JPS6020433A - Rotary anode for x-ray tube - Google Patents

Abstract

PURPOSE:To make mechanical strength yet stronger and keep a bearing in low temperature as well as to aim at the promotion of long service life in an X-ray tube, by solidly molding a target support shaft together with a rotor top part as one body, and covering this rotor top part with high heat transferrable materials including copper and so on, while joining the rotor top part and the covered metal both to a rotor cylindrical part in one. CONSTITUTION:A target support shaft 28 and a rotor top part 27 are solidly molded together by a material being excellent in mechanical strength against high temperature such as molybdenum. The rotor top part 27 is covered with a material excellent in heat transmission like copper or the like, while the rotor top part 27 and a covering metal 30 are joined by means of casting, brazing, pressure welding, etc. And, the rotor top part 27 and the covering metal 30 both are welded to a rotor cylindrical part 25 by means of brazing and makes up a rotor 24.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a rotating anode for an X-ray tube.

[The breakthrough of invention]

In general, a rotating 513 pole for an X-tube has a structure as shown in FIG. That is, a rotary shaft 3 is rotatably supported on the fixed portion 1 via a bearing 2, and a rotor 4 is fixed to this rotary shaft 3. Rotor 4 is a fixed part! a rotor cylindrical portion 5 that surrounds the outer circumference of the rotor cylindrical portion 5; a rotor top 7 that is integrally molded with the rotor cylindrical portion 5 and fixed to the front 1J rotary hoist 113 with a screw 6; and a target support shaft 8 joined to the rotor top 7. An umbrella-shaped target 9 is held and fixed to the target support shaft 8 by an oak 10.

In the rotating image body configured in this way, the fixing part 1 is fixed to the 1% pole sealing part of the glass bulb of the Then, a high voltage is applied between the anode and the cathode, and the electrons emitted from the cathode are accelerated by the high voltage and collide with the target 9 to generate xH.At this time, the high-speed electrons on the target 9 In order to prevent melting of the electron projection part, a rotating magnetic field is generated from a stator (not shown) surrounding the rotor cylindrical part 5 of the rotor 4 to rotate the rotor, and the target 9 is rotated at high speed. .

By the way, a large amount of high thermal energy is generated in the target 9 by the collision of high-speed electrons from &, and the target 9 reaches a high temperature of about 1000-1300''C.Therefore, the target 9 is usually made of tungsten. The support shaft 8 also becomes high in temperature due to the heat conducted from the target 9, so it is usually made of molybdenum.On the other hand, the rotor cylindrical part 5, which generates rotational force, is usually made of molybdenum from the viewpoint of performance as a rotor. ], made of copper or alloy metal with high air conductivity.

The high thermal energy of the target 9 is mainly radiated by radiation from the target 9 itself, the target support @8, the rotor top 7 and the rotor cylindrical portion 5. In addition, a part of the energy <- is conducted to the bearing 2 via the target support shaft 8, the four-way apex portion 7, and the d-rotation shaft 4, and the bearing 2 also becomes high in temperature.

However, in such a structure, since the rotor top part 7 is integrally molded with the rotor cylinder part 5 made of copper, the mechanical strength is small, and the target support shaft 8 is easily resistant to stress caused by rotational vibration during use. The rotor top 7 may undergo plastic deformation at the joint with the rotor and become unusable.

In order to improve these drawbacks, as shown in Fig. 2, the target support shaft 18 and the loaf top 1117 are integrally molded from a material such as molybdenum, which has a high mechanical strength and is stable at high temperatures. A structure in which the rotor 14 is joined to the cylindrical portion 15 is considered. As a result, the mechanical strength of the rotor cylindrical portion 17 is improved, and the ``1'' (property type) is less likely to occur. However, the thermal conductivity of molybdenum is lower than that of copper.
Since the temperature gradient is also small, the temperature gradient at the rotor top 17 becomes large, and the temperature at the attachment part of the rotating shaft 3 (see FIG. 1) to the rotor J shell 17 becomes high. As a result, the bearing 2 becomes hot, which shortens the life of the bearing 2.

[Purpose of the invention]

An object of the present invention is to provide a rotating anode for an X-ray tube that can improve the mechanical strength of the top of the rotor, reduce the amount of heat transfer conducted from the target to the bearing, and extend the life of the bearing. Our goal is to provide the following.

[Summary of the invention]

The present invention includes integrally molding the target support shaft and the row 211 portion, coating the rotor Jii portion with a metal having high thermal conductivity such as copper, and joining the rotor top 111S and the coated portion to the rotor cylindrical portion. I characteristics.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. The target support shaft 28 and the rotor top 27 are integrally molded from a material with excellent mechanical strength at high temperatures, such as molybdenum.
ing. The rotor top portion 27 is covered with forest material having excellent thermal conductivity, such as a plane, and the rotor m portion 27 and the covering metal 30
are joined by methods such as 1.°J construction, brazing, pressure welding, etc. Then, the rotor m section 27 and the drawn metal section 30 are joined to the rotor cylindrical section 25 by a method such as brazing, and the rotor 2
4.

In this way, since the rotor cylindrical portion 27 is integrally molded with the target support shaft 28 made of molybdenum or the like having excellent mechanical strength, plastic deformation is less likely to occur. Since the broken metal 30 such as copper is still bonded to the rotor m portion 27, the presence of the coating metal 30 causes the rotor top portion 27 to
The gradient of temperature is small. Therefore, the rotor top 2 of the rotating shaft
The temperature of the attachment part to the housing 7 can be lowered, and therefore the temperature of the receiving part 11 can also be lowered.

〔Effect of the invention〕

The ij developed by the present invention has high mechanical strength and can maintain the bearing at a low temperature, so that the life of the X 14 tM can be extended.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional rotating anode for an X-ray tube, Figure 2 is a cross-sectional view of the rotor remains for mechanical strength, and Figure 3 is a cross-sectional view of a four-turn anode for an X-ray tube according to the present invention. It is a cross-sectional view of a rotor structure showing one embodiment. l... Fixed part, 2... Bearing, 3... Rotating shaft, 4, 14° 24... Rotor, 5, 15 .25...
... Rotor cylindrical part, 7.17.27 ... Rotor top, 8.18. ．． 28...Target support shaft, 9...
...Target, 30...Target metal.

Claims (1)

[Claims] A rotating shaft rotatably supported by a fixed part; a rotor fixed to the rotating shaft and having a rotor cylindrical part, a rotor top, and a target supporting shaft; In a rotating anode for an X-ray tube, the target support shaft and the rotor top are integrally molded, and the rotor top is coated with a metal such as copper to provide a plated metal. A rotating anode for an X-ray tube, comprising a rotor top portion and the cylindrical portion of the rotor connected to the cylindrical portion of the rotor.