Rotary x-ray anode having an integrated liquid metal bearing outer shell

Abstract

The present invention relates to a rotary x-ray anode having an integrated liquid metal bearing outer shell, comprising an anode disc (5) made of Mo or a Mo-based alloy and having a hole (12), which is formed centrally in the region of the axis of rotation (4) and extends in the axial direction at least through part of the anode disc (5), and a bearing bushing (20) made of Mo or a Mo-based alloy. The bearing bushing (20) is connected to the anode disc (5) via an integral bond (21) in such a way that the inner wall (22) of the bearing bushing (20) extends the hole (12) in the anode disc (5), and that at least one axial portion of an inner wall (14) of the hole (12) in the anode disc (5) and at least one axial portion of an inner wall (22) of the bearing bushing (20) are formed circumferentially as a liquid metal bearing running surface and form at least part of a liquid metal bearing outer shell. The present invention also relates to a corresponding production method.

Claims

1. A rotary x-ray anode with integrated liquid metal bearing outer shell, comprising an anode disk (5; 5'; 5‴) made of Mo or an Mo-based alloy and having a hole (12) formed in the center in the region of the axis of rotation (4) and extending in axial direction at least through a portion of the anode disk (5; 5'; 5‴) and a bushing (20) made of Mo or of an Mo-based alloy, wherein the inner wall (22) of the bushing (20) is formed circumferentially as a liquid metal bearing running surface at least over an axial section thereof and forms a first subsection of the liquid metal bearing outer shell, and wherein the liquid metal bearing outer shell is formed by the first and an adjoining second subsection and has a continuous liquid metal bearing running surface, characterized in that the anode disk (5; 5'; 5‴), toward the side of the bushing (20), has a connection port (16; 16`), the inner wall (18) of which extends the hole (12) in the anode disk (5; 5'; 5‴), and which protrudes with respect to the peripheral face on the outside of the anode disk (5; 5'; 5‴), in that at least an axial section of the inner wall (18) of the connection port (16; 16`) is formed circumferentially as a liquid metal bearing running surface and forms a portion of the second subsection of the liquid metal bearing outer shell, and in that a material bonding connection (21) is formed between the protruding connection port (16; 16`) of the anode disk (5; 5'; 5‴) and the bushing (20), wherein the material bonding connection (21) is a bond established via a friction welding bond or a beam welding bond.

2. The rotary x-ray anode as claimed in claim 1, characterized in that the Mo-based alloy(s) is / are MHC and / or TZM, where MHC has the following composition: - an Hf content of 1.00-1.30% by weight, - a C content of 500-1200 µg / g, - balance: Mo, where the content of any metallic impurities present is ≤ 5000 µg / g and the total content of any H, N and O impurities present is ≤ 1000 µg / g; and wherein TZM has the following composition: - a Ti content of 0.40-0.55% by weight, - a Zr content of 0.06-0.12% by weight, - a C content of 50-500 µg / g, - balance: Mo, where the content of any metallic impurities present is ≤ 5000 µg / g and the total content of any H, C, N and O impurities present is ≤ 1500 µg / g.

3. The rotary x-ray anode as claimed in any of the preceding claims, characterized in that the anode disk (5; 5'; 5‴) and the bushing (20) are each formed from molybdenum or each formed from the same molybdenum-based alloy.

4. The rotary x-ray anode as claimed in any of the preceding claims, characterized in that the material bonding connection (21) is a friction welding bond.

5. The rotary x-ray anode as claimed in any of the preceding claims, characterized in that the hole (12) in the anode disk (5) is formed as a passage hole, in that the anode disk (5), on the opposite side from the bushing (20), has an extension port (24), the inner wall (26) of which extends the passage hole (12) of the anode disk (5), and which protrudes with respect to the peripheral face on the outside of the anode disk (5), in that at least an axial section of the inner wall (26) of the extension port (24) is formed circumferentially as a liquid metal bearing running surface and forms a portion of the second subsection of the liquid metal bearing outer shell.

6. The rotary x-ray anode as claimed in any of the preceding claims, characterized in that the thickness of the anode disk (5`) increases in radial direction toward the axis of rotation (4), wherein the increase in thickness proceeding from a reference thickness (dR) measured radially in the middle in the region of a beveled focal track surface (10) up to the thickness (dII) in the region of the hole (12) is 30-300%.

7. The rotary x-ray anode as claimed in any of the preceding claims, characterized in that the anode disk (5; 5'; 5‴) has multiple slits that are arranged uniformly over the circumference and pass through the thickness of the anode disk (5; 5'; 5‴), each of which extends over a radial section in the region between an outer circumference of the anode disk (5; 5'; 5‴) and the hole (12) in the anode disk (5; 5'; 5‴).

8. A rotary x-ray anode system comprising a rotary x-ray anode with integrated liquid metal bearing outer shell as claimed in any of the preceding claims and a liquid metal bearing inner shell that has been inserted into the liquid metal bearing outer shell and has a liquid metal bearing running surface, wherein the liquid metal bearing outer shell and the liquid metal bearing inner shell are matched to one another such that a defined bearing gap (30) is formed between them.

9. The rotary x-ray anode system as claimed in claim 8, characterized in that, in the region of at least one axial end section of the liquid metal bearing running surface at the liquid metal bearing outer shell and / or of the liquid metal bearing running surface at the liquid metal bearing inner shell, at least one circumferential mechanical boundary element is provided, which, in use, limits flow of liquid metal present in the bearing gap (30) in axial direction.

10. The rotary x-ray anode system as claimed in claim 8 or 9, characterized in that, in the region of at least one axial end section of the liquid metal bearing running surface at the liquid metal bearing outer shell and / or of the liquid metal bearing running surface at the liquid metal bearing inner shell, a circumferential coating is provided, which suppresses wetting by the liquid metal in the bearing gap (30) during use.

11. The rotary x-ray anode system as claimed in any of claims 8 to 10, characterized in that the liquid metal bearing inner shell is formed on a spigot (28') guided through the bushing (20) at least into the hole (12) in the anode disk (5‴).

12. The rotary x-ray anode system as claimed in any of claims 8 to 11, characterized in that the liquid metal bearing running surface at the liquid metal bearing outer shell and / or the liquid metal bearing running surface at the liquid metal bearing inner shell has at least two circumferential, superficially structured running sections (32, 34) that are spaced apart in axial direction.

13. A method of producing a rotary x-ray anode as claimed in any of claims 1 to 7, characterized by the following steps: • providing an anode disk (5; 5"; 5‴) having a connection port (16; 16`) made of Mo or an Mo-based alloy, • providing a stub of Mo or an Mo-based alloy, • materially bonding the stub to the anode disk (5; 5'; 5‴) having a connection port (16; 16`) in such a way that the stub is in a central arrangement based on an axis of rotation (4) of the anode disk (5; 5'; 5‴), and • mechanically working the anode disk (5; 5'; 5‴) having a connection port (16; 16`) and the stub to form the rotary x-ray anode (2) with integrated liquid metal bearing outer shell, wherein the stub forms the bushing (20) with the liquid metal bearing running surface and the anode disk (5; 5'; 5‴) has the hole (12), in which at least an axial section of the inner wall (14) is formed circumferentially as liquid metal bearing running surface.

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