In high-end equipment such as nanoscale focusing servo systems for semiconductor lithography machines, precision drive chains for industrial robot joints, and high-speed assembly platforms for new energy vehicle battery modules, ball screws serve as core transmission and execution components, undertaking crucial functions of motion conversion and positioning control. From five-axis CNC machine tools to aerospace attitude adjustment mechanisms, from precision medical imaging equipment to high-end intelligent manufacturing production lines, all high-end equipment with stringent requirements for transmission accuracy, dynamic response, and reliability uses ball screws as its core transmission solution. This article systematically analyzes the core technological advantages of ball screws and their suitability in high-end equipment, starting from their technical principles and engineering characteristics. The core technological advantage of ball screws stems from their innovative transmission principle. Compared to the surface contact sliding friction transmission of traditional sliding screws, ball screws employ a rolling friction transmission mechanism: high-precision balls are embedded as the transmission medium in the closed loop formed by the screw helical raceway and the nut raceway, converting the relative sliding between the screw and the nut into the rolling motion of the balls. Based on this innovation in the rolling friction principle, ball screws primarily possess highly efficient transmission characteristics. From the perspective of transmission efficiency, the mechanical transmission efficiency η of ball screws can reach 90%~98%, while that of ordinary sliding screws is only 20%~40%. According to the power balance equation, under the condition of constant load F and transmission stroke s, the driving torque M is inversely proportional to the transmission efficiency η. Therefore, using ball screws can reduce the output torque requirement of the drive motor to less than 1/3 of that of sliding screws. This characteristic not only significantly improves energy utilization efficiency, but more importantly, it reduces the heat generation power of the transmission system. For high-end equipment, thermal deformation of the transmission system is one of the core error sources affecting positioning accuracy. Low heat generation can effectively control the thermal elongation of the screw, ensuring the temperature stability of the equipment during long-term continuous operation, providing a fundamental guarantee for high-precision control. Precision positioning performance is the core technical indicator for ball screws to adapt to high-end equipment, and it is also a key advantage that distinguishes them from ordinary transmission components. In the field of high-end manufacturing, positioning accuracy and repeatability directly determine the processing/operation quality of equipment. For example, the wafer alignment accuracy requirement of semiconductor lithography machines is ≤±5nm, and the positioning accuracy requirement of five-axis CNC machine tools is ≤±1μm. Ball screws ensure precise positioning through three core technologies: first, high-precision helical raceway grinding technology, using ultra-precision grinding machines to achieve a raceway profile error ≤0.001mm; second, preload technology (such as double-nut washer preload and single-nut variable lead preload), eliminating axial backlash and generating a slight interference to achieve zero backlash in reverse transmission; and third, low-heat design, combined with a temperature control system to suppress thermal deformation. High rigidity and long lifespan are core engineering characteristics that allow ball screws to adapt to the harsh operating conditions of high-end equipment. The transmission systems of high-end equipment often face harsh conditions such as heavy loads (e.g., clamping forces in all-electric injection molding machines can reach thousands of kN), high-frequency start-stop (e.g., joint movement frequencies of industrial robots ≥10Hz), and impact loads, placing extremely high demands on the rigidity of transmission components. Ball screws, through preload design, achieve negative axial clearance (interference fit). Utilizing the elastic deformation of the balls to generate preload force, axial stiffness can be increased by more than three times. Compared to sliding screws, deflection under the same load can be reduced by more than 60%, ensuring stable motion accuracy under heavy load conditions. From a lifespan perspective, the low wear characteristics of rolling friction make the fatigue life of ball screws significantly superior to that of sliding screws. Using high-quality materials such as GCr15 bearing steel, combined with carburizing and quenching (surface hardness HRC≥60), ultra-precision grinding, and a labyrinth seal + grease lubrication system, wear and impurity intrusion can be effectively suppressed. According to the life calculation model of ISO 3408 standard, under rated dynamic load, the rated life (L10) of a ball screw can reach millions of cycles, which is 5 to 10 times that of a conventional sliding screw. Engineering test data shows that ball screws with optimized preload parameters can extend their continuous service life from 30,000 hours to 50,000 hours under 80% rated load, significantly reducing maintenance downtime and spare parts replacement costs for high-end equipment and improving overall equipment efficiency (OEE). High-speed response and flexible adaptability are key characteristics of ball screws for meeting the dynamic control requirements of high-end equipment. In terms of high-speed performance, the DN value (shaft diameter d × speed n) of ball screws can exceed 140,000, far exceeding the upper limit of the DN value for sliding screws (≤50,000). Combined with a high-speed ball circulation structure (such as an internal circulation reverser type), high-speed transmission with a maximum speed ≥3000 rpm can be achieved. In servo control systems, the synergistic effect of low friction coefficient and high rigidity can shorten the system's step response time to the millisecond level, improving dynamic tracking accuracy. In engineering applications, the welding equipment for new energy vehicle battery packs utilizes lightweight ball screws (carbon fiber composite nuts) and dynamic preload compensation technology, reducing acceleration time from 0.2s to 0.08s, increasing production line cycle time by 50%, and raising daily capacity from 1200 sets to 1800 sets. Humanoid robot joints employ small-lead, high-precision ball screws, achieving an angular velocity of 1.5 rad/s and a repeatability of 0.01° under a 20kg load, meeting the requirements of multi-degree-of-freedom collaborative control. The flexibility of the structural design allows the ball screws to adapt to the installation and operating conditions of various high-end equipment. Classified by ball recirculation method, external recirculation (insertion