Seal device for tire pressure-adjusting device

摘要

A seal device is adapted to be mounted at an area of relative rotation between two mounting portions of a tire pressure-adjusting device. The seal device includes a pair of first and second seal rings which are disposed in opposed relation to each other. Each of the first and second seal rings includes a main seal of an annular shape having a radially inwardly-directed lip formed on an inner periphery of the main seal, the lip having at its distal end a lip sliding surface to which a self-lubricating thin plate for sliding contact with one of the two mounting portion. Each seal ring further includes an auxiliary seal of an annular shape having a radially inwardly-directed lip which is formed on an inner periphery of the auxiliary seal and is adapted for sliding contact with the one mounting portion, the auxiliary seal being connected to the main seal to form therebetween a closed space for holding grease. A valve is mounted on each of the auxiliary seals for effecting the intake and exhaust of air relative to the closed space.