A hub structure includes an axle housing, a hub having an insertion hole in a vehicle width direction through which the axle housing is inserted, and an inner bearing disposed between the hub and the axle housing in the insertion hole and rotatably supporting the hub with respect to the axle housing, and an oil seal disposed between the hub and the axle housing in the insertion hole on an inner side relative to the inner bearing in the vehicle width direction. A spacer is provided between the inner bearing and the oil seal in the insertion hole. The spacer has an outer end surface that is contactable with an inner end surface of an inner race of the inner bearing.

An Automatic Tire Inflation System (ATIS) for use with a vehicle includes a controller, valves controlled by the controller and, for at least one drive axle having inner bearings and outer bearings, a channel formed in a spindle, first hosing coupling controlled by the controller to the channel formed in the spindle, a channel formed in a hub, a rotary air seal coupling the channel formed in the spindle to the channel formed in the hub, and second hosing coupling the channel formed in the hub to at least one wheel. The rotary air seal may transition from a sealed state that forms a seal between the spindle and the hub to support air flow between the channel formed in the spindle and the channel formed in hub and reside in an unsealed state to negate the seal between the spindle and the hub.

A hub structure includes an axle housing, a hub having an insertion hole in a vehicle width direction through which the axle housing is inserted, and an inner bearing disposed between the hub and the axle housing in the insertion hole and rotatably supporting the hub with respect to the axle housing, and an oil seal disposed between the hub and the axle housing in the insertion hole on an inner side relative to the inner bearing in the vehicle width direction. A spacer is provided between the inner bearing and the oil seal in the insertion hole. The spacer has an outer end surface that is contactable with an inner end surface of an inner race of the inner bearing.

The present invention relates to a roller for use in an agricultural or mowing machine, the roller comprising a pair of tapered roller bearings and a pair of roller bearings, wherein the tapered roller bearings are closer to the midpoint of the roller than the roller bearings. An agricultural or mowing machine comprising the roller is also described.

An Automatic Tire Inflation System (ATIS) for use with a vehicle includes a controller, valves controlled by the controller and, for at least one drive axle having inner bearings and outer bearings, a channel formed in a spindle, first hosing coupling controlled by the controller to the channel formed in the spindle, a channel formed in a hub, a rotary air seal coupling the channel formed in the spindle to the channel formed in the hub, and second hosing coupling the channel formed in the hub to at least one wheel. The the rotary air seal may transition from a sealed state that forms a seal between the spindle and the hub to support air flow between the channel formed in the spindle and the channel formed in hub and reside in an unsealed state to negate the seal between the spindle and the hub.

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.

Modified bidirectional cassette seals that are useful in wheel assemblies, especially wheel and track driven farm tractors and includes wagons and other gear subjected to harsh environments such as heavy equipment, such as backhoes, bulldozers and the like.