JP3228992B2 - X-ray tube device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray tube apparatus provided with a rolling bearing for supporting a rotating member.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional X-ray tube apparatus of this type. This X-ray tube device includes a cathode member 41.
The anode member 42 disposed so as to face the rotating member 43 is fixed to a cylindrical rotating member 43, and the rolling bearings 46 and 47 disposed between the rotating member 43 and the supporting member 45 allow the rotating member 43 to support the rotating member 43. 45 so as to be rotatable. Since the rolling bearings 46 and 47 are used in a vacuum atmosphere, normal oil lubrication cannot be adopted, and the rolling bearings 46 and 47 are lubricated with a solid lubricant such as MoS ₂ or Ag.

The X-ray tube apparatus accelerates the electrons generated by the cathode member 41 at a high speed by an electrostatic field to form an electron beam, and irradiates the electron beam to the anode member 42 to produce an X-ray. Occurs.

During operation of the X-ray tube apparatus, the support member 4
By rotating the rotating member 43 with respect to 5, the anode member 42 is rotated with respect to the cathode member 41.

[0005]

However, in the above-mentioned conventional X-ray tube apparatus, the heat generated by the anode member 42 receiving the electron beam generates heat from the rotating member 43 and the rolling bearings 46, 47.
Through the support member 45. That is, most of the heat generated by the anode member 42 is transmitted to the rolling bearings 46 and 47, so that the temperature of the rolling bearings 46 and 47 becomes high, and the solid lubricating film formed on the surfaces of the rolling bearings 46 and 47 comes off. In addition, there is a problem that the steel balls of the rolling bearings 46 and 47 are easily peeled off.

Further, when the rolling bearings 46, 47 are of an angular type, the gap between the outer ring and the inner ring fluctuates due to the temperature difference between the outer ring and the inner ring, and the contact diameter between the ball and the raceway surface of the outer and inner rings is reduced. Therefore, there is a problem that the load fluctuates and an excessive load or a backlash is easily generated on the bearing.

Accordingly, an object of the present invention is to provide a high-power X-ray tube capable of suppressing a rise in the temperature of the above-mentioned rolling bearing without deteriorating the intensity of the electron beam irradiated on the anode member and having a stable bearing operation. It is to provide a device.

[0008]

In order to achieve the above object, the invention according to claim 1 comprises an anode member disposed to face a cathode member, a rotating member fixed to the anode member, and a rotating member fixed to the anode member. In an X-ray tube device having a rolling bearing rotatably supporting a member with respect to a support member, the rolling bearings are arranged in a plurality in the axial direction so as to be spaced apart from each other in the axial direction. A cylindrical stopper that is disposed at an axially outer position and forms a slight gap between the support member and a cylindrical stopper that receives the rolling bearing in the axial direction, is fixed to the rotating member; By the stopper, a closed space including the plurality of rolling bearings is formed between the rotating member and the supporting member, and all of the closed space is melted at a predetermined temperature to be in a liquid phase, and the supporting member and the rotating member Both With contacts, it is characterized in that the fluid metal to lubricate the rolling bearing, and sealed.

[0009]

According to the first aspect of the present invention, the heat generated in the anode member is transmitted from the rotating member via the fluid metal to the anode member.
It is transmitted to the support member. Therefore, according to the first aspect of the present invention, the amount of heat transmitted from the anode member to the rolling bearing is reduced by the amount of heat transmitted from the anode member to the fluid metal, and the intensity of the electron beam irradiated to the anode member is reduced. Even without this, a rise in the temperature of the rolling bearing is suppressed, so that a high-output X-ray tube device with stable bearing operation can be realized.

According to the first aspect of the invention, the heat generated in the anode member is transmitted from the rotating member to the support member via the fluid metal. Further, the fluid metal itself lubricates the rolling bearing.

Therefore, according to the first aspect of the present invention, the amount of heat transmitted from the anode member to the rolling bearing is reduced by the amount of heat transmitted from the anode member to the fluid metal,
Even if the intensity of the electron beam applied to the anode member is not reduced, the temperature rise of the rolling bearing is suppressed, and the fluid metal itself serves as a lubricant for the rolling bearing. Therefore, a high-output X-ray tube device with particularly stable bearing operation can be realized.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 shows a reference example of an X-ray tube apparatus. This reference example includes a cathode member 2 fixed to the X-ray tube 1, an anode member 3 arranged to face the cathode member 2, a cylindrical rotating member 5 fixed to the anode member 3, and a rotating member 5 fixed to the anode member 3. To X
Angular-type rolling bearings 7 and 8 rotatably supported by a support member 6 fixed to the wire tube 1 are provided.

