System and method for liquid metal bearing assembly filler and plug

Abstract

Various methods and systems for a liquid metal bearing assembly (300) are provided. In one embodiment, a liquid metal bearing assembly includes a filler port (310) fluidly coupled to a liquid metal bath (312) of the liquid metal bearing assembly, the filler port including an inlet diameter (402) and an outlet diameter (404), the outlet diameter being smaller than the inlet diameter; and a pin (602, 702, 802, 902, 1002, 1004, 1102) formed to fit within the fill port and prevent the liquid metal from exiting the liquid metal bath via the fill port.

Description

Technical Field

[0001] Embodiments of the subject matter disclosed herein relate to systems having liquid metal bearing assemblies and methods for assembling liquid metal bearing assemblies. Background Art

[0002] Liquid metal bearings have a longer life and are more efficient at managing thermal loads relative to roller bearings and are therefore used in a variety of operating environments. For example, certain x-ray sources or x-ray tubes utilize liquid metal bearing assemblies, which may include at least one liquid metal bearing, at least in part due to the durability and thermodynamic properties of liquid metal bearing assemblies. However, asymmetric liquid metal distribution and gas formation may occur in the liquid metal interface of the bearing. Summary of the invention

[0003] In one embodiment, the liquid metal bearing assembly includes: a fill port, which is fluidly coupled to a liquid metal pool of the liquid metal bearing assembly, the fill port including an inlet diameter and an outlet diameter, the outlet diameter being smaller than the inlet diameter; and a pin, which is formed to fit within the fill port and prevent liquid metal from leaving the liquid metal pool via the fill port.

[0004] It should be understood that the above brief description is provided to introduce in a simplified form selected concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is solely defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The present invention will be better understood by reading the following description of non-limiting embodiments with reference to the accompanying drawings, in which:

[0006] Figure 1 shows a schematic block diagram of an exemplary x-ray imaging system according to one embodiment;

[0007] Figure 2 shows a pictorial view of a portion of an x-ray source according to one embodiment;

[0008] Figure 3 A first exemplary liquid metal bearing assembly according to one embodiment is shown;

[0009] Figure 4 A first embodiment of a filling port of a liquid metal bearing assembly according to one embodiment is shown;

[0010] Figure 5A second embodiment of a filling port of a liquid metal bearing assembly according to one embodiment is shown;

[0011] FIG. 6A to FIG. 6B A first plurality of embodiments of a pin for a liquid metal bearing assembly fill port and configured as a ball bearing are shown according to one embodiment;

[0012] FIG. 7A to FIG. 7B A second plurality of embodiments of a pin for a liquid metal bearing assembly fill port and configured as a plug are shown according to one embodiment;

[0013] Figure 8 According to one embodiment, the Figure 3 A first embodiment of a pin within a filling port of a liquid metal bearing assembly;

[0014] Fig. 9 According to one embodiment, the Figure 3 A second embodiment of a pin within a filling port of a liquid metal bearing assembly;

[0015] Fig.10 According to one embodiment, the Figure 3 Third multiple embodiments of a pin within a fill port of a liquid metal bearing assembly;

[0016] Fig.11 According to one embodiment, the Figure 3 A fourth embodiment of a pin within a liquid metal bearing assembly filler port; and

[0017] Fig.12 A method for assembling a liquid metal bearing assembly is shown. DETAILED DESCRIPTION

[0018] The following description relates to various embodiments for a liquid metal bearing assembly, and more particularly to a fill port for the liquid metal bearing assembly and a pin that may be placed therein. The liquid metal bearing assembly may be included in an x-ray source of an x-ray imaging system, an exemplary block diagram of which is provided in Figure 1 An embodiment of the x-ray source is shown in Figure 2 , wherein an x-ray source is provided with a liquid metal bearing assembly to enable the anode of the x-ray source to rotate. For purposes of explanation, the liquid metal bearing assembly is described herein for an x-ray source of an x-ray imaging system, and the liquid metal bearing assembly may be implemented in other systems, such as a computed tomography (CT) imaging system, without departing from the scope of the present disclosure. Figure 3 Shows Figure 2 An embodiment of a liquid metal bearing assembly, wherein the liquid metal bearing assembly is equipped with a rotating sleeve and a fixed shaft. Figure 4 Shown is the layout Figure 3 A first embodiment of a filling port in a rotating sleeve of a liquid metal bearing assembly. Figure 5 A second embodiment of a fill port is shown. The placement and configuration of the fill port as described herein may enable a method for assembling a liquid metal bearing assembly that may reduce degradation of seals and other components of the liquid metal bearing assembly compared to conventional assembly methods. FIG. 6A to FIG. 11 Various embodiments of a pin that may be inserted into the fill port and various methods for sealing the pin into the fill port to reduce leakage of liquid metal from the liquid metal bearing assembly during assembly and operation are shown. Fig.12 A method for assembling a liquid metal bearing assembly is shown, the method comprising inserting and sealing a pin into a fill port after inserting liquid metal into the liquid metal bearing assembly. Figures 2 to 11 are shown approximately to scale, but other relative dimensions may be used.

[0019] Conventional methods for assembling a liquid metal bearing assembly configured as a straddle bearing include exposing a seal of the liquid metal bearing assembly and introducing liquid metal, for example, by spilling the liquid metal onto the seal. In addition, the liquid metal bearing assembly can be assembled in an orientation in which the rotation axis of the liquid metal bearing assembly is parallel to the direction of gravity. When implemented in an x-ray source or an x-ray tube, the liquid metal bearing assembly can be placed horizontally so that the rotation axis is perpendicular to the direction of gravity. Additionally or alternatively, when implemented in an x-ray source or an x-ray tube, the liquid metal bearing assembly can be placed so that the rotation axis is placed at a non-parallel angle relative to the direction of gravity. For example, the x-ray source or the x-ray tube can be integrated into a mobile structure such as a rotating gantry of a CT imaging system. The above conventional assembly methods may result in degradation of the seal, generation of a force surface due to incomplete coating of the liquid metal flow path, leakage of liquid metal from the liquid metal bearing assembly, and shortened service life of the liquid metal bearing assembly. Systems and methods are desired for liquid metal bearing assemblies, such as assemblies configured as straddle bearings, in which liquid metal can be introduced to create a bearing surface without contaminating seals.

[0020] The present invention describes a system and method for a liquid metal bearing assembly having a filling port coupled to a liquid metal pool of the liquid metal bearing assembly, wherein the filling port is placed in a rotating element of the liquid metal bearing assembly and is at a radial distance from the center line of the bearing. The filling port includes an inlet diameter and an outlet diameter. In some embodiments, the outlet diameter is smaller than the inlet diameter. In some embodiments, the filling port also includes a step diameter between the inlet diameter and the outlet diameter, wherein the step diameter may be smaller than the inlet diameter and larger than the outlet diameter. In another embodiment, the inlet diameter may be equal to the outlet diameter. In addition, the liquid metal bearing assembly includes a pin formed to fit in the filling port and prevent the liquid metal from leaving the liquid metal pool via the filling port. For example, in an embodiment where the outlet diameter is smaller than the inlet diameter, or when the inlet diameter and the outlet diameter are equal, a pin with a constant diameter or a step diameter may be placed in the filling port. In an embodiment where the filling port includes a step diameter, a pin with a constant diameter or a step diameter may be placed in the filling port. Technical advantages of the system for a liquid metal bearing assembly disclosed herein may include retaining liquid metal during operation of the liquid metal bearing assembly (e.g., during operation of a system implementing the liquid metal bearing assembly); retaining a pin in a fill port; and reducing degradation of seals and other components of the liquid metal bearing assembly during assembly and operation.

[0021] Before further discussing a liquid metal bearing assembly having a fill port and a pin formed to fit within the fill port, an exemplary imaging system is shown in which the liquid metal bearing assembly may be implemented. Figure 1 An x-ray imaging system 100 designed to generate x-rays is shown. The x-ray imaging system 100 may be configured to Figure 1 The x-ray imaging system 100 may be used in a computer tomography (CT) imaging system, a radiographic imaging system, a fluoroscopic imaging system, a mammographic imaging system, an interventional imaging system, a tomographic system, or the like. However, the x-ray imaging system 100 can be applied to fields other than imaging, medical devices, and the like. For example, the x-ray imaging system 100 may be deployed in devices such as crystallographic systems, security scanners, industrial scanners, x-ray photography systems, and the like. In the imaging system example, the system may be configured to image a subject 102 (such as a patient, an inanimate object, one or more manufactured parts) and / or a foreign object (such as an implant, a stent, and / or a contrast agent present in the body).

[0022] The x-ray imaging system 100 may include at least one x-ray source 104, such as an x-ray tube, configured to generate and project an x-ray radiation beam 106. Specifically, in the illustrated embodiment, the x-ray source 104 is configured to project the x-ray radiation beam 106 toward a detector array 108 and through a subject 102. In some system configurations, the x-ray source 104 may project a conical x-ray radiation beam that is collimated to lie within an XYZ plane of a Cartesian coordinate system. However, other beam profiles and / or systems that omit the detector array have been envisioned. Each detector element of the array generates a separate electrical signal that is a measurement of the x-ray beam attenuation at the detector location.

[0023] although Figure 1 Only a single x-ray source 104 and detector array 108 are depicted, but in some embodiments, multiple x-ray sources and / or detectors may be employed to project multiple x-ray radiation beams and detect the x-ray radiation beams. For example, in a CT machine use case example, multiple detectors may be used in series with an x-ray source to acquire projection data corresponding to different energy levels of a subject.

