Abstract: A sealing device for a slot between two elements, which are rotatable relative to each other, e.g. an outer and an inner race ring in a rolling bearing, incorporates a flexible sealing portion having a lip, which contacts a sealing surface surrounding the lip. The sealing portion is rotatable, and the centrifugal force acts upon it thus that it tends to leave the surface at increasing rotational speed. In order positively to avoid that the lip is urged so hard against the surface at high rotational speeds, that an unallowable temperature increase occurs, the sealing portion and the surface have profiles of such shape, that the lip is displaced in a direction which has a component directed radially outwards relative to the rotational axis, when the sealing portion with the lip is bent by the centrifugal force.