| 摘要 |
<p>The rotatable hub (10) of the wheel of a heavy motor vehicle has a cylindrical axial cavity (12) at an axially outer position with respect to a bearing (20-22). The hub is supported by a shaft (70) composed of an axially outer portion (72) detachable from an axially inner portion (71) fitted centrally in the bearing. Into the cavity (12) there is inserted a pre-assembled unit including: a sealing device (30) for hermetically sealing a gap (13) between the cylindrical cavity (12) and the outer shaft portion (72) comprising two radially annular metallic inserts (31,32), each one bearing an elastomeric material for static sealing action (351,331) against the cylindrical cavity (12), and for dynamic sealing action (355,334) contacting the other insert. The sealing device can be axially constrained to an annular flat disk (80) axially lockable between the bearing (21) and a radial surface (74) of an axially outer shaft portion (72), by hooking tabs (313) formed by a first, radially inner annular insert (31) of the sealing device. The tabs (313) are inserted through openings (81) of the disc. A second, radially outer annular insert (32) supports a rubber gasket (331) for performing static sealing action against the cylindrical cavity (12).</p> |
