System and method of filling ports and plugs for liquid metal bearing assemblies

Abstract

To provide various methods and systems for a liquid metal bearing assembly.SOLUTION: A liquid metal bearing assembly includes: a fill port fluidly coupled to a liquid metal reservoir of the liquid metal bearing assembly, the fill port including an inlet diameter and an outlet diameter, the outlet diameter smaller than the inlet diameter; and a pin formed to fit the inside of the fill port and prevent liquid metal from leaving the liquid metal reservoir via the fill port.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] Embodiments of the subject matter disclosed herein relate to systems comprising a liquid metal bearing assembly and methods of assembling a liquid metal bearing assembly.

Background Art

[0002] Liquid metal bearings are used in various operating environments because they have a longer lifespan and can manage thermal loads more effectively compared to roller bearings. For example, certain x-ray sources or x-ray tubes utilize a liquid metal bearing assembly that includes at least one liquid metal bearing. However, an asymmetric distribution of the liquid metal and gas formation at the bearing’s liquid metal interface can occur within the bearing.

Summary of the Invention

[0003] In one embodiment, a liquid metal bearing assembly includes a fill port fluidly coupled to a liquid metal reservoir 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 fitted inside the fill port and configured to prevent liquid metal from exiting the liquid metal reservoir through the fill port.

[0004] It should be understood that the above brief description is provided to introduce, in a simplified form, a selection of concepts that are further described in the detailed description. This is not intended to identify key features or essential features of the claimed subject matter, the scope of which is uniquely defined by the claims that follow the detailed description. Further, the claimed subject matter is not limited to embodiments 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. [Figure 1] This is a schematic block diagram of an exemplary X-ray imaging system according to an embodiment. [Figure 2] This is a pictorial perspective view of a portion of an X-ray source according to an embodiment. [Figure 3] A first exemplary liquid metal bearing assembly according to an embodiment is shown. [Figure 4] A first embodiment of a filling port for a liquid metal bearing assembly is shown according to the embodiment. [Figure 5] A second embodiment of the filling port of a liquid metal bearing assembly is shown according to the embodiment. [Figure 6A] The following are some first embodiments relating to pins configured as ball bearings for filling ports of liquid metal bearing assemblies, according to the embodiments. [Figure 6B] The following are some first embodiments relating to pins configured as ball bearings for filling ports of liquid metal bearing assemblies, according to the embodiments. [Figure 7A] The following are some second embodiments relating to a pin configured as a plug for a filling port of a liquid metal bearing assembly, according to the embodiment. [Figure 7B] The following are some second embodiments relating to a pin configured as a plug for a filling port of a liquid metal bearing assembly, according to the embodiment. [Figure 8] A first embodiment of a pin seated in the filling port of the liquid metal bearing assembly shown in Figure 3 is presented according to the embodiment. [Figure 9] A second embodiment of a pin seated in the filling port of the liquid metal bearing assembly shown in Figure 3 is presented according to the embodiment. [Figure 10] A third set of embodiments is shown for a pin that seats in the filling port of the liquid metal bearing assembly shown in Figure 3. [Figure 11]A fourth embodiment of a pin seated in the filling port of the liquid metal bearing assembly shown in Figure 3 is presented according to the embodiment. [Figure 12] This document describes the assembly method for liquid metal bearing assemblies.

[0006] The following description relates to various embodiments of liquid metal bearing assemblies, more specifically to filling ports of liquid metal bearing assemblies and pins that may be located therein. Liquid metal bearing assemblies may be included in X-ray sources of X-ray imaging systems, and an example of a block diagram thereof is shown in Figure 1. One embodiment of an X-ray source is shown in Figure 2, which comprises a liquid metal bearing assembly that enables rotation of the anode of the X-ray source. For illustrative purposes, liquid metal bearing assemblies are described herein in relation to X-ray sources of X-ray imaging systems, and liquid metal bearing assemblies may be implemented in other systems, such as computed tomography (CT) imaging systems, without departing from the scope of this disclosure. Figure 3 shows one embodiment of the liquid metal bearing assembly of Figure 2, which comprises a rotating sleeve and a stationary shaft. Figure 4 shows a first embodiment of a filling port located in the rotating sleeve of the liquid metal bearing assembly of Figure 3. Figure 5 shows a second embodiment of a filling port. The positioning and configuration of filling ports described herein may enable a method for assembling liquid metal bearing assemblies that can reduce the deterioration of seals and other elements of the liquid metal bearing assembly compared to conventional assembly methods. Figures 6A–611 show several embodiments of pins that can be inserted into filling ports and several methods for sealing the filling ports with the pins to reduce leakage of liquid metal from the liquid metal bearing assembly during assembly and operation. Figure 12 is a diagram showing a method for assembling a liquid metal bearing assembly, which includes inserting and sealing the filling ports with pins following the insertion of liquid metal into the liquid metal bearing assembly. Figures 2–11 are shown to approximately scale, but other relative dimensions may be used.

[0007] Conventional methods for assembling liquid metal bearing assemblies configured as straddle bearings involve exposing the seals of the liquid metal bearing assembly and introducing the liquid metal, for example, by spilling liquid metal over the seals. Furthermore, the liquid metal bearing assembly can be assembled in a orientation such that the axis of rotation of the liquid metal bearing assembly is parallel to the direction of gravity. When mounted on an X-ray source or X-ray tube, the liquid metal bearing assembly may be positioned horizontally so that the axis of rotation is perpendicular to the direction of gravity. In addition or alternatively, when mounted on an X-ray source or X-ray tube, the liquid metal bearing assembly may be positioned at an angle that is not parallel to the direction of gravity. For example, an X-ray source or X-ray tube may be incorporated into a moving structure such as a rotating gantry of a CT imaging system. The conventional assembly methods described above can lead to seal degradation, incomplete coating of the liquid metal channels forming the bearing surface, leakage of liquid metal from the liquid metal bearing assembly, and a reduced usable life of the liquid metal bearing assembly. In liquid metal bearing assemblies, such as those configured as straddle bearings, there is a need for systems and methods that can introduce liquid metal to form the bearing surface without contaminating the seals.

[0008] This specification describes a system and method for a liquid metal bearing assembly having a filling port coupled to a liquid metal reservoir of the liquid metal bearing assembly, wherein the filling port is located within the rotating element of the liquid metal bearing assembly, at a radial distance from the bearing centerline. 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 further includes a stepped diameter between the inlet diameter and the outlet diameter, wherein the stepped diameter may be smaller than the inlet diameter and larger than the outlet diameter. In further embodiments, the inlet diameter may be equal to the outlet diameter. Furthermore, the liquid metal bearing assembly comprises a pin that fits inside the filling port and is formed to prevent liquid metal from flowing out of the liquid metal reservoir through the filling port. For example, in embodiments where the outlet diameter is smaller than the inlet diameter, or where the inlet and outlet diameters are equal, a pin having a constant diameter or a stepped diameter may be placed inside the filling port. In embodiments where the filling port includes a stepped diameter, a pin having a constant diameter or a stepped diameter may be placed inside the filling port. Technical advantages of the systems disclosed herein for liquid metal bearing assemblies may include retention of liquid metal during operation of the liquid metal bearing assembly (e.g., during operation of the system in which the liquid metal bearing assembly is implemented), retention of pins in filling ports, and reduction of deterioration of seals and other elements of the liquid metal bearing assembly during assembly and operation.

[0009] Before further describing liquid metal bearing assemblies having a filling port and a pin formed to fit into the filling port, an exemplary imaging system in which a liquid metal bearing assembly may be implemented is shown. Figure 1 shows an X-ray imaging system 100 designed to generate X-rays. In Figure 1, the X-ray imaging system 100 is configured as an X-ray imaging system that could be a computed tomography (CT) imaging system, a radiography imaging system, a fluoroscopy imaging system, a mammography imaging system, an interventional imaging system, a tomography system, etc. However, the X-ray imaging system 100 is applicable to fields other than diagnostic imaging and medical devices. For example, the X-ray imaging system 100 may be deployed in crystallography systems, security scanners, industrial scanners, x-ray photography systems, etc. In an example of an imaging system, the system can be configured to image subjects 102 such as a patient, an inanimate object, one or more manufactured parts, and / or foreign objects present in the body, such as implants, stents, and / or contrast agents.

[0010] 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 emission beam 106. Specifically, in the illustrated embodiment, the X-ray source 104 is configured to project the X-ray emission beam 106 towards a detector array 108 through a subject 102. In some system configurations, the X-ray source 104 can project a collimated conical X-ray emission beam located in the XYZ plane of the Cartesian coordinate system. However, other beam profiles and / or systems without a detector array are also envisioned. Each detector element of the array generates a separate electrical signal, which is a measurement of the X-ray beam attenuation at the detector location.

[0011] Although Figure 1 depicts only a single X-ray source 104 and detector array 108, in certain embodiments, multiple X-ray sources and / or detectors may be employed to project and detect multiple X-ray beams. For example, in the use of a CT scanner, multiple detectors can be used in parallel with the X-ray source to acquire projection data at different energy levels corresponding to the subject.

[0012] The X-ray imaging system 100 may further include an X-ray controller 110 configured to supply power and timing signals to the X-ray source 104. It will be understood that the system may also include a data acquisition system configured to sample analog data received from a detector element and convert the analog data into a digital signal for subsequent processing.