An end 6A of the support member 6 on the anode member 3 side has a cylindrical shape facing the inner bottom 5A of the rotating member 5. Outer peripheral portion and inner bottom portion 5A of cylindrical end 6A
Is set to 0.5 mm or less. Between the end 6A of the support member 6 and the inner bottom 5A of the rotating member 5, a fluid metal 10 made of gallium, which is in contact with both the end 6A and the inner bottom 5A, is sealed. The end 6A and the inner bottom 5A are made of tantalum having corrosion resistance to gallium. Further, since the gallium has poor wettability with respect to tantalum, the distance Z between the outer peripheral portion of the end portion 6A and the inner bottom portion 5A is set to 0.5 mm or less, so that the distance between the end portion 6A and the inner bottom portion 5A is reduced. The fluid metal 10 can be prevented from leaking from between. Further, if the end 6A and the inner bottom 5A are machined so that the gap between the outer peripheral portion of the end 6A and the inner bottom 5A has a labyrinth shape, the sealing performance for the fluid metal 10 can be further enhanced. .

The rolling bearings 7 and 8 are provided with the support member 6.
Press-fitted between the rotary member 5 and the step 5 of the rotary member 5
B, the outer peripheral portion of the end 6A of the support member 6, the spacer 11, and the annular stopper 12 pressed into the inner peripheral surface of the rotating member 5.
The position in the axial direction is fixed.

The outer surface of the rotating member 5 has a rotor 1
3 is fixed, and a stator 14 is fixed to the outer peripheral surface of the X-ray tube 1 so as to face the rotor 13. The X-ray tube 1 has a window 1A through which X-rays emitted from the anode member 3 pass. The X-ray tube 1 contains 10
It is kept in a high vacuum of ^-6 torr or less.

The X-ray tube device accelerates electrons generated by the cathode member 2 at a high speed by an electrostatic field formed between the cathode member 2 and the anode member 3 to form an electron beam.
By irradiating the electron beam to the anode member 3, X-rays are generated from the anode member 3, and a window 1 of the X-ray tube 1 is formed.
X-rays are emitted from A.

During operation of the X-ray tube apparatus, the stator 1
The rotor 13, the rotating member 5, and the anode member 3 are integrally rotated by the rotating magnetic field generated by the rotating member 4. During operation of the X-ray tube device, the inside of the X-ray tube 1 reaches approximately 500 ° C.

According to the above embodiment, the heat generated in the anode member 3 is transmitted from the rotating member 5 to the supporting member 6 via the fluid metal 10. Therefore, according to the embodiment, the amount of heat transferred from the anode member 3 to the rolling bearings 7 and 8 can be reduced by the amount of heat transferred from the anode member 3 to the fluid metal 10. Therefore, the temperature rise of the rolling bearings 7 and 8 can be suppressed without lowering the intensity of the electron beam applied to the anode member 3, so that a high-output X-ray tube device with stable bearing operation can be realized.

Next, FIG. 2 shows an embodiment of the present invention. This embodiment differs from the reference example shown in FIG. 1 only in the configuration of the rotating member 25 shown in FIG. 2 and the inside thereof. Therefore, components outside the rotating member 25 are assigned the same reference numerals as those in the reference example shown in FIG. 1 and the description thereof is omitted, and the description of the rotating member 25 and the configuration inside the rotating member 25 will be mainly given.

The cylindrical rotating member 25 and the rotating member 25
Rolling bearing 2 between support member 26 arranged inside
7 and 28 are press-fitted, and the rolling bearings 27 and 28 are fitted with the step 25B of the rotating member 25 and the end 26 of the supporting member 26.
The position in the axial direction is fixed by the outer peripheral portion of A, the spacer 31 and the cylindrical stopper 32 pressed into the inner peripheral surface of the rotating member 25. Disk portion 3 of cylindrical stopper 32
The distance Y between 2A and the supporting member 26 is set to 0.5 mm or less. The cylindrical rotating member 25 and the supporting member 2
6, a fluid metal 30 made of gallium is sealed. The fluid metal 30 lubricates the rolling bearings 27,28. The rotating member 25, the supporting member 26, the rolling bearings 27 and 28, the spacer 31, the stopper 32
Is made of tantalum, which is corrosion resistant to gallium. Further, since the gallium has poor wettability with respect to tantalum, the distance Y between the disk portion 32A of the cylindrical stopper 32 and the support member 26 is set to 0.5 mm or less, so that the disk portion 32A and the support member 26 can be prevented from leaking out of the fluid metal 30.