type, end cap type) is suitable for large lead and high-speed scenarios, while internal recirculation (reversing type) has the advantages of compact structure and stable operation, and can adapt to narrow installation spaces. In terms of materials and surface treatment, stainless steel (SUS440C) with hard chrome coating can be used for corrosive conditions, Inconel alloy with aluminum nitride coating can be used for high-temperature conditions, and carbon fiber reinforced composite nuts can be used for lightweight requirements, reducing weight by more than 50% compared to steel nuts. Furthermore, by customizing the lead (e.g., micro-lead ≤1mm, large lead ≥20mm), thread direction (left-hand, right-hand, bidirectional), and installation method (fixed-fixed, fixed-floating), precise adaptation to high-end equipment transmission systems can be achieved, improving system integration efficiency. With the development of intelligent manufacturing technology, ball screws are evolving towards integration and intelligence, becoming a core component of intelligent transmission systems. By incorporating built-in temperature, vibration, and displacement sensors, data such as temperature, vibration amplitude, and positioning error during the transmission process can be collected in real time. Combined with an industrial internet platform, this enables status monitoring and fault early warning. Dynamic preload compensation technology based on AI algorithms can correct accuracy deviations caused by thermal deformation and wear in real time, further improving the stability of transmission accuracy. Regarding breakthroughs in domestic technology, domestically produced ball screws have achieved mass production with C0-level precision. Through the adoption of independently developed ultra-precision grinding processes and material formulations, they have successfully entered the supply chains of international high-end machine tool manufacturers such as AgieCharmilles (Switzerland) and DMG MORI (Germany), providing core transmission component support for the high-end transformation of Chinese manufacturing. In summary, the technological advantages of ball screws stem from the fundamental innovation of their rolling friction transmission principle. Through the synergy of high-precision structural design, optimized material processes, and intelligent control technology, a multi-dimensional performance balance of high-efficiency transmission, precise positioning, high rigidity, long lifespan, and flexible adaptability is achieved, precisely matching the stringent requirements of high-end equipment for transmission systems.

The ability of a machine tool lead screw to operate efficiently and without jamming 24 hours a day is primarily due to the synergistic effect of three factors: suitable design and selection, proper lubrication and maintenance, and reasonable operating condition control. Specifically, this can be broken down into the following key dimensions: 1. High-precision structural design and manufacturing process Precision fit of the transmission pair: Ball screws use steel balls as rolling elements. Compared to the surface contact of sliding screws, this is point contact, resulting in an extremely low coefficient of friction (only 1/10 to 1/3 of that of sliding screws). This leads to low frictional resistance and less heat generation during operation, preventing jamming caused by overheating. Preload process eliminates backlash: A double-nut preload structure (such as washer type, variable lead type, or threaded type) eliminates axial backlash between the lead screw and nut, ensuring transmission accuracy and preventing axial movement and jamming during high-speed operation. High-Quality Materials and Heat Treatment: Lead screws and nuts are typically made of high-carbon steel (such as GCr15) or alloy structural steel, treated with quenching, tempering, and grinding to achieve a surface hardness of HRC58~62. This results in strong wear resistance, preventing wear and deformation during long-term operation and maintaining stable fit accuracy. 2. Stable and Reliable Lubrication and Sealing System Continuous and Efficient Lubrication:** Equipped with an automatic lubrication system (such as a grease pump or oil mist lubrication device), it replenishes the lead screw raceway with specialized grease or oil at regular intervals, forming an oil film that reduces direct friction between the steel balls and the raceway, lowering wear and heat generation. Machine tools operating 24 hours a day are generally equipped with intermittent automatic lubrication to prevent insufficient lubrication or grease aging. Excellent Sealing Protection:** Both ends of the lead screw are equipped with dustproof seals, scraper plates, and other components to prevent cutting fluid, metal shavings, and dust from entering the raceway. Impurities entering the raceway are a common cause of lead screw jamming; the sealing system effectively isolates contaminants and keeps the raceway clean. 3. Reasonable Operating Parameters and Load Control Load and Speed ​​Matching: During selection, the rated dynamic and static loads of the lead screw are determined based on the actual load of the machine tool (cutting force, table weight) to ensure that the load does not exceed the rated value during 24-hour operation, avoiding ball bearing deformation and lead screw bending due to overload. Simultaneously, the speed is controlled below the lead screw's critical speed to prevent resonance and vibration during high-speed rotation. Temperature Control: The machine tool is equipped with a cooling system to control the operating temperature of the lead screw and spindle. Heating the lead screw can cause thermal deformation, leading to pitch changes or even jamming. The cooling system can control temperature fluctuations within a minimal range, maintaining transmission stability. 4. Precise Coordination of Drive and Control Systems Rigid Connection between Servo Motor and Lead Screw: Couplings (such as diaphragm couplings and lamellar couplings) are used to achieve a gapless connection between the motor and the lead screw, ensuring smooth power transmission and avoiding transmission jerks caused by loose connections. Precise adjustment of the CNC system: Through a closed-loop or semi-closed-loop control system, the position and speed of the lead screw are monitored in real time, and the motor output torque is dynamically adjusted to compensate for the elastic deformation and temperature deformation of the lead screw, ensuring uniform speed and no impact during operation. Supplement: The crucial role of routine maintenance: Even with reasonable design and operating conditions, regular maintenance is essential for 24/7 uninterrupted operation. For example, regularly cleaning seals, checking the condition of the lubricating grease, detecting lead screw runout and backlash, and promptly replacing aged grease and worn balls can effectively extend the stable operating time of the lead screw.

