JPH1012168A - Rotating anode x-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rotating anode X-ray tube capable of maintaining stability eve if rotation is made again after a long rotation stop by disposing a lubricant liquid flow adjuster to be moved by gravity inside a lubricant housing chamber provided for a rotor or a fixer. SOLUTION: A rotor 12 for holding and rotating an anode target 11 is supported by means of a fixer 15 via radial slide bearings 18 and 19 and a thrust slide bearings 23 and 24. A flow adjuster 40 is rod-shaped and made of a material with its specific gravity heavier than a lubricant L is movably put in a lubricant housing chamber 31 for housing a lubricant L inside the fixer 15. At the time of using an X-ray tube, a center axis of the fixer 15 is changed in a various directions, and the flow adjuster 40 complexly moves in the lubricant housing chamber. Thus, the lubricant L is supplied to all slide bearings from an upper end opening 13a of the lubricant housing chamber 31 and a radial direction passage 32, and stable movement of the bearings can be maintained even at the time of rotation after a long stoppage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rotating anode X-ray tube.

[0002]

2. Description of the Related Art As is well known, a rotating anode type X-ray tube has a disk-shaped anode target supported by a rotating body and a fixed body having a bearing portion, which is rotated by an electromagnetic coil of a stator disposed outside a vacuum vessel. While being rotated at a high speed by the action of the magnetic field, the electron beam emitted from the cathode is collided with the anode target to emit X-rays. The bearing portion is a rolling bearing such as a ball bearing or a liquid metal lubricant such as gallium (Ga) or a gallium-indium-tin (Ga-In-Sn) alloy that forms a spiral groove on the bearing surface. It consists of a dynamic pressure type sliding bearing filled with parts.

A rotating anode type X using this dynamic pressure type sliding bearing
A rotary anode type X-ray tube in which a radial sliding bearing is formed in a small-diameter portion and a thrust sliding bearing is formed in a large-diameter portion is used as a tube.
For example, Japanese Patent Publication No. Hei 3-77617 and Japanese Patent Laid-Open No. 2-244
No. 545, JP-A-2-227947 or JP-A-2-227947.
No. 227948.

[0004]

In the rotary anode type X-ray tube, the spiral groove and the gap between the bearings are filled with a liquid metal lubricant. If the lubricant does not reach the entire bearing gap, sufficient dynamic pressure of the sliding bearing cannot be obtained, and stable operation of the dynamic pressure sliding bearing cannot be maintained. If there is a shortage or lack of the lubricant, the bearing surfaces may be galled with each other, which may cause an unrotatable state or breakage.

[0005] Such inconvenience is prevented beforehand,
A lubricant accommodating chamber is provided so that a sufficient amount of the liquid metal lubricant can be supplied to the bearing portion even during long-time operation. However, even in such a structure, if the stop continues in a state where the rotation axis of the anode is substantially coincident with the direction of gravity, the bearing surface of the anode rotating body and the fixed body is in close contact, and the amount of the liquid metal lubricant is in close contact with the surface. It suffices if it is sufficient, but if it is attempted to start the rotation from a small state, there is a possibility that the above-mentioned rotation impossible state or breakage may be caused.

An object of the present invention is to provide a rotary anode type X-ray tube which can solve the above-mentioned disadvantages and can maintain stability even when re-rotating after long-time rotation stop. And

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a rotary anode type X-ray tube in which a lubricant liquid flow adjuster moving by gravity is disposed inside a lubricant accommodating chamber provided on a rotating body or a fixed body. is there.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. A rotating shaft 1 in which a disk-shaped anode target 11 made of heavy metal is protruded from one end of a cylindrical rotating body 12
3 is fixed by a nut 14. The rotating body 12
An inner cylinder 12a made of an iron alloy and an outer cylinder 12b made of copper are doubly fitted. A fixed body 15 made of an iron alloy is inserted inside the rotating body 12.

The fixed body 15 has a small-diameter portion 15a having a small diameter in the upper part in the figure, a large-diameter part 15b having a large diameter in the lower part,
The lower end is the anode support 15c. In the fitting portion between the rotating body 12 and the fixed body 15, a helical groove sliding bearing of a dynamic pressure type as described in each of the aforementioned publications is formed. That is, two pairs of herringbone pattern spiral grooves 16, 17 are formed on the outer surface of the small diameter portion 15a,
Together with the inner peripheral surface of the inner cylinder 12a of the rotating body, dynamic pressure type radial sliding bearings 18 and 19 are formed.