[0024] The x-ray imaging system 100 may also include an x-ray controller 110 configured to provide power and timing signals to the x-ray source 104. It should be understood that the system may also include a data acquisition system configured to sample analog data received from the detector elements and convert the analog data into digital signals for subsequent processing.

[0025] In certain embodiments, the x-ray imaging system 100 may further include a computing device 112 having a processor 114 and controlling system operation based on operator input. The computing device 112 receives operator input, including, for example, commands and / or scan parameters, via an operator console 116 operatively coupled to the computing device 112. The operator console 116 may include a keyboard, a touch screen, and / or other suitable input devices that allow an operator to specify commands and / or scan parameters.

[0026] Although Figure 1Only one operator console 116 is shown, but more than one operator console may be included in the x-ray imaging system 100, for example, for inputting system parameters or outputting system parameters, requesting examinations, plotting data, and / or viewing images. In addition, in some embodiments, the x-ray imaging system 100 can be coupled to multiple displays, printers, workstations, and / or the like located, for example, locally or remotely and connected via a wired network and / or a wireless network. In one embodiment, the display 120 can be in electronic communication with the computing device 112 and is configured to display a graphical interface indicating information such as system parameters, control settings, imaging data, etc.

[0027] In one example, computing device 112 stores data in storage device 118. For example, storage device 118 may include a hard drive, a floppy disk drive, a compact disk read / write (CD-R / W) drive, a digital versatile disk (DVD) drive, a flash drive, and / or a solid-state storage drive.

[0028] In addition, the computing device 112 provides commands to the x-ray controller 110 and other system components for controlling system operation, such as x-ray beam formation, data acquisition and / or processing, etc. Therefore, in some embodiments, the computing device 112 controls system operation based on operator input. In detail, the computing device 112 can use operator-provided commands and parameters and / or system-defined commands and parameters to operate the x-ray controller 110, which in turn can control the x-ray source 104. In this way, the intensity and time when the x-ray beam is generated can be controlled. It should also be understood that the rotation speed of the sleeve in the x-ray source can be adjusted by the computing device 112 in conjunction with the x-ray controller 110. As described in more detail herein, the sleeve can be a rotating element of a liquid metal bearing assembly.

[0029] Various methods and processes may be stored as executable instructions in non-transitory memory on a computing device (or controller) in the x-ray imaging system 100. In one embodiment, the x-ray controller 110 may include the executable instructions in the non-transitory memory and may apply the methods to control the x-ray source 104. In another embodiment, the computing device 112 may include the instructions in the non-transitory memory and may at least partially relay the commands to the x-ray controller 110, which in turn adjusts the x-ray source output.

[0030] Figure 2 A detailed embodiment of a portion of an x-ray source, such as x-ray tube 200, is shown. Figure 2 The x-ray tube 200 shown is used as Figure 1 An example of an x-ray source 104 is shown. Thus, Figure 2The x-ray source shown and other x-ray source embodiments described herein may include a source from Figure 1 Functional features and / or structural features of the x-ray source 104 are shown, and vice versa. Additionally, alternative embodiments are contemplated that combine features from one or more of the systems. Figure 2 250 and a radial axis 252 are provided for reference. It should be understood that the radial axis is any axis perpendicular to the rotation axis 250.

[0031] The x-ray tube 200 includes a housing 202 having a low pressure enclosure 204 (eg, a vacuum enclosure) formed therein. It should be understood that low pressure enclosure means a relatively low pressure relative to atmospheric pressure. Thus, the pressure in the enclosure may be less than atmospheric pressure.

[0032] The x-ray tube 200 includes a liquid metal bearing assembly 205 having a rotating component 208 and a fixed component 206. In the illustrated embodiment, the rotating component 208 is a sleeve and the fixed component 206 is a shaft. However, embodiments in which the sleeve is fixed and the shaft rotates are envisioned. It should be understood that the motion represented by the "fixed" and "rotating" descriptors represents relative motion between the components. However, in certain use case examples, the x-ray tube may be integrated into a mobile structure. For example, in a CT imaging system use case, the x-ray tube may be integrated into a rotating gantry. Therefore, in a smaller scale frame of reference, the shaft is fixed relative to the sleeve, but in a larger scale frame of reference, the two components exhibit similar rotational motion in the gantry. However, in an alternative use case scenario, for a larger scale frame of reference, the x-ray tube may be integrated into a fixed structure. It should also be understood that in some cases, the liquid metal bearing assembly described in more detail herein may be deployed in an alternative type of system utilizing liquid metal bearings.

[0033] A rotor 218 and a stator 220 are also provided in the x-ray tube 200. The rotor 218 is coupled to the rotating component 208 and is designed to impart rotational motion thereto. The stator 220 is shown as being placed outside of the low voltage enclosure 204. However, other suitable stator locations are contemplated. In general, the rotor and stator may include windings, magnets, electrical connections, etc., which electromagnetically interact to provide a rotational motion between, for example, the rotor and the stator. Figure 1 The x-ray controller 110 is shown to generate rotor rotation upon receiving the control commands.

[0034] The x-ray tube 200 also includes an anode 210 and a cathode 212. The anode 210 is coupled to a rotating member 208, which can rotate the anode 210 during x-ray beam generation. The cathode 212 is part of a cathode assembly and can be controlled by a controller such as Figure 1An x-ray controller 110 is shown receiving signals to generate an electron beam toward the surface of anode 210. When the electron beam from cathode 212 strikes anode 210, an x-ray beam 214 is generated. The x-rays are emitted and pass through an x-ray window 216 in housing 202.

[0035] Turning to the liquid metal bearing assembly 205, a plurality of liquid metal bearings may include the assembly. In the illustrated embodiment, the liquid metal bearing assembly 205 may include a liquid metal journal bearing 222 and a liquid metal thrust bearing 224, both of which may be supplied with liquid metal from a liquid metal pool, as described in reference to Figure 3 20. However, in other embodiments, component configurations with additional or alternative bearings may be used. The liquid metal journal bearing 222 is designed to support radial loads, and the liquid metal thrust bearing 224 is designed to support axial loads. In this way, the load on the sleeve (e.g., rotating component 208) can be managed to achieve efficient sleeve rotation.

[0036] Each of the bearings of the liquid metal bearing assembly 205 includes an interface 226 in which the liquid metal acts as a lubricant and also supports radial and axial loads. The thickness of the interface can be selected based on factors such as the type of liquid metal used in the bearing, manufacturing tolerances of the components, expected system operating temperatures, and the like. Thus, in one use case example, the thickness of the liquid metal interface can be approximately 5 micrometers (μm) to 40 μm. The thickness of the liquid metal interface of the liquid metal journal bearing 222 can be in a radial direction of the liquid metal bearing assembly 205 (e.g., relative to the radial axis 252), and the thickness of the liquid metal interface of the liquid metal thrust bearing 224 can be in a radial direction of the liquid metal bearing assembly 205 and in an axial direction parallel to the rotating axis 250. The liquid metal used as a working fluid in the bearing assembly may include gallium, tin, indium, combinations thereof, and the like. References herein Figures 3 to 11 Embodiments of the described liquid metal bearing assemblies may use gallium as the liquid metal lubricant.

[0037] Figure 3 1 shows an embodiment of a liquid metal bearing assembly 300. In some examples, the liquid metal bearing assembly 300 can be used with Figure 2 The illustrated liquid metal bearing assembly 205 is similar or identical. Thus, features from the bearing assembly 205, and more broadly the x-ray tube 200, may be included in the liquid metal bearing assembly 300 and other liquid metal bearing assembly embodiments described herein. Figure 3 as well as Figures 3 to 11 A coordinate system 320 is provided in FIG. 1 for reference. In one example, the y-axis may be the vertical axis (e.g., when the liquid metal bearing assembly 300 is mounted to an imaging system (such as the one described above with reference to FIG. 1 ). Figure 1In the case of the x-ray imaging system 100 described above, the x-ray source is parallel to the direction of gravity), the x-axis can be a transverse axis (eg, a horizontal axis), and the z-axis can be a longitudinal axis. However, in other examples, the axes can have other orientations.

[0038] The liquid metal bearing assembly 300 includes a rotating component, which may be referred to herein as a sleeve 302, and a stationary component, which may be referred to herein as a shaft 304. The sleeve 302 and the shaft 304 may be coupled so that the sleeve 302 can rotate relative to the shaft 304. Each of the sleeve 302 and the shaft 304 is provided with a structure that forms a liquid metal flow path when the liquid metal bearing assembly 300 is assembled, such as Figure 3 As shown (e.g., shaft 304 enclosed in sleeve 302). The liquid metal flow path may include a fill port 310, a liquid metal pool 312 (e.g., a lubricant pool), a channel 314, and a gap 316. The fill port 310 may be machined as part of the sleeve 302 or formed (e.g., molded) with the sleeve 302 and placed radially away from the centerline of the bearing. For example, the centerline of the bearing may be a central rotational axis 350, which is equivalent to Figure 2 The fill port 310 may be positioned at a first radial distance 322 from the central rotational axis 350. In some embodiments, the fill port 310 may be positioned to be linearly aligned with (e.g., parallel to and along) the central rotational axis 350. The fill port 310 may be positioned to be parallel to or perpendicular to the central rotational axis 350. For example, Figure 3 As shown, the filling port 310 is perpendicular to the central rotation axis 350, and the inlet 318 of the filling port 310 is located on the first side 338 of the liquid metal bearing assembly 300. Figure 3 In other embodiments not shown in FIG. 3 , the fill port 310 may be oriented parallel to the central axis of rotation 350 , with the inlet 318 of the fill port 310 formed in a surface of the first end 326 of the sleeve 302 .

