JPS60158537A - X-ray tube rotary anode - Google Patents

Abstract

PURPOSE:To fix a rotor to a connector without deteriorating the thermal stress between the rotor and connector and the electric conductivity of the rotor by providing lugs in one body on one side of the joint surface between the connector and rotor and soldering the mutual joint surface. CONSTITUTION:A connector 1 uses a material such as stainless steel with a thermal expansion coefficient approximate to that of a bottomed cylindrical rotor 3 made of copper, and multiple lugs 11a are provided on the joint outer-diameter surface coupled with the inner-diameter surface of the rotor 3 and multiple lugs 11b are provided on the joint bottom surface facing the bottom surface of the rotor 3 in advance in one body with the connector 11 respectively. The rotor 3 is fixed to the connector 11 by mounting a solder material on the end surface of the connector 11, coupling the rotor 3 with the connector 11, and melting and soldering the solder material in gaps formed by the rotor and the opposite lugs 11a, 11b of the connector 11. The gaps on the joint surface between the rotor 3 and connector 11 are kept uniform by the lugs 11a, 11b, thereby the solder material can be uniformly fed to the gaps, thus the rotor 3 and connector 1 can be firmly held together and the thermal conduction can be kept excellent.

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, and particularly to a rotating anode suitable for an X-ray tube with a large load capacity.

[Background of the invention]

Generally, as shown in FIG. 1, a rotating anode X-ray tube has a cathode 2 provided at one end of an envelope 1 to emit thermoelectrons.
A rotor 3 is supported on the opposite side of the rotor 3 and is angled so as to hit a target plate 4 arranged thereon. That is, the rotor 3 is driven and rotated by an external rotating magnetic field (not shown), and the thermoelectrons flowing into the target plate 4 from the cathode 2 are dispersed so as not to concentrate at one point on the target plate 4. for a short period of time by increasing your receptive abilities.
This generates a large amount of X-rays. In order to increase the X-ray output of the rotating anode XIN tube, it is necessary to
Since the amount of thermoelectrons flowing in increases, the rotating anode must have a large load capacity.

In the conventional rotating anode, as shown in FIG. 2, a rotor 3 made of copper in the shape of a cylinder with a bottom and a target plate 4 are connected by a support 5 made of a heat-resistant metal. The material for the pillars 5 is usually molybdenum or an alloy containing molybdenum as a main component. The rotor 3 and the support column 5 are integrally bonded by melting copper, and the support column 5 and the target plate 4 are fitted together and fixed by tightening with a nut 6. The rotor 3 is the rotating shaft 7
A fixed portion 91 is connected to the housing 1 by a plurality of bolts 8 and further fixedly attached to the envelope 1, and is rotatably supported via a plurality of bearings 10.

In an X-ray tube with increased X-ray output and a large load capacity, the diameter or wall thickness of the target plate 4 is increased, and the rotation speed of the rotating anode is increased, so the support 5, which holds the target plate 4, and the It is necessary to mechanically strengthen the rotor 3, rotating shaft 7, and other parts that hold it. Since the rotor 3 is made of copper, it lacks strength when rotated at high temperatures and high speeds during operation, especially in Xil tubes with a large load capacity. The connector 11 is made of a material with good properties.

However, in conventional rotating anodes, the coefficient of thermal expansion of copper in the rotor 3 is large, whereas the coefficient of thermal expansion is small when the connector 11 is made of molybdenum. There is a problem in that the rotor 3 and the connector 11 are likely to be deformed due to thermal stress f when the temperature of the rotating anode changes. In addition, when iron is used as the connector 11, in addition to the problem of deformation due to the difference in thermal expansion coefficients, when the copper is melted and welded, a small amount of iron may be melted and mixed into the copper. There was a problem in that the electrical conductivity was lowered, and therefore the rotational performance was lowered. In the case of copper and iron, there is also a rotating anode that brazes using a brazing material, but as shown in FIG. In the rotating anode structure of a large load capacity X-ray tube configured to conduct and dissipate ζ, it is difficult to uniformly apply solder over the entire surface of the joint.

[Purpose of the invention]

An object of the present invention is to provide an X-ray tube rotating anode that can fix the rotor and the connector without causing thermal stress between the rotor and the connector and reducing the electric conductivity of the rotor.