In industrial automation and precision equipment, trapezoidal lead screws are the core transmission mechanism for achieving rotary-to-linear motion, directly affecting the accuracy and stability of the equipment. However, practitioners often suffer from decreased equipment efficiency and shortened lifespan due to a lack of in-depth understanding of the principles and improper selection. This article will break down the motion principle of trapezoidal lead screws and provide a practical selection guide. I. Product Motion Principle and Related Parameters 1. Motion Principle: The trapezoidal lead screw converts rotational motion into linear motion through the meshing of the screw and nut, simultaneously transmitting energy and power. II. Product Features 1. Simple structure, convenient processing and operation, and economical cost; 2. Self-locking function is achieved when the thread helix angle is less than the friction angle; 3. Smooth and stable transmission process; 4. Relatively high frictional resistance, with a transmission efficiency in the range of 0.3~0.7. In self-locking mode, the efficiency is below 0.4; 5. Possesses a certain degree of impact and vibration resistance; 6. Overall load capacity is stronger than that of ordinary rolling screws. III. Selection and Verification Calculations For general force-transmitting screws, the main failure modes are thread surface wear, fracture under tensile stress, shearing, and shearing or bending at the thread root. Therefore, the main dimensions of the screw drive are determined primarily based on wear resistance and strength calculations during design. For transmission screws, the main failure mode is excessive clearance due to wear or deformation leading to decreased motion accuracy. Therefore, the main dimensions of the screw drive should be determined based on thread wear resistance and screw stiffness calculations during design. If the transmission screw also bears a large axial load, its strength needs to be additionally calculated. Long screws (slenderness ratio exceeding 40) that are not manually adjustable may produce lateral vibration; therefore, their critical speed needs to be checked. IV. Usage Precautions 1. Load Considerations: Additional radial loads should be avoided as much as possible, as such loads can easily cause screw malfunction, increased wear, and jamming. 2. Dust Prevention Requirements: Foreign objects must be prevented from entering the thread. If impurities such as iron filings, tin dross, and aluminum shavings are easily generated under operating conditions, a protective cover should be installed to prevent foreign objects from entering the thread and causing abnormal wear or jamming. 3. Slenderness ratio requirement: When the slenderness ratio exceeds a certain range (60 or above), the screw will bend due to its own weight, resulting in radial off-center load on the nut. Depending on the actual operating speed and torque, this may lead to abnormal wear, jamming, shaft end bending, or even breakage. To solve this problem, an anti-runout device can be installed in the middle of the screw for constraint. 4. During installation, attention should be paid to the coaxiality and levelness calibration of the fixed-support installation method; for the fixed-free cantilever structure, attention should be paid to the control of shaft end tolerances and the locking and reinforcement of the head. 5. When installing a trapezoidal thread screw, runout verification must be performed. If suitable measuring equipment is lacking, the screw can be moved by hand along its entire length once or multiple times before installing the driving component. If the force required to move the outer diameter of the shaft is uneven and accompanied by wear marks, it indicates that the lead screw, nut support, and guide rail are not aligned. In this case, first loosen the relevant mounting screws, and then move the lead screw by hand once. If the required force becomes uniform at this time, the corresponding components can be recalibrated. If the force is still uneven, the mounting screws need to be loosened again to determine the location of the calibration error.

As a key transmission component for converting rotary to linear motion, ball screws have become the "heart" of high-end equipment such as precision instruments, CNC machine tools, and automated equipment, directly determining the operating accuracy and stability of the equipment, thanks to their three core advantages: "high precision, high efficiency, and high rigidity". Eight Key Points for Daily Maintenance Cleaning and Protection: Regularly clean the lead screw surface with a brush or compressed air to remove dust and chips, preventing impurities from entering the raceway; in harsh environments, install dust covers and protective sleeves. Scientific Lubrication: Select lubricant according to operating conditions, and replenish/change oil regularly according to operating time to ensure uniform lubrication of the raceway. Load Control: Strictly adhere to rated load requirements, avoiding instantaneous overload or impact loads to prevent lead screw deformation. Precise Installation: Ensure the lead screw is parallel and coaxial with the guide rail during installation, and tighten the bearings. Environmental Adaptability: Keep away from high temperature, high humidity, and corrosive environments. Take heat insulation, moisture-proof, and anti-corrosion measures when necessary. Regular Inspection: Establish an operation log, record changes in noise, temperature, and accuracy, and stop the machine for repair immediately if any abnormalities are found. Maintenance During Idle Time: When not in use for a long time, apply anti-rust oil and cover with a protective cover to prevent rust and dust accumulation. Synchronous Maintenance: Simultaneously check mating components (bearings, guide rails, drive motor) to ensure the stable and coordinated operation of the entire transmission system. Prevention and Inspection Techniques Visual Inspection: Inspect the lead screw surface for scratches, rust, and dents; check for intact and undamaged threads. Lubrication Check: Observe the even distribution of lubricant. If the color turns black or the viscosity decreases, replace it immediately. Smoothness Test: Manually rotate the lead screw or run it under no-load to check for any jamming or uneven resistance. Noise Identification: Listen for abnormal friction or impact sounds during operation, paying particular attention to the bearing area. Accuracy Inspection: Use a dial indicator and laser interferometer to check the positioning accuracy and repeatability, comparing them with standard values ​​to determine if the accuracy is satisfactory. Exceeding limits; Clearance Measurement: Use a feeler gauge or dial indicator to check the clearance between the lead screw and nut. If it exceeds the limit, the component needs to be replaced; Connection Tightness: Check the bolts of the bearing housing, coupling, and nut housing to prevent loosening that could cause vibration; Temperature Monitoring: Use a thermometer to check the temperature of the bearing and lead screw body after operation. If it exceeds 60℃, lubrication or installation problems need to be investigated; Cleanliness Assessment: Check for chips and oil accumulation around the lead screw and clean them promptly; Thread Flaw Detection: For lead screws in critical operating conditions, use magnetic particle testing or penetrant testing to check for hidden thread damage.

