressure > 0.2MPa), low to medium-speed machine guide rails (most feed guide rails fall into this category); heavy-duty, low-speed machinery guide rails can use 40#, 50#, or 70# oil (pressure > 0.4MPa); guide rails prone to dirt contamination should use low viscosity lubricating oil to prevent debris buildup and rail damage.
(3) Correct Selection and Heat Treatment of Friction Pair Materials
Proper selection of friction pair materials can lower the friction coefficient, while heat treatment can enhance wear resistance.
(4) Strengthen Protection
Enhanced protection effectively improves the wear resistance of friction pairs, preventing dust, abrasive particles, and water mist from entering the friction pair. One important method to prevent or reduce wear of guiding pairs is to protect guide rails. Statistics show that protected guide rails can reduce wear by about 60% compared to exposed guide rails. When designing and selecting protective devices for guide rails, the following requirements should be considered: seal the guide rail surface to isolate it from various abrasives; if sealing is not feasible, protective devices should thoroughly remove dust that falls on the guide rail to prevent it from entering the friction pair; the device should withstand coolant corrosion; the structure should facilitate easy installation and removal for cleaning the guide rail and should possess sufficient strength and rigidity, particularly for heavy-duty machinery guide rail protection devices.
Furthermore, factors such as ease of manufacturing, low cost, long service life, and aesthetic appearance should also be considered. Several common protection methods are introduced:
Scraper Type
This method scrapes dust off the guide rail and is an indirect protection device.
Cover Plate Type
Most cover plate protection devices fix plates at both ends of the moving guide rail. When the worktable moves, the cover plates cover the exposed guide rail surfaces, preventing chips from falling onto the guide rail surface. This device is usually used in conjunction with scraper protection devices.