JPS58126654A - X-ray tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to an X-ray tube, and more particularly to an X-ray tube having a drive device for effectively rotating an anode and a compact metal tube housing. It concerns wire tubes.

Existing rotating anode x-ray tubes have a cathode consisting of one or two filaments and a corresponding focusing cup, and a rotating anode assembly. These are mounted inside an evacuated tube vessel of glass only or glass and metal.
This container is mounted within the x-ray tube housing. The housing is filled with insulating oil and contains the thermal expansion system and the stator of the AC squirrel cage anode motor. Therefore, the stator will be separated from the rotor by the thickness of the tube wall plus the required clearance,
The squirrel cage motor becomes less efficient and generates heat.

An X-ray tube according to the invention has an anode rotatably mounted within the tube housing, the anode being connected to an internal rotating shaft which is mechanically coupled to an external drive for rotating the anode. This is the conclusion.

The internal rotor is located in close proximity to the interior of a tube vessel that includes iron segments that form part of a magnetic flux loop coupling the internal rotor to the external drive. . Therefore, the tube is relatively thick and structurally rigid, yet the gaps in the magnetically coupled flux loops are minimized.

The internal rotor may also be driven by a stator magnetic field surrounding the rotor portion of the anode-rotor assembly outside the tube. In such embodiments, the stator is a multi-pole DC stator having a pole shoe surrounding a cup portion that tightly receives the tube rotor. The rotor includes a plurality of bar magnets (preferably of the Rare type) that project outwardly from the surface of the ferrous sleeve and are separated by non-ferrous spacers. The rare earth magnet and sleeve are sealed within a non-ferrous casing to prevent the rare earth magnet from compromising the vacuum within the tube vessel. The axial length of the permanent magnet is larger than that of the magnetic pole shoe, which biases the anode rotor toward the structural stop at the cathode end of the X-ray tube, stabilizes the cathode-anode spacing, and A Hall device is mounted over the protruding permanent magnets to allow current to be switched to the stator. The cup portion of the tube vessel between the rotor and the stator may be made entirely of non-ferrous metal or may be composed of ferrous segments and non-ferrous spacers.

In another embodiment, a brushless AC induction motor, also known as a stator-rotor squirrel cage motor, is constructed. The stator pole shoes are disposed around a cup portion of the tube vessel, the walls of the cup portion having ferrous segments separated by non-ferrous spacers to reduce the effective cap between the stator rotor. There is. The stator, rotor, and iron wall segments are preferably all laminated to reduce eddy currents and are thin walled sleeves to avoid compromising the vacuum between the laminations. The rotor is made by copper casting and mounted on a ceramic insulator (attaching the anode).

In this copper casting method, the iron laminations of the rotor are aligned at the edges of the ceramic insulators, liquid steel is poured into the open spaces of the laminations to form the longitudinal non-ferrous bars of the rotor, and Liquid steel is poured over the outer surface of the rotor and adjacent portions of the ceramic insulator to form a sleeve that secures the rotor to the ceramic insulator. The ceramic insulator is preferably shaped so that the sleeve surrounds the flat surface and groove to provide a strong bond. The rotor also preferably includes a cam with iron lobes that close a magnetic flux loop through an externally mounted magnet and Hall device and surround at least the rotating anode of the tube vessel and the speed monitor. The main portion is generally cylindrical and made of metal, preferably copper, and may be lined with a ceramic insulating material. The end of the tube opposite the anode target surface is not lined with ceramic to improve heat transfer from the anode.

The outer surface of the tube end may be provided with fins to enhance heat dissipation. The tubing may be mounted within a housing and air cooled.

Other features of the X-ray tube according to the invention include:

By embedding the cathode power leads (both filament and grid) within the ceramic tube lining, the cathode and anode cables enter the tube vessel approximately opposite the x-ray tube window area, allowing for installation and use of the x-ray tube. There are some things that can be done easily. Additionally, power to the anode is supplied through a separate joint from the bearing to which the anode is attached, extending the life of the bearing. Cable terminations are also improved.

By combining all of the above features, the X-ray tube can be significantly improved. Other features and objects of the invention will be apparent to those skilled in the art, and will in part be apparent from the description of the preferred embodiments taken in conjunction with the accompanying drawings.

With reference to FIG. 1 and FIG. 2, an X-ray tube 220 according to the present invention
is the indication. To be more specific, the Fang 1 figure has an X-ray tube 2.
The other parts of the X-ray tube 220, including the reed, cathode, anode assembly, a part of the tube vessel, etc., are the same as the X-ray tube described above. good.

In Figure 1, the shaft 45 of the anode assembly is supported on and extends through a bearing 46.

These bearings are mounted within the disk 58 of the tube vessel 2o. Shaft 45 is also mounted within bearings 221 which are located within the end wall of cup 223 extending from vessel 2°.

The anode drive device 230 has a permanent magnet rotor 265,
It is driven by an external DC stator 240 connected to the rotor through the cylindrical wall 224 of the cup 226. The permanent magnet rotor 235 is attached to the shaft 45 and the cup 2
Located within 26. North pole 236 of permanent magnet rotor 265
and south pole 267 are diametrically opposed and located in close proximity to the inner surface of cylindrical wall 224, minimizing the air gap therebetween.