As a core component of precision transmission, the ball screw's performance directly determines the accuracy, lifespan, and stability of equipment, from small 3C devices to large industrial machine tools. The material is the key factor determining the ball screw's lifespan—choosing the right material allows for long-term stable operation under complex conditions; choosing the wrong material can lead to rapid accuracy degradation or even breakage. Today, we'll break down the underlying logic of ball screw material selection, from core considerations to comparisons of mainstream materials, helping you avoid selection pitfalls. I. Before Choosing a Material, Clarify These 3 Core Dimensions There is no "best" material, only "most suitable." Before finalizing the material, ask yourself three questions to anchor your selection direction: * **Operating Conditions:** What load will the ball screw withstand? What is the operating speed/rotation speed? Will it operate in high-temperature, humid, or corrosive environments? Will it experience frequent start-stop cycles or impact loads? * **Accuracy Requirements:** Is it for ordinary transmission (such as automated production lines) or high-precision positioning (such as CNC machine tools or semiconductor equipment)? Precision grade (C0-C10) directly affects material uniformity and heat treatment requirements. Cost budget: High-end materials (such as stainless steel alloys) offer excellent performance but are expensive, while ordinary carbon steel offers high cost-effectiveness but has limited applicability. A balance between performance and cost is necessary. II. Mainstream Ball Screw Materials: Characteristics, Applications, and Advantages/Disadvantages 1. Carbon Structural Steel (e.g., 45# steel) – Entry-level choice Core characteristics: Extremely low cost, good machinability, can be heat-treated to improve hardness, but poor hardenability, low surface hardness (HRC20-30), and poor wear and corrosion resistance. Applicable scenarios: Only suitable for ordinary transmission scenarios with low loads, low speeds, and no precision requirements, such as simple conveying equipment and manual adjustment mechanisms. Almost never used in industrial precision equipment. Advantages and disadvantages: Advantages include low cost and ease of machining; disadvantages include short lifespan, easy loss of precision, and inability to withstand impact loads. 2. Alloy Structural Steel (e.g., 40Cr, 20CrMnTi) – A Mid-Range General-Purpose Choice Core Characteristics: Based on carbon steel, alloying elements such as chromium, manganese, and titanium are added, significantly improving hardenability. After tempering and surface quenching, the surface hardness can reach HRC55-60. It has good core toughness, balancing wear resistance and impact resistance. Applicable Scenarios: Ball screws in industrial automation equipment, general machine tools, and construction machinery. Suitable for medium loads, medium speeds, and normal environmental conditions, it is currently the most widely used material. Advantages and Disadvantages: Advantages include high cost-effectiveness and balanced performance; disadvantages include moderate corrosion resistance, requiring additional rust prevention treatment (such as galvanizing or blackening) in humid/salt spray environments. 3. Bearing Steel (e.g., GCr15, GCr15SiMn) – High-Precision Core Choice Core Characteristics: High carbon content, with chromium as the main alloying element. After quenching and low-temperature tempering, the hardness can reach HRC60-64. It has excellent wear resistance and dimensional stability, low impurity content, and uniform internal structure, meeting the form and position tolerance requirements of high-precision ball screws. Applicable Scenarios: Ball screws for high-precision CNC machine tools, semiconductor processing equipment, and testing instruments. Suitable for high-load, high-speed, and high-precision positioning conditions, it is the "standard" material for precision transmission. Advantages and Disadvantages: Advantages include high hardness, good wear resistance, and stable precision; disadvantages include a cost 10%-20% higher than alloy structural steel, slightly lower core toughness than 40Cr, and the need to avoid overload impacts. 4. Stainless Steel (e.g., 304, 316, 9Cr18Mo) ​​– Special Environment Selection Core Characteristics: 304/316 stainless steel has excellent corrosion resistance, suitable for harsh environments such as humid, acidic, alkaline, and salt spray conditions; 9Cr18Mo (martensitic stainless steel) combines high hardness (HRC58-62) and corrosion resistance, offering a "wear-resistant + corrosion-resistant" combination. Applicable Scenarios: Ball screws in food processing equipment, marine engineering equipment, chemical equipment, or medical equipment where cleanliness and corrosion resistance are required. Advantages and Disadvantages: Advantages include strong corrosion resistance, eliminating the need for additional rust prevention; disadvantages include high cost (304 stainless steel is 2-3 times more expensive than GCr15), the difficulty in processing 9Cr18Mo, and slightly lower overall wear resistance compared to bearing steel. III. Four Practical Suggestions for Material Selection * Prioritize matching accuracy and working conditions: Choose GCr15 for high precision and high load; 40Cr for medium load and normal environments; 45# steel for low requirements and low cost; stainless steel for harsh environments. * Pay attention to heat treatment processes: For the same material, the heat treatment process directly determines performance—for example, GCr15 is prone to quenching cracks if it does not undergo sufficient spheroidizing annealing; 40Cr will lead to rapid surface wear if the surface quenching depth is insufficient. When selecting, confirm the supplier's heat treatment process (such as whether deep cryogenic treatment is performed to improve dimensional stability). * Optimize performance by combining surface treatment: Even if the right material is selected, shortcomings can be compensated for through surface treatment—for example, nitriding of GCr15 lead screws can improve surface hardness and corrosion resistance; hard chrome plating of 40Cr lead screws can enhance wear resistance and rust prevention. Avoid "over-selection": For example, choosing GCr15 for a standard production line lead screw, or 316 stainless steel for a lead screw in a normal environment, will only increase costs without improving performance. Precise matching of requirements is necessary. IV. Summary: The Core Logic of Material Selection Choosing the right material is only the first step. Subsequent machining accuracy, assembly processes, lubrication, and maintenance will also affect the lead screw's lifespan. However, the material, as the foundation, directly determines the lead screw's "performance ceiling." If you are unsure which material to choose for your equipment, you can consider four dimensions: load, speed, environment, and accuracy, or consult us for working condition matching.

