Ball screw is a common mechanical transmission element widely used in industry, mechanical equipment and automation systems. Choosing the right ball screw is a key factor in ensuring efficient operation and long-term use of mechanical equipment. Here are a few key points to consider when selecting a ball screw: 1. Load capacity: The load capacity of the ball screw is one of the key factors in selection. The maximum axial and radial loads required need to be determined to ensure that the ball screw can withstand the working load and maintain stable operation. 2. Accuracy requirements: Select the appropriate ball screw accuracy grade according to the accuracy requirements of the application. There are usually different accuracy levels such as C0, C3, and C5 to choose from. The higher the accuracy level, the higher the transmission accuracy. 3. Movement speed: Consider the maximum linear speed required by the ball screw to determine whether the selected ball screw can meet the movement speed requirements. Higher movement speeds may require the use of preload structures to reduce vibration and heat in the ball screw. 4. Lifetime requirements: Determine the required service life and reliability requirements. According to the rated life and selection life factors of the ball screw, consider the service life, maintenance cycle and reliability requirements, and select the appropriate product. 5. Installation space and dimensions: Consider the available installation space and the external dimensions of the ball screw. Make sure the ball screw you choose is suitable for the installation needs of your existing equipment or system. 6. Environmental conditions: Consider the special conditions of the use environment, such as temperature, humidity, corrosive media, etc. Choose a ball screw with high temperature resistance, corrosion resistance or good sealing performance to ensure reliable operation in harsh environments. 7. Lubrication method: Determine the lubrication method of the ball screw. You can choose grease lubrication or oil lubrication, choose the corresponding lubrication method according to different applications, and perform regular lubrication maintenance. In short, choosing a suitable ball screw requires comprehensive consideration of the requirements of mechanical equipment, application environment, reliability requirements and economic factors. Communicate with suppliers or professional engineers and refer to the technical parameters and performance indicators provided by the ball screw manufacturer to ensure the best ball screw product is selected.

A ball screw and nut assembly is a mechanical component commonly used in CNC (Computer Numerical Control) machines and other machinery. It is a type of linear motion system that converts rotational motion into linear motion. The assembly consists of two main components: the ball screw and the ball nut. The ball screw is a threaded rod with helical grooves, and the ball nut is a block-like component with matching helical grooves on its inner surface. The ball nut is mounted on the ball screw, and it contains a series of steel balls that recirculate within the grooves. When the ball screw is rotated, the balls inside the ball nut are pushed along the helical grooves, causing the nut to move linearly along the screw. This mechanism provides a smooth and efficient way to convert rotary motion into precise linear motion. The ball screw and nut assembly offers high accuracy, low friction, and high load-carrying capacity, making it suitable for CNC machines that require precise positioning and repeatability. In a CNC machine, the ball screw and nut assembly is typically used in the machine's motion control system, such as the axes that move the spindle, table, or cutting tool. It enables the machine to move with high precision and control, allowing for accurate machining operations.

A ball screw is a mechanical element commonly used to transmit motion and force. It consists of a threaded shaft and a nut, and the balls are used to transmit force and motion through the threads between the threaded shaft and the nut. The balls play the role of transmitting force, reducing friction and side motion, and improving transmission efficiency and precision. The identification criteria of ball screws can be described by the following aspects. The first is the pitch, which indicates the distance the ball screw moves forward per rotation. The pitch determines the speed and sensitivity of the ball screw, usually expressed in millimeters/turn or inches/turn. The second is the load capacity. The load capacity of a ball screw describes the maximum load it can withstand, usually in Newtons (N) or pounds-force (lbf). The load capacity directly affects the scope of use and application of the ball screw. Different working environments and requirements require the selection of appropriate load capacity. The third is the accuracy level. The accuracy level refers to the accuracy of the movement and transmission of the ball screw. Commonly used accuracy levels include C0, C3, C5, etc. The accuracy grade determines the positioning accuracy and repeatability of the ball screw, which is very important for applications that require high-precision position control. In addition, the diameter, length, material, etc. of the ball screw are also important contents in the identification description. The diameter and length affect the overall size and installation method of the ball screw, while the material determines the strength and durability of the ball screw. Nanjing Shuntai Precision Ball Screw Pair is standardized into 8 types of nuts as shown in the figure. In addition, in order to meet customer requirements, we can make non-standardized nuts with special shapes (such as square, axis intersection, etc.), special properties (such as high temperature resistance, corrosion resistance, etc.) and unconventional formats (such as extension, heavy load). If you have any needs, please consult.

