JPS58181261A - Rotary-anode x-ray tube - Google Patents

Abstract

PURPOSE:To maintain the temperature of a high-temperature-side bearing low by making the inner cylinder of a rotor to have a complex structure by constituting the inner cylinder of a low thermal conductivity non-magnetic body which is connected to a target-supporting shaft and a magnetic member which faces a stator. CONSTITUTION:A target 1 is supported by the supporting shaft 21 of a rotor 2. The rotor 2 is supported by a supporting shaft 5 through bearings 3 and 4 so that the rotor 2 can rotate freely. The rotor 2 is constituted of an inner cylindrical part 22 and an outer cylindrical part 23. The inner cylindrical part 22 is formed by joining by friction welding, a low thermal conductivity member 22a which is made of a stainless steel or the like and provided around the high-temperature-side bearing 3, and a magnetic body 22b which is made of iron or the like and provided around the low-temperature-side bearing 4. The inner cylindrical part 21 is covered with the outer cylinder 23 which is made of copper and formed by casting or something similar. Owing to the above constitution, the temperature of the high-temperature-side bearing 3 can be maintained low by increasing the thermal resistance between the target 1 and the bearing 3. As a result, any damage to the bearings 3 and 4 which might be caused during the exhaustion process can be prevented, and the service life of a roatry-anode X-ray tube can be extended.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to rotating anode X-ray tubes, and more particularly to anode structures.

In the structure of the rotor of a conventional rotating anode X-ray tube, the cylinder is made of a magnetic iron material, which is connected to a target support, and the outer periphery of the iron inner cylinder is coated with a steel material by means of casting or the like. However, since iron material has high thermal conductivity, the thermal resistance between the target and the high-temperature side bearing is low, and the heat of the target is easily conducted to the high-temperature side bearing. Due to the structure of the rotor, the inner cylinder requires a magnetic material and the outer cylinder requires a copper material.
This makes it easier to transmit the magnetic field from the stator placed around the rotor to the rotor. As a result, there were problems such as the temperature of the high-temperature side bearing rising too much during the degassing process from the target during the manufacture of the X-ray tube, deteriorating the rotational characteristics, and shortening the rotational life during use. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotating anode X-ray tube that improves the above-mentioned drawbacks and has a long rotational life.

In order to achieve the above object, the present invention divides the inner cylinder structure of the rotor into two in the length direction, uses magnetic material only in the peripheral part of the low temperature side bearing facing the stator, and uses the magnetic material in the peripheral part of the high temperature side bearing. By using a non-magnetic material with low thermal conductivity, such as stainless steel, we can increase the thermal resistance between the target and the high-temperature bearing, thereby reducing the temperature of the high-temperature bearing during use and extending the life of the bearing. It is intended to be extended.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The target] is supported by a target support shaft 21 of the rotor 2. The rotor 2 is rotatably supported by a support shaft 5 via a bearing 3.4, and the support shaft 5 is fixed to a fixed part 6. Furthermore, the rotor 2 is rotated by the rotating magnetic field of a stator (not shown) placed around the outer periphery of the X-ray tube.
The rotating magnetic field is applied near the bearing 4 on the low temperature side due to its structure. Further, a preload is applied to the bearings 3 and 41 by the spring 7 in the thrust direction. In the figure, 8 is a nut, 9 is a washer, 10 and 11 are spacers, 12 is a bush, 13 is a bearing valve, and 14 is a bolt.

The rotor 2 consists of a target support part 21, an inner cylinder part 22, and an outer cylinder part 23. In the inner cylinder part 22, the peripheral part of the high temperature side bearing 3 is made of a non-magnetic material 22a1 having low thermal conductivity, such as stainless steel, and the peripheral part of the low temperature side bearing 4 is made of a magnetic material 22b1, for example, an iron material. As a result, the former stainless steel material 22a increases the thermal resistance between the target roller l-1 and the bearing 3, and the latter iron material 22b efficiently receives the rotating magnetic field from the stator. Stainless steel material 22a and iron material 22
b is that the two are joined together by friction welding at the time of the material,
Use the processed product. The rotor inner cylinder 22 and the target support shaft 21 are connected by screws or the like, and the threaded portions are brazed when the steel outer cylinder 23 is covered by casting or the like.

As is clear from the above description, according to the present invention, by forming the rotor inner cylinder into a composite structure, the target can be
When operating at ,000℃, the temperature of the high temperature side bearing is 30~30℃.
It can be rubbed at a low temperature of 50°C.

As a result, the bearing is not damaged in the exhaust process of the tube manufacturing process, and the rotational life during actual use can be extended.

[Brief explanation of drawings]

The figure is a longitudinal sectional view of an anode structure showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Target, 2...Rotor, 21...Target support part, 22...Inner cylinder part, 22a...Nonmagnetic material, 22b...
Magnetic material, 23...outer cylinder part.

Claims (1)

[Claims] The side of the rotor cylindrical part that is connected to the target support shaft is made of a non-magnetic material with low thermal conductivity, and the side that faces the stator is made of a magnetic material. Both are connected by friction welding, and then the target is connected and cast. A rotating anode X-ray tube having a rotor whose outer periphery is coated with a steel material to form an outer cylindrical portion.