The ball screw (often called a "lead screw") of an injection molding machine is its core component, often referred to as the "heart" of the machine. Its operation is a complex process integrating physics, mechanics, and thermodynamics. Simply put, its core task is to transport, melt, compress, and homogenize solid plastic granules, ultimately injecting the molten plastic into the mold cavity with sufficient pressure and speed. To better understand its operation, we can divide its working cycle into the following stages: A complete working cycle of an injection molding machine ball screw. In a complete injection cycle, the ball screw mainly performs two actions: rotation and axial movement. Its working cycle can be divided into three stages: 1. Rotation (Plasticizing/Metering) Stage Objective: To transport, heat, melt, and homogenize the solid plastic granules in the hopper. Action: The lead screw rotates at high speed inside the barrel but does not move forward (at this time, the injection cylinder at the rear of the lead screw releases pressure, allowing the lead screw to retract due to the reaction force of the plastic during rotation). Operation Process: Feeding and Conveying: Plastic granules fall from the hopper into the barrel. The rotation of the screw, like a screw turning in a nut, uses the inclined plane of the thread to continuously push the plastic granules forward. Compression and Melting: The screw structure is divided into three sections from back to front: the feeding section, the compression section, and the metering section. Feeding Section: The thread depth is relatively deep, mainly used for stable conveying of solid granules. Compression Section: The thread depth gradually decreases. Here, the plastic is strongly compressed and sheared, while the heating coil outside the barrel also heats it. Under the combined action of "shear heat" and "external heating," the solid plastic rapidly melts into a viscous flow state. In fact, more than 80% of the melting heat comes from the shear heat generated by the screw rotation. Metering Section: The thread depth is the shallowest. Its main function is to further homogenize the temperature and composition of the melt, ensuring the uniform quality of the melt stored at the front end. Result: Uniformly molten plastic is pushed to the front of the screw (at the nozzle), and the accumulated pressure (back pressure) pushes the entire screw backward, reserving a fixed amount of molten material for the next injection. 2. Axial Movement (Injection/Holding Pressure) Stage Objective: To inject the molten plastic reserved in the previous stage into the mold cavity at high speed and high pressure. Action: The screw stops rotating and, under the powerful thrust of the injection cylinder, moves forward at high speed as a piston. Operation Process: Injection: The screw advances forward at extremely high speed, injecting the molten plastic reserved in the front through the nozzle, mold runner, and gate into the closed mold cavity. This process needs to be completed in a very short time to ensure that the molten material fills every corner of the cavity simultaneously. Holding Pressure: When the cavity is about to be filled, the injection speed slows down, transitioning to a high-pressure "holding pressure" stage. The screw continues to move forward slowly, using extremely high pressure to replenish the volume vacated by the cooling and shrinkage of the plastic, preventing defects such as shrinkage marks and insufficient material in the product. 3. Reset (Preparing for the Next Cycle) Objective: To prepare the melt for the next injection molding cycle. Action: After the holding pressure is completed, the screw stops axial movement and begins to rotate again (returning to the first stage) for the next plasticizing and metering. At this time, the mold opens, ejects the product, and then closes, awaiting the next injection. Key Design Features of the Ball Screw To accomplish the above complex tasks, the ball screw itself is designed with great precision: Length-to-Diameter Ratio (L/D): The ratio of the ball screw's length to its diameter. A larger L/D ratio results in better plasticizing and more uniform temperature. Common ratios are between 18:1 and 25:1. Compression Ratio: The ratio of the volume of the first threaded groove in the feeding section to the volume of the last threaded groove in the metering section. It determines the degree of plastic compression and is crucial to melting efficiency. Different plastics require different compression ratios. Three-Stage Design: As mentioned above, the feeding section, compression section, and metering section each perform their respective functions, forming the basis for the efficient operation of the lead screw. In summary, you can visualize the operation of an injection molding machine screw as follows: It's like a "meat grinder": as it rotates, it bites, shears, mixes, and conveys materials. It's like a "piston" or "syringe": as it propels forward, it injects the processed "fluid" under high pressure. It's also a "heat generator": through its own rotational shearing, it generates most of the heat needed to melt the plastic. This ingenious combination of "rotational plasticizing" and "axial injection" allows the injection molding machine screw to efficiently and precisely complete the transformation process from solid granules to precision plastic products.