[0013] In certain embodiments, the X-ray imaging system 100 may further include a computing device 112 having a processor 114 that controls system operation based on operator input. The computing device 112 receives operator input, including commands and / or scanning parameters, for example, via an operator console 116 operably coupled to the computing device 112. The operator console 116 may include a keyboard, a touchscreen, and / or other suitable input devices that enable the operator to specify commands and / or scanning parameters.

[0014] Although only one operator console 116 is illustrated in Figure 1, the X-ray imaging system 100 may include multiple operator consoles for, for example, inputting or outputting system parameters, requesting examinations, plotting data, and / or viewing images. Furthermore, in certain embodiments, the X-ray imaging system 100 may be coupled to multiple displays, printers, workstations, and / or similar devices, which are located either locally or remotely and connected via wired and / or wireless networks. In one embodiment, a display 120 can electronically communicate with a computing device 112 and is configured to display a graphical interface showing system parameters, control settings, imaging data, etc.

[0015] In one example, the computing device 112 stores data in a storage device 118. The storage device 118 may include, for example, a hard disk drive, a floppy disk drive, a compact disc read / write (CD-R / W) drive, a digital multipurpose disc (DVD) drive, a flash drive, and / or a solid-state storage drive.

[0016] Furthermore, the computing device 112 provides commands to the x-ray controller 110 and other system components to control system operations such as x-ray beam formation, data collection, and / or processing. Thus, in certain embodiments, the computing device 112 controls system operations based on operator input. More specifically, the computing device 112 can operate the x-ray controller 110 using commands and parameters supplied by the operator and / or defined within the system, and this controller 110 can control the x-ray source 104. In this way, the intensity and timing of x-ray beam generation can be controlled. It will also be appreciated that the rotational speed of the sleeve within the x-ray source is adjusted by the computing device 112 in conjunction with the x-ray controller 110. The sleeve may be a rotating element of a liquid metal bearing assembly, as will be described in more detail herein.

[0017] Various methods and processes can be stored as executable instructions on a non-transitory memory on a computing device (or controller) within the x-ray imaging system 100. In one embodiment, the x-ray controller 110 can include executable instructions in a non-transitory memory and can apply the method to control the x-ray source 104. In another embodiment, the computing device 112 includes instructions in a non-transitory memory and can at least partially relay the instructions to the x-ray controller 110 that adjusts the x-ray source output.

[0018] Figure 2 shows a detailed embodiment of some X-ray sources, such as the X-ray tube 200. The X-ray tube 200 shown in Figure 2 functions as an example of the X-ray source 104 depicted in Figure 1. Thus, not only the X-ray source shown in Figure 2, but also other embodiments of X-ray sources described herein may include functional and / or structural features from the X-ray source 104 shown in Figure 1, and vice versa. Furthermore, alternative embodiments combining features from one or more systems are also envisioned. A rotation axis 250, along with a radial axis 252, is provided in Figure 2 for reference. It will be understood that the radial axis is any axis perpendicular to the rotation axis 250.

[0019] The X-ray tube 200 includes a housing 202 having a low-pressure enclosure 204 (e.g., a vacuum enclosure) formed therein. It will be understood that the low-pressure enclosure is intended to have a relatively low pressure relative to atmospheric pressure. Therefore, the pressure inside the enclosure may be lower than atmospheric pressure.

[0020] The X-ray tube 200 includes a liquid metal bearing assembly 205 having a rotating component 208 and a stationary component 206. In the illustrated embodiment, the rotating component 208 is a sleeve and the stationary component 206 is a shaft. However, embodiments where the sleeve is stationary and the shaft rotates are also envisioned. It will be understood that the motions indicated by the descriptors stationary and rotating refer to the relative motion between the components. However, in some use cases, the X-ray tube may be incorporated into a movable structure. For example, in the case of a CT imaging system, the X-ray tube may be incorporated into a rotating gantry. Thus, in a smaller scale frame of reference, the shaft is stationary relative to the sleeve, but in a larger scale frame of reference, both components exhibit similar rotational motion within the gantry. However, in another use scenario, the X-ray tube may be integrated into a stationary structure with respect to a larger scale frame of reference. Also, it will be understood that the liquid metal bearing assembly, described in more detail herein, may in some cases be deployed in another type of system that utilizes liquid metal bearings.

[0021] A rotor 218 and a stator 220 are also provided in the X-ray tube 200. The rotor 218 is coupled to the rotating member 208 and is designed to impart rotational motion thereto. The stator 220 is shown disposed outside the low-pressure enclosure 204. However, other suitable stator positions are envisioned. Typically, the rotor and stator can include windings, magnets, electrical connections, etc., and interact electromagnetically to generate rotor rotation in response to, for example, control commands from the X-ray controller 110 shown in FIG. 1.

[0022] The X-ray tube 200 further includes an anode 210 and a cathode 212. The anode 210 is coupled to a rotational component 208, which can impart rotation to the anode 210 during X-ray beam generation. The cathode 212 is part of the cathode assembly and can receive signals from a controller, such as the X-ray controller 110 shown in Figure 1, to generate an electron beam toward the surface of the anode 210. When the electron beam from the cathode 212 collides with the anode 210, an X-ray beam 214 is generated. The X-rays are emitted through an X-ray window 216 within the housing 202.

[0023] Turning to the liquid metal bearing assembly 205, multiple liquid metal bearings can constitute 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 can be supplied with liquid metal by a liquid metal reservoir, as described with respect to Figure 3. However, in other embodiments, assembly 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., the rotating part 208) can be managed to enable efficient rotation of the sleeve.

[0024] Each bearing in 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, the manufacturing tolerances of the components, and the expected system operating temperature. Thus, in one use case, the thickness of the liquid metal interface can be on the order of 5 microns (μm) to 40 μm. The thickness of the liquid metal interface of the liquid metal journal bearing 222 may be radial (e.g., with respect to the radial axis 252) of the liquid metal bearing assembly 205, and the thickness of the liquid metal interface of the liquid metal thrust bearing 224 may be radial and axial parallel to the rotation axis 250 of the liquid metal bearing assembly 205. The liquid metal used as the working fluid of the bearing assembly may include gallium, tin, indium, or combinations thereof. Embodiments of liquid metal bearing assemblies described herein with respect to Figures 3 to 11 may use gallium as the liquid metal lubricant.

[0025] Figure 3 illustrates one embodiment of the liquid metal bearing assembly 300. In some examples, the liquid metal bearing assembly 300 is similar to, or may be identical to, the liquid metal bearing assembly 205 depicted in Figure 2. Thus, features from the bearing assembly 205, more generally from the X-ray tube 200, may be included in the liquid metal bearing assembly 300, as with other embodiments of the liquid metal bearing assembly described herein. An axis system 320 is provided for reference in Figure 3 and Figures 3 to 11. In one example, the y-axis may be the vertical axis (for example, parallel to the direction of gravity while the liquid metal bearing assembly 300 is mounted on an X-ray source of an imaging system such as the X-ray imaging system 100 described above with reference to Figure 1), the x-axis may be the horizontal axis (for example, the horizontal axis), and the z-axis may be the vertical axis. However, the axes may have other orientations in other embodiments.

[0026] The liquid metal bearing assembly 300 includes a rotating part which may be referred to herein as a sleeve 302 and a stationary part which may be referred to herein as a shaft 304. The sleeve 302 and the shaft 304 may be coupled such that the sleeve 302 is rotatable relative to the shaft 304. Each of the sleeve 302 and the shaft 304 is configured to have a structure that forms a liquid metal flow path when the liquid metal bearing assembly 300 is assembled, as shown in Figure 3 (e.g., the shaft 304 surrounded by the sleeve 302). The liquid metal flow path may include a filling port 310, a liquid metal reservoir 312 (e.g., a lubricant reservoir), a flow path 314, and a gap 316. The filling port 310 is machined as part of the sleeve 302 or formed together with the sleeve 302 (e.g., integrally molded) and is located radially away from the bearing centerline. For example, the bearing centerline may be a rotational axis 350 corresponding to the rotation axis 250 in Figure 2. The filling port 310 may be positioned at a first radial distance 322 from the rotational axis 350. In some embodiments, the filling port 310 may be positioned linearly aligned with the rotational axis 350 (for example, parallel to the rotational axis 350, or positioned along the rotational axis 350). The filling port 310 may be positioned parallel to the rotational axis 350 or perpendicular to the rotational axis 350. For example, as shown in Figure 3, the filling port 310 is perpendicular to the rotational axis 350, and the inlet 318 of the filling port 310 is on the first side surface 338 of the liquid metal bearing assembly 300. In other embodiments not shown in Figure 3, the filling port 310 may be oriented parallel to the rotational axis 350, with the inlet 318 of the filling port 310 formed on the surface of the first end 326 of the sleeve 302.

[0027] In some embodiments, the liquid metal bearing assembly 300 may be configured to have two or more filling ports. For example, the liquid metal bearing assembly 300 may include a filling port 310 on the first radial side of the sleeve 302 and further include a second filling port (not shown) directly opposite the filling port 310 with respect to the central rotation axis 350. In some examples, the second filling port may be located at different axial and / or different circumferential positions relative to the filling port 310. The filling port 310 may be positioned toward the first end 326 axially opposite the second end 328 of the liquid metal bearing assembly 300. The inlet 318 of the filling port 310 may be formed on the surface of the sleeve 302 extending around the rotation axis 350 such that the outlet 330 of the filling port 310 is closer radially to the rotation axis 350 than the inlet 318, and the filling port 310 extends toward the rotation axis 350 in a direction perpendicular to it. The filling port 310 may extend to 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 further be greater than the second radial distance 324 between the shaft 304 and the sleeve 302, and less than the shaft width 336 at an axial position along the same length of the sleeve 302 as the filling port 310. In some embodiments, the filling port 310 may have a wetting coating or an anti-wetting coating. Further details regarding the filling port 310 will be described with reference to Figures 4 and 5.

