leafspringassembly leafspring

1. Main leaf: The longest top leaf with rolled eyes at both ends for hinged connection with frame hangers, bearing the main tensile force.
2. Auxiliary leaves: Multiple spring‑steel plates with gradually reduced lengths stacked together to share loads.
3. Center bolt: Fastens all spring steel plates into an integral unit to ensure synchronous deformation of each leaf.
4. U‑bolts: Fasten the leaf‑spring assembly to the vehicle axle.
5. Spring clips: Restrict lateral offset of spring leaves and prevent transverse shifting between plates.
6. Eye bushings: Installed inside spring eyes, made of rubber or polyurethane, for friction buffering and abnormal noise reduction.
7. Limit pads / bump stops: Limit the maximum compression travel of the leaf spring and prevent damage caused by direct hard collision of steel plates.

Core Materials and Manufacturing Processes

1. Raw Material: High‑silicon‑manganese spring steel (such as 65Si2Mn), featuring high strength and excellent fatigue resistance, suitable for repeated bending deformation under heavy loads.
2. Key Procedures:

• Blanking and stamping: Cut steel plates according to designed dimensions.
• Hot‑rolled eye forming: Heat‑process both ends of the main leaf to form mounting eyes.
• Quenching and tempering heat treatment: Improve steel strength and toughness to avoid fracture.
• Pre‑stressing treatment: Apply reverse stress in advance to extend fatigue service life.
• Shot peening: Surface treatment to eliminate micro‑cracks and improve fatigue resistance.
• Paint coating: Anti‑rust and anti‑corrosion protection against erosion from mud, water and gravel.

Main Functions

1. Load‑bearing: Bear the weight of vehicle and cargo, serving as the major load‑bearing component for heavy‑duty vehicles.
2. Shock absorption and buffering: Steel plates bend and deform under road bumps to absorb impact from road surfaces.
3. Force transmission and guiding: Transfer driving and braking forces, constrain axle position, and realize positioning function without extra guiding mechanisms.

Application Scenarios

Advantages & Disadvantages

1. High load‑bearing capacity and strong impact resistance, adaptable to heavy‑load and poor‑road‑surface conditions.
2. Simple structure, low manufacturing cost, convenient inspection and field maintenance.
3. Reliable force transmission; no complicated air supply system required.

1. Inferior riding comfort compared with air‑spring suspension.
2. Friction occurs between spring leaves; long‑term overloading may lead to leaf fracture.
3. Large unsprung mass, not suitable for high‑speed lightweight transportation.

Installation & Maintenance Notes

1. Regularly inspect leaf springs for cracks, deformation and rust; replace damaged parts in time.
2. Tighten U‑bolts to specified torque value; avoid over‑tightening or insufficient fastening.
3. Inspect spring clips and eye bushings; replace worn bushings to eliminate rattling noise.
4. Avoid long‑term overloading, which will greatly shorten service life.
5. Properly lubricate friction surfaces to reduce wear between spring leaves.