Abstract:
A liquid metal or spiral groove bearing structure for an x-ray tube and associated process for manufacturing the bearing structure is provided in which journal bearing sleeve is formed with a number of structures thereon that function to dissipate heat transmitted to the sleeve during operation of the bearing assembly within the x-ray tube to minimize thermal deformation of the sleeve, thereby minimizing gap size alteration within the bearing assembly. The structures formed within the sleeve are slots disposed within the section of the sleeve in which the highest temperature gradients develop. The slots enable an increase in thermal conductance away from the sleeve while minimizing the stresses created from the deformation of the portion(s) of the sleeve between the slots.
Abstract:
A bearing structure for an X-ray tube is provided that includes a journal bearing shaft with a radially protruding thrust bearing flange encased within a bearing housing or sleeve. The sleeve includes a thrust seal that is engaged with the sleeve in a manner to maintain coaxiality for the rotating liquid metal seal formed in the sleeve about the shaft. The shaft includes a central bore containing a cooling tube that directs coolant within the bore to maximize the heat transfer from the shaft to the coolant, allowing materials with lower thermal conductivities, such as steel, to be used to form the bearing shaft. The thrust flange on the shaft is formed with channel(s) therein that enable the coolant and/or the liquid metal to effect greater heat transfer on the components of the sleeve through the thrust flange, thereby reducing thermal deformation of the bearing components.
Abstract:
An X-ray tube is provided. The X-ray tube includes a bearing configured to couple to an anode. The bearing includes a stationary member, a rotary member configured to rotate with respect to the stationary member during operation of the X-ray tube, and a support feature configured to minimize bending moment along a surface of the stationary member to reduce deflection of the stationary member relative to the rotary member due to radial loads during operation of the X-ray tube.
Abstract:
An X-ray tube is provided. The X-ray tube includes a bearing configured to couple to an anode. The bearing includes a stationary member, a rotary member configured to rotate with respect to the stationary member during operation of the X-ray tube, and a support feature configured to minimize bending moment along a surface of the stationary member to reduce deflection of the stationary member relative to the rotary member due to radial loads during operation of the X-ray tube.
Abstract:
A ring seal is engaged with a liquid metal bearing assembly and operates to contain metal fluid lubricant leaking through the primary compression seals of a liquid metal bearing to prevent the fluid from entering the high voltage space within the x-ray tube and causing high voltage instability. The ring seal engages the existing configuration for the bearing assembly without deforming the bearing, including effects of thermal expansion and inertial body forces, thus maintaining the tight tolerances for the proper operation of the component parts of the bearing structure. The ring seal retains the leaking liquid metal within the ring seal regardless of the operating state and/or condition of the bearing assembly, such as during operating conditions. i.e., rotation of the bearing assembly or gantry, and non-operating conditions, e.g., shipping and stand-by, and regardless of the corresponding pressures and their locations exerted on the ring seal by the liquid metal.
Abstract:
A bearing assembly is disclosed that includes a sleeve having an opening formed therein and a shaft positioned within the opening of the sleeve such that a gap is formed between an inner surface of the sleeve and an outer surface of the shaft. A lubricant is disposed in the gap and a plurality of grooves are formed on at least one of the outer surface of the shaft and the inner surface of the sleeve. An anti-wetting coating is disposed on the at least one of the outer surface of the shaft and the inner surface of the sleeve between adjacent grooves of the plurality of grooves.
Abstract:
A bearing structure for an X-ray tube is provided that includes a journal bearing shaft with a radially protruding thrust bearing flange encased within a bearing housing or sleeve. The sleeve includes a thrust seal that is engaged with the sleeve in a manner to maintain coaxiality for the rotating liquid metal seal formed in the sleeve about the shaft. The shaft includes a central bore containing a cooling tube that directs coolant within the bore to maximize the heat transfer from the shaft to the coolant, allowing materials with lower thermal conductivities, such as steel, to be used to form the bearing shaft. The thrust flange on the shaft is formed with channel(s) therein that enable the coolant and/or the liquid metal to effect greater heat transfer on the components of the sleeve through the thrust flange, thereby reducing thermal deformation of the bearing components.
Abstract:
A structure and method of operation of a journal bearing is disclosed that minimizes contact of the shaft with the sleeve during start up and slow down of the rotation of the shaft relative to the sleeve, or vice versa. The bearing assembly includes a gravitational load reduction mechanism with magnets disposed on the sleeve and on the shaft in alignment with one another. The magnet(s) on the shaft interacts with the magnet(s) disposed on the sleeve to provide a force against the pressure of the shaft towards the sleeve generated by gravity acting on the rotating component. The magnets enable centering of the rotating component within the stationary component during low rotation and non-rotation. This prevents rubbing of the rotating journal bearing component surfaces, e.g., sleeve, against the stationary journal bearing component, e.g., shaft, during assembly, ramp-up, and coast-down when the journal bearing fluid provides minimal or no bearing centering capability.
Abstract:
Various methods and systems are provided for providing coatings and textures to surfaces of a bearing assembly in an x-ray system to control the wettability of the surfaces when components of the bearing assembly rotate during operation of the x-ray system. A lubricant is disposed in a gap formed between a shaft and a sleeve of the bearing assembly such that textured and coated surfaces of the shaft and sleeve alter wetting properties between the lubricant and surfaces. The coatings and textures can be wetting or anti-wetting to further enhance control over the behavior of the lubricant.
Abstract:
Various methods and systems are provided for providing coatings and textures to surfaces of a bearing assembly in an x-ray system to control the wettability of the surfaces when components of the bearing assembly rotate during operation of the x-ray system. A lubricant is disposed in a gap formed between a shaft and a sleeve of the bearing assembly such that textured and coated surfaces of the shaft and sleeve alter wetting properties between the lubricant and surfaces. The coatings and textures can be wetting or anti-wetting to further enhance control over the behavior of the lubricant.