CN217405364U

CN217405364U - Rotary anode heat shield structure

Info

Publication number: CN217405364U
Application number: CN202221251134.7U
Authority: CN
Inventors: 李建北; 赵伟; 秦臻
Original assignee: Institute of Fluid Physics of CAEP
Current assignee: Institute of Fluid Physics of CAEP
Priority date: 2022-05-20
Filing date: 2022-05-20
Publication date: 2022-09-09
Anticipated expiration: 2032-05-20

Abstract

The utility model discloses a rotatory anode heat shield structure, including positive pole target, rotor copper sheathing and bearing, the bearing passes through the rotor copper sheathing to be connected with the positive pole target, is equipped with heat shield between positive pole target and rotor copper sheathing, heat shield adopts the structure that N layer heat shield piles up in proper order, N is the positive integer more than or equal to 1. The heat shield structure provided by the embodiment can effectively reduce the temperature of the bearing during working and reduce the heat damage of the bearing, thereby prolonging the service life of the bearing and improving the reliability and the service life of the X-ray tube and the CT bulb tube.

Description

Rotary anode heat shield structure

Technical Field

The utility model relates to an electricity vacuum technology field, concretely relates to rotatory anode X-ray tube's positive pole heat shield structure can be used to technical field such as medical instrument field, industry nondestructive test, X-ray irradiation.

Background

The X-ray tube and CT bulb tube are used to bombard radiation conversion target with electron beam to produce X-ray, and are key parts in X-ray machine and CT machine. Electrons emitted by a cathode (a common tungsten filament) bombard an anode target at a high speed under the action of a high-voltage electric field of the anode target, X-rays are generated due to bremsstrahlung radiation, but only 1% of energy of an electron beam is converted into the X-rays, and the rest 99% of energy is converted into heat to be deposited in the anode target, so that the temperature of the anode target is increased rapidly. The CT bulb tube adopts a rotating anode structure, the average temperature of an anode target can reach more than 1200 ℃, the temperature of a target surface bombarded by electron beams is higher, the heat energy of the anode target is radiated and conducted, the temperature drop of a bearing is greatly increased, and if the temperature of the bearing is too high, the bearing cannot normally work or even is damaged, so that the X-ray tube and the CT bulb tube are failed. Therefore, it is very important to reduce and control the temperature of the bearing when the X-ray tube and the CT bulb tube are in operation.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the technical problem that will solve is: traditional rotatory anode heat shield effect is relatively poor, and the heat energy of positive pole target is through radiation and conduction, and the temperature drop of bearing rises by a wide margin, easily causes the positive pole target to damage, the utility model provides a solve a rotatory anode heat shield structure of above-mentioned problem.

The utility model discloses a following technical scheme realizes:

the utility model provides a rotatory anode heat shield structure, includes anode target, rotor copper sheathing and bearing, and the bearing passes through the rotor copper sheathing to be connected with the anode target, is equipped with the heat shield between anode target and rotor copper sheathing, the heat shield adopts the structure that N layer heat shield piles up in proper order, N is the positive integer more than or equal to 1.

The heat deposited after the electron beam emitted by the cathode bombards the anode target is partially transmitted to the rotating shaft of the bearing through a molybdenum support rod connected with the anode target in a rotor copper sleeve; one part of the anode target is radiated to the rotor copper sleeve through heat, and then the heat is conducted to a rotating shaft of the bearing or radiated to the bearing through the heat from the inner surface of the rotor copper sleeve, so that the temperature of the bearing is greatly reduced, and if the temperature of the bearing is too high, the bearing cannot work normally or even is damaged, so that the X-ray tube and the CT bulb tube are failed. The heat shield structure provided by the invention is characterized in that a plurality of heat shield layers are arranged between an anode target and a rotor copper sleeve to form a heat shield main body structure, so that the heat radiated to the rotor copper sleeve by the anode target is greatly reduced.

Further, the at least one thermal shield layer is made of metal foil.

The heat shield layer is a heat shield body formed by stacking a plurality of heat shield layers in sequence by utilizing the surface of the heat shield layer facing the heat source to reflect a part of heat from the heat source, wherein at least one heat shield layer adopts metal sheets, the metal sheets type heat shield layer can reduce the weight and the volume of the heat shield layer, and more heat shield layers can be arranged in the same space; the more heat shields made of metal foil are used in a single heat shield, the higher the heat reflection efficiency due to multiple heat reflections, and the better the shielding effect, and therefore, it is preferable to use metal foil for all heat shields in the heat shield. Because the temperature of the anode target is high, the metal sheet can be made of high-temperature resistant metal such as molybdenum, tantalum, niobium, zirconium and the like or alloy material sheets thereof.

Furthermore, the thickness of the metal sheet is less than or equal to 0.5 mm.

The metal sheet has large heat resistance due to the thin material, and the heat conducted by the metal sheet is less, so that the heat conduction efficiency of the heat shield is favorably reduced.

Further, the thermal shield has a thermal emissivity of less than 0.4 at least at the surface facing the anode target and/or at the surface facing the rotor copper sleeve.

