| 摘要 |
<p>PURPOSE: To prevent damage of a bearing by providing a lubricant tank in a region between a pair of bearing surfaces, making this tank communicate with a lubricant in a pair of the bearing surfaces, also providing a duct connecting the tank to a vacuum space of an X-ray tube. CONSTITUTION: A relatively large gap is formed between an outer side surface of a portion 12 and a surface positioned in an opposite to a bearing shell 9, this gap is provided so as to surround a lubricant tank 15. Since the lubricant tank 15 is positioned in the largest distance from a shaft 16 of rotation, by centrifugal force produced in rotation of an anode, a lubricating material is left in the tank during ordinary operation. In order that the lubricant can be supplemented, in the portion 12 of a bearing shaft 8, a duct 19 connecting the lubricant tank 15 to a region of an opening is provided so as to communicate with a vacuum space of an X-ray tube. By this duct 19, all the bearing regions can automatically receive a necessary amount of the lubricant. In this way, destruction of a bearing can be prevented.</p> |
