ADJUSTABLE BEARING CENTERING MEANS FOR HELICOPTER ROTOR ELASTOMERIC BEARINGS

摘要

The invention relates to a helicopter rotor which has a hub member and at least one hub arm extending radially from the hub member. In accordance with the invention, the rotor includes a blade member which extends radially from the hub member and includes a spindle at its radial inner end. An elastomeric bearing connects the spindle to the hub arm so as to support the blade from the hub arm and so that the blade centrifugal force generated during rotor rotation will impart compressive loading on the elastomeric bearing. The elastomeric bearing includes a cylindrical elastomeric bearing joined to the spindle at its radial inner end and a spherical elastomeric bearing having a static apex and being joined to the hub arm at its radial outer end. A connector joins the cylindrical and spherical elastomeric bearings so that the bearings join the spindle to the hub arm and so that the elastomeric bearings operate in series. The elastomeric bearing is centered within the hub arm bore by a centering ring connected to the elastomeric bearing connector. The centering ring has at least two spherical surfaces at the outer periphery thereof coincident with the spherical elastomeric bearings static apex, and a centering socket positioned within and connected to the hub arm bore. The elastomeric bearing is also centered within the hub arm by at least two spherical bearing portions which are coincident with the spherical elastomeric bearing static apex and which are adapted to matingly engage the centering ring spherical surface so as to center the spherical elastomeric bearing about its static apex when the rotor is in a static mode.