ROTATION ANODE X-RAY TUBE AND X-RAY CT DEVICE USING THE X-RAY TUBE

摘要

A rotation anode X-ray tube (30), comprising a rotation anode (31) having a rotor (35) and a fixed part (32) changed in structure and material to reduce the amount of thermal elongations thereof, the fixed part (32) further comprising an inner tube part (33) supporting bearings (9) and an outer tube part (34) covering the inner tube part, wherein the inner tube part (33) is formed of a highly thermal conductive copper and the outer tube part (34) is formed of a molybdenum with low coefficient of thermal expansion, the amount of thermal elongation is suppressed by the outer tube part (34) and the temperature rise of the bearings (9) is suppressed by the inner tube part (33), and the connection of a rotor shoulder part (36) forming the rotor (35) with an insulation support body (7) is formed in a screwing structure (thread connection) and is formed of a molybdenum (stainless steel was used before) to suppress the amount of thermal elongation so as to reinforce the connection structure, whereby the amount of movement of the focus of the X-ray tube is reduced by approx. 70% over the conventional tubes, and thus the amount of movement of the focus of the X-ray tube itself can be reduced, a mechanical strength can be increased, and the effects of the movement of the focus on an image quality can be suppressed by the thermal control of the anode of the X-ray tube of an X-ray CT device.