In an era characterized by advancements in industrial automation, the high-performance ball screw emerges as a core precision transmission component within machine tools, playing an indispensable role across various transmission systems.
In the application of ball screws, the application of preload force to the nut stands out as a crucial strategy for enhancing performance. This operation can significantly increase the axial stiffness of the ball screw assembly and greatly improve the positioning accuracy. Theoretically, if we only focus on optimizing stiffness and positioning precision of the ball screws, it appears that increasing preload force yields increasingly favorable outcomes; indeed, a greater preload effectively mitigates axial clearance induced by elastic deformation. However, the actual situation is not so simple. Even if a small preload force can temporarily eliminate the axial clearance, it is difficult to truly improve the overall stiffness of the ball screws.
This complexity arises from the necessity for preload force to reach a specific threshold in order to effectively eliminate the "low stiffness area" of the preloaded nut. In configurations employing double-nut preloading structures, parameters such as lead errors are inevitably present within both ball screws and nut components. This deviation will cause that when the screw shaft and nut come into contact, some areas will fit more closely after being deformed by force, resulting in a higher contact stiffness; while other areas will become relatively loose after deformation, forming a "low stiffness area" with a lower contact stiffness. Only when a sufficiently large preload force is applied to eliminate these "low stiffness areas" can the axial contact stiffness be effectively enhanced, achieving the goal of optimizing performance.
However, it is imperative to note that greater preload does not equate to better outcomes universally. An excessively large preload force will bring a series of negative impacts:
Significantly increase the torque required for driving, thereby leading to a marked decline in transmission efficiency;
Exacerbate the contact fatigue and wear between the balls and raceways, which directly shortening the operational lifespan of both ball screws and ball nuts.
For more detailed product information, please email us at amanda@KGG-robot.com or call us: +86 152 2157 8410.
Post time: Jun-18-2025