Stator 240 surrounds cylindrical wall 224 and has diametrically opposed ferrous pole pieces 241, 242, each of which is located in close proximity to the outer surface of cylindrical wall 224. It has magnetic pole shoes 245,244. Coils 245 and 246 are wound around the pole pieces 241 and 242 to generate a magnetic field that drives the permanent magnet rotor 265.

The pole pieces 241,242 are connected to each other by an iron cylindrical outer wall 247, providing a magnetic flux path connecting the pole pieces.

The cylindrical wall 224 of the tube container cup 225 has iron segments 2
25 and 226, the iron segment 225 is the magnetic pole 24
The iron segment 226 is located adjacent to the pole shoe 244 of the pole 242. The other portions of the cylindrical wall 224 are non-ferrous;
It may be made of aluminum, preferably glass.

Here, magnetic pole shoes 243° 244, iron segment 22
5.226, it is noted that the permanent magnet rotor ends 236, 237 are of the same dimensions, in particular of the same width, and completely overlap when aligned.

The rotor 265 energizes coils 245, 246 surrounding the pole pieces 241 and 242, respectively, to create a magnetic field, and depending on the position of the rotor 235 and the direction of the magnetic field, the rotor 235 It is driven by applying repulsion or magnetic attraction to. For example, referring to FIG. 2, rotor 235 is shown rotating clockwise and energizing coils 245 and 246 causes pole piece 241 to become the north pole and pole piece 242 to become the south pole.

Therefore, the rotor's north pole 256 is the stator's pole piece 2.
41 and the south pole 257 also receives repulsion from the stator pole piece 242, continuing to drive the rotor clockwise. As the rotor rotates 180 degrees, the direction of current in coils 245, 246 continues to reverse direction and drive the rotor and hence the anode through shaft 45.

A sensor 250 is mounted through the end wall of cup 226 and determines the path of a sensor target 251 mounted on rotor 265. The sensor can be
It may be a magnetic sensor, an optical (especially fiber optic) sensor, or a mechanical sensor. The output of sensor 250 is processed by signal generator 252. This signal generator sends signals to position indicator 255 and speed indicator 254. A speed control circuit 255 receives the output from the speed selection controller 256 in addition to the output from the speed indicator 254, works in conjunction with a pulse generator/timing circuit 257, receives the output from the position indicator 255, and outputs the coil 245, 246 to generate the appropriate pulses to drive rotor 235 and thus the anode. These pulses are timed to the rotation of the rotor to provide maximum torque until the rotor and anode reach the desired speed, thus providing sufficient driving force to maintain that speed. By appropriately reversing the magnetic field, braking can be applied to slow the rotor and bring it to a stop. Since there are no external moving parts to provide cooling air flow, the x-ray tube 220 may be provided with an external cooling fan (not shown). As will be appreciated, the rotor 235 may have multiple pole pieces and the stator may have multiple pole pieces to increase the strength of the drive. In the illustrated embodiment, there are two pole pieces for simplicity of explanation.

A further preferred embodiment of the invention is found in the x-ray tube 400 of Figures 6-5. The X-ray tube 400 includes a tube container 410 rotatably mounted with an anode assembly 450, which includes an anode 451 and a drive motor 4700.
and a rotor part. The tube container 410 is the housing 4
02, the housing supports the stator of the drive motor.

The tube enclosure contains the cable terminations and is cooled by a fan that circulates air through a housing surrounding the tube enclosure.

The tube vessel 410 includes a cylindrical sidewall 411 surrounding the anode;
A radiolucent window 412 for emitting X-rays is provided. An annular end wall 413 connects side wall 411 to cup 415.

This cup 415 projects outwardly and has a cylindrical side wall 4.
16 and an end wall 417.

An axial stud 418 projects from the end wall 417 into the interior of the vessel and supports a rotating anode assembly 450, as will be explained in more detail below. The opposite end of the tube vessel 410 is closed by an end wall 420 attached to the cylindrical side wall 411 thereof. As will be explained in detail later,
End wall 420 supports terminals 425 and 430. side wall 4
11 and end wall 420 are preferably made of copper, and cup 415 is preferably made of 604 steel, Monel steel, or other non-ferromagnetic steel.

Anode assembly 450 is rotatably mounted within tube 410 on stud 418 of cup 415. This anode assembly 450 includes an anode 451, a ceramic insulator 455,
It includes a rotor 471 of a drive motor 470. The ceramic insulator includes a cylindrical shank 456 that projects into the cup 415 of the tube.

The shank surrounds the stud 418 and a bearing 457 is provided between the stud and the inner surface of the shank. The ceramic insulator 455 further includes a disc 4.58 that extends radially outward from the shank along the vessel end 4.11413 to protect the interior of the cup 415 from radiant heat from the anode. There is. Stud 4
59 (may be stepped as shown) is the disk 458
From there, a reflection point/bearing plate 460 of the shank 456 is attached. A metal sleeve 461 is fitted around the stud 459, and the anode 451 is attached to the metal sleeve.
2, and is fixed with a nut 462. A portion of the metal sleeve 461 (indicated by 463) is connected to the anode 451.
The anode engages the slot in the ceramic insulator 45.
Configure keys that allow 5 to rotate together.

