• Bear static and dynamic loads of car body and bogie frame
• Attenuate high‑frequency vibration and absorb impact energy from wheel‑rail contact
• Transmit longitudinal, lateral and vertical forces between car‑body, bogie and axle‑box
• Realize flexible positioning, allow controlled displacement for safe curve negotiation
• Suppress car‑body rolling motion; reduce structure‑borne noise
• Protect related mechanical structures and extend component service life