Sealed roller bearing
View Patent ↗A roller bearing which is sealed by a sealing washer that forms a rubbing seal and two gaps. As a result of positions which are spaced apart from one another in the axial direction of a pivot point and a center of mass of an elastic support part that bears the rubbing seal, the latter is loaded with an outwardly acting axial force in the event of an increased rotational speed as a result of the centrifugal force, with the result that the rubbing sealing lip is in contact with a lower force as the rotational speed increases.
1. A roller bearing, comprising:
a sealing washer installed between a bearing inner ring and a bearing outer ring, the sealing washer having a thickened portion, which has two chamfered faces, arranged predominately in a circumferential annular groove of a first of the two bearing rings, contacting only two faces of the annular groove and forming a gap between the thickened portion and the annular groove, and the thickened portion having a rounded undercut starting at an end of one of the chamfered faces, the sealing washer having a reinforcement, an elastic sealing material and an elastic support part at an end opposite the annular groove, the elastic support part comprising a foot, a first sealing lip and a second sealing lip protruding from the foot and interacting with an undercut arranged in a second of the two bearing rings, the undercut being of asymmetrical configuration in such a way that a first shoulder, which adjoins a raceway region, and a second shoulder, which lies opposite the first shoulder, have different diameters, the first sealing lip is directed axially inwardly and is in rubbing contact only with an inner wall of the undercut, and the second sealing lip, which is predominately rectangular, is directed axially outwardly, forming a first gap seal with the second shoulder, and, radially spaced apart from the first sealing lip and the second sealing lip, a third inwardly directed sealing lip is arranged parallel to a rotational axis and perpendicular to the foot forming a second gap seal with the first shoulder,
wherein, in an installed state, the elastic support part is inclined inwardly in an axial direction with respect to a plane, which extends at right angles, to the rotational axis, a pivot point and a center of mass of the elastic support part, which is arranged radially spaced apart from the latter, being arranged offset outwardly in the axial direction with respect to one another by an axial amount, with a result that, when a roller bearing rotates, a centrifugal force, which acts in the center of mass, triggers a force component, which acts in the axial direction outwardly on the first sealing lip.
2. The roller bearing of claim 1 , wherein a radial spacing of the first sealing lip from the pivot point and a thickness of the support part form the following relationship:
3= l/t= 6.
3. The roller bearing of claim 1 , wherein the radial spacing and the axial amount form the following relationship:
10< l/a< 150.
4. The roller bearing of claim 1 , wherein an axial spacing between the center of mass and the end of the second sealing lip and an axial spacing between the center of mass and the end of the first sealing lip form the following relationship:
1< k/m< 180.
5. The roller bearing of claim 1 , wherein the reinforcement of disc-shaped configuration of the sealing washer is surrounded at least on one side by the elastic sealing material, and the reinforcement has an angled-away flange at one end and a limb which is inclined obliquely in the direction of the undercut at the other end.