US4468801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary anode X-ray tube
Assignee: Toshiba Corp
•
Filing: 1982-07-26
•
Granted: 1984-08-28
•
Expires: 2002-07-26
Abstract
Abstract An evacuated casing has outer and inner tubes respectively covering the outer and inner peripheries of a hollow cylindrical rotor. Ring members of a ferromagnetic material are provided in the inner wall of the rotor and face permanent magnets, which are provided on the inner periphery of the inner tube and are magnetized in the radial directions of the rotor. The permanent magnets are fitted on a cylindrical yoke between first and second poles formed thereon, the fluxes being inserted in the rotor via the inner tube. The first poles are disposed to face the respective ring members, while the second pole is disposed to face the opposed end faces of the ring members. With this arrangement, contactless magnetic bearings are formed to support the rotor stably.
Inventors
- 👤 Hajime Sudo
- 👤 Atsushi Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:18
CPC Classifications
F; F16; F16C; F16C37/00; F16C37/005; F16C32/00; F16C32/04; F16C32/0406; F16C32/044; F16C32/0474; H; H01; H01J; H01J35/00; H01J35/02; H01J35/04; H01J35/08; H01J35/10; H01J35/101; H01J35/1017; H01J35/103
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
284 words
A rotary anode X-ray tube comprising: a hollow cylindrical rotor made of a material other than a ferromagnetic material having one end closed by a closing plate and having the other end open; a conductive shaft member secured to said closing plate and having an outwardly projecting portion coaxial with said rotor and projecting from said closing plate; a rotary anode secured to said projecting portion; a cathode disosed to face a rotating peripheral surface of said rotary anode; at least one ring member made of a ferromagnetic material provided on the inner periphery of said rotor; an evacuated casing made of a material other than a ferromagnetic material including an outer tube covering said cathode, rotary anode and outer periphery of rotor and having an X-ray emission window and an inner tube covering the inner periphery of said rotor and united by a uniting portion covering the open end of said rotor to said outer tube; at least one permanent magnet magnetized in the radial direction of said rotor and having one of the opposite pole sides, i.e. N and S magnetic poles, in contact with the inner periphery of said inner tube; a yoke provided inside said inner tube and in contact with the other pole end of said permanent magnet, said yoke having first and second poles provided on the inner periphery of said inner tube corresponding to the opposite sides of said permanent magnet in the axial direction of said rotor, said second pole corresponding to one of the opposite ends of said ring member; a control winding wound on at least one of said first and second poles; and means for giving a rotational driving force to said rotor.
Claim 2
Dependent Claim
284 words
A rotary anode X-ray tube comprising: a hollow cylindrical rotor made of a material other than a ferromagnetic material having one end closed by a closing plate and having the other end open; a conductive shaft member secured to said closing plate and having an outwardly projecting portion coaxial with said rotor and projecting from said closing plate; a rotary anode secured to said projecting portion; a cathode disosed to face a rotating peripheral surface of said rotary anode; at least one ring member made of a ferromagnetic material provided on the inner periphery of said rotor; an evacuated casing made of a material other than a ferromagnetic material including an outer tube covering said cathode, rotary anode and outer periphery of rotor and having an X-ray emission window and an inner tube covering the inner periphery of said rotor and united by a uniting portion covering the open end of said rotor to said outer tube; at least one permanent magnet magnetized in the radial direction of said rotor and having one of the opposite pole sides, i.e. N and S magnetic poles, in contact with the inner periphery of said inner tube; a yoke provided inside said inner tube and in contact with the other pole end of said permanent magnet, said yoke having first and second poles provided on the inner periphery of said inner tube corresponding to the opposite sides of said permanent magnet in the axial direction of said rotor, said second pole corresponding to one of the opposite ends of said ring member; a control winding wound on at least one of said first and second poles; and means for giving a rotational driving force to said rotor.
Claim 3
Dependent Claim
22 words
The rotary anode X-ray tube according to claim 1, wherein said evacuated casing is made of a material having a high emissivity.
Claim 4
Dependent Claim
24 words
The rotary anode X-ray tube according to claim 1, wherein a cooling medium path is formed along the outer periphery of said evacuated casing.
