Anode bearing structure and X-ray tube

Abstract

The present invention belongs to the field of X-ray technology and particularly relates to an anode bearing structure and an X-ray tube. The structure comprises a core shaft, a first outer ring, and a plurality of first rollers. The core shaft is used to connect to an anode target disk. The first outer ring is coaxially sleeved on the core shaft and is adjacent to the connection end between the core shaft and the anode target disk. A retainer is coaxially arranged with the core shaft. The retainer is provided with a plurality of pockets distributed along the circumference of the retainer, with the length direction of the pockets aligning with the extension direction of the retainer. The plurality of first rollers are arranged in a one-to-one correspondence with the plurality of pockets. The first rollers are adapted to conform to the pockets and are cylindrical, so that the outer circumference of the first rollers is in linear contact with both the core shaft and the first outer ring when rolling. Compared to ball rollers, the structure can increase the contact area between the first rollers and the core shaft, and between the first rollers and the first outer ring, thereby further improving the radial load capacity of the anode bearing structure and the service life of the X-ray tube.

Description

Technical Field

[0001] The present invention relates to the field of X-ray technology, and in particular to an anode bearing structure and an X-ray tube. Background Art

[0002] The anode bearing structure of an X-ray tube is the core rotating component of the X-ray tube. It is not only used to mount the anode target, but its service life also directly determines the service life of the X-ray tube. However, current anode bearing structures often use spherical rollers. Their point contact characteristics result in insufficient radial load-bearing capacity of the anode bearing structure. In particular, stress concentration is prone to occur at the end adjacent to the anode target, causing fatigue failure and seriously limiting the service life of the X-ray tube.

[0003] Therefore, the above problems need to be solved urgently. Summary of the Invention

[0004] An object of the present invention is to provide an anode bearing structure and an X-ray tube, so as to improve the radial bearing capacity of the anode bearing structure, thereby increasing the service life of the X-ray tube.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] An anode bearing structure comprising:

[0007] A mandrel, used to connect the anode target;

[0008] A first outer ring is coaxially sleeved on the core shaft and is adjacent to a connection end between the core shaft and the anode target disk;

[0009] a retainer disposed between the first outer ring and the core shaft, the retainer being coaxial with the core shaft, the retainer having a plurality of pockets uniformly distributed along the circumference of the retainer, the pockets extending along the axial direction of the retainer;

[0010] A plurality of first rollers are arranged in a one-to-one correspondence with a plurality of pockets. The first rollers are adapted to imitate the pockets so that the outer circumference of the first roller is rollingly connected with the core shaft and the first outer ring at the same time. The first roller is columnar so that there is linear contact between the first roller and the core shaft and between the first roller and the first outer ring.

[0011] Preferably, the outer contour curve of the first roller is:

[0012] ;

[0013] Taking the X-axis of the axis of the first roller as the coordinate axis, X represents the axial coordinate of the first roller, wherein the origin of the axial coordinate is the center point of the axis; y represents the radial protrusion height of the outer contour of the first roller; A represents the amplitude coefficient of the logarithmic curve; and B represents the curvature change rate adjustment coefficient.

[0014] Preferably, the selection range of A is 0.03 to 0.07, and the selection range of B is 150 to 250.

[0015] Preferably, the first roller is a tapered roller, which includes a small round end and a large round end. The axis of the tapered roller is tilted relative to the core shaft, with the small round end close to the core shaft and the large round end away from the core shaft.

[0016] Preferably, a raceway adapted to slide with the first roller is provided on the outer circumferential wall of the core shaft and / or the inner circumferential wall of the first outer ring, and the outer circumferential surface of the first roller can partially extend to the raceway.

[0017] Preferably, a lubricating coating is provided at a portion where the raceway and the first roller are in rolling connection.

[0018] Preferably, the lubricating coating is made of silver or diamond-like carbon film.

[0019] Preferably, the retainer is sintered from metal powder and lubricating powder, wherein the weight of the lubricating powder accounts for 8%-12% of the total weight of the retainer.

[0020] Preferably, the lubricating powder is molybdenum disulfide powder or tungsten disulfide powder.

[0021] An X-ray tube comprises the anode bearing structure as described above.