[0039] In some embodiments, the liquid metal bearing assembly 300 may be equipped with more than one filling port. For example, the liquid metal bearing assembly 300 may include a filling port 310 located on a first radial side of the sleeve 302, and further include a second filling port (not shown) directly opposite the filling port 310 relative to the central rotation axis 350. In some examples, the second filling port may be placed at a different axial position and / or a different circumferential position relative to the filling port 310. The filling port 310 may be placed toward a first end 326 of the liquid metal bearing assembly 300, which is axially opposite to the second end 328. The inlet 318 of the filling port 310 may be formed in the surface of the sleeve 302 extending around the central rotation axis 350, so that the radial distance between the outlet 330 of the filling port 310 and the central rotation axis 350 is closer than the radial distance between the inlet 318 and the central rotation axis 350, and the filling port 310 extends toward the central rotation axis 350 in a direction perpendicular to the central rotation axis. The fill port 310 may extend a first depth 332 from the inlet 318 to the outlet 330. The first depth 332 may be approximately equal to the thickness 334 of the sleeve 302. The first depth 332 may also be greater than the second radial distance 324 between the shaft 304 and the sleeve 302, and less than the shaft width 336 at the same axial position along the length of the sleeve 302 as the fill port 310. In some embodiments, the fill port 310 may have a wetting coating or an anti-wetting coating. Reference Figure 4 and Figure 5 Further details of the fill port 310 are described.

[0040] The liquid metal pool 312 may extend annularly around the shaft 304 and have a second radial distance 324 between the shaft 304 and the sleeve 302. The liquid metal pool 312 may be fluidly coupled to the fill port 310 and the channel 314. The liquid metal pool 312 may accommodate a volume greater than the combined filling volume of the channel 314 and the gap 316. For example, the combined filling volume may be between 2g and 20g, depending on the design of the bearing. Using the fill port 310 coupled to the liquid metal pool 312 may increase the available volume of the liquid metal pool 312 compared to a liquid metal pool not coupled to the fill port. For example, a conventional liquid metal pool may accommodate less than 2g of gallium. Increasing the amount of liquid metal that the liquid metal pool 312 may accommodate may improve the long-term tolerance of the bearing to liquid metal leakage and improve desired bearing performance, such as maintaining a continuous load surface, as further described herein.

[0041] The liquid metal flow path including the liquid metal pool 312, the channel 314, and the gap 316 may have an annular configuration between the sleeve 302 and the shaft 304. The inclined diameters (e.g., gradually narrowing) of the shaft 304 and the sleeve 302 reduce the width of the liquid flow path from the liquid metal pool 312 to the gap 316 (e.g., between the shaft 304 and the sleeve 302). Described in another way, at the channel 314, the diameter of the shaft 304 may be increased relative to the diameter of the shaft 304 at the liquid metal pool 312, and the diameter of the interior of the sleeve 302 may be reduced relative to the diameter of the interior of the sleeve 302 at the liquid metal pool 312, thereby reducing the total width of the liquid metal flow path between the shaft 304 and the sleeve 302 in the direction from the first end 326 of the shaft toward the second end 328.

[0042] During assembly of the liquid metal bearing assembly 300, liquid metal (e.g., gallium) can be injected or otherwise inserted into the liquid metal pool 312 via the fill port 310. The liquid metal can be delivered through the channel 314 to the intersection of the channel 314 and the gap 316. The width of the gap 316 can be less than the width of the liquid metal bead so that the liquid metal does not flow into the gap 316. The liquid metal bearing assembly 300 can be heated, and capillary forces can pull the liquid metal from the channel 314 into the gap 316. The liquid metal can thus coat the surface of the bearings (e.g., liquid metal journal bearings and / or liquid metal thrust bearings) of the liquid metal bearing assembly 300 to produce a force-bearing surface having a continuous layer of liquid metal extending between the sleeve 302 and the shaft 304. This can, for example, allow the sleeve 302 to rotate smoothly and uninterruptedly relative to the shaft 304 during operation of the x-ray tube to generate an x-ray beam, as shown in reference to FIG. Figure 1 and Figure 2 The liquid metal bearing assembly 300 may also include a seal located in the lower region 306 of the liquid metal bearing assembly 300, which may reduce the amount of liquid metal that leaks from the bearing. For example, the seal may be a rotary seal, a compression seal, etc. The seal may prevent liquid metal from leaking from the anode (such as the bearing assembly) in an axial direction (e.g., along the central rotation axis 350). Figure 2 Anode 210 shown in FIG. 2 flows away.

[0043] Steering Figure 4 , which shows a first configuration 400 of a filling port of a liquid metal bearing assembly. The filling port having the first configuration 400 may be a filling port 310 of a liquid metal bearing assembly 300, through which liquid metal such as gallium may be inserted into a liquid metal flow path during assembly of the liquid metal bearing assembly 300. Figure 4 The central axis 418 shown in FIG. 4 is understood to be perpendicular to Figure 3The central rotation axis 350 of the liquid metal bearing assembly 300. In some embodiments, as shown in reference Figure 3 Briefly described, the fill port can be placed parallel to the central rotation axis 350, in which case the central axis 418 is parallel to the central rotation axis 350. Liquid metal can flow from the inlet 318 to the outlet 330 (e.g., parallel to the central axis 418) through the fill port 310 in a direction indicated by the first arrow 444. The sleeve 302 is shown with an x-hatched mark, and the fill port 310 is not shown with an x-hatched mark to distinguish between them.

[0044] The fill port 310 is configured to have an inlet diameter 402 in an upper region 410 (e.g., at the inlet 318) and an outlet diameter 404 in a lower region 420 (e.g., at the outlet 330), wherein the outlet diameter 404 is smaller than the inlet diameter 402. The upper region 410 of the fill port 310 is provided with an upper wall 434 having a first length 412, and the lower region 420 of the fill port 310 is provided with a lower wall 436 having a second length 414. In some embodiments, the first length 412 can be greater than the second length 414. In other embodiments, the first length 412 can be less than the second length 414, or the first length 412 and the second length 414 can be equal. The upper region 410 and the lower region 420 of the fill port 310 can be coupled by a smooth linear transition region 430, wherein the diameter of the fill port 310 gradually decreases from the inlet diameter 402 to the outlet diameter 404. The transition region between the upper region 410 and the smooth linear transition region 430 may have an inlet diameter 402, and the transition region between the smooth linear transition region 430 and the lower region 420 may have an outlet diameter 404. The inclined wall 432 of the fill port 310 at the smooth linear transition region 430 may be inclined about 30 degrees from the x-axis relative to the coordinate system 416 of the third length 424. In other examples, the inclined wall 432 may be arranged at a different angle (e.g., less than 45 degrees) relative to the x-axis. In some embodiments, the first length 412 may be greater than the second length 414, and the second length 414 may be greater than the third length 424. In other embodiments, at least two of the first length 412, the second length 414, and the third length 424 may be equal.

[0045] The fill port 310 is fluidly coupled to the ( Figure 3The liquid metal pool 312 of the liquid metal bearing assembly 300 is configured such that when the pin is not placed in the filler port 310, the liquid metal pool 312 and other elements of the liquid metal bearing assembly 300 are connected to the exterior 352 of the liquid metal bearing assembly 300 (e.g., to the atmosphere) via the inlet 318. The inlet 318 has an inlet diameter 402, the outlet 330 has an outlet diameter 404, and thus the filler port 310 is configured to have a circular cross-section, as shown in reference FIG. 6A to FIG. 6B When the pin is placed in the fill port 310, the fill port 310 and thus the liquid metal pool 312 and other components of the liquid metal bearing assembly 300 can be sealed from the exterior 352. FIG. 6A to FIG. 11 Further details of the pin and its placement in the filler port 310 are described. In this manner, the filler port 310 may include a self-aligning feature between the filler port 310 and the pin to enable a press fit assembly of the pin with the filler port 310 without locking when inserted.

[0046] Steering Figure 5 , which shows a second configuration 500 of the filling port of the liquid metal bearing assembly 300, which can be Figure 3 The filling port 310 is provided. Figure 5 shown Figure 4 The elements are labeled identically and are not reintroduced for the sake of brevity. Figure 5 The central axis 518 shown should be understood to be perpendicular to Figure 3 The central rotation axis 350 of the liquid metal bearing assembly 300. The liquid metal can flow from the inlet 318 to the outlet 330 through the filling port 310 in the direction indicated by the second arrow 544 (e.g., parallel to the central axis 518). The sleeve 302 is shown with an x-hatched mark, and the filling port 310 is not shown with an x-hatched mark to distinguish between them.

[0047] In some embodiments, such as in the second configuration 500, the lower region 420 of the fill port 310 may have a step diameter 506, wherein a first portion 502 of the lower region 420 adjacent to the smooth linear transition region 430 has the step diameter 506 and a second portion 504 of the lower region 420 has the outlet diameter 404. The step diameter 506 may be smaller than the inlet diameter 402 and larger than the outlet diameter 404. The transition region between the upper region 410 and the smooth linear transition region 430 may have the inlet diameter 402, and the transition region between the smooth linear transition region 430 and the first portion 502 of the lower region 420 may have the step diameter 506. The transition region between the first portion 502 and the second portion 504 of the lower region 420 may have the outlet diameter 404. Additionally, in some embodiments, the fourth length 512 of the first portion 502 may be greater than the fifth length 514 of the second portion 504. In other embodiments, the fourth length 512 of the first portion 502 may be less than or equal to the fifth length 514 of the second portion 504. For example, each of the fourth length 512 and the fifth length 514 may be 1.5 mm. For example, when the step diameter 406 is 1 mm, the outlet diameter 404 may be 0.3 mm.

