An x-ray tube is disposed within an x-ray tube housing defining a chamber filled with oil or other cooling medium for cooling the x-ray tube. The x-ray tube includes an envelope enclosing an evacuated chamber in which an anode assembly is rotatably mounted to a bearing assembly and interacts with a cathode assembly for production of x-rays. The bearing assembly includes a bearing housing and a plurality of bearings disposed on a surface of the bearing housing. A heat sink is coupled to the bearing assembly and provides a thermally conductive path between the bearing assembly and the cooling medium in the x-ray tube housing for providing direct cooling of the bearing assembly during operation.