[0028] The liquid metal reservoir 312 extends annularly around the shaft 304 and may have a second radial distance 324 between the shaft 304 and the sleeve 302. The liquid metal reservoir 312 may be fluidly coupled to a filling port 310 and a flow path 314. The liquid metal reservoir 312 can hold a volume larger than the combined filling volume of the flow path 314 and the gap 316. For example, the combined filling volume can be between 2g and 20g, depending on the bearing design. The use of a filling port 310 coupled to the liquid metal reservoir 312 may increase the usable volume of the liquid metal reservoir 312 compared to a liquid metal reservoir not coupled to a filling port. For example, a conventional liquid metal reservoir can only hold less than 2g of gallium. Increasing the amount of liquid metal that can be held by the liquid metal reservoir 312 not only increases the long-term resistance of the bearing to liquid metal leakage but can also increase desirable bearing performance, such as the maintenance of a continuous bearing surface, as further described herein.

[0029] The liquid metal flow path, including the liquid metal reservoir 312, the flow path 314, and the gap 316, may have an annular configuration between the sleeve 302 and the shaft 304. The inclined diameter (e.g., tapering) of the shaft 304 and the sleeve 302 provides a narrowing in width of the liquid flow path from the liquid metal reservoir 312 to the gap 316 (e.g., between the shaft 304 and the sleeve 302). In other words, in the flow path 314, the diameter of the shaft 304 increases relative to the diameter of the shaft 304 in the liquid metal reservoir 312, and the internal diameter of the sleeve 302 decreases relative to the internal diameter of the sleeve 302 in the liquid metal reservoir 312, thus reducing the overall width of the liquid metal flow path between the shaft 304 and the sleeve 302 in the direction from the first end 326 to the second end 328 of the shaft.

[0030] During the assembly of the liquid metal bearing assembly 300, liquid metal (e.g., gallium) may be injected into the liquid metal reservoir 312 via the injection port 310 or otherwise inserted. The liquid metal may be funneled by the channel 314 to an intersection of the channel 314 and the gap 316. Since the width of the gap 316 may be smaller than the width of the liquid metal bead, the liquid metal may not flow into the gap 316. The liquid metal bearing assembly 300 may be heated, and the liquid metal may be drawn from the channel 314 into the gap 316 by capillary force. In this way, the liquid metal can coat the surface of the bearings of the liquid metal bearing assembly 300 (e.g., liquid metal journal bearings and / or liquid metal thrust bearings), forming a bearing surface with a continuous layer of liquid metal extending between the sleeve 302 and the shaft 304. This allows for smooth and uninterrupted rotation of the sleeve 302 relative to the shaft 304, as described with respect to Figures 1 and 2, such as during the operation of the X-ray tube for generating the X-ray beam. The liquid metal bearing assembly 300 may further include a seal in the lower region 306 of the liquid metal bearing assembly 300, designed to reduce the amount of liquid metal leaking from the bearing. For example, the seal may be a rotary seal, a compression seal, etc. The seal may obstruct the flow of liquid metal axially away from an anode, such as the anode 210 shown in Figure 2 (e.g., along the rotational axis 350).

[0031] Turning to Figure 4, a first configuration 400 of a filling port of a liquid metal bearing assembly is shown. The filling port having the first configuration 400 may be the filling port 310 of the liquid metal bearing assembly 300, through which a liquid metal such as gallium may be injected into the liquid metal flow path during the assembly of the liquid metal bearing assembly 300. The central axis 418 shown in Figure 4 should be understood to be perpendicular to the rotational central axis 350 of the liquid metal bearing assembly 300 in Figure 3. In some embodiments, as briefly described with respect to Figure 3, the filling port may be positioned parallel to the rotational central axis 350, in which case the central axis 418 is parallel to the rotational central axis 350. The liquid metal may flow through the filling port 310 in the direction indicated by the first arrow 444, from the inlet 318 toward the outlet 330 (for example, parallel to the central axis 418). Sleeve 302 is shown with diagonal cross-hatching (x-hatch marks), while filling port 310 is shown without cross-hatching, in order to distinguish between the two.

[0032] The filling port 310 is configured such that an upper region 410 (e.g., inlet 318) has an inlet diameter 402 and a lower region 420 (e.g., outlet 330) has an outlet diameter 404, the outlet diameter 404 being smaller than the inlet diameter 402. The upper region 410 of the filling port 310 is configured with an upper wall 434 having a first length 412, and the lower region 420 of the filling port 310 is configured with a lower wall 436 having a second length 414. In some embodiments, the first length 412 may be greater than the second length 414. In other embodiments, the first length 412 may be less than the second length 414, or the first length 412 and the second length 414 may be equal. The upper region 410 and the lower region 420 of the filling port 310 may be joined by a smooth, linear transition 430 in which the diameter of the filling port 310 gradually decreases from the inlet diameter 402 to the outlet diameter 404. The transition between the upper region 410 and the smooth, linear transition 430 may have an inlet diameter 402, and the transition between the smooth, linear transition 430 and the lower region 420 may have an outlet diameter 404. The angled wall 432 of the filling port 310 in the smooth, linear transition 430 may be inclined at about 30 degrees from the x-axis with respect to a third length 424 axial system 416. In other examples, the inclined wall 432 may be positioned at different angles (e.g., less than 45 degrees) with respect 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.

[0033] The filling port 310 is fluidly coupled to the liquid metal reservoir 312 (in Figure 3) at the outlet 330 of the lower region 420, and is configured such that when the pin is not positioned in the filling port 310, the liquid metal reservoir 312 and the other elements of the liquid metal bearing assembly 300 are open to the outside 352 (e.g., the atmosphere) of the liquid metal bearing assembly 300 via the inlet 318. The inlet 318 has an inlet diameter 402, and the outlet 330 has an outlet diameter 404, so the filling port 310 is configured to have a circular cross-section, as will be further described with respect to Figures 6A-6B. When the pin is positioned in the filling port 310, the filling port 310, and therefore the other elements of the liquid metal reservoir 312 and the liquid metal bearing assembly 300, can be sealed from the outside 352. Further details regarding the pin and its positioning in the filling port 310 are described with respect to Figures 6A-6B. In this way, the filling port 310 incorporates a self-alignment feature between the filling port 310 and the pin, enabling press-fit assembly of the pin and the filling port 310 without causing galling during insertion.

[0034] Looking at Figure 5, a second configuration 500 of the filling port of the liquid metal bearing assembly 300 is shown, which may be the filling port 310 in Figure 3. For brevity, the elements of Figure 4 shown in Figure 5 are equally labeled and not reintroduced. The central axis 518 shown in Figure 5 should be understood to be perpendicular to the rotational central axis 350 of the liquid metal bearing assembly 300 in Figure 3. The liquid metal can flow through the filling port 310 from the inlet 318 to the outlet 330 (for example, parallel to the central axis 518) in the direction indicated by the second arrow 544. The sleeve 302 is marked with diagonal cross-hatching (X-hatch marks), while the filling port 310 is not hatched.

[0035] In some embodiments, such as the second configuration 500, the lower region 420 of the filling port 310 may have a stepped diameter 506, where the first portion 502 of the lower region 420 adjacent to the smooth, linear transition 430 has a stepped diameter 506, and the second portion 504 of the lower region 420 has an outlet diameter 404. The stepped diameter 506 may be smaller than the inlet diameter 402 and larger than the outlet diameter 404. The transition between the upper region 410 and the smooth, linear transition 430 may have an inlet diameter 402, and the transition between the smooth, linear transition 430 and the first portion 502 of the lower region 420 may have a stepped diameter 506. The transition between the first portion 502 and the second portion 504 of the lower region 420 may have an outlet diameter 404. Furthermore, 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. The outlet diameter 404 may be 0.3 mm, for example, when the stepped diameter 406 is 1 mm.

[0036] As briefly described above, the liquid metal flow path of the liquid metal bearing assembly 300 may be sealed from the outside 352 (e.g., the atmosphere) by inserting a pin into the filling port 310. The pin may have multiple configurations, and multiple methods for sealing the pin into the filling port may be used, as described herein with respect to Figures 6A to 11. For example, the pin may be configured as a ball bearing or a plug, and may be sealed into the filling port by brazing, a threaded fastener, welding, an angled interference thread such as a pipe thread, and / or press-fitting of the pin. In some embodiments, the pin may have a wettable coating or an anti-wetting coating to enhance the sealing capability of interference fit with the filling port 310. In this way, the filling port 310 may include a sliding radial interference fit with optional axial compression, such as a knife-edge member and / or radial compression knife edge, as will be further explained with reference to Figures 6A-611.

