Bearing device having improved sealing mounting structure

A bearing device in which an inner member and an outer member are connected to each other in a relative rotation relationship through rolling elements, comprising a sealing member provided in an end portion of the bearing device so as to prevent an external foreign substance from flowing into the bearing device or prevent an internal lubricant from leaking out of the bearing device, wherein

• the sealing member comprises a frame constituting a basic body and an elastic sealing portion attached to the frame,
• the elastic sealing portion comprises one or more sealing lips,
• the one or more sealing lips comprises a main sealing lip 530 configured to perform a main sealing function and an auxiliary sealing lip located inward of the main sealing lip,
• the main sealing lip and the auxiliary sealing lip are configured as contact-type sealing lips that are brought into contact with a sealing surface of a counterpart member to perform a sealing, and
• a first sealing surface that is in contact with the main sealing lip and a second sealing surface that is in contact with the auxiliary sealing lip are formed to have different diameters.