Air spring suspension system with dual path isolation

Abstract

A suspension system for a vehicle having a shock absorber strut with a reciprocal piston rod located within a cylinder, and attachments for securing the piston rod and cylinder to spaced parts of the vehicle. An air spring includes a rigid annular canister mounted on the piston rod by a resilient rotatable mount. The canister forms a fluid pressure chamber in conjunction with a flexible diaphragm, one end of which is sealingly connected to the cylinder by an annular rigid sleeve which forms an air spring piston. The flexible diaphragm has inner and outer radially spaced portions connected by a rolling portion. A rigid member resembling a cutaway can is mounted on the rigid canister portion of the air spring and extends about a predetermined portion of the outer portion of the flexible diaphragm and restrains outward expansion of said portion. Restriction of the outward expansion of only a portion of the flexible diaphragm exerts a lateral force on the strut to counteract the unbalanced lateral forces acting thereon due to the offcenter mounting of the strut with respect to the point of contact of the vehicle wheel with the pavement. The suspension system furthermore provides dual path isolation for separating the canister from the vehicle by a primary elastomeric isolator ring and from the strut by secondary elastomeric bushings mounted on the strut, which bushings also provide an upper air seal for the fluid pressure chamber.