Drive motor 470 includes a rotor 471 that includes a plurality of permanent magnets, preferably of the rare earth type. Therefore, this drive motor can provide high torque despite the presence of a gap between the stator and rotor. The rotor structure seals the rare earth magnets and prevents them from contaminating the evacuated interior of the tube vessel 410.

More specifically, the rotor 471 includes eight substantially straight rare earth permanent magnets 472a-472h, which are spaced apart from each other and surrounded by an octagonal steel ring 4.
Extending outwardly from 76. This steel ring acts to close the flux loop between the magnets. As best seen in Figure 4, the permanent magnet 472 is attached to a spacer 47 made of non-ferrous material.
separated from each other by 4. A casing of non-ferrous material surrounds the permanent magnets and includes an outer sleeve 475 that extends over the ceramic insulator shank 456 and is secured thereto, such as by brazing, to the rotor 471. is attached to the shank. The casing further includes a stud 41
8 and an inner sleeve 476 concentric with the inner sleeve 476 . edge 1147
7.478 connects these inner and outer sleeves to complete the seal between the permanent magnet and the steel ring. The outer surface of the steel ring is octagonal, hence the eight permanent magnets 472a-
472h lies flat against the eight outward facing surfaces of the steel ring. The permanent magnets are arranged with alternating polarity. For example, permanent magnet 472a has its north pole on its outer surface and its south pole adjacent to a steel ring, and permanent magnet 472b has its north pole adjacent to the steel ring and its south pole on its outer surface. It is.

The rotor 471 may be made by steel casting, in particular by placing the steel ring 473 and magnets in a mold into which liquid steel is poured to form the end walls 477, 478, the spacers 474, the inner casing
A sleeve 476 may also be formed. This preassembly may be milled to round the outer surfaces of the magnet, spacer, and finish the diameter of the inner casing sleeve to the desired tolerance. In this way you can attach the preassembly to the outer casing.
Drop into sleeve 475 and seal the permanent magnet with suitable welding or brazing. The outer sleeve extension is brazed to the ceramic insulator shank and the rotor is attached to it.

Alternatively, the outer surface of the magnet may be pre-rounded and the entire casting body and spacer may be cast in one operation C-! Furthermore, the spacer may be made separately, the end wall and the sleeve may be welded together to form the rotor structure, and the steel ring, magnet, and spacer may be sealed. In short, there are several ways to make a sealed rotor, but the main feature is to seal the permanent magnets so that they do not contaminate the inside of the exhaust gas of the X-ray tube container.

A spear 2 bearing 464 is mounted between the interior of the rotor and the stud 418, and two spaced bearings are mounted on the anode assembly 4.
50 is rotatably supported. The tooth 2 bearing abuts the shoulder of the stud 418, the tooth 1 bearing abuts the shoulder of the opening in the shank of the ceramic insulator, and a spring 465 is installed between these two bearings. I want to be noticed. This arrangement biases the rotating anode assembly away from the cup end of the x-ray tube and structurally connects the assembly to a "ground" assembly, as will be explained further below.
let

The stator 480 of the drive motor 470 of the x-ray tube 400 is mounted within a ring 481 supported on struts 482 that extend around the cup 415 of the tube housing 410. The tube cup 415 slides in and out of the stator to displace the tube, and the stator supports and positions the tube within the housing.

With particular reference to Figure 4, stator 480 includes a plurality of pole pieces 4.
83 and the ends of these pole pieces are connected to pole shoes 484
These pole shoes surround the cylindrical side wall 416 of the cup 415. The pole pieces are connected to each other at the outer part of the stator by rings.

A winding wire is placed in the space between the cores, although this is not shown in detail, it is shown by 486 in the 3rd figure. The stator preferably consists of a laminate, as shown in Figure 5, which reduces eddy currents in the stator. The windings are made according to known motor technology depending on the number of magnets and the number of pole pieces. Although the illustrated embodiment has 24 pole pieces and 8 magnets, it should be understood that different numbers of pole pieces and magnets may be utilized and the stator windings determined accordingly.

Hall device 488 is adjacent to stator 480 on cup wall 3
It is attached to the outer surface of 16. Note that the axial length of the permanent magnet 472 is greater than that of the pole shoe and projects beyond the pole piece. This allows the Hall device to be positioned adjacent to the pole pieces and biased by the permanent magnets as the rotor rotates, and also to direct the rotating anode assembly away from the cup end of the tube vessel toward structure IE. It will be shifted to one side.

Note that the gap between the cup wall 416 and the outer surface of the rotor is exaggerated in the tooth 4 view for illustrative purposes. The drive electric motor Idiot 9 is powerful and can produce high torque for quick starting. The specific motor controller is not shown, but may be similar to that described above with respect to x-ray tube 220, and the Hall device generates the switching signal.

X-ray tube 400 further includes a cathode 440 mounted to end wall 420 opposite anode 4510;
Power is received through cable 420 via terminal 430 .

Terminal 430 is a ceramic or glass stud 431
, which is sealed against and extends through the tube end plate 42°.