Further, the disk portion 32A and the support member 26
Disk portion 32 so that the gap between
A by processing the inner peripheral surface of the fluid metal 30
Can be further improved.

The basic operation of X-ray generation in the above embodiment is shown in FIG.
Is the same as the embodiment shown in FIG.

According to the above embodiment, the rolling bearings 27, 2
Heat is transmitted from the anode member 3 to the support member 26 via the fluid metal 30 as well as the metal member 8. Therefore, the amount of heat transferred from the anode member 3 to the rolling bearings 27 and 28 can be reduced by the amount of heat transferred from the anode member 3 to the fluid metal 30. Therefore, the temperature rise of the rolling bearings 27 and 28 can be suppressed without lowering the intensity of the electron beam irradiated on the anode member 3. Moreover, since the fluid metal 30 itself serves as a lubricant for the rolling bearings 27 and 28, a high-output X-ray tube device with particularly stable bearing operation can be realized.

Although gallium is used as the fluid metal in the above embodiment, a gallium alloy may be used. Also,
In the above embodiment, the end 6A of the supporting member 6, the inner bottom 5A of the rotating member 5, the rotating member 25, the supporting member 26, the rolling bearings 27, 28, and the like were made of tantalum having corrosion resistance to the fluid metal composed of gallium. However, these portions may be made of tungsten, molybdenum, or ceramic.

FIG. 3 shows another reference example.

In this embodiment, the rolling bearings 7, 8 of the embodiment shown in FIG. 1 are formed in a so-called integral type. Track grooves 61 and 62 are formed in the support member 6 so as to be spaced apart in the axial direction. Track members 51 and 52 are also formed in the rotating member 5 so as to be spaced apart in the axial direction. A plurality of balls 33, 34 are provided. Ball 33,
Each track groove 51, 52, so that 34 is in angular contact.
61, 62 axial distances are set.

[0028]

As is apparent from the above description, the X-ray tube apparatus according to the present invention is such that the rotating member is rotatable with respect to the supporting member between the rotating member fixed to the anode member and the supporting member. A supporting rolling bearing is provided, and a fluid metal that contacts both the supporting member and the rotating member and lubricates the rolling bearing is sealed between the supporting member and the rotating member.

Therefore, heat generated in the anode member is transmitted from the rotating member to the support member via the fluid metal. Further, the fluid metal itself lubricates the rolling bearing. Therefore, according to the first aspect of the present invention, the amount of heat transmitted from the anode member to the rolling bearing can be suppressed by the amount of heat transmitted from the anode member to the fluid metal, and the intensity of the electron beam applied to the anode member can be reduced. Even if the temperature is not lowered, the temperature rise of the rolling bearing can be suppressed, and the fluid metal itself serves as a lubricant for the rolling bearing. Therefore, a high-output X-ray tube device with particularly stable bearing operation can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a reference example of an X-ray tube device.

FIG. 2 is a sectional view of an embodiment of the X-ray tube device of the present invention.

FIG. 3 is a cross-sectional view of another reference example of the X-ray tube device.

FIG. 4 is a cross-sectional view of a conventional X-ray tube device.

[Description of Signs] 1 X-ray tube 1A window 2 Cathode member 3 Anode member 5,25 Rotating member 5A Inner bottom 6,26 Supporting member 6A End 7,8,27,28 Rolling bearing 10,30 Fluid metal 11,31 Spacer 12, 32 Stopper 13 Rotor 14 Stator

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-14742 (JP, A) JP-A-48-73576 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 35/10 F16C 19/00

Claims (1)

(57) [Claims] 1. An X-ray tube comprising: an anode member arranged to face a cathode member; a rotating member fixed to the anode member; and a rolling bearing rotatably supporting the rotating member with respect to a supporting member. In the device, a plurality of the rolling bearings are arranged in the axial direction so as to be spaced apart from each other. The rolling bearings are arranged on an end side of the rotating member at an axially outer position of the rolling bearing, and form a slight gap between the rolling bearing and the support member. A cylindrical stopper having a disc portion to be fixed and receiving the rolling bearing in the axial direction is fixed to the rotating member; and the closed space including the plurality of rolling bearings between the rotating member and the supporting member by the cylindrical stopper. Is formed, and a fluid metal which melts at a predetermined temperature to be in a liquid phase, comes into contact with both the support member and the rotating member, and lubricates the rolling bearing is enclosed in the entire closed space. X-ray tube and wherein the.