Abstract: A seal assembly having first and second annular seal elements each having a generally axially extending base and an annular radial lip. Each of the bases includes a wear surface portion, a central portion and an end portion. Each of the annular radial lips extend from a respective end portion. Each of the central portions include at least one bore therethrough. The first and second seal elements are mounted on respective members and are arranged such that the wear surface portion of each seal element provides a wearing surface for the radial lip portion of the other seal element. Furthermore, when assembled, the seal assembly forms a fluid tight annular cavity between this first and second annular seal elements and the bores permit the passage of a fluid medium into and out of the annular cavity.

Abstract: An axle includes a central portion with a pair of hollow spindles welded thereon which spindles are each capable of supporting a rotatable hub having a wheel and tire mounted thereon. Each hub would include an intermediate cavity which is sealed to define with a wall of the spindle a reservoir for inflation air for the tire. Inflation air is supplied to the spindle at a region axially inwardly of the hub at a predetermined circumferential location thereon. The spindles include an outer cylindrical surface at the region. Air passages formed in the wall of the spindles communicate the intermediate cavity of the hub with a radially extending passage at the outer cylindrical surface. A pair of collar elements each have an inner cylindrical surface matching the outer cylindrical surface of the spindle and a coupling passage and fitting for mating with the supply of inflation air.