In automated equipment, CNC machine tools, and even 3D printers, linear guides function as the "skeleton" of precision transmission, bearing the critical responsibility for stable equipment operation. However, are you truly familiar with this seemingly simple mechanical component? This article will unveil the intricacies of linear guides. Linear guides consist of four core components: the rail body, sliding block, balls (or rollers), and sealing elements. The rail body is typically manufactured from high-carbon steel, with surfaces precision-ground and hardened to achieve a hardness of HRC 58–62, ensuring long-term wear resistance. The sliding block incorporates a recirculating ball mechanism, enabling low-friction motion through precisely machined raceways. The sealing system is an often-overlooked critical component. High-quality guides are equipped with multi-layer labyrinth seals, which effectively prevent contaminants such as metal chips and dust from entering while retaining lubricating grease. Certain specialized models also feature scrapers that automatically remove debris from the rail surface during high-speed operation. Load capacity is a primary performance indicator. Class C guides can withstand static rated loads of up to 30 kN, while Class H heavy-duty variants support loads exceeding 100 kN. Engineers must calculate vertical, horizontal, and moment loads simultaneously and incorporate a 20% safety margin. Under special operating conditions, impact load factors should also be considered. Accuracy grades directly influence equipment performance, ranging from standard and precision to ultra-precision levels. However, attention must be paid to the effect of temperature variations on accuracy: for every 1°C increase, a 1-meter-long guide rail expands thermally by approximately 11 μm. Lubrication management determines service life. It is recommended to replenish lithium-based grease every 100 kilometers of operation, switching to molybdenum disulfide lubricants in high-temperature environments. New self-lubricating guides employ oil-impregnated sintered bearing materials, extending maintenance intervals by threefold. Importantly, lubricants from different brands must not be mixed to avoid chemical reactions that degrade grease performance. Cleaning and protection protocols should be standardized. Dedicated guide rail covers are essential, with bellows-style guards recommended for dusty environments. Weekly cleaning of rail surfaces using non-woven cloths and specialized cleaners is advised, while corrosive solvents like acetone must be strictly avoided. For equipment idle exceeding 72 hours, anti-rust oil should be applied, and dehumidifiers utilized in humid conditions. If you have any needs, please contact us. We are available 24/7 for your inquiries.

Installation Preparation: Verify that the mounting surface is flat, clean, and free of burrs, oil, and other impurities. Inspect the mounting surface for flatness, straightness, and other precision indicators to ensure that it meets the guide rail installation requirements. Gather the necessary installation tools, such as wrenches, screwdrivers, and vernier calipers, and check their accuracy and reliability. Guide Rail Installation: Gently place the guide rail on the mounting surface. Use locating pins or locating blocks for initial positioning to ensure accurate installation. Initially secure the guide rail to the mounting surface with bolts, but do not tighten them to allow for subsequent adjustments. Guide Rail Adjustment: Use a gauge to check the straightness and levelness of the guide rail. Fine-tune the rail with shims or bolts to meet the required accuracy. After adjustment, tighten the bolts to the specified torque. Slider Installation: Gently install the slider onto the guide rail, paying attention to the slider's orientation and installation sequence. Secure the slider to the workbench or other component with bolts, also tightening to the specified torque. Lubrication and Protection: Apply a liberal amount of lubricating oil or grease to the sliding surfaces of the guide rail and slider to reduce friction and wear. Install protective devices, such as dust covers and scraper blades, to prevent dust and debris from entering the guide rails and sliders. Operational Inspection: After installation, manually push the workbench or other components to check whether the sliders run smoothly on the guide rails and for any abnormalities such as sticking or noise. Connect the power cord and perform a no-load test. Observe the equipment's operating conditions and record relevant parameters to ensure that the equipment meets performance requirements.