[0022] Beneficial effects of the present invention:

[0023] The anode bearing structure and X-ray tube of the present invention respectively place a plurality of first rollers in pockets on a retaining frame, so that the first rollers are evenly distributed between the core shaft and the first outer ring, so that the load on the anode bearing structure is more evenly dispersed, local stress concentration is avoided, and the radial load-bearing capacity of the anode bearing structure is improved, thereby increasing the service life of the X-ray tube. In addition, the use of columnar first rollers enables the first rollers to be in linear contact with the core shaft and the first outer ring during rolling connection. Compared with ball rollers, the contact area between the first rollers and the core shaft, and between the first rollers and the first outer ring can be increased, thereby further improving the radial load-bearing capacity of the anode bearing structure and the service life of the X-ray tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 12 is a schematic structural diagram of an anode bearing structure according to an embodiment of the present invention;

[0025] Figure 2 yes Figure 1 A partial enlarged view of the middle part;

[0026] Figure 3 2 is a schematic structural diagram of a retaining frame in an embodiment of the present invention.

[0027] In the picture:

[0028] 1. Mandrel; 11. Raceway;

[0029] 2. First outer ring;

[0030] 3. Cage; 31. Pocket;

[0031] 4. First roller; 41. Small round end; 42. Large round end;

[0032] 5. Second outer ring; 6. Second roller; 7. Spacer ring. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0034] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0035] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0036] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are used to refer to positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0037] See also Figures 1 to 3 In this embodiment, an anode bearing structure is proposed, which includes a core shaft 1, a first outer ring 2, and a plurality of first rollers 4. The core shaft 1 is used to connect to the anode target disk; the first outer ring 2 is coaxially sleeved on the core shaft 1 and is adjacent to the connection end of the core shaft 1 and the anode target disk; a retainer 3 is arranged between the first outer ring 2 and the core shaft 1, and the retainer 3 and the core shaft 1 are coaxially arranged. The retainer 3 has a plurality of pockets 31 uniformly distributed on the retainer 3 along the circumference, and the pockets 31 extend along the axial direction of the retainer 3; the plurality of first rollers 4 are arranged in a one-to-one correspondence with the plurality of pockets 31, and the first rollers 4 are adapted to imitate the pockets 31 so that the outer circumferential surfaces of the first rollers 4 are simultaneously in rolling connection with the core shaft 1 and the first outer ring 2. The first rollers 4 are cylindrical so that there is linear contact between the first rollers 4 and the core shaft 1, and between the first rollers 4 and the first outer ring 2.

[0038] It can be understood that placing multiple first rollers 4 in the pockets 31 on the retaining frame 3 respectively can make the first rollers 4 evenly distributed between the core shaft 1 and the first outer ring 2, so that the load on the anode bearing structure is more evenly dispersed, avoiding local stress concentration, and improving the radial load-bearing capacity of the anode bearing structure, thereby increasing the service life of the X-ray tube. In addition, the use of columnar first rollers 4 can make the first rollers 4 and the core shaft 1 and the first outer ring 2 in linear contact during rolling connection. Compared with ball rollers, the contact area between the first rollers 4 and the core shaft 1, and the first rollers 4 and the first outer ring 2 can be increased, thereby further improving the radial load-bearing capacity of the end of the anode bearing structure close to the anode target disk, and the service life of the X-ray tube.

[0039] In this embodiment, the outer contour curve of the first roller 4 is When the first roller 4 using this curve contacts the core shaft 1, the contact length between the two can be adaptively adjusted as the load on the first roller 4 changes, thereby reducing the stress fluctuation on the first roller 4 from the anode target plate, thereby improving the load-bearing capacity of the anode bearing structure and the service life of the X-ray tube.

[0040] The axis of the first roller 4 is taken as the X-axis, X represents the axial coordinate of the first roller 4, wherein the origin of the axial coordinate is the center point of the axis, y represents the radial protrusion height of the outer contour of the first roller 4, and the protrusion height refers to the height difference between the actual outer contour of the first roller 4 and the theoretical contour of the regular cylindrical first roller 4. A represents the amplitude coefficient of the logarithmic curve, which determines the overall longitudinal scaling ratio of the curve. The larger the A value, the larger the y value. The selection range of A is 0.03 to 0.07, preferably 0.05; B represents the curvature change rate adjustment coefficient, which is used to control the curvature change speed of the logarithmic curve. The larger the value of B, the flatter the central area of ​​the logarithmic curve, so as to disperse the radial load on the first roller 4, thereby improving the load-bearing capacity of the first roller 4. The selection range of B is 150 to 250, preferably 200. The setting can ensure that the position of the logarithmic curve is symmetrical about the origin, thereby avoiding the occurrence of stress eccentricity and thus improving the radial load capacity of the anode bearing structure;

[0041] The setting can make the area close to the origin of the logarithmic curve approximately flat, and smoothly transition at the edge away from the origin, thereby avoiding sudden changes in the curvature of the first roller 4 and suppressing edge stress concentration, so as to further improve the radial load-bearing capacity of the anode bearing structure.

