Design and vibration characteristics analysis of a novel permanent magnet eddy current damper for tracked vehicle suspension

Hydraulic dampers are widely used in tracked-vehicle suspensions but may suffer from oil leakage and temperature rise under high-frequency and high-load operating conditions. This study proposes a permanent-magnet eddy current damper driven by a planetary roller screw (RS-ECD). The planetary roller screw converts the relative linear motion of the suspension into rotary motion, while a Halbach permanent-magnet array enhances the air-gap magnetic field and electromagnetic damping torque. An analytical model and a finite-element electromagnetic model are established to investigate the mechanical and electromagnetic characteristics of the RS-ECD. The electromagnetic torque is calculated directly from the instantaneous rotor speed and coupled with a three-degree-of-freedom suspension-track dynamic model incorporating the equivalent mass of the ground-contact track segment and track-pitch-induced polygonal excitation. Under Classes D–G road conditions at 15 m/s, the RS-ECD reduces the RMS values of vehicle-body acceleration, road-wheel acceleration, suspension dynamic deflection, and dynamic wheel load by 10.3–34.6%, 29.9–66.2%, 51.3–57.5%, and 5.1–33.1%, respectively, compared with a linear hydraulic damper. Although localized peaks in vehicle-body acceleration and dynamic wheel load increase slightly under the rougher road conditions, the overall vibration intensity and suspension-stroke demand are reduced. These results demonstrate the potential of the RS-ECD for sustained vibration attenuation in tracked-vehicle suspensions while also revealing a trade-off in transient peak control.