[Summary of the invention]

The present invention provides an X-ray tube rotating anode in which a heat-resistant metal connector is attached to a column to which a target plate is attached, and the column side of the connector is surrounded by a cylindrical rotor made of copper. A protrusion is integrally provided on one of the joining surfaces, and the mutual joining surfaces are brazed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. Note that the same or equivalent members as in FIG. 2 will be described with the same reference numerals. The connector 11 is made of a material such as stainless steel whose coefficient of thermal expansion is close to that of the bottomed cylindrical rotor 3 made of copper, and has a protrusion 11a on the outer diameter surface of the joint that is fitted to the inner diameter surface of the rotor 3 in advance. Protrusions 11b are provided at a plurality of locations on the bottom surface of the joint facing the bottom surface of 3, integrally with the connecting piece 1.

Therefore, to fix the rotor 3 and the connector 11, a brazing material is placed on the end face of the connector 11 and the rotor 3 and the connector 11 are fitted together, and the protrusions 11a and 1l on the opposing surfaces of the rotor 3 and the connector 11 are fixed.
Brazing is performed by melting and pouring a brazing filler metal into the gap formed by bt.

The protrusions 11a and 1lbl maintain a uniform gap between the joint surfaces of the rotor 3 and the connector 11, allowing the brazing filler metal to flow evenly and uniformly into the gap, and making it possible for the rotor 3 and the connector 11 to It can be made into a state that is physically strong and has good heat conduction.

In this way, a rotating anode having a structure in which the connector 11 is surrounded by the rotor 3 can be formed by brazing.
Compared to the case where copper is melted and formed, there is a wider range of materials to choose from for the connector 11. For example, it is possible to use materials with a thermal expansion coefficient similar to that of copper, such as stainless steel, which reduces deformation due to thermal stress. It never occurs. Further, since the copper can be formed without melting, impurities are not mixed into the copper of the rotor 3, and the electrical conductivity of the rotor 3 can be kept high.

FIG. 5 shows another embodiment of the invention. In the above embodiment, the protrusions 11a and llb were formed on the connector 11, but in this embodiment, the protrusion 3a is formed on the inner diameter surface of the joint of the rotor 3, and the protrusion 3a is formed on the bottom surface of the joint.
A plurality of b are provided integrally with the rotor 3. Even with this configuration, the same effects as in the embodiment described above can be obtained.

In each of the above embodiments, the protrusions 11a and 3a are formed linearly in the axial direction, and the protrusions 11b are linearly formed in the radial direction, but a plurality of point-like protrusions may be provided. In addition, the protrusions 11a, llb or 3a, 3b are formed by pressing, casting,
Therefore, even if the connector 11 or the rotor 3 is formed by machining the connector 11 or the rotor 3 itself, the connector 11 or the rotor 3 and 6 can be made from another brazing material such as tungsten, molybdenum, iron, or nickel. Materials with a high melting temperature may be attached and integrated by welding. Also, the protrusion 11a, 11b or 3a
, 3b is preferably about 0.1 mm in height.

〔Effect of the invention〕

According to the present invention, since there is no thermal stress between the rotor and the connector and there is no reduction in the electrical conductivity of the rotor, a rotating anode suitable for an X-ray tube with a large load capacity can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a general rotating anode X-ray tube, FIG. 2 is a sectional view of a conventional rotating anode, and FIG. 3 is a sectional view of essential parts showing an embodiment of the rotating anode of the present invention. 4 shows the connector of FIG. 3, fa) is a side view, fbl is a bottom view, and FIG. 5 is a sectional view of a rotor showing another embodiment of the present invention. 3...Rotor, 3a, 3b...Protrusion, 4...Target plate, 5...Strut. 7- Figure 2 Figure 3 Figure 4 1 Figure 5

Claims (1)

[Claims] In an Xl1lil tube rotary anode, which is constructed by attaching a heat-resistant metal connector to a column on which a target plate is attached, and surrounding the column side of this connector with a cylindrical rotor made of copper, one of the joining surfaces of the connector and the rotor. An Xl#A tube rotating anode characterized by having a ζ projection and brazing the mutual joint surfaces.