Bearing unit for the hub of a vehicle wheel equipped with a tyre inflating system

A bearing unit for a wheel hub of a vehicle equipped with a system for supplying pressurized air to a tyre through the hub of the wheel, the bearing unit comprising:

• a radially outer stationary race,
• a pair of radially inner rotatable half-races,
• an intermediate annular chamber between the outer race and the inner half-races,
• at least a first inner air passage formed through the outer race and communicating with the intermediate annular chamber,
• at least a second essentially radial inner air passage defined between the inner half-races and communicating with the intermediate annular chamber;
• an intermediate annular member axially interposed between the inner half-races and defining at least partially said second passage,
• wherein the intermediate annular member forms at least one blade surface extending from the second passage to the intermediate chamber for capturing air from the intermediate chamber and conveying it into the second passage.