[0037] Now, looking at Figures 6A–6B, a first set of embodiments 600 for a pin is shown, where the pin is configured as a ball bearing. The elements of Figures 3–5 included in Figures 6A–6B are similarly numbered and not reintroduced for the sake of brevity. The central axis 646 shown in Figures 6A–6B is understood to be perpendicular to the rotational axis 350 of the liquid metal bearing assembly 300 in Figure 3, and each embodiment of the first set of embodiments 600 is understood to have the same orientation relative to one another. In other embodiments, the central axis 646 may be parallel to the rotational axis 350 of the liquid metal bearing assembly 300, and the filling port is positioned at a first radial distance from the rotational axis 350, or aligned linearly with the rotational axis 350. Each embodiment of the first plurality of embodiments 600 shows a cross-sectional view of a pin positioned within a fill port having a first configuration 400 (e.g., a fill port 310 in Figure 3), where the lower region 420 of the fill port has an outlet diameter 404 with a second length 414. Each embodiment of the pin described with respect to the first plurality of embodiments 600 may be implemented with respect to different configurations of the fill port, such as a second configuration 500 and / or additional configurations, without departing from the scope of the present disclosure. As described with respect to Figures 6A-6B, elements having vertical line filling are interpreted as pins (e.g., configured as ball bearings), and elements having horizontal line filling are interpreted as braze elements. During the assembly of a liquid metal bearing assembly (e.g., a liquid metal bearing assembly 300 in Figure 3), a pin can be inserted into the fill port, followed by the insertion of a braze element, and the braze element can be brazed to seal the pin in the fill port. Further details regarding the assembly of a liquid metal bearing assembly are described with respect to Figure 12.

[0038] Each of the first set of embodiments 600 includes a pin 602 configured as a ball bearing. For example, the pin 602 may be a sphere formed of a metal such as brass, copper, or stainless steel, or a sphere formed of ceramic. In some embodiments, the pin 602 may have a wettability coating or an antiwetting 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 set of embodiments 600, the pin 602 is located in the lower region 420 of the filling port. In the second embodiment 620 and the sixth embodiment 660, the pin 602 is located so that it spans the upper region 410, the smooth, linear transition 430, and the lower region 420. The diameter of the pin 602 may vary among the first set of embodiments 600. 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 less than the outlet diameter 404 of the lower region 420 of the filling port. For example, if the outlet diameter 404 is 1 mm, the first pin diameter 604 may be 0.9 mm. As will be further described with reference to Figure 12, during the assembly of a liquid metal bearing assembly configured to have a filling port, the pin 602 can be inserted into the filling port following the injection of liquid metal into the liquid metal reservoir. The pin 602 having the first pin diameter 604 may be inserted into the filling port, and the first pin diameter 604 may prevent, for example, the pin 602 from rolling or otherwise moving within the liquid metal reservoir. In some embodiments, the pin 602 may be coupled to a brazing element, as further described herein, before insertion of the pin 602 into the filling port, and the configuration of the brazing element may 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 may be greater than the exit diameter 404 of the upper region 410 and less than the inlet diameter 402.The second pin diameter 606 of pin 602 may be such that pin 602 is on a smooth, linear wall of the transition section 430 (for example, the angled wall 432 in Figure 4). For example, when the exit diameter 404 is 1 mm and the inlet diameter 402 is 5 mm, the second pin diameter 606 may be 3 mm.

[0039] 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 may be sealed within the filling port using a brazing element. In the first embodiment 610, the pin 602 is sealed in place using a plurality of braze beads 608, each of which in some embodiments may be a sphere with a diameter of 0.6 mm. The top view 615 of the first embodiment 610 shows the positioning of the plurality of braze beads 608 around the circumference of the pin 602, with gaps between each of the plurality of braze beads 608. The top view 615 should be understood as looking into the inlet 318 of the filling port. The axial system 699 shows the orientation of the top view 615, and the axial system 320 shows the orientation of all other embodiments in Figures 6A–6B. Regarding the axis system 699, the y-axis may, in one example, be a vertical axis (for example, parallel to the direction of gravity while the liquid metal bearing assembly 300 is attached to an X-ray source of an imaging system such as the X-ray imaging system 100 described above with reference to Figure 1), the x-axis may be a horizontal axis (for example, a horizontal axis), and the z-axis may be a vertical axis. However, the axes may have other orientations in other embodiments. As briefly described with reference to Figure 4, the filling port may have a circular cross-section. Top views 615 in Figures 6A-6B show a circular cross-section of the filling port, where the outermost circle 642 indicates the inlet 318 of the filling port, and the second circle 644 indicates the intersection between the smooth linear transition section 430 and the lower region 420. As shown in the first embodiment 610 and top view 615, a plurality of brazing beads 608 are positioned at the intersection between the smooth linear transition section 430 and the lower region 420.

[0040] In the second embodiment 620 and the third embodiment 630, the pin 602 is held in place by a wire ring 612. The wire ring 612 may have an annular configuration centered on a central axis 646, or the pin 602 may rest on the pin 602 such that it partially extends through the center of the wire ring 612. The diameter of the wire ring 612 may depend on the diameter of the corresponding pin. For example, the first wire ring diameter 614 of the wire ring 612 in the second embodiment 620 may be larger than the second wire ring diameter 616 of the wire ring 612 in the third embodiment 630. The wire ring 612 may be made of a metal such as brass, copper, or stainless steel, or it may be made of ceramics. The wire ring 612 may have a circular cross-section, as shown in the second embodiment 620 and the third embodiment 630.

[0041] In the fourth embodiment 640, the pin 602 is held in place by a washer 618. The washer 618 may be configured as an annular ring centered on a central axis 646 and may have a rectangular cross-section. The washer 618 can rest on the pin 602 such that the pin 602 partially extends through the center of the washer 618. The washer 618 may be made of a metal such as brass, copper, or stainless steel, or it may be made of ceramic.

[0042] In the fifth embodiment 650, the pin 602 is held in place by a braze ball 622. The braze ball 622 can consist of an oval disk 624 resting on the wall of a smooth, linear transition section 430 (for example, the angled wall 432 in Figure 4) and a sphere 626 coupled to the oval disk 624. For example, the oval disk 624 and the sphere 626 may be a single continuous element. The braze ball 622 is positioned within the filling port such that the sphere 626 is partially positioned in the upper region 410 of the filling port. The oval disk 624 may be in contact with the pin 602. The braze ball 622 may be made of a metal such as gold, silver, copper, palladium, platinum, or an alloy of these or similar metals.

[0043] The sixth embodiment 660 may have a similar configuration to the second embodiment 620, in which the pin 602 is positioned to span an upper region 410, a smooth, linear transition 430, and a lower region 420, and is held in place by a blaze formed by melting a braze ring 628. The braze ring 628 has an annular configuration centered on a central axis 646, has a rectangular cross-section, and may have a gap around its circumference. The braze ring 628 may rest on the pin 602 such that the pin 602 partially extends through the center of the braze ring 628. When the braze ring 628 melts, the molten material of the braze ring 628 flows into the gap between the pin 602 and the sleeve 302, holding the pin 602 in place. The braze ring 628 may be made of a metal such as gold, silver, copper, palladium, platinum, or an alloy of these or similar metals.

[0044] The seventh embodiment 670 does not require a brazing element; instead, the pin 602 may be held in place in the filling port using a threaded fastener 632. The threaded fastener 632 may have a stepped cylindrical body, the lower extension 634 of the stepped body extending into a smooth linear transition 430, and the upper extension 636 positioned within the upper region 410. The upper extension 636 may further have a plurality of threads 638 extending radially from the upper extension 636. In some embodiments, the plurality of threads 638 may graze the wall of the upper region 410 (e.g., the upper wall 434 in Figure 4). In other embodiments, the wall of the upper region 410 may have a pair of threads so that the threaded fastener 632 can be screwed into the upper region 410 of the filling port after the pin 602 has been inserted into the filling port (e.g., the lower region 420). For example, multiple threads 638 and mating threads may be configured to directly engage with each other through face-sharing contact. For example, in some embodiments, the threaded fastener 632 may be a tapered interference thread, such as a pipe thread. As described herein, face-sharing contact includes surfaces that directly engage with each other without any other components positioned between them. In the embodiments described herein, surfaces in face-sharing contact (e.g., directly engaging with each other) may form a sealed interface so that a fluid (e.g., liquid metal) does not flow through the interface between the surfaces. The threaded fastener 632 may be made of a metal such as brass, copper, or stainless steel, or it may be made of ceramic. In some embodiments, the threaded fastener 632 may be coupled to a pin 602. In other embodiments, the threaded fastener 632 may be a separate element from the pin 602 (e.g., not coupled to the pin 602).

[0045] By screwing the threaded fastener 632 into the filling port, the pin 602 can be secured within the filling port and / or a seal can be formed to hold the liquid metal in the liquid metal reservoir and isolate the liquid metal reservoir from the outside of the liquid metal bearing assembly. In the embodiment of the first of several embodiments 600, which includes a brazed element, the brazed element, the pin 602, and the filling port may be brazed to secure the pin 602 within the filling port and isolate the liquid metal reservoir 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. In addition, or alternatively, the brazing material may be integrated with the pin 602. By inserting the liquid metal through a filling port positioned radially from the bearing centerline, degradation of elements of the liquid metal bearing assembly, such as seals, can be reduced compared to conventional assembly methods of liquid metal bearing assemblies, which include pouring liquid metal onto the bearing elements and / or thrusting the shaft of the liquid metal bearing assembly through its seals.

