JPH0348837Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a rotating anode type X-ray tube, and particularly to improvements in its rotation mechanism. [Technical background of the invention] Generally, X-ray tubes are used for medical purposes, for example, for X-ray diagnosis, but in cases such as gastric examination, an X-ray tube as shown in Fig. 3 has traditionally been used. ing. This X-ray tube is of the so-called rotating anode type, in which an eccentric negative electrode 2 and a substantially umbrella-shaped anode target 3 are arranged facing each other in a vacuum envelope 1, and the anode target 3 is supported by a rotating mechanism 4. It is designed so that it can be rotated. Further, a stator (not shown) is disposed outside the vacuum envelope 1 in correspondence with the rotation mechanism 4, and drives the rotation mechanism 4. In this type of rotating anode X-ray tube, the conventional anode target and rotation mechanism are shown in detail.
5 and 5, a support column 6 is provided coaxially and integrally protruding from one end (lid portion) of a covered rotary cylinder 8, and a substantially umbrella-shaped anode target 3 is attached to this support column 6. is secured by a nut (not shown). Inside the cylinder 8, a disk is integrally formed at one end of the rotating shaft 9, and this disk 10 is fixed to the inner surface of the lid portion of the cylinder 8 with screws 11. Further, a cylindrical anode fixing base 14 is inserted between the rotating shaft 9 and the cylinder 8, and the anode fixing base 14 is fixed to the vacuum envelope 1 (see FIG. 3). . Ball bearings 12 and 13 are interposed between the anode fixed base 14 and the rotating shaft 9, and each of the ball bearings 12 and 13 is composed of an inner race 18, an outer race 19, and a ball 20. The race 18 is fixed to the rotating shaft 9, and the outer race 19 is fixed to the anode fixed base 14. Furthermore, a coil spring 15 is disposed between the pair of ball bearings 12 and 13 to apply a preload to at least one of the ball bearings, and a ring-shaped fixed spacer is in contact with one end of the coil spring 15 and the outer race 19 of the ball bearing 12 . 16
is provided and fixed to the anode fixing base 14 with screws 7. Further, a ring-shaped movable spacer 17 is provided in contact with the other end of the coil spring 15, the outer race 19 of the ball bearing 13 , and the inner surface of the anode fixing base 14. A cylindrical spacer 21 is provided between each inner race 18 of the pair of ball bearings 12 and 13 , and is in close contact with the outer periphery of the rotating shaft 9. A nut 22 is tightened at the tip of the rotating shaft 9. ing. [Problems with the Background Art] In the conventional rotating anode X-ray tube as described above, the outer diameter of the movable spacer 17 and the outer diameter of the outer race 19 of the ball bearing 13 are equal, and the movable spacer 17 and the outer race 19 is not fitted. Therefore, during operation, the movable spacer 17 slipped in the radial direction between the outer race 19 and rubbed against the anode fixed base 14, so that the pressure on the outer race 19 was not constant. As a result, the smoothness of rotation was impaired, and the movable spacer 17 and the anode fixed base 14 became caught. [Purpose of the invention] The purpose of the invention is to provide a rotating anode type X-ray tube that prevents the movable spacer from rubbing against the anode fixed base during operation and has significantly improved reliability. [Summary of the invention] This invention is configured so that a gap of 30 μm or more exists between the outer peripheral surface of the movable spacer and the inner surface of the anode fixed base, and the movable spacer is fitted with the outer race of the ball bearing. It is a rotating anode type X-ray tube. [Example of the invention] The rotating mechanism of the rotating anode type X-ray tube according to this invention is constructed as shown in Figs. 1 and 2, and Fig. 2 shows an enlarged view of the main part of Fig. 1. It is something. That is, the same parts as in the conventional example (FIG. 4) are given the same reference numerals. In this invention, the outer ring race 1 of the ball bearing 13 is moved by the coil spring 15.
Ring-shaped movable spacer 2 pressed against 9
3 is different from the conventional one, and its outer diameter is that of the outer race 1.
9 (inner diameter of the anode fixing base 14)
It is formed smaller than 30μm. As a result, a gap 24 of 30 μm or more is created between the outer peripheral surface of the movable spacer 23 and the inner surface of the anode fixed base 14. Further, a stepped portion 23 a is formed on the inside of one surface of the movable spacer 23 , and this stepped portion 23 a is fitted into one end of the coil spring 15 . Furthermore, a stepped portion 23b is formed on the outside of the other surface, and this stepped portion 23b is fitted into the outer race 19 of the ball bearing 13 . The rotary anode type X-ray tube of this invention has the same structure as the conventional example (FIGS. 3 and 4) except for the above, so a detailed explanation will be omitted. [Effect of the invention] According to this invention, a gap 24 of 30 μm or more exists between the outer peripheral surface of the movable spacer 23 and the inner surface of the anode fixed base 14, and the movable spacer 23 is fitted into the outer race 19 of the ball bearing 13 . Since they are aligned, the movable spacer 23 is reliably prevented from rubbing against the anode fixed base 14 during operation, and as a result, reliability is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the main part (near the rotating mechanism) of a rotating anode X-ray tube according to an embodiment of the invention, FIG. 2 is an enlarged sectional view of a part of FIG. 1, and FIG. 3
The figure is a schematic configuration diagram showing a commonly used rotating anode type X-ray tube, Figure 4 is a sectional view showing the vicinity of the rotation mechanism of a conventional X-ray tube, and Figure 5 is a partially enlarged view of Figure 4. FIG. 3... Anode target, 8... Rotating cylinder, 9...
... Rotating shaft, 12 , 13 ... Ball bearing, 1
4...Anode fixing base, 15...Coil spring, 16
...Fixed spacer, 18...Inner race, 19...
...Paddle race, 20...Ball.

Claims (1)

[Claims for Utility Model Registration] A rotating cylinder to which an anode target is fixed, a rotating shaft coaxially fixed to the inside of the cylinder, and a cylindrical anode disposed between the rotating shaft and the cylinder. a fixed base, a pair of ball bearings consisting of an inner race, an outer race, and a ball interposed between the anode fixed base and the rotating shaft; a coil spring disposed between the pair of ball bearings; A rotating anode X-ray tube comprising a fixed spacer provided in contact with one end of the coil spring and one of the pair of ball bearings, and a movable spacer provided in contact with the other end of the coil spring and the other of the pair of ball bearings. In the above, the movable spacer is formed so that its outer diameter is smaller than the outer diameter of the outer race,
A rotating anode X-ray tube, wherein a part of the movable spacer is fitted into the outer race.