Integrated hydro-pneumatic spring device

The invention discloses an integrated hydro-pneumatic spring device. An inerter working chamber is coaxially arranged in a damping working cylinder, a piston portion in the inerter working chamber is arranged as a screw rod structure, a ball screw nut is arranged on the screw rod in the inerter working chamber according to a ball screw principle, a flywheel is coaxially fixed on the ball screw nut, the nut is limited in the middle section and can only rotate around the screw rod through two stop collars fixed at the top and bottom of the working cylinder, and ball circular grooves are arranged on contact surfaces of the stop collars with the nut. As an improvement, self-weight of a vehicle body is not increased when sprung mass of a suspension is improved, driving comfort and handling stability of vehicles are improved, complex mechanical network combined process is avoided, and spatial arrangement limitation is reduced due to coaxial parallel connection of the inerter and the damping.