[0046] Now, looking at Figures 7A–7B, a second set of embodiments 700 for a pin are shown, where the pin is configured as a plug. The elements of Figures 3–5 included in Figures 7A–7B are similarly numbered and not reintroduced for the sake of brevity. The central axis 746 shown in Figures 7A–7B is understood to be perpendicular to the rotational axis 350 of the liquid metal bearing assembly 300 in Figure 3, and each embodiment of the second set of embodiments 700 is understood to have the same orientation with respect to one another. In other embodiments, the central axis 746 may be parallel to the rotational axis 350 of the liquid metal bearing assembly 300, and the filling port is located at a first radial distance from the rotational axis 350, or is located linearly aligned with the rotational axis 350. Each embodiment of the second set of embodiments 700 shows a cross-sectional view of a pin positioned within a filling port having the first configuration 400 (e.g., filling port 310 in Figure 3), wherein the lower region 420 of the filling port has an exit diameter 404 with respect to a second length 414. For example, the pin 702 may include self-aligning features such as a pin-shaped undercut via a knife-edge member that assists in retaining the pin 702 within the filling port and / or radial expansion of the pin body. Each embodiment of the pin described with respect to the second set of embodiments 700 can be implemented with different configurations of the filling port, such as the second configuration 500 and / or additional configurations, without departing from the scope of the present disclosure. As described with respect to Figures 7A-7B, elements having vertical line fillings are interpreted as pins (e.g., configured as plugs), and elements having horizontal line fillings are interpreted as brazed elements. During the assembly of a liquid metal bearing assembly (for example, the liquid metal bearing assembly 300 in Figure 3), a pin can be inserted into the filling port, followed by the insertion of a brazing element, and the brazing element can be brazed to seal the pin into the filling port. In some embodiments, the brazing element may be bonded to the pin before the pin is inserted into the filling port, or the brazing element may not be used, and instead the pin may be press-fitted into the filling port. Further details regarding the assembly of the liquid metal bearing assembly are described with reference to Figure 12.

[0047] Each of the second set 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 can correspond to the type of brazing element used to braze the pin 702, as will be further described herein. In the first embodiment 710, the pin 702 has a stepped configuration in which the first plug height 706 is comprised of a second plug height 712 having a second plug width 714 and a third plug height 716 having a third plug width 718. The second plug width 714 is, for example, greater than the third plug width 718, and the second plug height 712 is smaller than the third plug height 716. The pin 702 may be formed of a metal such as brass, copper, or stainless steel, or of a plastically deformable material such as ceramic, rubber, or plastic. In each of the second set of embodiments 700, the pin 702 is located in the lower region 420 of the filling port. In the sixth embodiment 760, the pin 702 has a plug height that extends from the lower region 420 through a smooth, linear transition 430 to the upper region 410 of the filling port. For example, if the outlet diameter 404 of the lower region 420 is 1 mm, the first plug width 704 and the second plug width 714 may be 0.8 mm, and the third plug width 718 may be 0.9 mm. The first plug height 706 may be 2.8 mm, the second plug height 712 may be 0.5 mm, and the third plug height 716 may be 2.3 mm, for example, if the second length 414 of the lower region 420 is 3 mm.

[0048] In the first embodiment 710, the pin 702 may be press-fitted into a predetermined position in the filling port using a stepped configuration of the pin 702. The second plug width 714 may be approximately equal to the outlet diameter of the filling port (e.g., outlet diameter 404 in Figure 4) such that when the pin 702 is inserted into the filling port, the pin 702 bites against the lower wall of the filling port (e.g., lower wall 436 in Figure 4) and is prevented from moving into the liquid metal reservoir (e.g., liquid metal reservoir 312 in Figure 3).

[0049] 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 may be held in place by a brazing element to prevent it from moving into the liquid metal reservoir. As further described with reference to Figure 12, during the assembly of a liquid metal bearing assembly configured to have a filling port, the pin 702 may be inserted into the filling port following the injection of liquid metal into the liquid metal channel. In some embodiments, the pin 702 may be coupled to a brazing element prior to the insertion of the pin 702 into the filling port, as further described herein, and the configuration of the brazing element may prevent the pin 702 from moving into the liquid metal reservoir. The second embodiment 720 includes a disc 722 as the brazing element, which has height and flat, circular upper and lower surfaces, and the disc 722 may rest on the angled wall 432 of a smooth, linear transition 430, or the disc 722 may rest on the upper surface 724 of the pin 702. In the third embodiment 730, fasteners 726 such as washers 618 or brazing rings 628 described with respect to Figures 6A-6B may be used as brazing elements. The fasteners 726 of the third embodiment 730 may rest on the upper surface 724 of the pin 702. Similar to the fasteners 726, the fourth embodiment 740 includes wiring such as wiring 612 described with respect to Figures 6A-6B, which may have an annular configuration with respect to the central axis 746 and may rest on the upper surface 724 of the pin 702. The fifth embodiment 750 includes a brazing ball such as brazing ball 622 described with respect to Figures 6A-6B, which may rest on the upper surface 724 of the pin 702, and / or the elliptical disc may rest on the wall of a smooth linear transition section 430 (e.g., the angled wall 432 in Figure 4). As briefly described above, in the sixth embodiment 760, pin 702 may extend from the lower region 420 through a smooth linear transition 430 to the upper region 410. Pin 702 may be surrounded by wiring such as wiring 612 in the fourth embodiment 740.For example, the wiring 612 of the sixth embodiment 760 may be positioned 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 430. Each of the brazed elements described herein with respect to the second plurality of embodiments 700 may be formed of a metal such as brass, copper, or stainless steel, or of a ceramic. In embodiments of the second plurality of embodiments 700 that include a brazed element, the brazed element, the pin 702, and the filling port may be brazed together to fix the pin 702 within the filling port, and the liquid metal reservoir may be isolated from the outside of the liquid metal bearing assembly after the liquid metal is inserted into the liquid metal reservoir through the filling port.

[0050] Figure 8 shows an embodiment 800 of the first pin which can be welded or laser brazed to a second configuration 500 of the filling port. In other words, the first pin embodiment 800 includes a straight pin that fits into a stepped hole. The elements of Figures 4 and 5 included in Figure 8 are numbered similarly. The pin 802 of the first pin embodiment 800 may be configured as a plug, as described with respect to Figures 7A-7B. The pin 802 is shown with a vertical line filling to distinguish it from the filling port. The pin 802 may have a first pin height 804 and a first pin diameter 806. As described with respect to Figure 5, the filling port has an outlet diameter 404 in the second portion 504 of the lower region 420 and a stepped diameter 506 in the first portion 502 of the lower region 420. For example, the stepped configuration includes a corner 812 at the intersection between the first portion 502 and the second portion 504 of the lower region 420. For example, the corner portion 812 may engage with the pin 802 by direct surface-sharing contact and may be configured as a lip, step, etc. The transition between the smooth, linear transition portion 430 and the lower region 420 may have a stepped diameter 506, and the transition between the first portion 502 and the second portion 504 may have an exit diameter 404. The first pin diameter 806 may be smaller than the stepped diameter 506 and larger than the exit diameter 404. In some embodiments, the fourth length 512 and the fifth length 514 may each be equal, and the height 804 of the first pin may be greater than the fourth length 512 and the fifth length 514. The second portion 504 may have an exit diameter 404 smaller than the first pin diameter 806.

[0051] The pin 802 can be formed from a plastically deformable material that is more deformable than the material of the filling port, such as metal, ceramic, plastic, or rubber. In this way, when the pin 802 is inserted into the lower region 420 of the filling port and a force is applied in the direction indicated by arrow 810 to further push the pin 802 into the second portion 504 of the lower region 420 (for example, to press-fit the pin 802), the pin 802 can be plastically deformed to fit the second portion 504. For example, the pin 802 can be sheared or grafted against the wall of the filling port in the lower region 420 (e.g., the lower wall 436) such that the first pin diameter 806 is smaller than the exit diameter 404. The resulting interference of the pin 802 in the second portion 504 of the lower region may be 50 μm in some embodiments. Thus, the first pin embodiment 800 may have a size slip fit, allowing for brazing flow and guiding the pin 802 into the second portion 504 of the lower region 420 (e.g., the interference region). In some embodiments, the pin 802 may be brazed directly to the filling port without the use of additional brazing elements, or it may include brazing elements such as those described with respect to Figures 7A-7B.

[0052] Turning to Figure 9, a second pin embodiment 900 is shown, the pin having a stepped configuration and being press-fitted into a filling port having a stepped configuration. The elements in Figure 9 are numbered similarly to those in Figures 4 and 5. Pin 902 of the second pin embodiment 900 may be configured as a plug, as described with respect to Figures 7A-7B. Pin 902 is shown with a vertical filling to distinguish it from the filling port. Pin 902 may be configured to have a shape similar to the inside of the filling port. For example, pin 902 may include a tapered surface, which may be located on a smooth linear transition 430 of the filling port 310, where the tapered surface of pin 902 has the same angle as the tapered surface of the filling port on the smooth linear transition 430. In other words, pin 902 may be configured to have a surface that is paired with the filling port 310. The pin 902 includes an upper pin region 910, a lower pin region 920, and a smooth, linear pin transition section 930 between them. Each of the upper pin region 910, the smooth, linear pin transition section 930, and the lower pin region 920 is coupled to form a continuum of the pin 902. The lower pin region 920 may have a lower pin diameter. For example, the dimensions of the pin 902 are proportionally smaller than the internal dimensions of the filling port. For example, the pin 902 has a third pin diameter 904 in the upper pin region 910. The diameter of the pin 902 in the smooth, linear pin transition section 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 stepped transition section between the smooth, linear pin transition section 930 and the lower pin region 920. For example, the diameter of pin 902 at the intersection between the smooth, linear pin transition section 930 and the lower pin region 920 may be the fourth pin diameter 906 in the smooth, linear pin transition section 930 and the lower pin diameter 908 in the lower pin region 920. The third pin diameter 904 is smaller than the entrance diameter 402, and the fourth pin diameter 906 and the lower pin diameter 908 are smaller than the stepped diameter 506.

