Claims
- 1. An X-ray tube comprising:
- (A) an evacuated tube envelope having a window for passing X-rays from the interior thereof;
- (B) a cathode mounted in the tube envelope;
- (C) an anode rotatably mounted in the tube envelope;
- (D) DC motor anode drive means for rotating the anode during operation of the X-ray tube, including
- (1) an internal rotor mounted within the tube envelope and coupled to the anode, to rotate the anode, the internal rotor comprising at least one permanent magnet having at least two poles
- (2) a multiple pole DC stator positioned on the exterior of the tube envelope and having a number of pole pieces equal to or greater than the number of poles of the permanent magnet of the internal rotor and
- (3) electrical means for supplying electrical DC power to the stator to create a magnetic field for driving the internal rotor; and
- (E) electrical means connected to the anode and cathode for producing X-rays during rotation of the internal rotor.
- 2. An X-ray tube as defined in claim 1 wherein the tube envelope is fabricated of non-ferrous metal.
- 3. An X-ray tube as defined in claim 1 together with a housing enclosing the tube envelope and wherein the tube envelope is fabricated of metal and is mounted in the housing to provide an annular space and together with a fan mounted on the housing to cause a flow of air through the annular space for cooling the tube envelope.
- 4. An x-ray tube as defined inclaim 1 wherein the permanent magnet is a rare earth magnet encapsulated in a casing so that the rare earth magnet will not contaminate the interior of the evacuated tube envelope.
- 5. An x-ray tube as defined in claim 1 wherein said electrical means includes means for producing pulses and further comprising a sensor for sensing the position and/or speed of the rotating anode for controlling the timing of the pulses supplied to the stator for controlling the speed at which the anode rotates and/or to confirm anode rotation at the desired speed.
- 6. An X-ray tube as defined in claim 5 wherein the sensor is positioned outside the tube envelope.
- 7. An improvement in X-ray tubes of the type comprising a metal tube envelope having a wall portion, a rotating anode assembly therein and drive means for it, a cathode and power supply means for the anode and cathode including supply cables, the improvement comprising terminal means for connecting the supply cables to the anode and cathode, including:
- (A) a feedthrough formed of insulating material sealed to and extending through the wall portion of the tube envelope and having a receptacle therein;
- (B) wire means embedded in the feedthrough and extending from the receptacle to the interior of the tube for connection with the anode or cathode;
- (C) metal shield means secured to the tube envelope and surrounding the feedthrough;
- (D) insulating material within the metal shield means; and
- (E) a terminal end fitting receiving one of the supply cables and having electrical connectors carried by the terminal end fitting, said metal shield means and said insulating material in the metal shield means being provided with an opening which is sized to receive the terminal end fitting, said insulating material in the metal shield and the metal shield means having a small air channel therein extending from the receptacle to ambient exterior of the metal shield means to permit the escape of air from the opening when the terminal end fitting is inserted in the opening.
Parent Case Info
This is a continuation of application Ser. No. 326,752 filed Dec. 2, 1981, which is a continuation-in-part of Ser. No. 90,501 filed Nov. 1, 1979, which is a continuation-in-part of Ser. No. 71,192 filed Oct. 30, 1979.
US Referenced Citations (22)
Non-Patent Literature Citations (1)
Entry |
"Foundations of Electromagnetic Theory", by Reitz, Milford & Christy, 3d Ed., Addison-Wesley Publ., 1979, p. 198. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
326752 |
Dec 1981 |
|
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
90501 |
Nov 1979 |
|
Parent |
71192 |
Oct 1979 |
|