Patent ID: 7746982
Filing Date: 2010-06-29
Classification: H01J

Abstract:
1. A rotary anode X-ray tube comprising: a rotary anode being provided with a target on which an electron beam is irradiated to generate X-rays, and having a first hollow portion; a rotary shaft supporting the rotary anode and having a second hollow portion; a disc portion fitted into the first hollow portion of the rotary anode with a first gap therebetween and having a third hollow portion; a fixed shaft being fitted into the rotary shaft with a second gap therebetween, and having a fourth hollow portion communicating with the third hollow portion of the disc portion; a liquid metal filled in the first and second gaps; a dynamic pressure bearing portion which is formed between an inner surface of the second hollow portion of the rotary shaft and an outer surface of the fixed shaft; and a passage which directly communicate the first gap to the second gap to supply the liquid metal to the first gap from the second gap, wherein the passage is formed in the rotary shaft.