The utility model discloses it is lower at the surface towards the positive pole target and/or the surface thermal radiation coefficient towards rotor copper sheathing at least for on the route of passing radiation rotor copper sheathing at the sedimentary heat of positive pole target, go out some heat by the reflection, reduce the heat that the positive pole target radiated to the thermal shield, simultaneously, reduce the heat that the thermal shield radiated to the rotor copper sheathing, further improve the shielding effect of thermal shield.

Further, the heat shield is provided with a bright layer at least on the surface facing the anode target and/or on the surface facing the rotor copper sleeve; or the heat shield layer on at least two sides of the heat shield body is made of a plate material with a bright surface.

The utility model discloses bright heat shield in surface has good heat reflectivity, and preferably all heat shields all adopt bright plate construction in surface.

Further, the heat shield layer is made of metal thin sheet with a bright surface.

Thus, on the path of the heat deposited by the anode target radiating to the rotor copper sleeve, a part of heat is reflected out and cannot be transferred to the heat shielding layer, and the surface is brighter, the thermal emissivity is smaller, and the thermal reflectivity is higher; a part of heat absorbed by the heat shield is intercepted by the bright heat shield with higher heat resistance, and then only a small part of heat is transmitted to the rotor copper sleeve through radiation or conduction.

Further, the surface roughness of the metal sheet with bright surface is less than or equal to 0.4 mu m.

The utility model discloses a bright foil in surface as heat shield, its roughness is lower, and heat reflection efficiency is higher.

Further, the heat shield is fixedly connected with the anode target and the rotor copper sleeve through a welding or riveting structure.

The welding may be performed using a spot or laser welded structure.

Furthermore, the ring surface of the heat shield connected with the anode target is connected through a plurality of spot welding points which are uniformly distributed along the circumferential direction of the ring surface of the heat shield connected with the anode target; the ring surface of the heat shield connected with the rotor copper sleeve is connected through a plurality of spot welding points, and the spot welding connections are evenly distributed along the circumferential direction of the ring surface of the heat shield connected with the rotor copper sleeve.

Connect heat shield and positive pole target, and/or heat shield and rotor copper sheathing between through spot welding structural connection, improve the face-to-face contact of heat shield and positive pole target for the point contact like this, improve to the point contact between heat shield and the rotor copper sheathing, area of contact reduces, the heat transfer efficiency between heat shield and positive pole target and the rotor copper sheathing reduces, the heat of positive pole target transmission mainly reaches the heat shield through heat radiation, a small part reaches the heat shield through conducting, the heat of heat shield transmission also mainly passes through heat radiation transmission to the rotor copper sheathing, a small part passes through spot welding point transmission to the rotor copper sheathing, thereby greatly reduced whole heat transfer efficiency.

Further, adjacent two-layer heat shielding layer in the heat shield is connected through spot welding, and a plurality of spot welding joints are evenly distributed between the lower surface of the upper layer heat shielding layer and the upper surface of the lower layer heat shielding layer of the adjacent two layers.

The utility model discloses can choose for use wherein to adopt the spot welding point to connect between the two-layer adjacent heat shield, perhaps adopt the spot welding point to connect in the multilayer shielding layer between several groups of adjacent heat shields, perhaps further preferably connect through the spot welding point in the heat shield between arbitrary adjacent two-layer heat shield.

The utility model discloses have following advantage and beneficial effect:

the utility model discloses a multilayer heat shield structure, X fluorescent tube, CT bulb during operation can effectively reduce the temperature of bearing, reduces the heat damage of bearing to the life of extension bearing can improve the reliability and the life of X fluorescent tube, CT bulb.

The heat deposited after the electron beam bombards the anode target, one part of the heat transferred between the anode target and the rotor copper sleeve through the heat shield is reflected by the heat shield layer and cannot reach the heat shield, and the other part of the heat mainly reaches the heat shield through heat radiation and a small part of heat conduction; after the heat reaching the heat shield is transmitted by the heat shield thermal resistance and radiation, part of the heat mainly reaches the rotor copper sleeve through thermal radiation and matching heat conduction; the heat reaching the rotor copper sleeve is conducted to a rotating shaft of the bearing through heat conduction or radiated to the bearing through the heat from the inner surface of the rotor copper sleeve; eventually the amount of heat actually reaching the bearing is significantly reduced.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 is a schematic diagram of an exemplary structure of an X-ray tube and a CT bulb tube with a rotating anode;

fig. 2 shows the multi-layer thermal radiation shielding structure of the present invention.

Reference numbers and corresponding part names in the drawings: 1-anode target, 2-heat shield, 3-rotor copper sleeve, 4-bearing, 5-cathode glass shell, 6-metal shell, 7-anode glass shell and 8-cathode.

Detailed Description

To make the objects, technical solutions and advantages of the present invention more clearly understood, the following description is given for further details of the present invention with reference to the accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention, and are not intended to limit the present invention.