In the precision operation of industrial equipment, transmission components act like "joints," determining the accuracy and lifespan of the entire machine. However, many buyers often make mistakes when selecting ball screws and linear guides due to parameter confusion and application mismatches. Nanjing Shuntai (https://www.nanjingshuntai.com/), a company deeply involved in the precision transmission field, will share its practical experience to help you clarify your thinking. I. Selection: Five Common Misconceptions Common Selection Misconceptions (Nanjing Shuntai Helps You Avoid): Misconception 1: Focusing on Diameter, Not Lead. Error: Thinking Larger Diameter is Better. Correct: Diameter primarily affects rigidity and critical speed, while lead directly determines speed and thrust. For high-speed applications, a larger lead should be prioritized, and rigidity should be ensured by increasing the diameter. Misconception 2: Ignoring the Stress Rod Stability. Misconception: For lead screws with a large aspect ratio (slender types), only checking the lifespan without checking the allowable axial load can lead to unstable bending during operation. Correct: For applications with a large aspect ratio, stress rod stability must be checked. Misconception 3: Exceeding the critical speed. Error: Motor speed can be increased indefinitely. Correct: The operating speed must be kept below the critical speed, otherwise severe vibration will occur. Increase the critical speed by changing the mounting method, increasing the diameter, or shortening the span. Misconception 4: Selecting too high or too low an accuracy grade. Error: Blindly pursuing the highest accuracy, or choosing too low an accuracy grade to save money. Correct: Comprehensively consider the equipment's positioning accuracy, repeatability, and budget. Grade C7 is sufficient for most general applications. Misconception 5: Ignoring the importance of preload. Error: Not understanding the role of preload. Correct: Preload eliminates axial play and improves rigidity, but it also increases wear and heat generation. Select preload for high-precision, high-rigidity applications; select light or no preload for light loads and high speeds. II. Installation: Details determine accuracy and lifespan. Many users report that "a new lead screw makes unusual noises after just six months of use." This is likely due to installation problems. Nanjing Shuntai's lead screw installation and commissioning video emphasizes that guideway parallelism errors exceeding 0.02mm/m will cause abnormal wear of the slider; coaxial misalignment of the bearing seats at both ends of the lead screw is a major cause of vibration. Jining local customers can schedule on-site installation services, where technicians will perform on-site calibration with a laser interferometer to ensure optimal performance of each device. III. Maintenance: Simple Operations Extend Lifespan by Three Times Regular lubrication is the lifespan of transmission components, but using the wrong grease can be detrimental. Nanjing Shuntai's technical advice: Use lithium-based grease for high-speed lead screws, extreme-pressure grease for heavy-duty guide rails, and high-temperature grease if the ambient temperature exceeds 80°C. IV. Summary: The selection of ball screws and linear guides requires rigorous engineering calculations. By keeping in mind the five core factors of "load, speed, accuracy, rigidity, and lifespan," following a scientific selection process, and leveraging the expertise of a professional team like Nanjing Shuntai, you can easily avoid 90% of selection errors and create a stable, precise, and durable linear motion system for your equipment.

The role of the ball screw is to achieve "precise, efficient, and fast electronically controlled linear motion," serving as a critical bridge between electrical signals and physical action. Its role is specifically reflected in the following aspects: 1. Core Role: Enabling Electronic Control and Replacing Traditional Systems The core characteristics of new energy vehicles are electronic control and intelligence, requiring electrical signals to control all physical movements. The ball screw serves as a perfect replacement for traditional hydraulic and pneumatic systems, becoming an ideal electronically controlled actuator. Traditional vehicles use hydraulic and vacuum assist systems. New energy vehicles use a combination of motors and ball screws, directly generating precise linear force and motion through electrical energy. 2. Three Key Roles [Intelligent Safety Actuator] - Primarily in electronic braking and steer-by-wire systems Function: Instantly converts electrical signals from the brake pedal or autonomous driving computer into tangible braking or steering force. Value: Response speeds far exceed those of hydraulic systems (in the millisecond range), providing the fast and precise execution necessary for advanced automated driving systems (ADAS), directly impacting driving safety. [Energy Regeneration Amplifier] - Primarily used in electronically controlled braking systems Function: Enables extremely precise control of brake pad clamping force, achieving seamless and perfect coordination between friction braking and electric motor-generated regenerative braking. Value: Maximizes braking energy recovery, converting it into electricity and charging it back into the battery, directly increasing the vehicle's range. This is difficult to achieve with ordinary hydraulic braking systems. [Ride Comfort Regulator] - Primarily used in active suspension systems Function: Based on road conditions and driving mode, the motor-driven ball screw quickly and precisely adjusts shock absorber damping or air suspension height. Value: Enhances vehicle comfort, stability, and handling, achieving a "magic carpet"-like ride, while also lowering the vehicle at high speeds to save energy. Conclusion: In new energy vehicles, the ball screw is far more than a simple mechanical component; it is a key enabling technology. By providing efficient and precise linear motion, it helps new energy vehicles achieve smarter driving, longer battery life, more comfortable experience and simpler design. It is one of the indispensable core components for new energy vehicles to move towards higher levels of electrification and intelligence.