[0053] Furthermore, the filling port may have a stepped configuration, similar to the second configuration 500. In the embodiment shown in Figure 9, the stepped configuration includes corners 912 at the intersection of a smooth, linear transition section 430 and a lower region 420 that directly engages with the pin 902 by sharing surface contact and may be configured as a lip, step, etc. As described with respect to Figures 4 and 5, the filling port has an inlet diameter 402 in the upper region 410. The diameter of the filling port may gradually transition from the inlet diameter 402 to a stepped diameter 506 in the smooth, linear transition section 430. In the configuration of Figure 9, the diameter of the filling port at the intersection between the smooth, linear transition section 430 and the lower region 420 may be the stepped diameter 506 in the smooth, linear transition section 430 and the outlet diameter 404 in the lower region 420. The corner 912 extends the width 936 of the lower wall 436 of the lower region 420 toward the interior of the filling port, and thus the diameter of the filling port in the lower region 420 can be reduced to the outlet diameter 404.

[0054] If the pin 902 is configured to have a fourth pin diameter 906 over the entire lower pin region 920 (for example, the pin 902 is not stepped), the fourth pin diameter 906 may be plastically deformed and thus reduced when the pin 902 is press-fitted into the filling port in the stepped configuration described herein. The plastic deformation of the pin 902 may form a flared interface between the pin 902 and the filling port, which may form a seal between the pin 902 and the filling port to isolate the liquid metal reservoir from the atmosphere and help to retain the pin 902 within the filling port. In other embodiments, the pin 902 may have a stepped configuration as described herein with respect to Figure 9, in which case the lower pin diameter 908 may be smaller than the outlet diameter 404 of the lower region 420. Thus, the lower pin region 920 can be positioned within the lower region 420 of the filling port without causing galling of the pin 902 within the filling port. When inserted into the filling port, the pin 902 may rest on the angled wall 432 of the smooth, linear transition section 430.

[0055] The stepped configuration of the pin 902 and the filling port described herein may allow the pin 902 and the filling port to self-align when the pin 902 is inserted into the filling port. For example, the walls of the upper region 410 (e.g., upper wall 434) and the walls of the smooth, linear transition section 430 of the filling port (e.g., angled wall 432) can guide the pin 902 into the filling port. Radial interference between the pin 902 and the walls of the filling port may help to seal the pin 902 in place within the filling port. The pin 902 can further be press-fitted into the filling port by applying force in the direction indicated by the second arrow 916.

[0056] Figure 10 shows an additional configuration 1000 of a pin configured as a plug that can be press-fitted into a filling port having a stepped configuration. For example, the filling port may have the second configuration 500 described with respect to Figure 5, the stepped configuration described with respect to the second pin embodiment 900 of Figure 9, or another stepped configuration. The additional configuration 1000 is described herein with respect to the stepped filling port configuration of Figure 9. For the sake of brevity, elements of Figure 9 included in Figure 10 are similarly numbered and may not be reintroduced.

[0057] Similar to pin 902 described with respect to Figure 9, each of the tapered pin 1002 and button head pin 1004 may be configured as a plug having a shape similar to the inside of the filling port. For example, each of the tapered pin 1002 and button head pin 1004 includes an upper pin region 1010, a lower pin region 1020, and a smooth, linear pin transition section 1030 between them. The diameters of each of the upper pin region 1010, the lower pin region 1020, and the smooth, linear pin transition section 1030 may be as described with respect to the upper pin region 910, the lower pin region 920, and the smooth, linear pin transition section 930 (for example, with respect to the diameter of the filling port).

[0058] The tapered pin 1002 is further configured to have a weld prep in the upper pin region 1010. As shown in Figure 10, the weld prep can be visualized as a right triangle extending from the upper pin region 1010 toward the inlet 318 of the filling port. Figure 10 shows a profile diagram of the filling port and the tapered pin 1002 located therein, and thus the weld prep may be a single weld prep 1006 having an annular configuration with a right triangular profile. The single weld prep 1006 may be coupled to and extending from the upper surface 1008 of the tapered pin 1002. In some embodiments, the right triangles of the single weld prep 1006 may be spaced apart by a distance 1012 (e.g., inside the annular configuration) equal to the lower pin diameter 908 of the lower pin region 1020. In other embodiments, the weld prep may include a plurality of weld preps having right-angled triangular or other shaped profiles arranged radially with respect to the circumference of the upper surface 1008 of the tapered pin 1002, with spaces between each weld prep. The weld preps can be formed from the same material as the tapered pin 1002, such as brass, copper, stainless steel, or ceramic.

[0059] The button head pin 1004 is configured to have a flat top 1022 in the upper pin region 1010. The flat top 1022 may have a first width 1024 and a first height 1026, the first height 1026 being 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 button head pin 1004 (e.g., the third pin diameter 904) so ​​that the flat top 1022 extends radially wider than the upper pin region 1010. The flat top 1022 may be formed from the same material as the button head pin 1004, such as brass, copper, or stainless steel, or it may be brazed to ceramic.

[0060] Each of the tapered pins 1002 and buttonhead pins 1004 can be press-fitted into the filling port by inserting the pin into the filling port and applying force in the direction indicated by the third arrow 1014. Press-fitting the pins into the filling port (e.g., by applying force) can cause each of the tapered pins 1002 and buttonhead pins 1004 to plastically deform, causing the pin tops to widen and potentially creating radial contact between the pin and the filling port. For example, when the tapered pin 1002 is press-fitted into the filling port, the distance 1012 between the right triangles of a single weld prep 1006 increases, causing the single weld prep 1006 (or, in some embodiments, multiple weld pretreatments) to flare out radially towards the upper wall 434 of the upper region 410 of the filling port, creating radial contact between them. When the button head pin 1004 is press-fitted into the filling port, the first width 1024 of the flat top 1022 increases, and the first height 1026 of the flat top 1022 may decrease so that the flat top 1022 flares radially out toward the upper wall 434 of the upper region 410 of the filling port, creating radial contact between them. The radial contact between the flared portions of the tapered pin 1002 and the button head pin 1004 (e.g., the weld prep and the flat top, respectively) can reduce the shear stress during the insertion of each pin. Furthermore, the increased interference between each pin and the filling port may facilitate welding or brazing the pin to the filling port to isolate the liquid metal reservoir from the atmosphere. In some embodiments, the flaring of the pin can provide contact for welding and / or additional press-fit sealing (e.g., between the flat top 1022 of the button head pin 1004 and the inlet 318 of the filling port).

[0061] Figure 11 shows an embodiment 1100 of pin 1102 configured as a threaded fastener plug and / or as a pin having radial interference in addition to a threaded fastener. Pin 1102 can be inserted into a filling port of a liquid metal bearing assembly, such as a filling port having a first configuration 400 (e.g., non-stepped) and / or a filling port having a second configuration 500 (e.g., stepped). Figure 11 is described in relation to a filling port having the first configuration 400, and therefore the elements of Figure 4 included in Figure 11 are similarly numbered for brevity and not reintroduced. The configuration of pin 1102 can radially seal pin 1102 within the filling port so that the liquid metal reservoir is isolated from the outside of the liquid metal bearing assembly. For example, the configuration of pin 1102 may be similar to the configuration of threaded fastener 632 in Figures 6A-6B. The pin 1102 may have a stepped body, the lower plug extension 1104 of such a stepped body extending to the lower region 420 through a smooth linear transition 430, and the upper plug extension 1106 positioned in the upper region 410. The upper plug extension 1106 is configured to further have a plurality of threads 1108 extending radially from the upper plug extension 1106. The plurality of threads 1108 may be circumferential ridges arranged along the upper region 410 with some axial spacing between them (for example, between each thread of the plurality of threads 1108). In the 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.

[0062] Following the insertion of the pin 1102 into the filling port, the diameter of the upper plug extension 1106 may increase. For example, the diameter of the first upper extension 1116 may increase to a second upper extension diameter 1118, as shown in the second embodiment 1120, where the second upper extension diameter 1118 is greater than the diameter of the first upper extension 1116. In some embodiments, the diameter of the upper plug extension 1106 may be increased using Poisson's ratio, or a third body may be used to deform the upper plug extension 1106 outward (e.g., towards the upper wall 434). When the pin 1102 is compressed axially (e.g., along the x-axis relative to the axial system 320), the pin 1102 undergoes radial plastic deformation to the diameter 1118 of the second upper extension, such that there is radial interference between the multiple threads 1108 and the upper wall 434. In this way, the multiple threads 1108 can form a seal (e.g., a secondary gallium seal) between the pin 1102 and the filling port without shearing of any element, thereby helping to retain the pin 1102 within the filling port. In other embodiments, the wall of the upper region 410 may be composed of mating threads so that the pin 1102 can be screwed into the upper region 410 of the filling port following insertion into the filling port (e.g., the lower region 420). For example, the multiple threads 1108 and the mating threads may be configured to engage directly in contact with each other, sharing surfaces. In this way, the pin 1102 can function as a radial seal pin that isolates the liquid metal reservoir from the outside of the liquid metal bearing assembly. Figure 12 shows a method 1200 for assembling a liquid metal bearing assembly such as the liquid metal bearing assembly 300 of 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 coupled to a rotor and stator (e.g., rotor 218 and stator 220 in Figure 2), the liquid metal bearing assembly can impart rotational motion to an element coupled to a rotating component (e.g., sleeve 302 in Figure 3).The bearing surface formed by a continuous layer of liquid metal extending between the sleeve 302 and the shaft 304 can enable smooth and uninterrupted rotation of the sleeve 302 relative to the shaft 304. The method for assembling the liquid metal bearing assembly described herein can generate the bearing surface while reducing the potential degradation of elements of the liquid metal bearing assembly, such as seals, which may degrade during other assembly methods, such as those involving thrusting a stationary component (e.g., the shaft 304) through the seals and pouring liquid metal onto the stationary component and seals. Although method 1200 is described herein in relation to the liquid metal bearing assembly 300, method 1200 can be used to assemble other liquid metal bearing assemblies having filling ports positioned radially relative to the bearing centerline on the rotating component.

