Ball screw is a mechanical transmission device used to convert rotary motion into linear motion. It is commonly used in various CNC machine tools, mechanical equipment and automation systems. Calculating the torque of a ball screw requires considering the following factors: 1. Input torque: Input torque is the external torque acting on the ball screw. It can be provided by the driving force, which can be a motor or other power device. The input torque is transmitted to the output through the ball system of the ball screw. 2. Ball screw transmission efficiency: The transmission efficiency of the ball screw is usually above 90%, which may vary depending on the specific ball screw type and usage conditions. The higher the transmission efficiency, the smaller the difference between output torque and input torque. 3. Ball screw dynamic parameters: The dynamic parameters of the ball screw include pitch, lead and ball diameter. Pitch refers to the distance the ball screw moves axially during one revolution of the nut. Lead refers to the angle of rotation required for a ball screw to move axially for one revolution. Ball diameter refers to the diameter of the balls used in the ball screw. Generally speaking, the following formula can be used to calculate the torque of a ball screw: Torque = (input torque × transmission efficiency) / (pitch × 2π) Among them, the input torque and transmission efficiency are known parameters, the pitch represents the axial movement distance of the ball screw, and 2π represents the rotation angle of one revolution. Please note that the units in the above formula must be consistent, for example, the unit of torque is Newton·meter (N·m) and the unit of pitch is meter (m). It should be noted that the torque calculation of the ball screw is a simplified model. In actual applications, some other factors may need to be considered, such as the loading conditions of the ball screw, friction and wear, etc., which may affect the torque. When designing and selecting a ball screw, it is recommended to refer to the relevant ball screw design manual or consult a professional engineer for more accurate calculation methods and parameter selection.

The preload of a ball screw bearing refers to the intentional application of a small axial force to eliminate any clearance between the rolling elements (balls) and the raceways of the bearing. This preload helps to minimize backlash and improve the positioning accuracy and stiffness of the ball screw system. The preload force is typically applied by using spring elements or by adjusting the bearing arrangement. The specific preload value depends on the application requirements, such as the desired rigidity, operating conditions, and load characteristics. Preload is usually specified as a percentage of the dynamic load rating (e.g., 2% of the dynamic load rating). However, it's important to note that the actual preload force might vary depending on factors like the manufacturer's recommendations, size and type of ball screw bearing, and the specific application requirements. It is recommended to consult the manufacturer's documentation or contact their technical support to obtain the specific preload values and guidelines for a particular ball screw bearing.

The following issues may arise when using ball screws in large applications: 1. Load and torque limitations: The load and torque bearing capacity of ball screws is limited. In large equipment applications, large loads and torques need to be borne, and ball screws may not be able to meet these requirements. This may lead to overload, deformation or damage to the ball screw. 2. Length limitation: Another important factor for ball screws is length. Longer ball screws are prone to deflection and vibration, which reduces the accuracy and stability of the system. In large applications, if longer strokes are required, other more suitable transmission methods may be required. 3. Accuracy and return error: The accuracy of ball screws is limited by factors such as thread processing and material quality. In large applications, if higher accuracy is required, other higher accuracy transmission methods may need to be considered. In addition, ball screws may have a certain return error when moving in reverse, which may affect the positioning accuracy of the system. 4. Maintenance and life: In large applications, ball screws are usually required to withstand large loads and working pressures, which may cause wear and fatigue of the ball screws. Maintenance and care of ball screws may require more frequent inspections and replacements to ensure system reliability and life. When selecting a transmission method, it is necessary to comprehensively consider factors such as application requirements, load, accuracy, axial stiffness and life, and evaluate whether the ball screw is suitable for a specific large application. In some cases, other transmission methods such as linear guides, gear transmissions or hydraulic transmissions may need to be considered to meet the requirements of large applications. If you have any other supplements, please contact us, and I will discuss the relevant issues together.