[0048] As briefly described above, the liquid metal flow path of the liquid metal bearing assembly 300 can be sealed from the exterior 352 (e.g., atmosphere) by inserting a pin into the fill port 310. The pin can have a variety of configurations and a variety of methods can be used to seal the pin into the fill port, as described herein with reference to FIG. 6A to FIG. 11 For example, the pin can be configured as a ball bearing or a plug and can be sealed into the fill port by brazing, threaded fasteners, welding, angled interference threads (such as pipe threads), and / or a press fit of the pin. In some embodiments, the pin can have a wetting coating or an anti-wetting coating to enhance the sealing capability of the interference fit with the fill port 310. In this way, the fill port 310 can combine a sliding radial interference fit with an optional axial compression (e.g., a knife edge member and / or a radial compression knife edge), as described in reference FIG. 6A to FIG. 11 Further described.

[0049] Now turn to FIG. 6A to FIG. 6B , wherein a first plurality of embodiments 600 for a pin are shown, wherein the pin is configured as a ball bearing. FIG. 6A to FIG. 6B In Figures 3 to 5 The elements are numbered identically and are not reintroduced for the sake of brevity. FIG. 6A to FIG. 6B The central axis 646 shown should be understood to be perpendicular to Figure 3350 of the liquid metal bearing assembly 300, and it should be understood that each of the first plurality of embodiments 600 has the same orientation relative to each other. In other embodiments, the central axis 646 can be parallel to the central rotational axis 350 of the liquid metal bearing assembly 300, wherein the fill port is placed at a first radial distance from the central rotational axis 350 or linearly aligned with the central rotational axis 350. Each of the first plurality of embodiments 600 shows a fill port (e.g., Figure 3 310) in a cross-sectional view of a pin in a fill port 310 of the embodiment of the present invention, wherein the lower region 420 of the fill port has an outlet diameter 404 for a second length 414. Each of the embodiments of the pin described with respect to the first plurality of embodiments 600 can be implemented in different configurations of the fill port, such as the second configuration 500 and / or other configurations, without departing from the scope of the present disclosure. As shown in reference FIG. 6A to FIG. 6B In the description, elements with vertical line fills will be interpreted as pins (e.g. configured as ball bearings) and elements with horizontal line fills will be interpreted as brazing elements. Figure 3 During the liquid metal bearing assembly 300), a pin may be inserted into the filling port, followed by inserting a brazing element and brazing the brazing element to seal the pin in the filling port. Fig.12 Further details of the assembly of the liquid metal bearing assembly are described.

[0050] Each of the first plurality of embodiments 600 includes a pin 602 configured as a ball bearing. For example, the pin 602 can be a sphere formed of a metal such as brass, pure copper, stainless steel, or a sphere formed of ceramic. In some embodiments, the pin 602 can have a wetting coating or an anti-wetting coating. In the first embodiment 610, the third embodiment 630, the fourth embodiment 640, the fifth embodiment 650, and the seventh embodiment 670 of the first plurality of embodiments 600, the pin 602 is placed in the lower region 420 of the filler port. In the second embodiment 620 and the sixth embodiment 660, the pin 602 is placed so that the pin 602 spans the upper region 410, the smooth linear transition region 430, and the lower region 420. In the first plurality of embodiments 600, the diameter of the pin 602 may vary. For example, in the first embodiment 610, the third embodiment 630, the fourth embodiment 640, the fifth embodiment 650, and the seventh embodiment 670, the first pin diameter 604 of the pin 602 may be approximately equal to or smaller than the outlet diameter 404 of the lower region 420 of the filler port. For example, when the outlet diameter 404 is 1 mm, the first pin diameter 604 may be 0.9 mm. Fig.12As further described, during assembly of a liquid metal bearing assembly equipped with a filling port, the pin 602 can be inserted into the filling port after the liquid metal is injected into the liquid metal pool. For example, a pin 602 having a first pin diameter 604 can be inserted into the filling port, and the first pin diameter 604 can prevent the pin 602 from rolling or otherwise moving into the liquid metal pool. In some embodiments, as further described herein, before the pin 602 is inserted into the filling port, the pin 602 can be coupled to a brazing element, and the construction of the brazing element can prevent the pin 602 from moving into the liquid metal filling port. In the second embodiment 620 and the sixth embodiment 660, the second pin diameter 606 of the pin 602 can be larger than the outlet diameter 404 and smaller than the inlet diameter 402 of the upper region 410. The second pin diameter 606 of the pin 602 can cause the pin 602 to rest on the wall of the smooth linear transition region 430 (e.g., Figure 4 For example, when the outlet diameter 404 is 1 mm and the inlet diameter 402 is 5 mm, the second pin diameter 606 may be 3 mm.

[0051] In each of the first embodiment 610, the second embodiment 620, the third embodiment 630, the fourth embodiment 640, the fifth embodiment 650, and the sixth embodiment 660, the pin 602 can be sealed in the filler port using a brazing element. In the first embodiment 610, the pin 602 is sealed in place using a plurality of brazing beads 608, wherein in some embodiments, each of the plurality of brazing beads 608 can be a sphere of 0.6 mm diameter. The top view 615 of the first embodiment 610 shows the placement of the plurality of brazing beads 608 around the circumference of the pin 602, wherein there is a gap between each of the plurality of brazing beads 608. The top view 615 should be understood as a perspective looking into the inlet 318 of the filler port. Coordinate system 699 shows the orientation of the top view 615, and coordinate system 320 shows FIG. 6A to FIG. 6B In one example, for coordinate system 699, the y-axis can be the vertical axis (e.g., when the liquid metal bearing assembly 300 is mounted to an imaging system (such as the one described above in reference to Figure 1 In the case of the x-ray imaging system 100 described above, the x-ray source is parallel to the direction of gravity), the x-axis can be a transverse axis (e.g., a horizontal axis), and the z-axis can be a longitudinal axis. However, in other examples, the axes can have other orientations. Figure 4 Briefly described, the fill port may have a circular cross-section. FIG. 6A to FIG. 6BThe top view 615 of the embodiment shows a circular cross-section of the filler port, wherein the outermost circle 642 represents the inlet 318 of the filler port, and the second circle 644 represents the intersection between the smooth linear transition region 430 and the lower region 420. As shown in the first embodiment 610 and the top view 615, a plurality of brazing beads 608 are placed at the intersection between the smooth linear transition region 430 and the lower region 420.

[0052] In the second embodiment 620 and the third embodiment 630, the pin 602 is fixed in place by the coil 612. The coil 612 can have an annular configuration around the central axis 646 and can rest on the pin 602 so that the pin 602 partially extends through the center of the coil 612. The diameter of the coil 612 can depend on the diameter of the corresponding pin. For example, the first coil diameter 614 of the coil 612 in the second embodiment 620 can be greater than the second coil diameter 616 of the coil 612 in the third embodiment 630. For example, the coil 612 can be formed of a metal such as brass, pure copper, stainless steel, or formed of ceramic. The coil 612 has a circular cross-section, as shown in the second embodiment 620 and the third embodiment 630.

[0053] In the fourth embodiment 640, the pin 602 is secured in place by a washer 618. The washer 618 may be configured as an annular ring around the central axis 646 and have a rectangular cross-section. The washer 618 may rest on the pin 602 such that the pin 602 partially extends through the center of the washer 618. For example, the washer 618 may be formed of a metal such as brass, pure copper, stainless steel, or formed of a ceramic.

[0054] In the fifth embodiment 650, the pin 602 is secured in place by a brazing ball 622. The brazing ball 622 may be configured to rest on the wall of the smooth linear transition region 430 (e.g., Figure 4 The brazing ball 622 is provided in the embodiment of the present invention and is provided on the inclined wall 432 of the filling port, and the elliptical disk 624 on the inclined wall 432 of the filling port, and the sphere 626 coupled to the elliptical disk 624. For example, the elliptical disk 624 and the sphere 626 can be a single continuous element. The brazing ball 622 is placed in the filling port so that the sphere 626 is partially arranged in the upper area 410 of the filling port. The elliptical disk 624 can contact the pin 602. For example, the brazing ball 622 can be formed of a metal such as gold, silver, copper, palladium, platinum, or an alloy of these metals or similar metals.

[0055] The sixth embodiment 660 may have a similar configuration to that of the second embodiment 620, wherein the pin 602 is placed such that the pin 602 spans the upper region 410, the smooth linear transition region 430, and the lower region 420, and is secured in place by a braze formed by melting a brazing ring 628. The brazing ring 628 may have an annular configuration around the central axis 646 and have a rectangular cross-section and a gap located in the circumference of the brazing ring 628. The brazing ring 628 may rest on the pin 602 such that the pin 602 partially extends through the center of the brazing ring 628. When the brazing ring 628 melts, the molten material of the brazing ring 628 flows into the gap between the pin 602 and the sleeve 302 to retain the pin 602. For example, the brazing ring 628 may be formed of a metal such as gold, silver, copper, palladium, platinum, or an alloy of these metals or similar metals.