Preload adjustment of ball screws is a key step to ensure their high precision, high rigidity and long life. The role of preload is to eliminate the gap between the ball and the raceway, reduce the reverse clearance (backlash), and improve the axial rigidity and vibration resistance of the system. However, excessive preload may cause heating, increased wear and even jamming, so the adjustment must strictly follow the technical specifications. The following are the detailed methods and precautions for preload adjustment: 1. Purpose of preload adjustment Eliminate axial clearance: Ensure that the screw has no empty stroke when moving forward and backward. Improve rigidity: Enhance the system's ability to resist deformation due to load changes. Extend life: Reasonable preload can evenly load the ball and avoid local wear. Reduce vibration and noise: Reduce impact and abnormal noise caused by clearance. 2. Main methods of preload adjustment a. Double nut preload method (most common) Principle: Apply opposite axial forces through two nuts to squeeze the ball into contact with the raceway. Steps: Install double nuts: Install two ball nuts in reverse on the same screw shaft. Apply preload: rotate the two nuts to bring them closer together, compress the elastic element in the middle (such as a disc spring) or directly lock them through the thread. Adjustment method: Torque control method: tighten the nut to the specified torque value with a torque wrench (refer to the manufacturer's data). Displacement control method: measure the distance between the two nuts and adjust to the preset compression amount (usually 1%~3% of the lead). Lock the nut: use a locking washer or thread glue to fix the adjusted position. b. Shim adjustment method Applicable scenarios: single nut structure or occasions where the preload needs to be accurately adjusted. Steps: Add a shim between the nut end face and the mounting seat. Change the axial relative position of the nut and the screw by increasing or decreasing the thickness of the shim, and compress the ball and raceway. The preload needs to be tested repeatedly until the target value is reached. c. Spacer adjustment method Principle: add a spacer (sleeve) of a specific length between the double nuts, and control the preload by changing the length of the spacer. Advantages: High preload accuracy, suitable for equipment with high rigidity requirements (such as CNC machine tools). Steps: Measure the original spacing between the two nuts. Calculate the required spacer length based on the preload amount (usually the required compression amount = spacer length - original spacing). Install the spacer and lock the nut. d. Variable lead method (preload type ball screw) Principle: The manufacturer changes the lead of the ball circulation path to make the ball preload in the nut. Features: Users do not need to adjust, and can obtain standard preload by direct installation (need to select according to the load). 3. Key parameters for preload adjustment Preload level: usually divided into light preload (C0/C1), medium preload (C2/C3), heavy preload (C5), which needs to be selected according to the load and accuracy requirements. Preload amount calculation: Preload amount ≈ 0.05~0.1 times the elastic deformation corresponding to the rated dynamic load. Empirical formula: preload = (5%~10%) × lead (refer to the manufacturer's manual). Preload detection indicators: Axial rigidity: The displacement after applying external force must be less than the allowable value (such as 1μm/N). Reverse clearance: measured with a micrometer, the target value is usually ≤5μm. IV. Detection and verification after adjustment Torque test: Manually rotate the screw to feel whether the resistance is uniform and avoid local jamming. Use a torque meter to measure the driving torque and compare it with the manufacturer's recommended range (re-adjustment is required if it exceeds the limit). Reverse clearance detection: Fix the micrometer contact to the nut, move the screw in the forward and reverse directions, and record the displacement difference. Temperature monitoring: Run without load for 30 minutes to check whether the temperature rise is normal (generally ≤40℃). V. Precautions Avoid over-preloading: Excessive preloading will cause a sharp increase in friction heat, accelerated wear and even sintering. Lubrication management: After preload adjustment, it is necessary to add an appropriate amount of grease. It is recommended to use high-speed and high-load lubricants. Environmental adaptability: The preload amount needs to be re-checked in high or low temperature environments (affected by the thermal expansion coefficient of the material). Regular maintenance: Check the preload status every 300-500 hours of operation and readjust it if necessary. VI. Common problems and solutions Problem 1: Large running resistance after preload adjustment Cause: Excessive preload or insufficient lubrication. Solution: Reduce the thickness of the gasket or the length of the spacer sleeve and increase lubrication. Problem 2: The reverse clearance still exceeds the standard Cause: The nut is worn or the screw shaft is bent. Solution: Replace the nut, straighten the screw or replace a new screw. Problem 3: Abnormal noise and vibration Cause: Uneven preload or broken balls. Solution: Readjust the preload and check the ball circulation system. Through the above understanding of ball screw preload, if you want to learn more, please contact us, we are online 24 hours a day to serve you.