[0063] In 1202, method 1200 includes inserting a shaft of a liquid metal bearing assembly into a sleeve of the liquid metal bearing assembly. For example, the sleeve may be formed as a hollow cylinder, and the shaft may be inserted from a second end of the sleeve (e.g., second end 328) and extend through a first end of the sleeve (e.g., first end 326). In some embodiments, the shaft may have a flange at the end of the shaft that can prevent the shaft from passing through the sleeve completely. A sleeve cap is coupled to the second end of the sleeve, surrounding the flange of the shaft, and thus the shaft can be sealed within the sleeve. When the shaft is inserted into the sleeve, a liquid metal reservoir is formed between them. The liquid metal reservoir may be fluidically coupled to the atmosphere (e.g., outside 352) of the liquid metal bearing assembly via a filling port when no pin is positioned in the filling port. In this way, the elements of the liquid metal bearing assembly can be assembled before the liquid metal is introduced into the liquid metal reservoir. This allows the rotary seal and compression seal to be kept intact during the assembly of the liquid metal bearing assembly.

[0064] In 1204, method 1200 includes filling the liquid metal reservoir of a liquid metal bearing assembly with a lubricant (e.g., liquid metal) by injecting the lubricant into the liquid metal reservoir through a filling port located in the rotating member (e.g., sleeve) of the liquid metal bearing assembly. In some embodiments, such as those described herein, the lubricant is a liquid metal such as gallium. In other embodiments, the liquid metal may include tin, indium, or combinations thereof. The liquid metal may be dispensed into the liquid metal reservoir by pouring the liquid metal into the filling port by inserting a needle or other dispensing device into the filling port and injecting the liquid metal. Different methods for distributing the lubricant into the liquid metal reservoir 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), etc. The lubricant (e.g., liquid metal) fills the liquid metal reservoir and may not flow into the gap between the shaft and sleeve downstream of the liquid metal reservoir with respect to the liquid metal flow path (e.g., gap 316). For example, the size of the liquid metal bead (e.g., gallium) may be larger than the width of the gap (e.g., the distance between the shaft and the sleeve). Therefore, the liquid metal dispensed into the liquid metal reservoir through the filling port may be partially contained within the flow path (e.g., flow path 314) between the liquid metal reservoir and the gap, and may not flow into the gap to form a bearing surface.

[0065] In 1206, method 1200 optionally includes heating the liquid metal bearing assembly. Heating the liquid metal bearing assembly can increase the reactivity of the shaft and sleeve surfaces and enhance the capillary force inside the sleeve that draws gallium into the gap between the shaft and the sleeve.

[0066] In 1208, method 1200 includes sealing a liquid metal reservoir from the atmosphere (e.g., outside the liquid metal bearing assembly 352) by inserting a pin into a filling port of the liquid metal bearing assembly. The pin may be configured as a ball bearing, as described with respect to Figures 6A-6B, or as a plug, as described with respect to Figures 7A-711. The filling port may have a first configuration, such as the first configuration 400 described with respect to Figure 4, or a second configuration, such as the second configuration 500 described with respect to Figure 5. The dimensions of the filling port and the pin may be such that the insertion of the pin into the filling port partially or completely isolates the liquid metal reservoir from outside the liquid metal bearing assembly. In some embodiments, a brazing element (e.g., a wiring, brazing bead, brazing ball, washer, brazing ring) may be attached to the pin (e.g., brazed) before inserting the pin into the filling port. The configuration of the brazing element can prevent the pin from moving into the liquid metal reservoir. Furthermore, or alternatively, the configuration of the pin and filling port can prevent the pin from moving into the liquid metal reservoir. For example, the filling port may be configured to have self-aligning features (e.g., an inlet diameter, a smooth, linear transition, and an outlet diameter) that allow the pin to be positioned within the filling port without galling during insertion. In some embodiments, the filling port may incorporate a sliding radial interference fit with arbitrary axial compression (e.g., a stepped diameter and outlet diameter in a second portion of the lower region of the filling port).

[0067] In 1210, method 1200 includes securing a pin within a filling port of a liquid metal bearing assembly. As described with reference to Figures 6A to 11, securing the pin may include brazing a brazing element to the pin and the filling port, laser welding the pin to the filling port, screwing a threaded fastener coupled to the pin into the filling port, and / or crimping the pin to the wall of the filling port and / or press-fitting the pin to position it in the filling port by plastically deforming the pin.

[0068] In 1212, method 1200 includes heating the liquid metal bearing assembly. Heating the liquid metal bearing assembly increases the reactivity of the surfaces of the shaft and sleeve, which may increase the capillary force inside the sleeve that draws gallium into the gap between the shaft and the sleeve. The liquid metal in the liquid metal reservoir flows into the gap, forming a bearing surface in the gap, and the rotation of the sleeve relative to the shaft is no longer hindered. Method 1200 is completed.

[0069] In this way, deterioration of the seals of the liquid metal bearing assembly due to liquid metal overflow during assembly can be reduced. The liquid metal may be placed inside the liquid metal bearing assembly (e.g., liquid metal reservoir) through radially positioned filling ports of the rotating parts of the liquid metal bearing assembly. Pins are placed in the radially positioned filling ports and sealed therein by press-fitting, welding or brazing, thereby isolating the inside of the liquid metal reservoir, and thus the liquid metal bearing assembly, from the outside of the liquid metal bearing assembly. Technical effects of the liquid metal bearing assembly configurations described herein may include an increase in usable bearing life due to reduced leakage of liquid metal through the compression seals of the bearings and / or an increase in the amount of liquid metal filling in the liquid metal reservoir. The manufacture of liquid metal bearing assemblies may be simplified compared to conventional configurations, and specifically, the number of usable liquid metal bearing assemblies manufactured using the method described herein may be greater than the number of usable liquid metal bearing assemblies manufactured using a method that includes high-pressure insertion of a shaft into a sleeve.

[0070] Figures 2 to 11 show exemplary configurations with various relative positional relationships of components. When components are shown in direct contact with each other or directly joined together, such components can be said to be in direct contact or directly joined, respectively, in at least one example. Similarly, components shown continuous or adjacent to each other may be continuous or adjacent, respectively, in at least one example. For example, components laid in surface contact with each other may be said to be in surface contact. As another example, elements that are spaced apart from each other with only space between them and no other components present may be referred to as such, in at least one example. As yet another example, elements shown above / below each other, on opposite sides of each other, or to the left / right of each other may be referred to as such relative to each other. Furthermore, as shown in the figures, in at least one example, the topmost element or point of an element may be referred to as the “top” of a component, and the bottommost element or point of an element may be referred to as the “bottom” of a component. As used herein, top / bottom, upper / lower, above / below are relative to the vertical axis of the figure and may be used to describe the relative positions of elements in the figure. Thus, an element shown above another element is, in one example, positioned above the other element in the vertical direction. In yet another example, the shape of an element depicted in the figure may be referred to as having that shape (e.g., circular, straight, flat, curved, rounded, chamfered, angled, etc.). Furthermore, elements shown intersecting each other may, in at least one example, be referred to as intersecting elements or elements that intersect each other. Furthermore, an element shown within another element or outside of another element may, in one example, be referred to as such.

[0071] The disclosure also provides a support for a liquid metal bearing assembly, comprising a filling port fluidly coupled to a liquid metal reservoir of the liquid metal bearing assembly, the filling port having an inlet diameter and an outlet diameter, the outlet diameter being smaller than the inlet diameter, and a pin fitted inside the filling port and shaped to prevent liquid metal from flowing out of the liquid metal reservoir. In a first embodiment of the system, the system further comprises a rotating part and a stationary part, the rotating part at least partially surrounding the stationary part in the circumferential direction, and the liquid metal reservoir is formed as a second radial distance between the rotating part and the stationary part. In a second embodiment of the system, optionally including the first embodiment, the filling port is positioned on the rotating part at a first radial distance from the bearing centerline. In a third embodiment of the system, optionally including one or both of the first and second embodiments, the outlet diameter of the filling port is positioned between the inlet diameter of the filling port and the liquid metal reservoir of the liquid metal bearing assembly. In a fourth embodiment of the system, optionally comprising one or more of the first to third embodiments, the inlet and outlet diameters are joined by a smooth linear transition, the diameter of which gradually transitions from the inlet diameter to the outlet diameter. In a fifth embodiment of the system, optionally comprising one or more of the first to fourth embodiments, the pin is configured as a ball bearing. In a sixth embodiment of the system, optionally comprising one or more of the first to fifth embodiments, the pin is configured as a plug. In a seventh embodiment of the system, optionally comprising one or more of the first to sixth embodiments, the pin is press-fitted, brazed, and / or welded into the filling port. In an eighth embodiment of the system, optionally comprising one or more of the first to seventh embodiments, the liquid metal bearing assembly is a straddle bearing. In the ninth embodiment of the system, one or more of the first to eighth embodiments are optionally included, and each of the filling port and pin includes a self-aligning feature that enables press-fitting of the pin into the filling port.In the tenth embodiment of the system, optionally comprising one or more or each of the first to ninth embodiments, the self-alignment feature of the pin includes an undercut of the pin shape and / or radial extension of the pin body via a knife-edge member.