Ceramic fist stud 451 has a cup portion 452 that extends into the x-ray tube and supports one or more filaments and a grid of cathode 440 of x-ray tube 400. Referring to Figures 3 and 5, the outer end of the ceramic or glass stud 461 has a side-facing flat surface 436 to which a plug receptacle 464 is mounted. Wires are embedded in the studs to connect the plug receptacle to the filament and grid. The end plate 420 has a metal shield 455.
is attached having a curved closed end 436 generally surrounding the protruding stud and an elongated portion 437 of U-shaped cross section extending clearly into the end plate 420. A plastic insulator 4 is placed between the metal shield 435 and the stud 431.
38 is provided, which constitutes an opening for receiving the terminal end 442 of the cathode power cable 441.

The terminal end 442 of the cathode power cable has a plurality of plugs 443
is inserted into the opening in the plastic insulator 438 and fits into the plug receptacle 454 on the stud 461. Terminal end 442 is shaped for this purpose and includes a flange 444 that can be attached to metal to retain the cable. One narrow air channel 439 is provided on the outer surface of the cable terminal, extending through the plastic insulation and metal shield, and extending through the opening in the plastic cover when the terminal end of the cable is inserted. Air can be forced out.

The anode power cable 445 is terminated in the tube in a similar manner. A terminal 425 also extends through the end plate 420 and includes a hermetically sealed ceramic or glass stud 426 having a laterally facing flat surface 427 forming a plug receptacle 428 . Attached to the end plate 42o is a metal shield 429 fitted with a plastic insulator 424 for receiving a terminal end 446 of an anode Ichihara cable 445, the anode cable being inserted into a plug receptacle 428. to fit. The plug receptacle 428 is connected to the wire lead 452, which protrudes into the X-ray tube housing and is connected to the terminal 455.
has. This terminal is attached to the end plate and rests on a ceramic stud 454 that extends toward the anode. Thus, metal plate 460 on the rotating anode assembly contacts this terminal 456. Wire leads 449 from the metal plate to the metal sleeve 461 complete the electrical circuit to the rotating anode.

Note that rotating anode assembly 450 is biased toward terminal 456 supported by ceramic stud 454, thereby axially positioning anode 451 within the vessel. This is advantageous in that both the anode and cathode have a reference position with respect to the end plate 420 and the distance between the cathode and anode remains constant within close tolerances regardless of thermal expansion of the tube. It is.

The entire tubing 410 is mounted within a housing 402, which essentially includes an outer cylindrical wall 406 and end covers 404,405. The tube container is supported within the housing by sliding the end cup 415 into a stator 480 which is attached to the cylindrical wall of the tube housing by struts 482. At the terminal end of the tube housing, a number of lugs 421 extend radially outward and are stopped by complementary installed lugs fi 406 extending from the tube housing. This can best be seen in Figure 5. Housing wall 406 is slotted at 407 (FIG. 5).
It accommodates anode and cathode power cables 441 and 445.

Fan motor 491 driving fan blades 492
A fan assembly 490 including a fan assembly 490 is mounted within the tube housing and is adapted to air cool the x-ray tube 400.

The fan assembly is preferably mounted to the cathode end of the x-ray tube, and in the preferred embodiment shown, bracket 49
6 is provided which extends from the terminal shield 429, 165 and supports the fan motor. End covers 404, 405 at the ends of the tube housing are slotted to provide air flow. When the fan is activated, air is blown against the end wall 420, pushing the air along the sides of the tube vessel and out the opposite end of the housing.

If desired, end wall 420 may be fully equipped with cooling fins.

The tube housing side wall 406 includes a collimator 408 that is aligned with the tube envelope window 412 to emit x-rays. This is motor 496
It is convenient to mount a sliding filter 495 driven by the cylindrical filter 495 within the tube housing adjacent to the tube container. The filter is slidably installed to cover the window 412.

The cylindrical tube housing is easily adapted to trunnion mounts commonly used in x-ray tube equipment.

X-ray tube 400 operates in the usual manner. That is, anode cable 445. Anode terminal 425° lead wire 452
．． A high voltage is applied to the anode 451 via terminal 453.

The cathode is heated, a grid voltage is applied, and the drive motor 470 is activated to rotate the anode while x-rays are generated. It will be appreciated that the copper tube casing acts as an effective shield against scattered x-rays and also has excellent thermal conductivity for transferring heat from within the x-ray tube to the outside. The fan assembly provides cooling air that keeps the x-ray tube relatively cool during operation. Ceramic insulator 55, particularly its cylindrical disk portion 458, helps keep the temperature of cup 415 at a relatively low level. Therefore, the rare earth magnets of rotor 471 can also maintain their magnetic properties for a considerable period of time.