Example 1

The embodiment provides a rotatory anode heat shield structure, including positive pole target 1, rotor copper sheathing 3 and bearing 4, bearing 4 passes through rotor copper sheathing 3 and is connected with positive pole target 1, is equipped with the heat shield between positive pole target 1 and rotor copper sheathing 3, and the heat shield adopts the structure that N layer heat shield 2 piled up from top to bottom in proper order, and N is the positive integer that is greater than or equal to 1, and the preferred has two-layer heat shield 2 at least.

Example 2

In a further improvement of example 1, at least one of the thermal shields 2 is made of a metal sheet, and in this embodiment, preferably, all of the thermal shields 2 are made of metal sheets, and the thickness of the metal sheets is less than or equal to 0.5mm, such as 0.1 mm.

Example 3

In a further improvement over example 1, the thermal shield is provided with a bright layer at least on the surface facing the anode target 1 and/or on the surface facing the rotor copper sleeve 3; alternatively, the heat shield is made of a bright-surfaced sheet material for at least the heat shield layers 2 on both sides. The thermal shield has a thermal emissivity lower than 0.4, such as 0.2, at least at the surface facing the anode target 1 and/or at the surface facing the rotor copper sheath 3. The heat shield layer 2 adopts a metal sheet with a bright surface, the thickness of the metal sheet is less than or equal to 0.5mm, and the surface roughness of the metal sheet with the bright surface is less than or equal to 0.4 mu m. This embodiment preferably employs a bright-surfaced foil having a thickness of 0.1mm for all thermal shields, and a surface roughness of 0.1 μm for the bright-surfaced foil.

Example 4

In addition to embodiment 3, the heat shield is fixedly connected with the anode target 1 and the rotor copper sleeve 3 through a welding or riveting structure. The ring surface between the outer surface of the heat shield and the inner surface of the anode target 1 is connected through 3-16 spot welding points, and the spot welding points are uniformly distributed along the circumferential direction of the ring surface connected with the anode target 1 at equal intervals; the inner surface of the heat shield is connected with the outer surface of the rotor copper sleeve 3 through 3-16 point welding points on the ring surface, and the point welding connection is uniformly distributed along the circumferential direction of the ring surface connected with the rotor copper sleeve 3 at equal intervals.

Example 5

In addition, the structure is further improved on the basis of the embodiment 4, the adjacent two layers of heat shields 2 in the heat shield body are connected through spot welding, and a plurality of spot welding points are uniformly distributed between the lower surface of the upper layer of heat shield layer 2 and the upper surface of the lower layer of heat shield layer 2.

The above-mentioned embodiments, further detailed description of the objects, technical solutions and advantages of the present invention, it should be understood that the above description is only the embodiments of the present invention, and is not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The utility model provides a rotatory anode heat shield structure, includes anode target (1), rotor copper sheathing (3) and bearing (4), and bearing (4) are connected with anode target (1) through rotor copper sheathing (3), its characterized in that is equipped with the heat shield between anode target (1) and rotor copper sheathing (3), the heat shield adopts the structure that N layer heat shield (2) stacked gradually, N is the positive integer more than or equal to 1.

2. A rotary anode heat shield structure as claimed in claim 1, characterized in that the at least one heat shield layer (2) is of sheet metal.

3. A rotating anode heat shield structure as set forth in claim 2 wherein said sheet metal is 0.5mm thick.

4. A rotating anode heat shield according to claim 1, characterized in that the heat shield has a thermal emissivity below 0.4 at least at the surface facing the anode target (1) and/or at the surface facing the rotor copper sheath (3).

5. A rotating anode heat shield according to claim 4, characterized in that the heat shield is provided with a bright layer at least on the surface facing the anode target (1) and/or on the surface facing the rotor copper sheath (3); or the heat shield is made of a bright-surfaced sheet material at least on the heat shield layers (2) on both sides.

6. A rotating anode heat shield structure according to claim 5, characterized in that the heat shield (2) is a bright-surfaced foil.

7. A rotating anode heat shield structure as claimed in claim 6 wherein said bright-surfaced foil has a surface roughness of 0.4 μm or less.

8. A rotating anode heat shield according to any of claims 1 to 7, characterized in that the heat shield is fixedly connected to the anode target (1) and the rotor copper sleeve (3) by means of a welded or riveted connection.

9. A rotating anode heat shield structure according to claim 8, characterized in that the annular surface of the heat shield to the anode target (1) is connected by a plurality of spot welds, which are evenly distributed circumferentially along the annular surface of the heat shield to the anode target (1); the ring surface of the heat shield connected with the rotor copper sleeve (3) is connected through a plurality of spot welding points, and the spot welding connections are evenly distributed along the circumferential direction of the ring surface of the heat shield connected with the rotor copper sleeve (3).

10. A rotating anode heat shield structure according to any of claims 1 to 7, characterized in that the heat shields (2) of two adjacent layers in the heat shield are connected by spot welding, and that spot welds are evenly distributed between the lower surface of the upper heat shield (2) and the upper surface of the lower heat shield (2) of two adjacent layers.