In the world of precision manufacturing, there's a seemingly inconspicuous yet crucial component that converts rotational motion into precise linear motion. It carries tremendous force yet strives for micron-level accuracy. It's the ball screw, the indispensable "heart of precision transmission" in modern high-end equipment. I. What is a ball screw? The core principle revealed Simply put, a ball screw can be thought of as a "super screw with countless steel balls embedded in its threads." It consists of three main parts: The screw: A long shaft with a precision helical raceway. The nut: A component that mates with the screw and also contains matching helical raceways. The balls: Precision steel balls that circulate between the raceways of the screw and nut. The core operating principle is to replace sliding friction with rolling friction. When either the screw or the nut rotates, the balls circulate within the raceways, driving the other component for precise, smooth linear motion. This circulation system significantly reduces frictional resistance and significantly improves efficiency. II. Why is it so indispensable? Unparalleled Performance Advantages High Precision: Eliminating backlash (lost motion) and preloading capabilities enable precise positioning at the micron or even nanometer level, the cornerstone of CNC machine tool machining of complex parts. High Efficiency: Transmission efficiency can reach over 90%. This translates to lower drive torque, greater energy efficiency, and reduced heat generation. Long Life: Rolling friction causes far less wear than sliding friction, resulting in an extremely long lifespan and high reliability with proper use and maintenance. High Rigidity: Preloading eliminates internal clearance, allowing the ball to withstand significant axial loads without deformation, ensuring transmission rigidity and stability. Smooth Movement: The extremely low coefficient of friction results in low starting torque, smooth operation, and zero slip, making it ideal for high-speed reciprocating motion. III. Applications: From "Industrial Mother Machines" to "The Stars and Oceans" Ball screws are used in nearly all high-end manufacturing and precision equipment fields: CNC machine tools: This is their most classic application. The motion of the turret, spindle, and worktable directly determines the machining accuracy and speed of machine tools. Industrial Robots: The robot's joints and arm extension and retraction require precise, high-rigidity linear motion, and ball screws are the core actuators. Semiconductor Equipment: Photolithography machines, wafer inspection equipment, and die bonders require extremely smooth and precise motion; even the slightest vibration can be fatal. Medical Equipment: The scanning platforms of medical CT and MRI machines, as well as the robotic arms of surgical robots, all require quiet, precise, and reliable linear drives. Automotive Manufacturing: Electric power steering systems, brake actuators, and assembly robots on automated production lines. Aerospace: Aircraft control surfaces, landing gear retraction and extension, and satellite antenna deployment mechanisms require components to remain reliable in extreme environments. IV. Manufacturing Difficulty: The Ultimate Art of Precision Material Selection: High-quality alloy steels, such as chromium-molybdenum steel, are typically used, offering high strength, high wear resistance, and excellent heat treatment properties. Precision Grinding: Ultra-high-precision CNC grinding machines guarantee the shape, lead accuracy, and surface roughness of the screw raceway, ensuring this precision. Heat Treatment: Through processes such as carburizing, quenching, and tempering, the surface achieves an extremely high hardness (HRC58 and above) for wear resistance, while the core maintains toughness for impact resistance. Nut Machining: The design and machining of the internal deflector are crucial, determining the smoothness of ball circulation and noise levels. Inspection and Matching: Ultimately, equipment such as a coordinate measuring machine and laser interferometer is required for 100% inspection of lead error, stroke accuracy, and other parameters, as well as precise ball matching to achieve optimal preload. Conclusion The ball screw, a precision component hidden within the equipment, is the backbone of modern industry. If you are interested in ball screws, please contact us for further information and discussion.

I. Introduction In modern machining, lathes are fundamental and critical processing equipment. Their precision and efficiency directly impact product quality and production profitability. With the continuous advancement of industrial technology, traditional sliding screws are no longer able to meet the demands of high-precision, high-efficiency machining. As an advanced transmission element, ball screws, due to their superior performance, have been widely used in lathes, significantly improving their overall performance. II. Basic Structure and Working Principle of Ball Screws A ball screw consists of a screw shaft, nut, balls, a circulation system, and a sealing device. Its operating principle is to convert rotational motion into linear motion through the rolling motion of the balls between the screw shaft and nut. Compared to traditional sliding screws, ball screws use rolling friction instead of sliding friction, a fundamental change that results in significant performance improvements. III. Specific Applications of Ball Screws in Lathes Feed Systems: Modern CNC lathes commonly use ball screws as the core transmission component of the feed system to control the precise movement of the tool. X- and Z-axis movement is typically achieved by servo motors driving ball screws. Spindle Stock Positioning: In high-precision lathes, ball screws are often used for axial positioning of the spindle stock to ensure accurate spindle position. Tailstock Movement: Some advanced lathe designs use ball screws to control tailstock movement, improving adjustment accuracy and ease of operation. Automatic Tool Changer: In the automatic tool changing system of a turning center, ball screws are responsible for precise toolholder position control. IV. Technical Advantages of Ball Screws in Lathe Applications High Transmission Efficiency: The transmission efficiency of ball screws can reach over 90%, far exceeding the 20-40% of sliding screws, significantly reducing energy loss. Excellent Positioning Accuracy: Through precision manufacturing and preload adjustment, ball screws achieve micron-level repeatability, meeting high-precision machining requirements. Long Service Life: Due to their rolling friction principle, wear is minimal, with a service life of up to 5-10 times that of sliding screws. Excellent High-Speed Performance: Suitable for high-speed feed motion. Modern high-speed lathes can achieve rapid traverse speeds of 30-60 m/min. High Axial Rigidity: Preloading can improve axial rigidity, reducing deformation and vibration during machining. V. Considerations for Ball Screw Applications in Lathes Protective Measures: Dust protection and sealing must be ensured to prevent chips and coolant from entering the ball screw circulation system. Lubrication Management: Although friction is low, regular lubrication is still required, generally using lithium-based grease or circulating oil. Installation Precision: During installation, ensure parallelism between the screw and the guide rail to avoid additional bending moments that may affect service life. Anti-Reverse Measures: Vertical installation requires a brake to prevent reverse rotation. Thermal Deformation Control: Heat generated during high-speed operation may affect accuracy, so thermal compensation measures should be considered. VI. Future Development Trends in Ball Screw Technology Higher Precision Levels: Research and development of nanometer-level precision ball screws is ongoing. Intelligent Functions: Integrated sensors enable condition monitoring and predictive maintenance. New Material Applications: Exploring new materials such as ceramic balls and composite nuts. High-Speed Development: DN values (screw diameter x rotational speed) continue to increase, meeting the demand for higher machining efficiency. Environmentally Friendly Design: Development of lubrication-free or self-lubricating technologies reduces environmental pollution. VII. Conclusion The application of ball screws in lathes has become an important support for modern high-precision and high-efficiency processing. Shuntai ball screws can be customized in different models. Welcome to consult us. We are online 24 hours a day to answer your questions.