1.6-9, another x-ray tube 500 according to the present invention is shown. A feature of this X-ray tube 500 is that it uses a rotating magnetic field-driven induction motor, commonly called a cage-carving motor, which moves the laminated segments of the tube vessel wall between the stator and the rotor. j to operate. X
Another feature of line tube 500 is a cam actuated Hall device speed monitor, which can be used in feedback mode to control motor speed. Figures 66 to 9 are fragmentary views of the X-ray tube 500, showing the cup portion 520 of the tube container 510, a portion of the rotating anode assembly 540 including the rotor 550 of the electric motor, and the fixing of the electric motor surrounding the cup 520. A child 570 is shown. As can be seen, the X-ray tube 50
The remaining portions of the X-ray tube 500 may be the same as those of the X-ray tube 400 described above, and the motor of the X-ray tube 500 may also be the same as that of the specific motor disclosed in connection therewith, as well as the other forms of the X-ray tube described above. Can be used instead.

End cup 520 of x-ray tube 500 includes a cylindrical sidewall 525, an end plate 535, and a stud 558 for mounting a rotating anode assembly 540. The cylindrical side wall 525 of the cup has a plurality of laminated iron segments 526a-526f disposed between the rotor and stator of the motor, which segments accumulate in the wall in the area between the rotor and stator and extend axially. It extends and is interrupted along the circumference of the cylindrical wall by narrow non-ferrous segments 530 as best seen in Figure 1, t-7. The stator 570 has magnetic pole pieces 5
71, includes the pole shoe 572 and surrounds the cup 520, thereby allowing the iron segments 526a to 52
6f actually becomes an extension of the pole shoes 572 of the stator 570, reducing the effective gap between the stator and rotor.

This gap is exaggerated for purposes of explanation, and is actually 0.
, on the order of 0 O5 inches.

Segments 5268-526f are preferably laminated to reduce eddy current effects. however,
Laminated segments cannot maintain a vacuum. Accordingly, the cylindrical wall of the cup further includes a cylindrical sleeve 528, preferably made of a thin non-ferrous material, which prevents the loss of vacuum through the laminated segments. This sleeve 528 need not be a non-ferrous material as long as it is thin enough not to disturb the magnetic circuit, although it can prevent vacuum loss through the laminated segments. Also, materials that are not ferrous or non-ferrous, such as glass or ceramic, may be used with this sleeve 528.
It can be used for.

Referring to Figures 10 and 3□11, the process of making an end cup 520 with laminated segments is illustrated. A plurality of annular stacks 524 are created that include spaced apertures 525. At this point, the diameter of the laminate is larger than the final wall diameter, which corresponds to the lower right portion of Figure 11.

The cylindrical cup portion 521 has an aperture that corresponds to the aperture in the stack. Nonferrous pins 560 are inserted into these openings. After the laminate is inserted into these pins, the end wall,
The stud, the second portion 522 of the cup consisting of a portion of the cylindrical side wall, is press fit onto the pin, sandwiching the laminate between the two solid portions of the cup. As shown in Figure 11, the partially completed cup is milled to reduce its diameter and expose the non-ferrous pin to the outside surface. What should be noted here is that the pins are already exposed on the inner surface due to the position of the openings in the stack. Therefore, the annular stack is formed between the nonferrous pins 530 and the stacked ferrous segments 526a to 526a.
A 526f rotor 550 is mounted on the end of the ceramic insulator 545 of the rotating anode assembly, generally opposite the anode (not shown), and includes a cup 52 surrounded by a stator 570.
It is located within 0. The rotor 550 consists of ferrous laminations that are filled in their outer portions with non-ferrous material, shown at 552 in a typical squirrel cage shape, and have longitudinal openings therein. Again, the laminate is used to reduce eddy currents. However, it is difficult to completely clean the laminations, so the rotor laminations are sealed within the casing 555 to prevent contamination of the tube vessel. More specifically, the laminate includes an outer cylindrical sleeve 5
56, inner cylindrical sleeve 557, end wall 558.559
An outer cylindrical sleeve 556 extends over a portion of the shank 546 of the ceramic insulator 545 and mounts the rotor thereto. The rotor is formed by casting non-ferrous bars 552 and casing 555 from copper. The casing 555 can also provide a good mechanical bond to the ceramic insulator shank 546. As you can see in Figure 9, the shank of the insulator 5
46 is formed with a flat surface 547 and a circumferential groove 548. When the outer sleeve 556 is cast copper, the copper seals against the flats and grooves of the shank to securely mount the rotor both axially and rotationally.

The rotor is best seen in Figures 1 and 6 and Figure 8.
It also has a cam 561 that is part of the speed monitoring assembly 560 of the x-ray tube 500. The speed monitoring assembly 560 also includes two spaced apart iron segments 562, 563 that extend through the cylindrical wall 525 of the cup 520 (inner sleeve 528).
).

A magnet 564 is arranged over one of the segments;
A Hall device 565 is installed on the other segment, and an iron bar 566 connects these magnets and the Hall device. The cam 561 has iron lobes 568 which, when passing through the iron segments 562, 563, close the magnetic flux loop through the Hall device.

A signal is therefore generated from the Hall device, which indicates the speed at which the anode is rotating.

It is convenient to install the cam 561 adjacent to the rotor,
It may be incorporated into the rotating anode assembly structure by copper casting with the rotor. As is clear, the cam
It may consist of any ferrous element mounted on or near the exterior surface of the rotating anode assembly and positioned and dimensioned to create or break a magnetic flux loop through the Hall device.