Claim 5
Dependent Claim
25 words
The rotary anode X-ray tube according to claim 1, wherein a cooling medium path is formed in said yoke and also in said permanent magnet.
Claim 6
Dependent Claim
69 words
The rotary anode X-ray tube according to claim 1, wherein a detector for detecting the displacement or the rate of displacement of said rotor in the axial directions thereof and directions normal to said axial directions is provided on the outer periphery of said outer tube, and also wherein units for supplying the flux by current in said control winding, according to the output of said detector, is provided.
Claim 7
Dependent Claim
47 words
The rotary anode X-ray tube according to claim 1, wherein said conductive shaft member includes a portion coaxially extending in said hollow cylindrical rotor and said inner tube of said evacuated casing has a closed end having a central hollow cylindrical projection surrounding said coaxially extending portion.
Claim 8
Dependent Claim
30 words
The rotary anode X-ray tube according to claim 6, wherein emergency ball bearings are provided on the inner periphery of said central hollow cylindrical projection along said coaxially extending portion.
Claim 9
Dependent Claim
52 words
The rotary anode X-ray tube according to claim 1, wherein a contact member is provided in a bottom portion of said central hollow cylindrical projection of said inner tube so as to face the corresponding end of said coaxially projecting portion, and an anode current lead conductor connected to said contact member.
Claim 10
Dependent Claim
30 words
The rotary anode X-ray tube according to claim 1, wherein a ferromagnetic ring member is provided on the pole surface of said permanent magnet on the side nearer the rotor.
Claim 11
Dependent Claim
28 words
The rotary anode X-ray tube according to claim 1, wherein one end of said ring member has an end face extending normal to the axis of said rotor.
Claim 12
Dependent Claim
29 words
The rotary anode X-ray tube according to claim 10, wherein said ring member consists of a plurality of thin ring elements laminated in the axial direction of said rotor.
Claim 13
Dependent Claim
18 words
The rotary anode X-ray tube according to claim 11, wherein said ring elements are made of silicon steel.
Claim 14
Dependent Claim
25 words
The rotary anode X-ray tube according to claim 11, wherein said ring member is made of a sintered material or of a press powder material.
Claim 15
Dependent Claim
33 words
The rotary anode X-ray tube according to claim 10, wherein said means for giving a rotational driving force to said rotor includes a stator provided on the outer periphery of said outer tube.
Claim 16
Dependent Claim
27 words
The rotary anode X-ray tube according to claim 14, wherein a conductive ring is provided on a portion of said rotor corresponding in position to said stator.
Claim 17
Dependent Claim
26 words
The rotary anode X-ray tube according to claim 14, wherein at least a portion of said rotor facing said stator is made of a conductive material.
Claim 18
Dependent Claim
16 words
The rotary anode X-ray tube according to claim 16, wherein said conductive material is titanium alloy.
Claim 19
Dependent Claim
70 words
The rotary anode X-ray tube according to claim 15, wherein said two ring members made of ferromagnetic material are provided on the inner periphery of said hollow cylindrical rotor and spaced apart at a predetermined distance in the axial direction of said rotor, and said conductive ring is provided on a portion of the outer periphery of said rotor corresponding to the inner periphery portion thereof, between said ring members.
Claim 20
Dependent Claim
34 words
The rotary anode X-ray tube according to claim 15, wherein said conductive ring is provided on the inner periphery of said rotor between said two ferromatnetic rings in the axial direction of said rotor.
Claim 21
Dependent Claim
53 words
The rotary anode X-ray tube according to claim 15, wherein said conductive ring is provided on a portion of the outer periphery of said rotor corresponding to the inner periphery portion of the center of the ring member in case of providing a single ring member on the inner surface of the rotor.
Claim 22
Dependent Claim
60 words
The rotary anode X-ray tube according to claim 1, wherein the anode current supplying means is so supported on a ball bearing as to allow the projection portion of the shaft rotate with substantially the same rotation speed as that of the top of the anode current supplying means, when the projection portion of the shaft contacts with said top.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-28 | 1988-02-27 | 1988-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-28 | 1992-02-27 | 1992-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-28 | 1996-02-27 | 1996-08-28 | $7700.00 | Window Closed / Lapsed |