A spiral groove 20 having a herringbone pattern is formed in a circular shape on the upper surface of the large diameter portion 15b of the fixed body. Lower end opening 12 of inner cylinder 12a of rotating body
The thrust ring 21 is screwed in such a manner as to close the lower ring c.
The spiral groove 22 of the pattern is formed. These two
A pair of helical grooves 20, 22 and a bearing surface of a rotating body which is close to and opposed to the helical grooves 20, 22 are provided with a dynamic pressure type thrust sliding bearing 23, 2.
4 are configured. The fixed body 15 is formed with a lubricant accommodating chamber 31 and a radial passage 32 extending along the axial direction.

Therefore, a lubricant liquid flow regulator 40 made of a rod-shaped material having a specific gravity greater than that of the liquid metal lubricant L is movably accommodated in the lubricant storage chamber 31. The lubricant liquid flow adjusting member 40 is moved downward by gravity, and therefore is located below in the state shown in the figure. When an actual X-ray tube is used, the direction of the center axis, that is, the rotation axis of the X-ray tube changes in various directions.
Move complicatedly in the containment room. As a result, the liquid metal lubricant L is supplied to the dynamic pressure sliding bearing surface through the upper end opening 31a of the storage chamber and the space Sb, and is similarly supplied to the dynamic pressure sliding bearing surface from the space Sc through the radial passage 32, and There is no danger of exhaustion. Therefore, a stable operation of the bearing can be maintained even during re-rotation after a long stop.

The embodiment shown in FIG.
This is an X-ray tube in which the rotating body 12 is arranged inside. And
The rotating body 12 is provided with a lubricant accommodating chamber 31, in which a liquid metal lubricant L and four spherical lubricant liquid flow adjusting bodies 41 are placed. Spherical lubricant liquid flow regulator 4
Numeral 1 allows the lubricant to move in the accommodation chamber in accordance with the direction change of the X-ray tube, and helps the lubricant to flow to the bearing portion. In addition, as in the above-described embodiment, the lubricant storage chamber 31
A radial passage may be formed so as to open to a region between the radial bearings 18 and 19 from the radial direction. In the figure, reference numeral 15e denotes a fixed body thrust ring. Note that one or more lubricant liquid flow adjusters can be arranged. It is also desirable that it be a material that is not attacked by the liquid metal lubricant.

[0013]

As described above, according to the present invention,
Depletion of the liquid metal lubricant in the dynamic pressure sliding bearing portion is prevented for a long time, and stable bearing performance is maintained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a side view of a part of the fixed body of FIG. 1;

FIG. 3 is a top view of the thrust ring of FIG. 1;

FIG. 4 is a longitudinal sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 12: Rotating body 15: Fixed body 31: Lubricant accommodating chamber 40, 41: Lubricant liquid flow regulator L: Liquid metal lubricant

Claims (5)

[Claims] A first bearing component having a cylindrical shape;
A cylindrical second bearing component member fitted to the outer periphery of the bearing component member with a bearing gap maintained therebetween, an anode target fixed to one part of these bearing component members, and at least one of the above-mentioned dual bearing component members; In a rotary anode X-ray tube including a lubricant accommodating chamber provided on one side and the bearing gap and a liquid metal lubricant supplied into the lubricant accommodating chamber, lubrication movable into the lubricant accommodating chamber. A rotary anode type X-ray tube containing a liquid agent for fluid flow. 2. The rotary anode X-ray tube according to claim 1, wherein the lubricant liquid flow regulator is made of a material having a specific gravity heavier than the liquid metal lubricant. 3. The rotating anode type X-ray tube according to claim 1, wherein the lubricant liquid flow regulator is a rod or at least one sphere. 4. The rotary anode type X-ray tube according to claim 1, wherein the lubricant liquid flow adjusting member is movable by its own weight. 5. The first bearing component and the second bearing component, one of which is a rotating body and the other of which is a fixed body.
The rotating anode type X-ray tube according to claim 1.