[0056] The seventh embodiment 670 may not include a brazing element, but may use a threaded fastener 632 to secure the pin 602 in place in the filler port. The threaded fastener 632 may have a stepped cylindrical body, such that a lower extension 634 of the stepped body extends into the smooth linear transition region 430 and an upper extension 636 is placed in the upper region 410. The upper extension 636 may also be provided with a plurality of threads 638 extending radially from the upper extension 636. In some embodiments, the plurality of threads 638 may engage with a wall (e.g., Figure 4 434 of the upper wall 434). In other embodiments, the wall of the upper region 410 may be provided with a corresponding threaded connection so that the threaded fastener 632 can be screwed into the upper region 410 of the filler port after the pin 602 is inserted into the filler port (e.g., the lower region 420). For example, a plurality of threads 638 and corresponding threaded connections may be configured to directly engage with each other in a coplanar contact manner. For example, in some embodiments, the threaded fastener 632 may be a tapered interference thread, such as a pipe thread. As described herein, coplanar contact includes surfaces that are directly engaged with each other without other components being arranged therebetween. In the embodiments described herein, surfaces in coplanar contact (e.g., directly engaged with each other) may form a sealing interface so that a fluid (e.g., liquid metal) may not flow through the interface between the surfaces. For example, the threaded fastener 632 may be formed of a metal such as brass, pure copper, stainless steel, or may be formed of ceramic. In some embodiments, the threaded fastener 632 may be coupled to the pin 602. In other embodiments, the threaded fastener 632 can be a separate element from the pin 602 (eg, not coupled to the pin 602).

[0057] Screwing the threaded fastener 632 into the filling port can fix the pin 602 in the filling port and / or form a seal that keeps the liquid metal in the liquid metal pool and isolates the liquid metal pool from the outside of the liquid metal bearing assembly. For embodiments of the first plurality of embodiments 600 including a brazing element, the brazing element, the pin 602, and the filling port can be brazed to fix the pin 602 in the filling port and isolate the liquid metal pool from the outside of the liquid metal bearing assembly. This can reduce the amount of liquid metal (e.g., gallium) that may leak from the liquid metal bearing assembly during assembly and / or operation of the liquid metal bearing assembly. Additionally or alternatively, the brazing element can be integrated into the pin 602 by coating an area of ​​the pin with a brazing material. By inserting the liquid metal through a fill port positioned radially from the centerline of the bearing, degradation of components of the liquid metal bearing assembly (such as seals) can be reduced compared to conventional methods for assembling liquid metal bearing assemblies (including pouring liquid metal onto bearing elements and / or passing the shaft of the liquid metal bearing assembly through its seals).

[0058] Now turn to FIG. 7A to FIG. 7B , wherein a second plurality of embodiments 700 of a pin are shown, wherein the pin is configured as a plug. FIG. 7A to FIG. 7B In Figures 3 to 5 The elements are numbered identically and are not reintroduced for the sake of brevity. FIG. 7A to FIG. 7B The central axis 746 shown should be understood to be perpendicular to Figure 3 , and it should be understood that each of the second plurality of embodiments 700 has the same orientation relative to each other. In other embodiments, the central axis 746 can be parallel to the central rotational axis 350 of the liquid metal bearing assembly 300, wherein the fill port is placed at a first radial distance from the central rotational axis 350 or linearly aligned with the central rotational axis 350. Each of the second plurality of embodiments 700 shows a fill port (e.g., Figure 3 4 and 5. The cross-sectional view of a pin in a filler port 310 of the embodiment of the present invention is shown in FIG. 4 , wherein a lower region 420 of the filler port has an outlet diameter 404 for a second length 414. For example, the pin 702 may include self-aligning features, such as undercuts in the pin geometry and / or radial expansion of the body of the pin via a knife edge member that helps retain the pin 702 in the filler port. Each of the embodiments of the pin described with respect to the second plurality of embodiments 700 may be implemented in different configurations of the filler port, such as the second configuration 500 and / or other configurations, without departing from the scope of the present disclosure. As described in reference FIG. 7A to FIG. 7B In the description, elements with vertical line filling will be interpreted as pins (e.g. configured as plugs) and elements with horizontal line filling will be interpreted as brazing elements. Figure 3 During the liquid metal bearing assembly 300), a pin may be inserted into the filling port, followed by the insertion of a brazing element, and the brazing element may be brazed to seal the pin in the filling port. In some embodiments, a brazing element may be coupled to the pin before the pin is inserted into the filling port, or a brazing element may not be used and the pin may be press-fit into the filling port. Fig.12 Further details of the assembly of the liquid metal bearing assembly are described.

[0059] Each of the second plurality of embodiments 700 includes a pin 702 configured as a plug. For example, the pin 702 may have a cylindrical configuration having a first plug width 704 and a first plug height 706. The first plug height may correspond to a brazing element for brazing the pin 702 in place, as further described herein. In the first embodiment 710, the pin 702 has a stepped configuration, wherein the first plug height 706 includes a second plug height 712 having a second plug width 714 and a third plug height 716 having a third plug width 718. For example, the second plug width 714 is greater than the third plug width 718, and the second plug height 712 is less than the third plug height 716. For example, the pin 702 may be formed of a metal such as brass, pure copper, stainless steel, or formed of ceramic, rubber, plastic, or other plastically deformable material. In each of the second plurality of embodiments 700, the pin 702 is placed in the lower region 420 of the filler port. In the sixth embodiment 760, the pin 702 has a plug height that extends from the lower region 420, through the smooth linear transition region 430, and into the upper region 410 of the fill port. For example, when the outlet diameter 404 of the lower region 420 is 1 mm, the first plug width 704 and the second plug width 714 can be 0.8 mm, and the third plug width 718 can be 0.9 mm. For example, when the second length 414 of the lower region 420 is 3 mm, the first plug height 706 can be 2.8 mm, the second plug height 712 can be 0.5 mm, and the third plug height 716 can be 2.3 mm.

[0060] In the first embodiment 710, the stepped configuration of the pin 702 may be used to press fit the pin 702 into place in the fill port. The second plug width 714 may be approximately equal to the outlet diameter of the fill port (eg, Figure 4 The outlet diameter 404 is such that when the pin 702 is inserted into the filling port, the pin 702 is aligned with the lower wall of the filling port (eg Figure 4 The lower wall 436 of the embodiment is locked and prevented from moving into the liquid metal pool (e.g. Figure 3 in the liquid metal pool 312).

[0061] In the second embodiment 720, the third embodiment 730, the fourth embodiment 740, the fifth embodiment 750 and the sixth embodiment 760, the pin 702 can be fixed in place and prevented from moving into the pool of liquid metal by the brazing element. Fig.12 As further described, during assembly of a liquid metal bearing assembly equipped with a fill port, the pin 702 can be inserted into the fill port after the liquid metal is injected into the liquid metal flow path. In some embodiments, as further described herein, before the pin 702 is inserted into the fill port, the pin 702 can be coupled to a brazing element, and the construction of the brazing element can prevent the pin 702 from moving into the liquid metal pool. The second embodiment 720 includes a disk 722 as a brazing element and having a convex and flat circular top and bottom surfaces, wherein the disk 722 can rest on the inclined wall 432 of the smooth linear transition region 430, or the disk 722 can rest on the top surface 724 of the pin 702. In the third embodiment 730, the fastener 726 (such as reference FIG. 6A to FIG. 6B The washer 618 or brazing ring 628 described above may be used as a brazing element. The fastener 726 of the third embodiment 730 may rest on the top surface 724 of the pin 702. Similar to the fastener 726, the fourth embodiment 740 includes a coil, such as the one described in reference FIG. 6A to FIG. 6B The coil 612 described above may have an annular configuration relative to the central axis 746 and may rest on the top surface 724 of the pin 702. The fifth embodiment 750 includes a brazed ball, such as the one described with reference to FIG. 6A to FIG. 6B The solder ball 622 depicted may rest on the top surface 724 of the pin 702 and / or the oval disk may rest on the wall of the smooth linear transition region 430 (eg, Figure 4 As briefly described above, in the sixth embodiment 760, the pin 702 may extend from the lower region 420 through the smooth linear transition region 430 and extend into the upper region 410. The pin 702 may be surrounded by a coil (such as the coil 612 of the fourth embodiment 740). For example, the coil 612 in the sixth embodiment 760 may be placed between the pin 702 and the upper wall 434 of the upper region 410, at the intersection between the upper region 410 and the smooth linear transition region 430. For example, each of the brazing elements described herein with respect to the second plurality of embodiments 700 may be formed of a metal such as brass, pure copper, stainless steel, or formed of ceramic. For embodiments of the second plurality of embodiments 700 including the brazing element, the brazing element, the pin 702, and the filling port may be brazed to fix the pin 702 in the filling port and isolate the liquid metal pool from the outside of the liquid metal bearing assembly after the liquid metal is inserted into the liquid metal pool via the filling port.

[0062] Figure 8A first pin embodiment 800 is shown that can be welded or laser brazed into the second configuration 500 of the filler neck. In other words, the first pin embodiment 800 includes a cylindrical pin that fits into a stepped hole. Figure 8 In Figure 4 and Figure 5 The elements are numbered identically. The pin 802 of the first pin embodiment 800 can be configured as a plug, as shown in reference FIG. 7A to FIG. 7B The pin 802 is shown filled with vertical lines to distinguish it from the fill port. The pin 802 may have a first pin height 804 and a first pin diameter 806. Figure 5 As depicted, the fill port has an outlet diameter 404 in the second portion 504 of the lower region 420 and a step diameter 506 in the first portion 502 of the lower region 420. For example, the step configuration includes a corner 812 located at the intersection between the first portion 502 and the second portion 504 of the lower region 420. For example, the corner 812 can directly engage the pin 802 in a coplanar contact manner and be configured as a lip, a step, etc. The transition area between the smooth linear transition area 430 and the lower region 420 can have a step diameter 506, and the transition area between the first portion 502 and the second portion 504 can have an outlet diameter 404. The first pin diameter 806 can be smaller than the step diameter 506 and larger than the outlet diameter 404. In some embodiments, each of the fourth length 512 and the fifth length 514 can be equal, and the first pin height 804 can be larger than the fourth length 512 and the fifth length 514. The second portion 504 may have an outlet diameter 404 that is smaller than the first pin diameter 806 .

