Patent attributes
A seal member with its base end connected to a metal core has three seal lips. The thickness of the tip end of the intermediate seal lip in the intermediate position is d1, and the thickness of the base end is d2. The thickness of the tip end of the innermost inner seal lip is D1 and that thickness of the base end is D2. In this case, at least part of the base end of the intermediate seal lip and inner seal lip has its thickness regulated to be 0.2·d1≦d2≦0.8·d1, and 0.5·D1≦D2<D1. The tip edge of the inner seal lip is fitted onto the outer peripheral surface of the radially inside cylindrical portion of a slinger with substantially zero interference. Consequently, even if the slinger and metal core are displaced relative to each other, excellent seal performance is secured while increase of torque is inhibited.