A rotating anode assembly 540 is mounted on stud 558 by bearings 542, 543 and biased toward the cathode end of the x-ray tube by a spring 544 similar to that described above with respect to x-ray tube 400.

The motor stator 570 is similar to that previously described and has windings 571 in accordance with known motor technology. For example, the windings may be provided for two-phase or six-sum operation.

The motor can be operated with standard frequency alternating current, but is preferably energized by a variable frequency motor controller (not part of this invention).

X-ray tube 500 can be effectively driven primarily because the use of segment walls reduces the effective gap between the stator and rotor.

It will be appreciated that the x-ray tube shown and described herein is a preferred embodiment, and many changes may be made by those skilled in the art without departing from the spirit or scope of the invention. As a very basic example, various drive means can be used in combination with a rotating cathode or a fixed earth cathode,
It is even possible to suitably modify the tube envelope of the wire tube to accommodate the drive device according to the invention. Similarly, structural changes may be made to the illustrated tubing, terminals, bearing locations, etc. Accordingly, the invention is limited only by the scope of the claims.

[Brief explanation of drawings]

Figure 1 is a partially cutaway cross-sectional view of an X-ray tube according to the present invention, Figure 2 is a sectional view taken along line 15-15 of Figure 1, and Figure 6 is a longitudinal section of another X-ray tube according to the present invention. Fig. 4 is a sectional view taken along line 17-17 of Fig. 3 and shows the drive motor, Fig. 5 is a sectional view taken along line 18-18 of Fig. 3, and Fig. 6 is the main This is a fragmentary vertical cross-sectional view of another X-ray tube according to the invention, particularly showing the drive motor part.
Figure 8 is a cross-sectional view taken along line 21-21 of Figure 6, Figure 9 is a cross-sectional view taken along line 22-22 of Figure 6, and Figure 10 is a cross-sectional view taken along line 21-21 of Figure 6.・Figure 6 is a schematic diagram showing the assembly stage when manufacturing the X-ray tube. Figure 11 is a schematic diagram further illustrating the assembly stage when manufacturing the X-ray tube shown in Figure 6. [Explanation of symbols of main parts] X-ray tube −11−−−−−−−−−−−−−−−−−−
−−−−m−−−−−−−−−−−−'−220 anode drive device −−−−−−−=−−−−−−−−−−−−−
250 axes-------------1-=----------
---45 tube container---1--------
−−−−−1−−−−−−−−−−−−−−−1・2
0 katsupoo---11------------
---11111~---223 Permanent magnet rotor---1111---1---1----
−−−−・265 Stator−−−−−−−−=−−−−−
−−−−−−−−−−−−−−−−−−−−−240
Iron segment −−−−−−−−−−−−−−−−−1 to −−225,226 coil, −1111−−−−−−
−−−−〜−−−−−−−−−−−1−−245,24
6 sensor---=-'-----=-----
−−−−−= 250 drive motor −−−−−−−=−−
−−−−−−−=−=−=−−−−470 rotor−−−
−−”−−−−−−−−−−−1=−−−−−−” 4
71 Tube container--------------
---1---------410 permanent magnet--
−−−−−−−−−−−−−−−1111−−−−−1=−= 472 Shanku−1−−−−−−−−−−−
−−−−−−−−−1111−−−−−−−−−・4
56 stats
-111～-------"418 End wall-1---------
−−−−−−…−1−−−477, 47f3 permanent a
Stone--------------
--472a~472 fX-ray tube-1--------For shaft---11--------
400 tube container
11111--------------410 Yang
Pole---1---Yamaichi------1-
−−−−−−−−−−−−・451 drive motor−−−
−−−−〜−−−−−−−−−−−−−−−−−−−−
--111.470 cups 11---111------
−−−−−−−−−−1 −−−−−・4
15 rotation anode assembly---------=-1------
--450 Ceramic insulator, ---------For 111---455 Shank-1------
−−−−−−−−−−−−−1−−−−−−−−−−
To-456 day school --=----------=-
−−−−−458 Stator−−−−−−−−−−=−=
-480 Procedural Amendment June 2, 1980 Director of the Patent Office Mr. Kazuo Wakasugi 1゜Indication of Case 1980 Patent Application No. 210712 2
, Title of the invention 3 Relationship with the person making the amendment Patent applicant 4 Agent (2) ``Application'' (1) As shown in the attached sheet, we will submit one copy each of the power of attorney and the translation. (2) We will submit one amended application form that accurately states the name of the representative of the applicant in paragraph 4 of the application dated December 2, 1980. (3) We will submit one official drawing as shown in the attached sheet.

