A wheel structure for an automobile having a wheel rim, a central part, and spoke elements connected to the wheel rim and individually connected to the central part. Spoke elements have through-holes for wheel screws or bolts and the central part has holes for screwing in or pushing through same wheel screws or bolts. The through-holes of the spoke elements form a first hole circle and the holes in the central part form a second hole circle. The diameter of the first hole circle is smaller than the diameter of the second hole circle if the spoke elements are not connected to the central part, and the diameter of the first hole circle corresponds to the diameter of the second hole circle if the spoke elements are also connected to the central part.

A valve unit (1) with a single-piece valve body (4) includes a cylindrical collar (5), a valve seat (7), a main duct (9) and an auxiliary duct (10). The cylindrical collar (5) projects from a reference plane (12) obtained in the valve body (4) and is configured so that it can be arranged against a rim (2) when the cylindrical collar (5) is inserted in a hole (6). The cylindrical collar (5) has an end (5a) configured so that it can be deformed and can define a flared portion (13) of the main duct (9) which interferes with the rim (2) at the level of the hole (6) thus providing a mechanism (11) for fixing the valve unit (1) to the rim (2).

Axial relative movement of an auxiliary member (30) and a hub body (22z) is performed, the hub body (22z) and an inner race (21) are combined with each other in an axial direction, and a part of the hub body (22z) deformed by a blade (33) of the auxiliary member (30) is disposed inside an engagement concave portion (26) of the inner race (21).