JPS61198599A - Rotating anode x-ray tube device - Google Patents

Abstract

PURPOSE:To prevent breakage and fault due to faulty insulation by giving a rectifying effect of cooling insulating oil to a supporting member of X-ray tube bulb and preventing carbonization caused by deterioration decomposition of insulating oil, so as to maintain its insulating property. CONSTITUTION:Insulating oil 13 is supplied from a oil-introducing inlet 10a, which is prepared at a negative electrode-side hauberk 10, into a surrounding container, and is exausted from an oil exhaust outlet 12a, which is prepared at an anode side hauberk 12, and then is returned to 10a by way of a cooler and pump (both are not illustrated). Since the gap between a vacuum container 8 and negative electrode-side supporting member 16 is kept constant towards the axial direction of the vacuum container 8, insulating oil 13 flows at a nearly constant speed along the surrounding of the vacuum container and absorbs heat effectively. Therefore, the vacuum container 8 can be prevented from breaking down.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cooling and supporting device for a rotating anode X-ray tube in a rotating anode X-ray tube apparatus.

[Background of the invention]

2. Description of the Related Art Conventionally, there has been a rotary anode X-ray tube device having a small structure in which a vacuum container containing a rotary anode and a cathode body is disposed in a housing filled with oil.

By the way, the recent XX-ray T (CamputeaTo
With the spread and progress of mograph devices, there is a strong desire to increase the capacity of rotating anode X-ray tube devices. When the X-ray tube is operated as the capacity increases, the temperature of the rotating anode, especially the tourniquet of the X-ray source, increases, so cooling of the vacuum vessel and
Another problem is maintaining insulation performance against the high voltage required to generate X-rays. If the vacuum container is partially heated to high temperatures, gas may be released from the vacuum container even if the vacuum container is not melted, lowering the degree of vacuum, and a discharge phenomenon may occur when high voltage is applied, causing X-ray imaging. If the temperature of the vacuum container becomes high and the surface of the oil is heated above the thermal temperature, it deteriorates and decomposes, forming char (sludge). When carbides occur, the insulation properties of the oil decrease,
If this adheres to the vacuum vessel, when a high voltage is applied to the X-ray tube device, a discharge will occur against the carbide, resulting in damage to the vacuum vessel in the worst case. As a countermeasure for this, a vacuum container and
・The distance from the structure inside the housing is kept sufficiently large to maintain insulation and prevent electrical discharge.

However, until now there has been no fundamental measure to cope with increasing the capacity, and the reality is that X-ray tube devices are used under limit conditions that do not cause problems, making it difficult to increase the capacity.

Japanese Utility Model Application No. 58-160 (to) is an invention aimed at improving the cooling of stator coils by focusing on the flow of insulating oil. It does not take into account heat dissipation to.

[Object of the Invention] An object of the present invention is to prevent deterioration and decomposition of insulating oil, and to provide a long-life, high-performance, large-capacity X-ray tube device.

[Summary of the invention]

A feature of the present invention is that the supporting member of the X-ray tube has a rectifying effect on the cooling insulating oil and prevents carbonization due to deterioration and decomposition of the insulating oil, thereby maintaining insulation properties. The purpose is to prevent damage and defects.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a rotating anode X-ray tube device according to the present invention. A target 1, a motor rotor 4, a rotating shaft 5, and a bearing support member 7 constitute a rotating anode, a cathode body 2 is disposed facing the target 1, and the cathode body 2 has an electrode 3 and a filament (not shown). are doing. The target 1 is supported at one end of a motor rotor 4, which is attached to a rotating shaft 5 rotatably held by a ball bearing 6. The ball bearing 6 is housed and arranged in a bearing support member 7, a part of the bearing support member is vacuum-sealed and fixed at the end of the vacuum container 8, and the cathode body 2 is similarly vacuum-sealed at the other end of the vacuum container 8. Fixed. The vacuum vessel 8 assembled and configured in this manner is called a rotating anode X-ray tube. Further, a motor stator 9 is disposed on a frame 9a disposed on the outer peripheral side of a portion of the vacuum vessel 8 corresponding to the motor rotor 4, and the rotating anode including the target 1 is exposed to the rotating magnetic field of the motor stator 9. Driven by occurrence.

