X-ray tube device and X-ray CT apparatus

An X-ray CT apparatus, comprising:

• an X-ray detector;
• and
• an X-ray tube device disposed on an opposite side from the X-ray detector, the X-ray tube device comprising:
• a cathode that produces an electron beam;
• an anode that produces X rays upon irradiation with the electron beam;
• a rotating portion that supports and rotates the anode;
• bearings that are placed at a predetermined distance from each other in a direction of a rotation axis of the rotating portion, each of the bearings having an outer ring and an inner ring between which rolling elements are sandwiched;
• and
• a holder that holds the outer rings,
• wherein the holder has an inner wall that is spaced from an edge of the outer ring,
• wherein the inner wall of the holder is installed with a foreign matter collecting portion to collect foreign matters originating on a contact surface between the holder and the outer ring, and
• wherein the foreign matter collecting portion is a groove located approximately in the center of the contact surface in the direction of the rotation axis.