A coupling device for transferring a medium from a stationary part to a rotating part, including a stationary first ring, which is fixed in place on a stationary part, a second, rotatable ring, which is fixed in place on a rotatable part and rotates along with the rotatable part, a bearing, which is situated between the first ring and the second ring, an annular gap, which is situated between the first ring and the second ring, a supply line, which is disposed at the first ring for the supply of the medium, a discharge line, which is situated at the second ring for the conveying of the medium, the discharge line rotating along with the second ring, an inner sealing element, which seals the annular gap at a radially inner side, and an outer sealing element, which seals the annular gap at a radially outer side.