A wind turbine drive train component (22) comprising a rotating shaft (61) with a radial seal (50) is provided. The radial seal (50) comprises a stationary part and a rotating part. The stationary part comprises a ring (51) with an inner edge and an outer edge, the inner edge being configured for contactlessly surrounding the shaft (61). The rotary part comprising a disc (52), coaxially connected to the shaft (61) for rotation therewith and comprising a flange (53) that wraps around the outer edge of the ring (51). The radial seal (50) further comprises an annular air lock gap (55) for containing an amount of lubrication fluid (64) and thereby closing off the air lock gap (55) when the rotary part rotates at a rotational speed above a predetermined threshold speed, the annular air lock gap (55) being formed by an inner surface of the flange (53), an outer part of the opposing parallel surface of the disc (52) and the outer edge of the ring (51).