[0042] Specifically, in this embodiment, the operating condition where the rotation speed of the anode target disk is 8000 rpm is used as an example for explanation. During the rotation of the anode target disk, due to the change in acceleration, the radial load range of the anode bearing structure is 800-1200 N. In the outer contour curve of the first roller 4, A is 0.05 and B is 200. Through finite element analysis, the first roller 4 using this curve has a contact stress fluctuation of ≤5%, and its load-bearing capacity is significantly improved compared with the ball roller.

[0043] In this embodiment, the first roller 4 is a tapered roller. It is understood that the tapered roller forms a linear contact with the core shaft 1 and the first outer ring 2 when rolling. Compared to a ball roller, this can increase the contact area between the first roller 4 and the core shaft 1, and between the first roller 4 and the first outer ring 2, thereby increasing the radial and axial load-bearing capacity of the anode bearing structure. Of course, in some other feasible embodiments, the first roller 4 can also be a cylindrical roller.

[0044] Furthermore, the tapered roller includes a small round end 41 and a large round end 42. The axis of the tapered roller is tilted relative to the core shaft 1, with the small round end 41 closer to the core shaft 1 and the large round end 42 farther away from the core shaft 1. The taper angle of the tapered roller is selected within a range of 15° to 20°. It is understood that during rotation, the anode target disk exerts an axial thrust on the core shaft 1 due to thermal expansion. At this time, a normal force is generated on the contact surface between the first roller 4 and the core shaft 1. The axial component of this normal force is opposite to the thrust, forming a dynamic balance in the axial direction, thereby further improving the service life of the anode bearing structure.

[0045] In this embodiment, a raceway 11 is provided on the outer circumferential wall of the core shaft 1 and / or the inner circumferential wall of the first outer ring 2, adapted to slide with the first roller 4. The outer circumferential surface of the first roller 4 can partially extend into the raceway 11. It will be appreciated that the provision of the raceway 11 can prevent the position of the first roller 4 from shifting during the rotation of the core shaft 1, thereby ensuring the radial load-bearing capacity of the anode bearing structure.

[0046] It should be noted that the raceway 11 has an inclined surface, and the angle between this inclined surface and the axis of the core shaft 1 is consistent with the taper angle of the tapered roller, thereby ensuring the coaxiality between the first outer ring 2 and the core shaft 1. Correspondingly, the retainer 3 is truncated cone-shaped, and the inclination angle of the truncated cone generatrix is ​​also consistent with the taper angle.

[0047] Furthermore, a lubricating coating is provided at the portion where the raceway 11 and the first roller 4 are in rolling contact. It is understood that the provision of the lubricating coating can reduce the film coefficient between the first roller 4 and the raceway 11, thereby reducing wear on the first roller 4 and increasing the service life of the X-ray tube.

[0048] Preferably, the lubricating coating is made of silver. As will be appreciated, silver's low shear strength at high temperatures (shear modulus G = 28 GPa) allows it to form a nanoscale lubricating film, reducing the friction coefficient to below 0.08 (compared to μ ≥ 0.15 for conventional grease lubrication). The lubricating coating can be applied by electroplating using conventional techniques, with a thickness between 280 and 320 nm, preferably 300 nm. In other feasible embodiments, the lubricating coating can also be made of diamond-like carbon film.

[0049] In addition, the retaining frame 3 is sintered from metal powder and lubricating powder. The metal powder and lubricating powder can be transformed into a dense body through sintering, thereby improving the structural strength of the retaining frame 3. It can be understood that the first roller 4 can generate friction with the retaining frame 3 during the rotation process, thereby causing the retaining frame 3 to wear. During this process, the lubricating powder will be released to form self-lubrication of the retaining frame 3, thereby further reducing the wear of the first roller 4.

