COOLANT FLOW CONTROL SYSTEM FOR A LIQUID-METAL FILLED ANODE BEARING IN AN X-RAY APPARATUS

COOLANT FLOW CONTROL SYSTEM FOR A LIQUID-METAL FILLED ANODE BEARING IN AN X-RAY APPARATUS

FIELD OF THE INVENTION

[0001]   This invention relates to coolant flow control systems, and more particularly, to a flow control system e.g. for Gallium filled bearing in a rotating anode-type X-ray apparatus.

BACKGROUND OF THE INVENTION

[0002]    Generally, rotating anode-type X-ray apparatus use liquid metal filled bearings such as Gallium filled bearings for supporting an anode for generation of X-rays within an X-ray tube. 

[0003]    Such liquid metal filled bearings use a variety of sealing configurations such as, for example, a contact type sealing and a non-contact type sealing, for sealing the liquid metal within the bearing.  

[0004]    In a non-contact type-sealing configuration, the sealing is effected by the surface tension created in the liquid metal that flows along the circumferential direction between a rotating shaft and a stationary housing, wherein the clearance between the rotating and stationary parts is inn the order of few microns.

[0005]    In such non-contact type-sealing configuration, especially for a liquid metal filled ball bearing, a velocity and a pressure spike is created (see FIG. 1) due to the flow of the liquid metal through the space between rotating/spinning balls and the bearing races. 

[0006]   Generally, due to space constraints, the end face of the seal is configured very close to the end face of the bearing, due to which the spike creates a flow instability, which tends to substantially affect the performance of the seal.

[0007]    Thus, known systems do not provide for a coolant flow control system, wherein the liquid metal flow does not create any spike and hence provide a high seal performance and improved bearing endurance. 

BRIEF DESCRIPTION OF THE INVENTION

[0008]    In an embodiment, a coolant flow control system in a liquid-metal filled anode bearing in an X-ray apparatus comprises a flow straightener disposed in-between a bearing and a clearance seal, wherein the flow straightener substantially reduces the velocity and pressure spike at the end face of the seal.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]    FIG. 1 shows the flow pattern in a conventional bearing.

[0010]   FIG. 2 shows the cross-section of a liquid metal cooled bearing with a coolant flow control system according to one embodiment of the present invention. 

[0011]    FIG. 3 shows a side view of a bearing shaft and a clearance seal according to one embodiment of the present invention.

[0012]    FIG. 4A-4C show a cross-section of the clearance seal according to various embodiments of the present invention. 

DETAILED DESCRIPTION OF THE INVENTION

[0013]    Various embodiments of the present invention describe a c...