Koninklijke Philips Corporation N.v.

Philips Medical Systems (cleveland), Inc.

Richardson Electronics, Ltd.

Norman Wandke

Qing Kelvin Lu

Donald Charles Mueller

Mark S Maska

Salvatore G Perno

Paul Xu

Todd Russell Bittner

Min He

Thomas Muchowicz

Embodiments of the invention provide a conductive coating on an insulator of an x-ray tube and a method for applying the conductive coating. The method may use a first process, such as brazing, to join a support to the insulator and a second process, such as vapor deposition, to apply the conductive coating onto a substrate surface of the insulator. The second process may be carried out after the first process without any damage to x-ray tube insulator assembly.

Insulator with conductive dissipative coating

An x-ray tube ( ) includes an evacuated envelope ( ), a cathode assembly ( ) located in the evacuated envelope and a disk shaped anode assembly ( ) located in the evacuated envelope in operative relationship with the cathode assembly for generating x-rays ( ). The anode assembly includes an axis of rotation ( ) and a target substrate ( ) facing the cathode assembly. A heat pipe ( ) is located within the anode assembly ( ). The heat pipe is comprised of an evacuated shell ( ) and is vacuum sealed at a first end ( ) of the shell and at a second end ( ). A material ( ) within the shell is a working fluid for the heat pipe at x-ray tube operating conditions. A porous wick ( ) is located within the shell and the wick has a length extending from the first end ( ) of the shell to the second end ( ) of the shell. A shield ( ) is attached to the wick to reduce working fluid loss out of the wick during x-ray tube operation.

Liquid metal heat pipe structure for x-ray target

An x-ray tube assembly ( ) includes a housing ( ) and an insert frame ( ) supported within the housing ( ), such that the insert frame ( ) defines a substantially evacuated envelope in which cathode ( ) and anode ( ) assemblies operate to produce x-rays. An x-ray transmissive window assembly ( ) extends between and in a fluid-tight relationship with the housing ( ) and the insert frame ( ). The window assembly ( ) includes an insert window ( ) brazed to the insert frame ( ), a top plate ( ), which is connected to and substantially surrounded by a flange ( ), where the flange ( ) is fastened to the x-ray tube housing ( ). An annular side plate ( ) is connected to a fluid-tight relationship with both the insert frame/window interface ( ) and the flange ( ). The window assembly ( ) cools the window through enhanced heat transfer while preventing housing coolant from contacting the insert window ( ), thereby eliminating coolant carbonization on the window ( ) and enhancing x-ray beam quality.

Liquid-free x-ray insert window

A high energy x-ray tube includes an evacuated chamber ( ) containing a rotor ( ) which rotates an anode ( ) in the path of a stream of electrons (A) to generate an x-rays (B) and heat. The rotor includes a bearing shaft ( ) connected to the anode by a thermally conductive structure ( ). The bearing shaft carries soft metal-lubricated bearing balls ( F, R) in forward and rear bearing races ( ). An annular groove ( ) is defined longitudinally in the shaft which, particularly when evacuated, provides a thermal barrier between the forward race and the portion of the shaft that is thermally connected with the anode. The groove lengthens the path heat entering the bearing shaft travels in order to reach the forward bearing race. As a result, the temperature of the forward race, and hence the evaporation of lubricant during operation of the x-ray tube, is reduced. The groove may be formed by electrical discharge machining the bearing shaft or by forming the shaft from inner and peripheral components ( ) which are connected together adjacent the rear bearing race ( ).

Thermally isolated x-ray tube bearing

A high energy x-ray tube includes an evacuated chamber ( ) containing a rotor ( ) which rotates an anode ( ) in the path of a stream of electrons (A) to generate an x-ray beam (B) and heat. Heat is carried away from the anode to a bearing shaft ( ) which rotates relative to a stationary rotor ( ) on forward and rear lubricated bearings ( P, R). The heat is directed away from the forward bearings ( F), by a core ( ) of a thermally conductive material, such as copper, disposed in a central cavity ( ) within the shaft. Annular insulating regions ( ) are optionally defined between the core and the bearing shaft adjacent the races to increase the thermal path between the anode and the races. The reduction in temperature of the forward bearings results in a decrease in the evaporation rate of the lubricant ( ) and a corresponding increase in the lifetime of the x-ray tube.

Growing community of inventors

Naperville, IL, United States of America

Norman Wandke