Claims (1)

[Scope of Claims] 1. A. An evacuated tube container having a window through which X-rays from the inside can pass; B. A cathode installed in this tube container; C6 A cathode rotatably installed in this tube container. an anode; D. a variable speed anode drive for rotating the anode, comprising: 1) mounted within the vessel adjacent to the wall of the vessel for rotation with the anode as a rotating anode assembly; an internal rotor including at least one permanent magnet having at least two magnetic poles;
2) a DC stator located outside the tube vessel and having a number of magnetic pole pieces equal to or greater than the number of magnetic poles of the permanent magnets of the internal rotor; and 3) a pulse applied to this DC stator. an electric device connected to E, the anode, and the cathode for generating X-rays; An X-ray tube in which the anode rotates while the X-ray tube is operating and generates X-rays, preventing rapid deterioration of the anode. 2. The X-ray tube according to claim 1, characterized in that the permanent magnet is a rare earth magnet sealed in a non-ferrous casing so as not to contaminate the inside of the evacuated tube container. X-ray tube. 6.% An X-ray tube according to claim 2, wherein the at least one permanent magnet includes an even number of permanent magnets, the permanent magnets extending longitudinally on the outwardly facing surface of the polygonal iron sleeve. The ferrous sleeve provides alternating north and south poles on the outer surface of the rotor, the ferrous sleeve also provides a magnetic flux path between the magnets, and non-ferrous spacers are placed around the sleeve between adjacent magnets. An X-ray tube characterized by: 4. The X-ray tube according to claim 6, wherein at least a portion of the spacer and the casing are integrally formed of copper by a steel casting method.
wire tube. 5. An X-ray tube according to claim 2, wherein the anode is mounted on a ceramic insulator having a shank projecting in the opposite direction thereof, and the rotor/casing includes a cylindrical outer sleeve. An X-ray tube, characterized in that the sleeve extends over at least a portion of the shank and is affixed thereto to mount the rotor to the anode. 6. An X-ray tube according to claim 6, wherein the anode is mounted on a ceramic insulator having a shank projecting in the opposite direction thereof, the rotor/casing includes a cylindrical outer sleeve, X characterized in that the sleeve extends over at least a portion of the shank and is affixed thereto to mount the rotor to the anode.
wire tube. 2. The X-ray tube according to claim 1, wherein the axial length of the rotor magnet is greater than the axial length of the stator, and the rotor magnet extends beyond the rotor in the opposite direction of the anode. an x-ray tube, wherein the rotating anode assembly is biased into abutment with a structural stop that positions the anode relative to the cathode. 8. The X-ray tube according to claim 1, wherein the tube container includes an end wall facing the anode, and the end wall has a cathode;
An X-ray tube characterized in that the anode is mounted with a structural stop to which the anode is biased. 9. The X-ray tube according to claim 8, wherein the structural stop includes an insulating stud extending from the end wall of the tube vessel, and the free end of the stud is provided with a conductive terminal connected to a bi-anode power cable. , wherein the portion of the rotor anode assembly biased into contact with the terminal is a conductive plate electrically connected to the anode. In the X-ray tube according to paragraph 1, a rotor is disposed within a cup portion of the tube housing, the cup portion including a stud projecting axially into an axial opening in the rotor, and a rotating anode assembly. An X-ray tube, characterized in that the X-ray tube is rotatably mounted on the stud by three-dimensionally spaced bearings. 11. The X-ray tube according to claim 1, further comprising: or include a sensor that senses speed or both, and the output of the sensor is used to control the timing of pulses to the DC stator to control the speed at which the anode rotates, or to ensure that the anode rotates at a desired speed. 12. The X-ray tube according to claim 11, wherein:
An X-ray tube characterized in that the axial length of the rotor is greater than the axial length of the stator, and the sensor is a Hall device installed outside the tube vessel and in the path of the rotor magnet. 13. The X-ray tube according to claim 1, wherein the tube container is made of a non-ferrous metal. 14. The X-ray tube according to claim 13, wherein the tube container includes a cup made of non-ferromagnetic metal, the cup closely receives the rotor and is surrounded by the stator, An X-ray tube characterized in that the other parts of the tube container are made of copper. 15. The X-ray tube according to claim 1, wherein the portion of the tube vessel wall between the rotor and the stator is made of alternating ferrous and non-ferrous segments, and the ferrous segments are extensions of the stator. 1. An X-ray tube characterized in that it acts as an X-ray tube to reduce the effective air gap between the stator and the rotor. 16. In the X-ray tube according to claim 1,
The tube vessel is constructed of metal and is mounted within a tube housing containing a generally cylindrical sidewall spaced apart from the tube vessel, the fan being mounted to flow air through the tube housing to cool the tube vessel. An X-ray tube comprising: 17 In the X-ray tube according to claim 16, a fan is installed to flow air to a portion of the tube container on the opposite side of the anode, and a cooling effect is exerted on a portion of the tube container that receives radiant heat from the anode. An X-ray tube characterized by maximizing the 18. The X-ray tube according to claim 16, further comprising a filter mounted in the tube housing and slidable to a position covering the window of the tube container. X-ray tube. 19A, an evacuated tube having a window through which X-rays from the inside can pass, B. a cathode mounted within this tube, C0 an anode rotatably mounted within this tube, D. this anode. A rotating variable speed anode drive comprising: 1) mounted within a tube vessel adjacent to its wall and adapted to rotate with the anode as a rotating anode assembly; 2) an AC stator that is installed outside the tube vessel and surrounds the rotor; and 6) an AC stator that applies AC current to drive the internal rotor. E, an electric device connected to the anode, the cathode, and generating X-rays, the variable speed anode drive device including a device for generating an electric field and rotating the anode; and the rotor includes ferrous segments separated from each other by non-ferrous spacers, these ferrous segments acting as extensions of the stator to maintain effective air flow between the rotor and stator. An X-ray tube characterized in that the gap is reduced. 