Roller bearing with air passage in a bore provided with grooves

The bearing has a path forming an air passage between exterior of a fixed unit (2) and a front side of a rotating unit. The path includes an outer channel (25) and an inner channel (26) to traverse through each unit. The path includes a groove formed by suppression of a front part of a spline (11) from an intermediate zone of a bore (10) up to its front side. A downstream end of the inner channel emerges into the groove.