Ⅰ. Trapezoidal Screw Assembly
A trapezoidal Lead Screw system is an important mechanical component, primarily based on the design of the thread pair and profile optimization. 1. Function of the Lead Screw Assembly
The trapezoidal screw and nut has external and internal nuts at both ends. Through the threaded contact surface, rotation is achieved. When it rotates, the external nut moves along the main body (the Trapezoidal threaded screw), thereby transferring force and motion. This design allows the trapezoidal lead screw to withstand larger loads while maintaining efficient power transmission.
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2. Optimized Profile Design
The profile of the trapezoidal lead screw is carefully designed with a steep angle on the threads. This design increases friction, improving transmission efficiency and load-bearing capacity. Additionally, the trapezoidal profile's geometric structure optimizes the forces' distribution, ensuring stable force transmission during rotation.
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3. Advantages of High Load Capacity and High Efficiency
The trapezoidal lead screw’s inclined design increases the coefficient of friction, allowing it to bear higher mechanical loads. The optimized trapezoidal profile also enhances transmission efficiency (typically over 98%), making it widely used in fields such as machine tools, automotive, and aerospace.
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4. Performance in Practical Applications
Due to its high strength, load-bearing capability, and long service life, trapezoidal Lead Screws are commonly used in mechanical transmission systems that require precise control and high reliability. For example: 1)Machine Tool Manufacturing: Used to transfer rotational power to the spindle
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2)Automotive Industry: Applied in parts like gearboxes and engines.
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3)Aerospace: Used in aircraft engines and other high-precision mechanical systems.
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Ⅱ. Main Performance Parameters of Trapezoidal Lead Screw Set
1. Outer Diameter: The diameter of the imaginary cylinder that coincides with the crest of the external thread—also known as the nominal diameter.
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2. Inner Diameter: The diameter of the imaginary cylinder that coincides with the root of the external thread, used as the critical diameter for strength calculations.
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3. Pitch Diameter: The diameter of the imaginary cylinder where the thickness of the thread and the width between the threads are equal, approximately equal to the average diameter of the thread: d2≈0.5.
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4. Pitch: The axial distance between two adjacent threads at the pitch diameter.
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5. Lead: The axial distance between two corresponding points on the same helix of adjacent threads at the pitch diameter.
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6 . Number of Threads: The number of helical threads, generally n≤4 for ease of manufacturing. The relationship between pitch, lead, and number of threads is: L = nP.
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7. Helix Angle: The angle between the tangent to the helix on the pitch diameter and the plane perpendicular to the screw axis.
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8. Thread Angle: The angle between the two sides of the thread in the axial plane.
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9. Thread Flank Angle: The angle between the flank of the thread and the plane perpendicular to the screw axis.
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