When the linear guide mechanism is used, there are various ways of loading, and the difference in load directly affects the number of sliders used. The following is a more typical use of the guide rail on the level plane, and the guide rail is below the slider above it. The slider accepts the load acting vertically above it (e.g. the weight of the table). Due to the small size of the device surface of the individual slider, when the mass center of the load is just in the center of the slider, the load can be reduced to a concentrated force.
The problems often encountered are: on the one hand, the size of the workbench of the device above the slider is much larger than the size of the slider, on the other hand, the actuator of the workbench and the device above it is often eccentric, and the mass center of the load is not just located in the center of the slider. Assuming that the load has a certain eccentricity along the length of the guide rail, in this case, the slider not only accepts the gravity of the load, but also accepts the torque load in the MA direction due to the eccentric load. Under the action of this torque, the load is later transmitted to the balls inside the slider, and the local balls will accept a large part of the load. Working in this state for a long time will cause abnormal wear of the balls, reduce the service life of the slider, and thus reduce the service life of the mechanism. In addition to the load with the above-mentioned mass eccentricity, the inertial force during the acceleration and deceleration of the load also generates a torque load similar to the above-mentioned effects.
In addition, the actuator above the slider may also generate additional torque in the MA or M. direction when working. If two sliders are used at a distance on one rail along the length direction, the original eccentric structure becomes an equilibrium structure, which not only reduces or eliminates the torque load caused by the eccentric structure to the slider, but also improves the ability of the linear guide mechanism to accept the additional torque in the Mn direction, thus improving the rated life of the entire mechanism, which is why double sliders are used in most cases.