The anode side of the vacuum vessel 80 is supported by an anode tube support member 14 via a tube fixture 15, and the cathode side is supported by a cathode tube support member 16 via an elastic body 17.

Note that some devices include a suitable vibration damping mechanism in the tube fitting 15. The anode side support member 14 has a cylindrical shape with one end closed and a flange portion at the other end, and is attached to the center hub 11. Note that the center Haube 11 constitutes an envelope together with the cathode side Haube 10 and the anode side Haube 12,
Insulating oil 13 is sealed inside the envelope for insulation and cooling. The insulating oil 13 is supplied into the envelope container from an oil inlet 10a provided on the cathode side Haube 10, and is discharged from an oil outlet 12a provided on the anode side Haube 12 to a cooler,
It returns to 10a via a pump (both not shown). The cathode side tube support member 16 has a cylindrical cup shape with seven ends constricted and a flange portion at the other end, and is attached to the center hub 11 .

In this embodiment, both the anode tube support member 14 and the cathode tube support member 16 are attached to the center Haupe 11, but the cathode tube support member 16 may be attached to the cathode Haupe 10.

In the above configuration, thermionic electrons generated in the filament of the electrode 3 of the cathode body 2 are focused and accelerated by a high voltage applied between the cathode side and the rotating anode side, and are caused to collide with the surface of the target 1 (arrow A). X-rays are generated in the direction of the arrow (arrow B). lla is the X-ray emission window. The average temperature of the target 1 of the rotating anode, where thermoelectrons collide and generate X-rays, reaches a maximum of 1300 C, but since the inside of the vacuum chamber 8 is a high vacuum, the heat of the target 1 is transferred through the vacuum chamber 8 to the Haube 10 by radiation heat transfer. , 11. 12 is radiated to the insulating oil 13. However, when increasing the capacity of the rotary anode X-ray tube, the amount of heat generated in the targera 1-1 is increased to the limit that can be transmitted to the insulating oil 13, and the insulating oil 13 is heated to the edge of the surface 1 thermal temperature. In this case, if the insulating oil 13 deteriorates and decomposes due to high temperature and carbide is generated, the insulating oil 13 surrounding the vacuum container 8
The thicker the layer 3, the less likely a discharge will occur to the Haube 10, 11, 12 or the bulb support member, but if the carbide adheres to the vacuum vessel 8, the cathode 2.3 will discharge there. It will not be possible to take pictures, and in the worst case, the vacuum container will be damaged. In other words, the fundamental solution to the problem of increasing capacity lies in a technique for preventing deterioration of the insulating oil 13. One possible countermeasure is to improve the oil itself to eliminate deterioration and prevent the formation of carbides. But absolutely.

Rim oil 13 is originally a synthetic oil with high purity and is the least likely to deteriorate compared to other general oils. Therefore, there is a limit to the improvement in quality, and if it remains in the high-temperature part of the vacuum container 8, it will gradually produce carbide.

Therefore, the inventors focused on oil stagnation, that is, stagnation. In recent years, in order to improve the performance and output of automobiles, an increasing number of car models are equipped with turbochargers.However, the lubricating oil of the turbocharger forms carbide, which enters the bearing part as a foreign object and burns out. This may cause problems such as sticking. This is because the lubricating oil adhering to the impeller, which is at a high temperature of 300C or more after the engine has stopped, is carbonized due to the heat. It is a good idea to cool the car to a temperature that does not cause carbonization of the lubricating oil. The inventors focused on this phenomenon, and the rotating anode
We thought this would be a fundamental solution to preventing the dielectric strength of wire tubes from decreasing, or in other words, increasing capacity.