[0063] The pin 802 may be formed of a plastically deformable material such as metal, ceramic, plastic, rubber that is more deformable than the material of the filler port. In this manner, when the pin 802 is inserted into the lower region 420 of the filler port and a force is applied in the direction indicated by the arrow 810 to push the pin 802 further into the second portion 504 of the lower region 420 (e.g., to press fit the pin 802), the pin 802 may be plastically deformed to fit into the second portion 504. For example, the pin 802 may shear or lock with the wall (e.g., the lower wall 436) of the filler port in the lower region 420, such that the first pin diameter 806 is reduced to less than the outlet diameter 404. In some embodiments, the resulting interference of the pin 802 in the second portion 504 of the lower region may be 50 μm. Thus, the first pin embodiment 800 may have a sliding fit of a certain size to enable braze flow and guide the pin 802 into the second portion 504 of the lower region 420 (e.g., the interference region). After the pin 802 is press-fitted, the pin 802 can be additionally welded or laser brazed into the filler port. In some embodiments, the pin 802 can be brazed directly to the filler port without using an additional brazing element, or can include a brazing element, such as reference 802. FIG. 7A to FIG. 7B A brazing element is described.

[0064] Steering Fig. 9 , which shows a second pin embodiment 900 in which the pin has a stepped configuration and can be press-fit into a filler port having a stepped configuration. Fig. 9 In Figure 4 and Figure 5 The elements are numbered identically. The pin 902 of the second pin embodiment 900 can be configured as a plug, as shown in reference FIG. 7A to FIG. 7BDescribed. Pin 902 is shown filled with vertical lines to distinguish it from the filling port. Pin 902 can be configured to have a shape similar to the shape of the inside of the filling port. For example, pin 902 may include a tapered surface that can be placed in the smooth linear transition area 430 of the filling port 310, wherein the tapered surface of pin 902 has the same angle as the tapered surface of the filling port at the smooth linear transition area 430. In other words, pin 902 can be configured to have a corresponding surface relative to the filling port 310. Pin 902 includes an upper pin area 910, a lower pin area 920, and a smooth linear pin transition area 930 therebetween. Each of the upper pin area 910, the smooth linear pin transition area 930, and the lower pin area 920 is coupled to form a continuous body of pin 902. The lower pin area 920 may have a lower pin diameter. For example, the size of pin 902 is proportionally smaller than the size of the inside of the filling port. For example, the pin 902 has a third pin diameter 904 at the upper pin region 910. The diameter of the pin 902 in the smooth linear pin transition region 930 gradually transitions from the third pin diameter 904 (e.g., adjacent to the upper pin region 910) to the fourth pin diameter 906 (e.g., adjacent to the lower pin region 920). In some embodiments, the pin 902 may have a step transition region between the smooth linear pin transition region 930 and the lower pin region 920. For example, the diameter of the pin 902 at the intersection between the smooth linear pin transition region 930 and the lower pin region 920 may be the fourth pin diameter 906 at the smooth linear pin transition region 930 and the lower pin diameter 908 at the lower pin region 920. The third pin diameter 904 is smaller than the inlet diameter 402, and the fourth pin diameter 906 and the lower pin diameter 908 are smaller than the step diameter 506.

[0065] Additionally, the fill port may have a stepped configuration similar to the second configuration 500. Fig. 9 In the illustrated embodiment, the stepped configuration includes a corner 912 located at the intersection between the smooth linear transition region 430 and the lower region 420, which can directly engage the pin 902 in a coplanar contact manner and be configured as a lip, a step, etc. Figure 4 and Figure 5 As depicted, the fill port has an inlet diameter 402 in an upper region 410. The diameter of the fill port may gradually transition from the inlet diameter 402 to a stepped diameter 506 in a smooth linear transition region 430. Fig. 9In the configuration of FIG. 4 , the diameter of the fill port at the intersection between the smooth linear transition region 430 and the lower region 420 may be the step diameter 506 at the smooth linear transition region 430 and the outlet diameter 404 at the lower region 420. The corner 912 may extend the width 936 of the lower wall 436 of the lower region 420 toward the interior of the fill port and thus reduce the diameter of the fill port at the lower region 420 to the outlet diameter 404.

[0066] When the pin 902 is configured to have a fourth pin diameter 906 for the entire lower pin region 920 (e.g., the pin 902 is not stepped), the fourth pin diameter 906 can be plastically deformed and thereby reduced when the pin 902 is press-fitted into the filler port having the stepped configuration described herein. The plastic deformation of the pin 902 can create a flared interface between the pin 902 and the filler port, which can help form a seal between the pin 902 and the filler port to isolate the pool of liquid metal from the atmosphere and retain the pin 902 within the filler port. In other embodiments, the pin 902 can have a fourth pin diameter 906 as described herein. Fig. 9 4. The step configuration depicted in FIG. 4 shows a step configuration in which the lower pin diameter 908 may be smaller than the outlet diameter 404 of the lower region 420. Thus, the lower pin region 920 may be placed in the lower region 420 of the filler port without the pin 902 locking in the filler port. When inserted into the filler port, the pin 902 may rest on the sloped wall 432 of the smooth linear transition region 430.

[0067] The configuration of the pin 902 and the filler port having the stepped configuration described herein can allow the pin 902 and the filler port to self-align when the pin 902 is inserted into the filler port. For example, the walls of the upper region 410 of the filler port (e.g., upper wall 434) and the walls of the smooth linear transition region 430 (e.g., inclined wall 432) can guide the pin 902 into the filler port. The radial interference between the pin 902 and the walls of the filler port can help seal the pin 902 in place in the filler port. The pin 902 can also be press-fit into the filler port by applying a force in the direction indicated by the second arrow 916.

[0068] Fig.10 Another configuration 1000 of a pin configured as a plug is shown that can be press-fit into a filler port having a stepped configuration. For example, the filler port may have a reference Figure 5 The second configuration 500 described, with reference to Fig. 9 The step configuration described in the second pin embodiment 900 or another step configuration. Fig. 9 The filler step configuration of FIG. 1000 describes other configurations. Fig.10 In Fig. 9 Elements are numbered identically and may not be introduced again for the sake of brevity.

[0069] Similar to reference Fig. 9 Each of the described pin 902, tapered pin 1002, and round head pin 1004 can be configured as a plug having a shape similar to the inner shape of the filler port. For example, each of the tapered pin 1002 and round head pin 1004 includes an upper pin region 1010, a lower pin region 1020, and a smooth linear pin transition region 1030 therebetween. The diameter of each of the upper pin region 1010, the lower pin region 1020, and the smooth linear pin transition region 1030 can be as described with respect to the upper pin region 910, the lower pin region 920, and the smooth linear pin transition region 930 (e.g., relative to the diameter of the filler port).

[0070] The tapered pin 1002 is also provided with a welding preparation in the upper pin region 1010. Fig.10 As shown in , the weld preparation can be viewed as a right triangle extending from the upper pin area 1010 toward the inlet 318 of the filler port. Fig.10 A cross-sectional view of a fill port and a tapered pin 1002 disposed therein is shown, so the weld preparation can be a single weld preparation 1006 having an annular configuration with a right triangle cross section. The single weld preparation 1006 can be coupled to and extend from the top surface 1008 of the tapered pin 1002. In some embodiments, the right triangles of the single weld preparation 1006 can be separated by a distance 1012 (e.g., inside the annular configuration), which can be equal to the lower pin diameter 908 of the lower pin region 1020. In other embodiments, the weld preparation can include a plurality of weld preparations having a right triangle or other shaped cross section, which are radially arranged around the circumference of the top surface 1008 of the tapered pin 1002, with a space between each of the weld preparations. The weld preparation can be formed of the same material as the tapered pin 1002 (such as brass, pure copper, stainless steel, ceramic, etc.).

[0071] A flat top 1022 is provided in the upper pin region 1010 of the round head pin 1004. The flat top 1022 may have a first width 1024 and a first height 1026, wherein the first height 1026 is included in the height of the upper pin region 1010. The first width 1024 of the flat top 1022 may be greater than the width of the round head pin 1004 (e.g., the third pin diameter 904), such that the flat top 1022 extends radially wider than the upper pin region 1010. The flat top 1022 may be formed of the same material as the round head pin 1004 (such as brass, pure copper, stainless steel, etc.), and may be brazed to the ceramic.

[0072] Each of the tapered pin 1002 and the round head pin 1004 can be press-fitted into the filler port, such as by inserting the pin into the filler port and applying a force in the direction indicated by the third arrow 1014. Pressing the pin into the filler port (e.g., applying a force) can cause each of the tapered pin 1002 and the round head pin 1004 to plastically deform, thereby causing the top of the pin to flare outwardly so that the pin is in radial contact with the filler port. For example, when the tapered pin 1002 is press-fitted into the filler port, the distance 1012 between the right triangles of the individual weld preparations 1006 can increase, and the individual weld preparations 1006 (or in some embodiments, multiple weld preparations) can flare radially outwardly toward the upper wall 434 of the upper region 410 of the filler port so that radial contact occurs therebetween. When the round head pin 1004 is press-fitted into the filling port, the first width 1024 of the flat top 1022 can increase and the first height 1026 of the flat top 1022 can decrease, so that the flat top 1022 is radially outwardly expanded toward the upper wall 434 of the upper region 410 of the filling port to allow radial contact therebetween. The radial contact between the outwardly expanded portion of the tapered pin 1002 and the outwardly expanded portion of the round head pin 1004 (e.g., the weld preparation and the flat top, respectively) can reduce shear stress during the insertion of the corresponding pin. In addition, the increased interference between the corresponding pin and the filling port can facilitate welding or brazing the pin into the filling port to isolate the liquid metal pool from the atmosphere. In some embodiments, the flaring of the pin can provide contact for welding and / or for adding a press-fit seal (e.g., between the flat top 1022 of the round head pin 1004 and the inlet 318 of the filling port).

