• For tread cleaning device: Provide elastic support and buffering for tread cleaner; absorb impact during wheel‑roller contact; compensate installation and running deviation; reduce transmission of wheel‑rail vibration to vehicle body.
• For coupler system: Absorb huge impact energy during coupling, uncoupling and train operation; buffer longitudinal compression & tension loads; allow yaw, pitch and roll relative displacement; reduce impact shock to car‑body; protect coupler and vehicle under marshalling conditions.