A radial lip seal includes a sealing lip body having a contact point defining an inner diameter of the radial lip seal, and a heelstock body defining an outer diameter and having a supporting section arranged radially inwardly relative to the outer diameter and extending along a boundary of the sealing lip body toward the contact point. The heelstock body is formed of a heelstock material that is flexible, and the heelstock material is stiffer relative to a material of the sealing lip body.

In an outer race rotation bearing in which an outer race rotates, a mounting portion is fitted in each annular groove of the outer race. A pair of seals are provided which close the respective axial ends of an annular space defined between a fixed inner race and the outer race. Each of the seals has an elastic lip which protrudes toward the interior of the bearing, and which is kept in close contact with a groove edge portion of the annular groove from the inner peripheral side of the outer race. In this arrangement, when the seals are pressed axially outwardly by grease to which centrifugal force is applied, the grease leakage preventing lips of the respective seals function as lids to close the gaps generated between the mounting portions and the annular grooves, thereby making it possible to prevent grease from leaking through these gaps.

In an outer race rotation bearing in which an outer race rotates, a mounting portion is fitted in each annular groove of the outer race. A pair of seals are provided which close the respective axial ends of an annular space defined between a fixed inner race and the outer race. Each of the seals has an elastic lip which protrudes toward the interior of the bearing, and which is kept in close contact with a groove edge portion of the annular groove from the inner peripheral side of the outer race. In this arrangement, when the seals are pressed axially outwardly by grease to which centrifugal force is applied, the grease leakage preventing lips of the respective seals function as lids to close the gaps generated between the mounting portions and the annular grooves, thereby making it possible to prevent grease from leaking through these gaps.

A shaft seal assembly for establishing a liquid-tight seal between a steering knuckle and an axle shaft is provided. The shaft seal assembly includes an outer case and a first elastomeric member attached to one another. The elastomeric member has a castellated feature including a plurality of projections extending in a radially outward direction and separated from one another by a plurality of grooves. When the shaft seal assembly is installed in the steering knuckle, a cavity is presented between the steering knuckle and the first elastomeric member. Together, the grooves and cavity allow air to flow from a hub on one side of the seal assembly to a vacuum port in the steering knuckle. The cavity extends circumferentially around the seal assembly, and thus, air flow from the hub to the vacuum port is not dependent upon the orientation of the seal assembly relative to the steering knuckle.

A shaft seal assembly for establishing a liquid-tight seal between a steering knuckle and an axle shaft is provided. The shaft seal assembly includes an outer case and a first elastomeric member attached to one another. The elastomeric member has a castellated feature including a plurality of projections extending in a radially outward direction and separated from one another by a plurality of grooves. When the shaft seal assembly is installed in the steering knuckle, a cavity is presented between the steering knuckle and the first elastomeric member. Together, the grooves and cavity allow air to flow from a hub on one side of the seal assembly to a vacuum port in the steering knuckle. The cavity extends circumferentially around the seal assembly, and thus, air flow from the hub to the vacuum port is not dependent upon the orientation of the seal assembly relative to the steering knuckle.

A shaft seal in which a seal element a seal element and a gasket as held members are held between an outer case and an inner case, and, a protruding portion to locally increase holding pressure on the seal element is disposed on a pressing face for held member of the inner case.

A shaft seal in which a seal element a seal element and a gasket as held members are held between an outer case and an inner case, and, a protruding portion to locally increase holding pressure on the seal element is disposed on a pressing face for held member of the inner case.

A sealing device has a first sealing member and a second sealing member. The first sealing member has a cylindrical part mounted on an outer member, and a lip. The second sealing member has a sleeve into which an inner member is fitted, and a flange extending radially outward. The flange has a rigid flange portion connected to the sleeve, and a circular annular elastic flange portion that adheres to the rigid flange portion. An annular protrusion is formed on an inner periphery of the elastic flange portion, and is in contact with an outer peripheral surface of the inner member. In an initial state, the inner peripheral surface of the protrusion has a cylindrical portion having an inner diameter that is less than that of the sleeve. The cylindrical portion has a length of at least 0.15 mm in the initial state.

A sealing device has a first sealing member and a second sealing member. The first sealing member has a cylindrical part mounted on an outer member, and a lip. The second sealing member has a sleeve into which an inner member is fitted, and a flange extending radially outward. The flange has a rigid flange portion connected to the sleeve, and a circular annular elastic flange portion that adheres to the rigid flange portion. An annular protrusion is formed on an inner periphery of the elastic flange portion, and is in contact with an outer peripheral surface of the inner member. In an initial state, the inner peripheral surface of the protrusion has a cylindrical portion having an inner diameter that is less than that of the sleeve. The cylindrical portion has a length of at least 0.15 mm in the initial state.

A shaft seal mechanism (11) that blocks a fluid (G) flowing within a ring-shaped space (14) is equipped with: a ring-shaped seal housing (21) disposed on a fixed section (12); a plurality of thin-plate seal pieces (22) that are secured to the seal housing (21), are in sliding contact with a rotating shaft (13), and are layered in a ring shape; a ring-shaped high-pressure-side plate (25) that forms a high-pressure-side gap (δH) between itself and the seal housing (21); a ring-shaped low-pressure-side plate (26) that forms a low-pressure-side gap (δL) between the seal housing (21) and the thin-plate seal pieces (22); stepped sections (31, 32) that are formed on side edge sections (22c, 22d) of the thin-plate seal pieces (22); and locking sections (25b, 26b) that lock the stepped sections (31, 32).