[0073] Fig.11 An embodiment 1100 of a pin 1102 is shown that is configured as a threaded fastener plug and / or a pin having radial interference in addition to a threaded fastener. The pin 1102 can be input into a fill port of a liquid metal bearing assembly, such as a fill port having a first configuration 400 (e.g., non-stepped) and / or having a second configuration 500 (e.g., stepped). Fig.11 The description is directed to a filler port having a first configuration 400, and thus includes Fig.11 In Figure 4 The elements of are numbered identically and are not re-introduced for the sake of brevity. The configuration of pin 1102 can radially seal pin 1102 into the fill port so that the liquid metal pool is isolated from the exterior of the liquid metal bearing assembly. For example, the configuration of pin 1102 can be similar to FIG. 6A to FIG. 6BThe pin 1102 may have a stepped body such that a lower plug extension 1104 of the stepped body extends through a smooth linear transition region 430 and into the lower region 420, and an upper plug extension 1106 is disposed in the upper region 410. The upper plug extension 1106 is also provided with a plurality of threads 1108 extending radially from the upper plug extension 1106. The plurality of threads 1108 may be circumferential ridges spaced apart along the upper region 410 with some axial spacing therebetween (e.g., between each of the plurality of threads 1108). In a first embodiment 1110 of the pin 1102, the lower plug extension 1104 has a first plug diameter 1114, and the upper plug extension 1106 has a first upper extension diameter 1116.

[0074] After the pin 1102 is inserted into the filler port, the diameter of the upper plug extension 1106 can increase. For example, the first upper extension diameter 1116 can increase to a second upper extension diameter 1118, as shown in the second embodiment 1120, wherein the second upper extension diameter 1118 is greater than the first upper extension diameter 1116. In some embodiments, the diameter of the upper plug extension 1106 can increase according to the Poisson's ratio, or a third body can be used to deform the upper plug extension 1106 outward (e.g., toward the upper wall 434). When the pin 1102 is compressed axially (e.g., along the x-axis relative to the coordinate system 320), the pin 1102 plastically deforms radially to the second upper extension diameter 1118, so that radial interference occurs between the plurality of threads 1108 and the upper wall 434. The plurality of threads 1108 can thus form a seal (e.g., a secondary gallium seal) between the pin 1102 and the filler port without shearing either component, which helps retain the pin 1102 in the filler port. In other embodiments, the wall of the upper region 410 can be provided with a corresponding threaded connection so that the pin 1102 can be screwed into the upper region 410 of the filler port after being inserted into the filler port (e.g., the lower region 420). For example, the plurality of threads 1108 and the corresponding threaded connection can be configured to directly engage each other in a coplanar contact manner. In this way, the pin 1102 can be used as a radial sealing pin to isolate the liquid metal pool from the exterior of the liquid metal bearing assembly. Fig.12 A method for assembling a liquid metal bearing assembly such as Figure 3 As briefly described above, the liquid metal bearing assembly can be implemented in a system such as an x-ray imaging system. When combined with a rotor and a stator (e.g. Figure 2 When the liquid metal bearing assembly is coupled to a rotating component (e.g., a rotor 218 and a stator 220), the liquid metal bearing assembly can provide a liquid metal bearing assembly coupled to a rotating component (e.g., Figure 3The method 1200 is described herein for liquid metal bearing assembly 300, however, the method 1200 may be used to assemble other liquid metal bearing assemblies having a filling port arranged radially in a rotating component relative to a centerline of the bearing.

[0075] At 1202, method 1200 includes inserting the shaft of the liquid metal bearing assembly into the sleeve of the liquid metal bearing assembly. For example, the sleeve can be formed as a hollow cylinder, and the shaft can be inserted from the second end of the sleeve (e.g., second end 328) and extend through the first end of the sleeve (e.g., first end 326). In some embodiments, a flange may be provided at one end of the shaft, which prevents the shaft from passing through the sleeve all the way. A sleeve cover may be coupled to the second end of the sleeve to close the flange of the shaft and thus enclose the shaft in the sleeve. Inserting the shaft into the sleeve may form a liquid metal pool therebetween. When the pin is not placed in the filling port, the liquid metal pool may be fluidly coupled to the atmosphere (e.g., exterior 352) of the liquid metal bearing assembly via the filling port. In this way, the elements of the liquid metal bearing assembly may be assembled before the liquid metal is introduced into the liquid metal pool. This may allow the rotary seal and the compression seal to remain intact during the assembly of the liquid metal bearing assembly.

[0076] At 1204, method 1200 includes injecting a lubricant into the liquid metal pool via a filling port disposed in a rotating member (e.g., a sleeve) of the liquid metal bearing assembly, thereby filling the liquid metal pool of the liquid metal bearing assembly with a lubricant (e.g., liquid metal). In some embodiments, such as the embodiments described herein, the lubricant is a liquid metal, such as gallium. In other embodiments, the liquid metal may include tin, indium, a combination thereof, and the like. The liquid metal may be distributed into the liquid metal pool by inserting a needle or other dispensing device into the filling port and injecting the liquid metal, pouring the liquid metal into the filling port, and the like. Different methods for distributing the lubricant into the liquid metal pool may depend on the type of lubricant, the orientation of the liquid metal bearing assembly (e.g., the orientation of the bearing centerline relative to the direction of gravity), and the like. The lubricant (e.g., liquid metal) may fill the liquid metal pool, and for the liquid metal flow path (e.g., gap 316), it may not flow into the gap between the shaft and the sleeve downstream of the liquid metal pool. For example, the size of the liquid metal (e.g., gallium) beads may be larger than the width of the gap (e.g., the distance between the shaft and the sleeve). Therefore, the liquid metal distributed into the liquid metal pool via the filling port may be partially arranged in the channel (e.g., channel 314) between the liquid metal pool and the gap, and may not flow into the gap to form a force-bearing surface.

[0077] At 1206, method 1200 optionally includes heating the liquid metal bearing assembly. Heating the liquid metal bearing assembly can increase the reactivity of the surfaces of the shaft and sleeve and increase capillary forces inside the sleeve that pull gallium into the gap between the shaft and sleeve.

[0078] At 1208, method 1200 includes sealing the liquid metal pool from the atmosphere (e.g., exterior 352 of the liquid metal bearing assembly) by inserting a pin into a fill port of the liquid metal bearing assembly. The pin may be configured as a ball bearing, as described in reference FIG. 6A to FIG. 6B described, or may be configured as a plug, as described in reference FIG. 7A to FIG. 11 The fill port may have a first configuration, such as that described in reference Figure 4 The first configuration 400 described, or having a second configuration, such as reference Figure 5The second configuration 500 described. The size of the filling port and the pin can be such that the liquid metal pool is partially or completely isolated from the outside of the liquid metal bearing assembly when the pin is inserted into the filling port. In some embodiments, a brazing element (e.g., a coil, a brazing bead, a brazing ball, a washer, and a brazing ring) can be coupled to (e.g., brazed to) the pin before the pin is inserted into the filling port. The configuration of the brazing element prevents the pin from moving into the liquid metal pool. Additionally or alternatively, the configuration of the pin and the filling port prevents the pin from moving into the liquid metal pool. For example, the filling port can be provided with a self-aligning feature (e.g., an inlet diameter, a smooth linear transition region, and an outlet diameter) that allows the pin to be placed in the filling port without locking during the insertion of the pin. In some embodiments, the filling port can combine a sliding radial interference fit with an optional axial compression (e.g., a step diameter and an outlet diameter at a second portion of the lower region of the filling port).

[0079] At 1210, method 1200 includes securing a pin in a fill port of a liquid metal bearing assembly. FIG. 6A to FIG. 11 As described, securing the pin may include brazing a brazing element to the pin and the filler port, laser welding the pin in the filler port, screwing a threaded fastener coupled to the pin into the filler port, and / or press-fitting the pin to place the pin in the filler port by locking the pin with a wall of the filler port and / or plastically deforming the pin.

[0080] At 1212, method 1200 includes heating the liquid metal bearing assembly. Heating the liquid metal bearing assembly can increase the reactivity of the surfaces of the shaft and the sleeve and increase the capillary force inside the sleeve, which pulls the gallium into the gap between the shaft and the sleeve. The entire volume of liquid metal in the liquid metal pool can flow into the gap, thereby creating a force-bearing surface at the gap, which can allow the sleeve to rotate uninterruptedly relative to the shaft. Method 1200 ends.

[0081] In this way, degradation of the seals of the liquid metal bearing assembly due to pouring of liquid metal during assembly can be reduced. The liquid metal can be arranged in the liquid metal bearing assembly (e.g., a liquid metal pool) via a radially arranged filling port in the rotating part of the liquid metal bearing assembly. The pin can be placed in the radially arranged filling port and sealed therein via press fit and welding or brazing to isolate the liquid metal pool and therefore the interior of the liquid metal bearing assembly from the outside of the liquid metal bearing assembly. The technical effects of the liquid metal bearing assembly structure described herein may include reduced leakage of liquid metal through the compression seal of the bearing and / or increased filling of the liquid metal pool to extend the service life of the bearing. Compared with conventional structures, the manufacture of the liquid metal bearing assembly can be simplified, and specifically, the number of available liquid metal bearing assemblies manufactured using the method described herein can be greater than the number of available liquid metal bearing assemblies manufactured using a method including inserting a shaft into a sleeve at high pressure.

