Application of High-Temperature Disc Springs in Machine Tool Spindles

High-temperature disc springs are designed to perform in extreme thermal environments ranging from -200°C to 750°C, offering a superior alternative to conventional spring materials. Their exceptional thermal compensation properties help maintain consistent preload by offsetting thermal expansion and contraction. This prevents bolt fatigue and gasket failure, ensuring long-term sealing and mechanical integrity.

These springs are widely used in high-temperature valves, pump flanges, and especially in machine tool spindles, where stability and precision are critical. This article focuses on their performance in CNC spindle clamping systems.

1. Function in Spindle Drawbar Mechanism

High-temperature disc springs are key components in CNC spindle drawbar systems. With their "small deformation, high load capacity" characteristic, they provide the required clamping force to keep tool holders firmly in place — a solution to the common problem of insufficient clamping force.

Working Principle:

• The spring set generates a clamping force of ~10,000 N, pushing the drawbar;

• Steel balls transfer this force to the piston and tool holder;

• Compressed air flows through the drawbar’s center to clean the spindle taper and tool holder interface;

• When the piston retracts, the springs re-clamp the tool holder.

2. Common Failure Causes and Solutions

Despite their advantages, disc spring failure (e.g., cracking or fracturing) is still common in service, primarily due to issues in the following areas:

• Material Selection: Prefer chrome-manganese steel with high toughness and elastic limit;

• Precision Manufacturing: Ensure tight tolerances and surface flatness;

• Surface Treatment: Use shot peening to induce beneficial compressive stress, improving fatigue life under dynamic loads;

• Assembly Considerations: Leave proper clearance between the guide rod/sleeve and the spring stack;

• Design Validation: Proper selection of spring dimensions and stack configuration is essential for long-term reliability.

High-temperature disc springs significantly improve the performance and reliability of CNC spindle systems. Their unique ability to maintain preload in fluctuating temperatures makes them indispensable in modern machine tool applications. However, continued improvement in material selection, surface treatment, precision control, and installation practices is crucial to minimizing spring failure and extending spindle service life.

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Raleigh Spring Technology Co., Ltd.