[0050] Among them, if the content of lubricating powder increases, the content of metal powder will decrease. If the content of lubricating powder is too high, it will affect the structural strength of the cage 3. If the content of lubricating powder is too low, it will affect the self-lubricating property of the cage 3. In this embodiment, the weight of the lubricating powder accounts for 8%-12% of the total weight of the cage 3, so as to take into account both self-lubricating property and structural strength.

[0051] Preferably, the metal powder is copper powder or titanium alloy powder to ensure the structural strength of the cage 3 , and the lubricating powder is molybdenum disulfide powder or tungsten disulfide powder to ensure the self-lubricating property of the cage 3 .

[0052] In this embodiment, the anode bearing structure further includes a second outer ring 5 and a plurality of second rollers 6. The second outer ring 5 is coaxially sleeved on the core shaft 1, located at the end of the core shaft 1 facing away from the connection end. Along the circumference of the core shaft 1, the plurality of second rollers 6 are evenly distributed between the second outer ring 5 and the core shaft 1, with the outer circumferences of the second rollers 6 being in rolling contact with both the core shaft 1 and the second outer ring 5. Furthermore, a spacer ring 7 is disposed between the first outer ring 2 and the second outer ring 5. The first outer ring 2, the second outer ring 5, and the spacer ring 7 constitute the outer ring of the anode bearing structure. The first and second rollers 4 and 6 maintain the outer ring coaxially with the core shaft 1, thereby improving the radial load capacity of the anode bearing structure. Since the second rollers 6 are located away from the anode target, the load on the second rollers 6 is less than that on the first rollers 4. Therefore, the second rollers 6 can be ball rollers to reduce the production cost of the anode bearing structure.

[0053] Based on the above, this embodiment further provides an X-ray tube comprising an anode target and the anode bearing structure, wherein the anode target is connected to the core shaft 1 of the anode bearing structure. It is understood that the service life of the X-ray tube suitable for the anode bearing structure is increased.

[0054] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Anode bearing structure, characterized in that, include: A core shaft (1) for connecting the anode target plate; A first outer ring (2) is coaxially sleeved on the core shaft (1) and is adjacent to a connection end between the core shaft (1) and the anode target disk; A retainer (3) is arranged between the first outer ring (2) and the core shaft (1), and the retainer (3) and the core shaft (1) are coaxially arranged. A plurality of pockets (31) are evenly distributed on the retainer (3) along the circumference of the retainer (3), and the pockets (31) extend along the axial direction of the retainer (3); A plurality of first rollers (4) are arranged in a one-to-one correspondence with a plurality of pockets (31), the first rollers (4) and the pockets (31) are adapted to imitate each other so that the outer peripheral surface of the first roller (4) is simultaneously in rolling connection with the core shaft (1) and the first outer ring (2), and the first roller (4) is columnar so that the first roller (4) and the core shaft (1) and the first roller (4) and the first outer ring (2) are in line contact; Wherein, the outer contour curve of the first roller (4) is: ； The axis X of the first roller (4) is used as the coordinate axis, where X represents the axial coordinate of the first roller (4), wherein the origin of the axial coordinate is the center point of the axis; y represents the radial protrusion height of the outer contour of the first roller (4); A represents the amplitude coefficient of the logarithmic curve; and B represents the curvature change rate adjustment coefficient.

2. The anode bearing structure according to claim 1, characterized in that: The selection range of A is 0.03 to 0.07, and the selection range of B is 150 to 250.

3. The anode bearing structure according to claim 1, characterized in that: A raceway (11) adapted to slide with the first roller (4) is provided on the outer peripheral wall of the core shaft (1) and / or the inner peripheral wall of the first outer ring (2), and the outer peripheral surface of the first roller (4) can partially extend to the raceway (11).

4. The anode bearing structure according to claim 3, characterized in that: A lubricating coating is provided at a portion where the raceway (11) and the first roller (4) are in rolling connection.

5. The anode bearing structure according to claim 4, characterized in that: The material of the lubricating coating is silver or diamond-like carbon film.

6. The anode bearing structure according to claim 1, characterized in that: The retaining frame (3) is formed by sintering metal powder and lubricating powder, wherein the weight of the lubricating powder accounts for 8%-12% of the total weight of the retaining frame (3).

7. The anode bearing structure according to claim 6, characterized in that: The lubricating powder is molybdenum disulfide powder or tungsten disulfide powder.

8. An X-ray tube, characterized in that: The anode bearing structure comprises the anode bearing structure according to any one of claims 1 to 7.

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