[0082] Figures 2 to 11 An exemplary configuration showing the relative position of various components is shown. In at least one example, if shown as being in direct contact or directly coupled to each other, such elements may be referred to as being in direct contact or directly coupled, respectively. Similarly, in at least one example, elements shown as being adjacent or adjacent to each other may be adjacent or adjacent to each other, respectively. For example, components placed in coplanar contact with each other may be referred to as being in coplanar contact. For another example, in at least one example, elements positioned to be spaced apart from each other and having only space therebetween without other components may be described and referenced as such. For another example, elements shown as being located above / below each other, located on opposite sides, or located on the left / right sides of each other may be described and referenced as such relative to each other. In addition, as shown in the figure, in at least one example, the topmost element or the point of the element may be referred to as the "top" of the component, and the bottommost element or the point of the element may be referred to as the "bottom" of the component. As used herein, top / bottom, upper / lower, above / below may be relative to the vertical axis of the figure, and may be used to describe the position of the elements relative to each other in the figure. Thus, in one example, elements shown as being above other elements are positioned vertically above other elements. For another example, the shapes of the elements depicted in the figures may be referred to as having those shapes (e.g., such as being round, straight, planar, curved, rounded, chamfered, angled, etc.). In addition, in at least one example, elements shown as intersecting each other may be referred to as intersecting elements or intersecting each other. In addition, in one example, elements shown as being within another element or being shown as being outside another element may be described and referenced as such.

[0083] The present disclosure also provides support for a liquid metal bearing assembly, the liquid metal bearing assembly comprising: a fill port, the fill port is fluidly coupled to a liquid metal pool of the liquid metal bearing assembly, the fill port having an inlet diameter and an outlet diameter, the outlet diameter being smaller than the inlet diameter; and a pin shaped to fit within the fill port and prevent liquid metal from leaving the liquid metal pool. In a first example of the system, the system further comprises: a rotating component and a fixed component, wherein the rotating component at least partially circumferentially surrounds the fixed component, and the liquid metal pool is formed as a second radial distance between the rotating component and the fixed component. In a second example of the system that optionally includes the first example, the fill port is arranged in the rotating component at a first radial distance from the centerline of the bearing. In a third example of the system that optionally includes one or both of the first and second examples, the outlet diameter of the fill port is placed between the inlet diameter of the fill port and the liquid metal pool of the liquid metal bearing assembly. In a fourth example of the system, which optionally includes one or more or each of the first to third examples, the inlet diameter and the outlet diameter are coupled by a smooth linear transition zone, and the diameter of the smooth linear transition zone gradually transitions from the inlet diameter to the outlet diameter. In a fifth example of the system, which optionally includes one or more or each of the first to fourth examples, the pin is configured as a ball bearing. In a sixth example of the system, which optionally includes one or more or each of the first to fifth examples, the pin is configured as a plug. In a seventh example of the system, which optionally includes one or more or each of the first to sixth examples, the pin is press-fit, brazed and / or welded into the filling port. In an eighth example of the system, which optionally includes one or more or each of the first to seventh examples, the liquid metal bearing assembly is a straddle bearing. In a ninth example of the system, which optionally includes one or more or each of the first to eighth examples, each of the filling port and the pin includes a self-aligning feature to allow the pin to be press-fitted into the filling port. In a tenth example of the system which optionally includes one or more or each of the first to ninth examples, the self-aligning feature of the pin includes an undercut in the pin geometry and / or radial expansion of the body of the pin via a knife-edge member.

[0084] The present disclosure also provides support for a method, the method comprising: injecting lubricant into a liquid pool of a liquid metal bearing via a filling port in a rotating member of the liquid metal bearing, thereby filling the liquid pool with lubricant, and sealing the liquid pool from the atmosphere by inserting a pin into the filling port. In a first example of the method, the method further comprises: welding, brazing and / or press-fitting the pin into the filling port. In a second example of the method that optionally includes the first example, the method further comprises: applying a wetting coating or an anti-wetting coating to at least one of the filling port or the pin.

[0085] The present disclosure also provides support for an imaging system, the imaging system comprising: a cathode, an anode having a rotating feature, wherein the rotating feature is rotated by a liquid metal bearing assembly having a rotating component circumferentially surrounding a fixed component, the rotating component including a filling port positioned at a radial distance from the rotation axis of the liquid metal bearing assembly, and wherein the lubricant pool of the liquid metal bearing assembly can be selectively isolated from the atmosphere by inserting a pin into the filling port. In a first example of the system, the filling port has: an upper region having an inlet diameter; a lower region having an outlet diameter less than the inlet diameter; and a smooth linear transition region coupling the upper region to the lower region, wherein the diameter of the smooth linear transition region gradually transitions from the inlet diameter adjacent to the upper region to the outlet diameter adjacent to the lower region. In a second example of the system that optionally includes the first example, the lower region is provided with a first portion and a second portion, the first portion having an outlet diameter, the second portion having a second diameter less than the outlet diameter, and a stepped transition region between the first portion and the second portion. In a third example of the system, which optionally includes one or both of the first and second examples, the pin is configured as a ball bearing that is press-fit and optionally welded or brazed into the filler port using at least one of a coil, a washer, a brazing ring, a brazing ball, and a plurality of brazing beads. In a fourth example of the system, which optionally includes one or more or each of the first to third examples, the pin is configured as a plug that is press-fit and optionally welded or brazed into the filler port using at least one of a disk, a washer, a coil, a brazing ring, and a brazing ball. In a fifth example of the system, which optionally includes one or more or each of the first to fourth examples, the pin has at least one of a stepped configuration and a press-fit configuration, the stepped configuration having a first plug height having a first plug width and a second plug height having a second plug width, the second plug width being smaller than the first plug width, the press-fit configuration having an upper pin region having an upper pin diameter, a lower pin region having a lower pin diameter, and a smooth linear pin transition region, wherein the diameter of the smooth linear pin transition region gradually transitions from an upper pin diameter adjacent to the upper pin region to a lower pin diameter adjacent to the lower pin region, and optionally includes radial threads located in the upper pin region.

[0086] As used herein, the element or step that is listed in the singular and begins with the word "one" or "an" should be understood as not excluding a plurality of the elements or steps, unless such exclusion is explicitly stated. In addition, the reference to "an embodiment" of the present invention is not intended to be interpreted as excluding the existence of the additional embodiment that also includes the quoted feature. In addition, unless explicitly stated to the contrary, the embodiment of "including", "comprising" or "having" the element or multiple elements with a specific characteristic may include additional such elements without the characteristic. The terms "including" and "in..." are used as the concise language equivalents of the corresponding terms "including" and "wherein". In addition, the terms "first", "second" and "third" etc. are only used as marks, and are not intended to impose numerical requirements or specific position order on their objects.

[0087] This written description uses examples to disclose the invention, including the best mode, and also to enable a person skilled in the relevant art to practice the invention, including making and using any devices or systems and performing any included methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to a person skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insignificant differences from the literal language of the claims.

Claims

1. A liquid metal bearing assembly (300), comprising: a fill port (310) fluidly coupled to a pool of liquid metal (312) of a liquid metal bearing assembly, the fill port having an inlet diameter (402) and an outlet diameter (404), the outlet diameter being smaller than the inlet diameter; and A pin (602, 702, 802, 902, 1002, 1004, 1102) is shaped to fit within the fill port and prevent liquid metal from leaving the pool of liquid metal via the fill port.

2. The liquid metal bearing assembly according to claim 1, further comprising a rotating component (302) and a fixed component (304), wherein: The rotating component at least partially circumferentially surrounds the stationary component, and the pool of liquid metal is formed a second radial distance (324) between the rotating component and the stationary component.

3. The liquid metal bearing assembly according to claim 2, wherein: The fill port is disposed in the rotating component at a first radial distance (322) from a bearing centerline.

4. The liquid metal bearing assembly according to claim 3, wherein: The filling port is arranged perpendicular to the center line of the bearing.

5. The liquid metal bearing assembly according to claim 3, wherein: The filling port is arranged parallel to the center line of the bearing.

6. The liquid metal bearing assembly according to claim 1, wherein: The fill port also includes a step diameter (506) between the inlet diameter and the outlet diameter, the step diameter being larger than the outlet diameter and smaller than the inlet diameter.

7. The liquid metal bearing assembly according to claim 1, wherein: The pin is configured as at least one of a ball bearing or a plug.

8. The liquid metal bearing assembly according to claim 1, wherein: The pin is press-fitted, brazed and / or welded into the filler neck.

9. The liquid metal bearing assembly according to claim 1, wherein: The liquid metal bearing assembly is a straddle bearing.

10. The liquid metal bearing assembly according to claim 1, wherein: Each of the filler port and the pin includes a self-aligning feature to allow a press-fit insertion of the pin into the filler port.

11. The liquid metal bearing assembly according to claim 10, wherein: The self-aligning features of the pin include an undercut in the pin geometry and / or radial expansion of the body of the pin via a knife edge member.

12. A method comprising: filling the sump of the liquid metal bearing with the lubricant by injecting the lubricant into the sump through a fill port in a rotating member of the liquid metal bearing; as well as The sump is sealed from the atmosphere by inserting a pin into the fill port.

13. The method of claim 12, further comprising welding, brazing and / or press fitting the pin into the filler neck to retain the pin within the filler neck.

14. The method of claim 12, further comprising applying a wetting coating or an anti-wetting coating to at least one of the fill port or the pin.

15. The method of claim 12, further comprising rotating a rotating feature of an anode of an x-ray source by rotating the rotating member of the liquid metal bearing assembly.

Images