Self-aligning vibration mount with compound-angled flexing elements

Abstract

A bushing style mount with low stiffness in two directions oriented with one of the low stiffness directions vertically to provide better isolation. Two elastomeric layers are bonded to two non-parallel surfaces of an inner member, on the one hand, and to a pair of plates on the other. Each of the plates has a contoured, non-planar configuration which increases the axial stiffness of the mount so that the truck cab's lateral motion is minimized. The inner member's non-parallel surfaces are also non-planar, preferably matching the non-planar configuration of the plates, such that the bonded elastomer is deflected into a vee configuration, for example. The inner member with the two elastomeric layers bonded thereto with the two plates bonded, in turn, to the outer faces of the elastomer, form a subassembly that is installed into a generally cylindrical housing. The housing and the outside faces of the plates have a mating contour which provides an alignment feature. For example, the housing may have a pair of inward protrusions which may take the form of darts formed in the tubular housing that engage in notches on the back sides of the two plates. The inner dimension of the housing is less than the maximum outer dimension of the subassembly such that the plates are deflected inward by the inner diameter of the housing compressing the elastomeric layers, while the darts engage in the locator notches. The inward deflection of the plates preloads the elastomeric members in both shear and compression. While this precompression may lie in the range of between 5% and 20% of the elastomeric member's pre-installed thickness, it is more preferably in the 10% to 15% range. The preload enhances durability and the notches perform a locator function as the mount functions during the cab tilt process.