2. The X-ray tube according to claim 19, in which the iron segments are laminated to reduce eddy currents, and the tube vessel further covers the laminated iron segments to maintain vacuum integrity within the tube vessel. An X-ray tube characterized in that it includes a thin non-ferrous sleeve. 2. The X-ray tube according to claim 19, in which the iron segments are laminated to reduce eddy currents, and the tube vessel further includes a sleeve covering the laminated iron segments, and the sleeve prevents the vacuum in the tube vessel. An X-ray tube characterized in that it is of such material and thickness that it can maintain the integrity of the tube but does not disturb the magnetic circuit. 2. Xa according to claim 2o or 21
In the tube, non-ferrous spacers are inserted through openings in the existing laminates, contain bins that keep these laminates aligned during wall fabrication, and reduce the radial width of the laminates in the final wall. x characterized by exposing a non-ferrous bottle
A tube. 23. In the X-ray tube according to claim 2G or 21, the rotor includes a plurality of laminated bodies and is sealed in a non-ferrous casing to prevent contamination of the evacuated tube container. An X-ray tube characterized by: 2. An X-ray tube according to claim 26, wherein the anode is mounted on a ceramic insulator having a shank projecting opposite thereto, the rotor casing includes a cylindrical outer sleeve, and the rotor casing includes a cylindrical outer sleeve; An x-ray tube, characterized in that a sleeve extends over and is affixed to at least a portion of the shank for attaching the rotor to the anode. 2. An X-ray tube according to claim 24, characterized in that the rotor casing includes a sleeve, and the non-ferrous longitudinal segments of the rotor are integrally formed of copper by a steel casting process. X-ray tube. 26. The X-ray tube according to claim 25, characterized in that the shank of the insulator is non-cylindrical and interlocks with the copper sleeve to provide a good structural connection between the shank and the rotor. X-ray tube. 27 The X-ray tube according to claim 19, further comprising a speed sensor device, the speed sensor device comprising: 1) two spaced apart tubes disposed on the tube vessel wall adjacent to the rotor; 2) a permanent magnet with one magnetic pole located in one of these segments, 6) a Hall device located in the other segment, and 4) a Hall device with the other magnetic pole of the magnet. 5) an iron rotor segment positioned to pass near two iron wall segments and pass near a magnetic flux loop through a Hall apparatus. 28. An X-ray tube according to claim 27, characterized in that the iron rotor segment includes a cam with iron lobes. 29. The X-ray tube according to claim 19, wherein the rotor is located in a cup portion of the tube vessel, and the cup portion protrudes axially into an axial opening in the rotor. a rotating anode assembly rotatably mounted on the stud by spaced bearings with a spring arrangement disposed therebetween, whereby the rotating anode assembly positions the anode relative to the cathode; An X-ray tube characterized by being moved to one side so that it can collide with a stop. 30 In the X-ray tube according to claim z9, the tube container has an end wall facing the anode, and the cathode and the anode are mounted on this end wall. Characteristic X-ray tube. 61. The X-ray tube of claim 50, wherein the structural stop includes an insulating stud projecting from the end wall of the tube vessel, the stud having a conductive terminal at its free end;
This terminal is connected to the anode power cable, and the rotor
An X-ray tube characterized in that the portion of the anode assembly biased to contact the terminal is a conductive plate electrically connected to the anode. 32. An X-ray tube according to claim 19, wherein the tube envelope is made of metal and is mounted within a tube housing, the tube housing including a generally cylindrical side wall spaced from the tube envelope. and further comprising a fan mounted to flow air through the tube housing to cool the tube envelope. 6b In the X-ray tube described in claim 32,
An X-ray tube characterized in that a fan is installed to flow air from a tube container portion on the opposite side of an anode, and the cooling effect is maximized in the tube container portion that receives radiant heat from the anode. 34. The X-ray tube according to claim 52, further comprising a filter mounted in the tube housing and slidable to a position covering the window of the tube container. . 35, of the type comprising a metal tube, a rotating anode assembly therein, a device for driving the assembly, a cathode, and a power supply comprising a power cable for powering the anode and cathode. In an X-ray tube, the power cable is the anode,
It includes a terminal arrangement for connection to the cathode, the terminal arrangement extending in a sealed manner through a generally flat end wall of the tubing and extending over a flat surface perpendicular to the end wall on the outside of the tubing. B. a plug receptacle mounted on the flat surface of the stud; and a wire device embedded within the stud and extending from the plug receptacle to the interior of the tube for connection with the anode or cathode. and D. a metal shielding device mounted on the C0 end wall and having one end surrounding the protruding stud and an open end of the fang two spaced therefrom; an insulating material forming an aperture extending from the flat surface to the open end of the metal shield; and a terminal end fitting for placing a vial into the plug receptacle. 66 In the X-ray tube according to claim 65, a small air flow path is formed from the flat surface of the stud to the outer surface of the metal shield, and when the terminal end fitting is inserted, the As the material opens, air escapes.