A power transmission device includes: an axle housing having a central hole where a drive shaft is penetrated; a wheel hub disposed in an outer portion of the axle housing via wheel bearings; a speed-reducer housing chamber provided in the wheel hub to cover an opening end portion of the axle housing; a gear speed reducer, formed inside the speed-reducer housing chamber, to decelerate a rotation of the drive shaft and transmit the rotation to the wheel hub; and a wet-type brake mechanism housed in a brake chamber formed between the axle housing and the wheel hub, and actuated such that braking is applied to a rotation of the wheel hub relative to the axle housing. Further, floating seals are disposed between a lubrication space and the speed-reducer housing chamber, and a circulation passage for oil that includes an oil filter is connected to the lubrication space.

A wheel bearing assembly for a vehicle includes at least one rolling-element bearing having a first bearing ring and a second bearing ring defining therebetween a bearing interior, rolling elements disposed in the interior, and a seal assembly for sealing the bearing assembly. The seal assembly includes a sleeve-shaped element connected to the second bearing ring such that the sleeve-shaped element rotates with the second bearing, and the sleeve-shaped element includes a flange that forms an axial stop for the rolling elements. A carrier element is connected to the first bearing ring such the carrier element rotates with the first bearing ring, and the carrier element includes a radially extending annular flange. The radially extending annular flange supports a radially encircling seal having at least one seal lip, and the seal lip extends toward the second bearing ring and sealingly abuts on the sleeve shaped element.

Construction of a double-row tapered-roller bearing unit that is able to improve the contact state between the rolling contact surfaces of plural tapered rollers and a first inner-ring raceway (7) and second inner-ring raceway (8), and a method of manufacturing the same are provided. The inclination angle .sub.1 of the first inner-ring raceway (7) and the inclination angle .sub.2 of the second inner-ring raceway (8) in a state before the first inner ring (10) and the second inner ring (11) are press-fitted onto the fitting surface section (13a) of the hub main body (12a), the amount of decrease .sub.a in the inclination angle of the first inner-ring raceway (7) and the amount of decrease .sub.b in the inclination angle of the second inner-ring raceway (8) occurring due to press-fitting of the first inner ring (10) and the second inner ring (11) onto the fitting-surface section (13a), and the amount of increase .sub.k in the inclination angle of the first inner-ring raceway (7) occurring due to formation of the crimped section (15) are adjusted, so that the inclination angle .sub.1 of the first inner-ring raceway (7) and the inclination angle .sub.2 of the second inner-ring raceway (8) in a state after the crimped section (15) has been formed are kept within respective proper ranges.

A wheel hub unit comprises a wheel hub body (100, 200), a first tapered roller bearing (101, 201) and a second tapered roller bearing (102, 202). Two bearings are oppositely disposed in the wheel hub body (100, 200). A bearing bush (104) or a shaft sleeve (204) is sleeved in the inner rings of the first tapered roller bearing (101, 201) and that of the second tapered roller bearing (102, 202), so as to form a rolling and sliding bearing, and the high strength load is effectively absorbed. A seal element is disposed between the outside end of the bearing and the wheel hub body (100, 200) to form the integral type independent seal. The problem that the inner rings of the bearings are exchanged and assembled in a mixed way during the assembly process is avoided, and the efficiency and accuracy of assembly are improved.

A vehicle wheel end assembly comprising a wheel hub, rotatably mounted on a wheel axle spindle by a wheel bearing s comprising a roller bearing. The wheel bearing has a bearing inner ring mounted on an external section of the wheel axle spindle and a bearing outer ring mounted in an internal section of the wheel hub. The assembly further comprises a threaded hub nut mounted at the end of the wheel axle spindle to fix the bearing inner ring on the wheel axle spindle and a rotational lock mechanism to prevent relative rotation between the bearing inner ring and the wheel axle spindle. The rotational lock mechanism comprises a tangential surface arranged to intersect a part of an inner circumference of the bearing inner ring at right angles to the axis of rotation in a plane located at or adjacent an outer radial end surface of the bearing inner ring.

In one aspect, a wheel hub assembly having a wheel hub body, an inboard bearing assembly, an outboard bearing assembly, and a seal. The inboard bearing assembly has a radially outer ring mounted to the wheel hub body, a radially inner ring, and a plurality of bearing elements that permit the radially outer ring to rotate relative to the radially inner ring. The seal includes a seal case mounted to the wheel hub body and a sleeve having a sleeve body mounted to the radially inner ring of the inboard bearing assembly. The sleeve body extends inboard from the radially inner ring and is configured to extend along the spindle and be spaced radially therefrom with the inboard and outboard bearing assemblies rotatably connecting the wheel hub body to the spindle.

A split torsion axle is configured to provide the advantages of a torsion axle while also allowing for the independent adjustment of related wheel assemblies positioned on opposite ends thereof. The split torsion axle also provides for additional stability provided by having a continuous axle member spanning the width of the trailer or vehicle upon which the split torsion axle is deployed. To provide these capabilities, the split torsion axle comprises a first torsion axle beam and a second torsion axle beam, which are rotatably coupled to one another by a central joint. The central joint comprises a first spindle coupled to the first torsion axle beam, a second spindle coupled to the second axle beam, and a bearing assembly rotatably coupling the first and second spindles to one another. Both the first torsion axle beam and the second torsion axle beam are configured to be coupled to respective wheel assemblies.