[0072] The disclosure also provides support for a method comprising the steps of filling a reservoir of a liquid metal bearing with a lubricant by injecting the lubricant into the reservoir through a filling port provided in the rotating member of the liquid metal bearing, and sealing the reservoir from the atmosphere by inserting a pin into the filling port. In a first embodiment of the method, the method further comprises welding, brazing, and / or press-fitting the pin into the filling port. In a second embodiment of the method, optionally comprising the first embodiment, the method further comprises applying a wetting coating or a wetting-preventing coating to at least one of the filling port or the pin.

[0073] The disclosure also provides a support for an imaging system comprising a cathode and an anode having a revolving feature, the revolving feature being rotated by a liquid metal bearing assembly having a revolving component circumferentially surrounding a stationary component, the revolving component including a filling port positioned radially away from the axis of rotation of the liquid metal bearing assembly, and the lubricant reservoir of the liquid metal bearing assembly being selectively isolated from the atmosphere by inserting a pin into the filling port. In a first embodiment of the system, the filling port has an upper region having an inlet diameter, a lower region having an outlet diameter smaller than the inlet diameter, and a smooth, linear transition between the upper and lower regions, the diameter of which gradually changes from the inlet diameter adjacent to the upper region to the outlet diameter adjacent to the lower region. In a second embodiment of the system, optionally including the first embodiment, the lower region comprises a first portion having an outlet diameter and a second portion having a second diameter smaller than the outlet diameter, and is configured to have a stepped transition between the first and second portions. In a third embodiment of the system, optionally comprising one or both of the first and second embodiments, the pin is configured as a ball bearing that is press-fitted and optionally welded or brazed to the filling port using at least one of a wire, washer, brazing ring, brazing ball, and a plurality of brazing beads. In a fourth embodiment of the system, optionally comprising one or more or each of the first to third embodiments, the pin is configured as a plug that is press-fitted and optionally welded or brazed to the filling port using at least one of a disc, washer, wire, brazing ring, and brazing ball.A fifth embodiment of the system optionally includes one or more of the first to fourth embodiments, wherein the pin comprises a lower pin region having a lower pin diameter, having at least one of the following press-fit configurations: a 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, and an upper pin region having an upper pin diameter; and a smooth, linear pin transition portion, the diameter of which 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 in the upper pin region.

[0074] Where used herein, an element or step described in the singular form and preceded by the word "a" or "an" should be understood not to exclude the plural form of such element or step unless such exclusion is expressly stated. Furthermore, a reference to "one embodiment" of the present invention is not intended to be construed as excluding the existence of additional embodiments that also incorporate the mentioned features. Furthermore, unless the opposite is expressly stated, an embodiment that "contains," "includes," or "has" an element or a plurality of elements having a particular characteristic may include additional such elements that do not possess that characteristic. The terms "contains" and "has" are used as plain equivalents of the terms "contains" and "has," respectively. Furthermore, terms such as "first," "second," and "third" are used simply as labels and are not intended to impose numerical requirements or a specific positional order on their subjects.

[0075] This specification discloses the present invention, including best embodiments, using examples, so that a person of the ordinary skill in the relevant art can carry out the invention, including the manufacture and use of any device or system, and the execution of methods incorporating the invention. The patentable scope of the present invention is defined by the claims and may include other examples that a person skilled in the art can conceive. Such other embodiments are intended to be included in the claims if they have structural elements that are not different from the language of the claims, or if they include equivalent structural elements that are substantially different from the language of the claims. [Explanation of Symbols]

[0076] 100: X-ray imaging system 102: Subject 104: X-ray source 106: X-ray beam 108: Detector array 110: X-ray controller 112: Computing device 114: Processor 116: Operator console 118: Memory device 120: Display 200: X-ray tube 202: Housing 204: Low-pressure enclosure 205: Liquid metal bearing assembly 206: Stationary parts 208: Rotating parts 210: Anode 212: Cathode 214: X-ray beam 216: X-ray window 218: Rotor 220: Stator 222: Liquid metal journal bearing 224: Liquid metal thrust bearing 226: Interface 250: Rotating axis 252: Radial axis 300: Liquid metal bearing assembly 302: Sleeve 302a: First body 302b: Second body 302c: Interface 304: Shaft 306: Lower region 310: Filling port 312: Liquid metal reservoir 314: Flow path 316: Gap 318: Inlet 320: Axis system 322: First radial distance 324: Second radial distance 326: First end 328: Second end 330: Outlet 332: Large depth 334: Depth 336: Shaft width 338: First side 350: Rotational central axis 352: External 400: First configuration 402: Inlet diameter 404: Outlet diameter 406: Stepped diameter 410: Upper region 412: First length 414: Second length 418: Central axis 420: Lower region 424: Third length 430: Transition section 432: Angled wall 434: Upper wall 436: Lower wall 444: First arrow 500: Second configuration 502: First part 504: Second part 506: Stepped diameter 12: Fourth length 514: Fifth length 518: Central axis 544: Second arrow 600: Multiple first embodiments 602: Pin 604: First pin diameter 606: Second pin diameter 608: Wax bead 610: First embodiment 612: Wiring 614: First wiring diameter 615: Top view 616: Second wiring diameter 618: Washer 620: Second embodiment 622: Brazed ball 624: Elliptical disc 626: Sphere 628: Braze ring 630: Third embodiment 632: Threaded fastener 634: Lower extension636: Upper extension 638: Thread 640: Fourth embodiment 642: Outermost circle 644: Second circle 646: Central axis 650: Fifth embodiment 660: Sixth embodiment 670: Seventh embodiment 699: Axis system 700: Second multiple embodiments 702: Pin 704: First plug width 706: First plug height 710: First embodiment 712: Second plug height 714: Second plug width 716: Third plug height 718: Third plug width 720: Second embodiment 22: Disk 724: Top surface 726: Fastener 730: Third embodiment 740: Fourth embodiment 746: Central axis 750: Fifth embodiment 760: Sixth embodiment 800: First pin embodiment 802: Pin 804: Height of the first pin 806: Diameter of the first pin 810: Arrow 812: Corner 900: Embodiment of the second pin 902: Pin 904: Diameter of the third pin 906: Diameter of the fourth pin 908: Diameter of the lower pin 910: Upper pin region 912: Corner 916: Second arrow 920: Lower pin region 930: Smooth and linear pin transition 936: Width 1000: Additional pin configuration 1002: Tapered pin 1004: Button head pin 1006: Single weld prep 1008: Top surface 1010: Upper pin region 1012: Distance 1014: Third arrow 1020: Lower pin region 1022: Flat top 1024: First width 1026: First height 1030: Smooth and linear pin transition section 1100: Embodiment 1102: Pin 1104: Lower plug extension 1106: Upper plug extension 1108: Thread 1110: First embodiment 1114: First plug diameter 1116: First upper extension diameter 1118: Second upper extension diameter 1120: Second embodiment

Claims

1. A filling port (310) fluidly coupled to a liquid metal reservoir (312) of a liquid metal bearing assembly (300), wherein the filling port has an inlet diameter (402) and an outlet diameter (404), the outlet diameter being smaller than the inlet diameter, and A spherical pin fitted inside the filling port to prevent liquid metal from flowing out of the liquid metal reservoir through the filling port, A liquid metal bearing assembly, including a liquid metal bearing assembly.

2. The liquid metal bearing assembly according to claim 1, further comprising a rotating part (302) and a stationary part (304), wherein the rotating part at least partially surrounds the stationary part in a circumferential direction, and the liquid metal reservoir is formed over a second radial distance (324) between the rotating part and the stationary part.

3. The liquid metal bearing assembly according to claim 2, wherein the filling port is located within the rotating part at a first radial distance (322) from the bearing centerline.

4. The liquid metal bearing assembly according to claim 3, wherein the filling port is arranged perpendicular to the bearing centerline.

5. The liquid metal bearing assembly according to claim 3, wherein the filling port is arranged parallel to the bearing centerline.

6. The liquid metal bearing assembly according to claim 1, wherein the filling port further includes a stepped diameter (506) between the inlet diameter and the outlet diameter, the stepped diameter being greater than the outlet diameter and less than the inlet diameter.

7. The liquid metal bearing assembly according to claim 1, wherein the pin diameter (604) of the pin is substantially equal to the outlet diameter (404).

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

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 filling port and the pin includes a self-aligning feature that enables press-fit insertion of the pin into the filling port.

11. The liquid metal bearing assembly according to claim 10, wherein the self-aligning feature portion of the pin includes a linear transition portion.

12. A method for assembling a liquid metal bearing assembly (300) according to any one of claims 1 to 11, The steps include: filling the reservoir of the liquid metal bearing assembly (300) with the lubricant by injecting the liquid metal lubricant into the reservoir through the filling port provided in the rotating member of the liquid metal bearing assembly (300); The steps include inserting the spherical pin into the filling port to seal the reservoir from the atmosphere, Methods that include...

13. The method according to claim 12, further comprising the step of welding, brazing, and / or press-fitting the pin of the sphere into the filling port in order to hold the pin of the sphere in the filling port.

14. The method according to claim 12, further comprising the step of applying a wetting coating or a wetting-proof coating to at least one of the filling port or the pin of the sphere.

15. The method according to claim 12, further comprising the step of rotating the rotating member of the liquid metal bearing assembly (300) to rotate the rotational feature portion of the anode of the X-ray source.

Images