Dongyouda linear module techniques

To meet the rapid development of the machine tool industry driven by industrial automation, more and more companies are adopting rolling linear guides and other rolling element guiding systems, increasing the forward and backward speed from a few meters per minute to tens of meters per minute. The use of rolling linear guides greatly improves machine tool production efficiency. During its service life, the maintenance rate of linear module machine tools is reduced, allowing for continuous operation. When designing and manufacturing machine tools, the following issues need to be considered: 1. The machine tool should have high vibration resistance. Machine tools using linear rolling guides are prone to vibration. The high-speed forward and backward movement of moving parts will subject the machine tool bed to huge impacts. Rolling linear guide pairs have low damping, and synchronous belt modules have poor vibration resistance. This periodic impact easily causes the bed to vibrate, leading to shape errors and ripples on the machined surface. This effect is particularly pronounced in grinding machines and high-precision machine tools, and can also cause system instability in closed-loop servo control. 2. The machine tool vibration model using linear rolling guides is similar to undamped forced vibration and can be approximated using the laws of conservation of momentum and energy: Where: m—mass of the moving parts, M—mass of the machine tool body, k—static stiffness of the machine tool, v—rapid forward and backward speed of the moving parts, Amax—maximum amplitude of the machine tool. From the above formula, it can be seen that decreasing m, increasing M, and adding k can all reduce the maximum amplitude Amax of the machine tool. However, increasing the mass of the machine tool body is generally less effective because increasing the machine tool body mass M will lower the natural frequency of the machine tool, resulting in a lower resonant frequency, which is detrimental to eliminating resonance. Therefore, simply increasing the wall thickness to improve the rigidity of the machine tool is of no help in improving its vibration resistance. 3. During design, attention should be paid to improving the static stiffness per unit mass. For servo electric cylinders, adding appropriate reinforcing ribs, constructing a reasonable cross-sectional shape and dimensions, reducing the opening area on the bed surface, and improving the rigidity of the connection between the machine tool and the foundation are all important considerations. Some manufacturers of rolling linear guides believe that applying a large preload can effectively eliminate vibration. However, it has been proven that increasing the preload of the synchronous belt module only changes the resonant frequency and has no effect on vibration reduction. Excessive preload only leads to deformation of the rolling elements, increasing the resistance to displacement of the guiding system and reducing the service life of the guiding elements. Therefore, excessive preload is not a feasible method. 4. Damping should be added reasonably to machine tool applications. There are various methods to increase the dynamic stiffness and damping of machine tools using linear motors. For example, a layer of high-resistance viscoelastic polymers made of asphalt or paint soap can be added to the outer wall of the machine tool; viscoelastic damping materials can be embedded in the structure; molding sand can be retained within the casting; or special fine iron shot can be sealed within the casting. The sliding friction coefficient of rolling linear guides is f = 0.003~0.004, while traditional plastic-coated guides have f = 0.04, and cast iron guides have f = 0.12. Therefore, the frictional resistance of rolling linear guides is less than one-thirtieth of that of traditional guides. Taking a rolling linear guide as an example, a relatively small feed force can propel the slide, and the movement is simple and stable. However, if the rigidity of the feed system is poor, it can easily cause the slide to creep or swerve. This creep is different from traditional creep; it is not caused by friction on the guide surface, but by the poor rigidity of the system feed. Therefore, the solution will also be different, and the stability of the system should be improved. When the feed system is driven by a hydraulic cylinder, the piston in the cylinder is affected by the fluctuation of the sealing ring and the oil in the device groove. The creep of the miniature electric steel piston is affected by the creep of the slide. General solutions include: selecting sealing rings with low friction coefficient and good sealing performance; and strictly controlling the dimensional tolerances of the grooves and the surface roughness of the machined surfaces. Rolling linear guides are common components in the machinery industry, and their quality directly affects the precision and service life of mechanical equipment. Therefore, the guides are required to have high wear resistance and stability. While ion-nitrided guideways offer high hardness and wear resistance, their significant deformation during nitriding limits their commercial applicability. Precision linear guideways are ultra-thin and ultra-lightweight linear guideways. Precision linear guideways are ideal for applications requiring precision measuring instruments, semiconductor manufacturing and inspection equipment, and other applications where precise linear motion is crucial. For coarse adjustment of the rails, we generally use the wire-pulling method. A slider is placed on the rail, and a graduated microscope is mounted on the slider. The microscope lens is aligned with a 0.3mm diameter steel wire, and the lens is placed vertically. The steel wire is fixed at one end of the rail, and a weight is suspended from the other end of the robot arm via a pulley. The two ends of the steel wire are then adjusted so that when the microscope is at either end of the rail, the steel wire aligns with the graduated lines on the lens. The steel wire becomes an ideal straight line in the horizontal plane. Moving the slider checks the straightness of the rail in any position, adjusting the rail to within 0.3mm of straightness in the horizontal plane. Then, a precision guideway is installed using a fitting method, facilitating further adjustments.