The cooled insulating oil 13 supplied from the oil inlet Boa of the cathode side Haube 10 flows as indicated by the arrow in FIG. That is, it flows into the cathode side of the vacuum container 8 through the opening 16 a provided at the top of the cathode side tube support member 16 and flows through the gap between the vacuum container 8 and the cathode side support member 16 . This gap is constant in the axial direction of the vacuum container 8, and the insulating oil 13 flows at a substantially constant flow rate on the outside of the vacuum container toward the anode side. FIG. 2 shows a conventional rotating anode X-ray tube device for comparison. In FIG. 2, it is clear that the flow rate of the insulating oil 13 in the sa and sb portions of the vacuum vessel 8 is extremely slow and stagnation is likely to occur. 8b that directly receives heat from target 1
This is the part where the insulating oil 13 is heated the most, and upward decomposition that causes stagnation progresses. Here, returning to FIG. 1, the X-ray tube device of the present invention
The flow is almost the same as the conventional example. However, X
'The gap between the vacuum vessel 8 and the vacuum vessel 11 becomes constant according to the constriction of the vacuum vessel 8 leading to the anode portion of the wire tube.

The frame 9a of the motor stator 9 is attached as shown. 8d of vacuum container 8 on the back side of target 1
The bee also reaches a high temperature and is heated close to the heat-resistant temperature of the vacuum container 8 itself, but the insulating oil 13 effectively absorbs the heat without stagnation, so the vacuum container 8
damage and gas release can be prevented. The insulating oil 13 flowing between the frame 9a and the vacuum vessel 80 is transferred to the anode side tube support member 14.
The flow is blocked by the flow, the direction is turned 180 degrees, the flow flows between the motor stator 9 and the anode side support member 14, and the flow flows to the outside of the anode side support member 14 from the outlet 14a provided on the cathode side of the motor stator 9. The oil is led from the oil outlet 12a of the anode side Haube 12 to a cooler and a pump (both not shown). Since the motor stator 9' is a large-capacity X-ray tube and is continuously driven at high speed, it generates a large amount of heat, and insufficient cooling may result in a reduction in driving force or damage to the motor stator coil. In the present invention, the entire flow rate of the insulating oil 13 effectively cools the motor stator 9.

In this embodiment, the i' insulating oil 13 was flowed from the cathode side to the anode side, but the effect of the present invention does not change even if it is flowed from the anode side to the cathode side.

〔Effect of the invention〕

As described above, according to the present invention, the supporting member of the X-ray tube has a rectifying effect on the cooling insulating oil and prevents carbonization due to deterioration and decomposition of the insulating oil, thereby maintaining insulation properties. Since damage and defects due to defects can be prevented, it is possible to provide a long-life, high-performance, large-capacity X-ray tube device.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of a rotating anode X-ray tube device according to the present invention, and FIG. 2 is a longitudinal sectional view of a conventionally known rotating anode X-ray tube device.

Claims (1)

[Claims] 1. A rotating anode X-ray tube consisting of a cathode, a rotating anode placed opposite the cathode, and a tube container that covers these, with the container being evacuated, a rotating magnetic field generator, and these are housed and supported in cooling insulating oil. In a rotary anode X-ray tube apparatus consisting of an envelope, tube support members for supporting the rotary anode X-ray tube are provided on the anode side and cathode side of the rotary anode X-ray tube, and the cathode side tube support member is provided on the anode side and the cathode side of the rotary anode X-ray tube. The cathode side support member has a cylindrical cup shape with a certain distance from the spherical container, the cathode side support member has a cylindrical cup shape with a certain distance from the rotating magnetic field generator, and the cathode side tube support member has the cooling insulation on the top of the head. An oil outflow inlet is provided, and the anode-side tube support member is provided with the cooling insulating oil inlet in a portion closer to the cathode than the magnetic field generating device in the cylindrical portion, and the entire flow rate of the cooling insulating oil flows through the tube container and the A rotating anode X-ray tube device characterized by flowing without stagnation around a heat generating member of a magnetic field generator.