ROTARY JOINT WITH SHIELDING COMPRISING FILLED SMC AND/OR BMC MATERIALS

Abstract

A CT scanner with a device configured to improve the electromagnetic properties and/or the shielding of the rotation transmission devices in the CT scanner. A corresponding method for improving the electromagnetic properties and/or the shielding, of the rotation transmission devices inserted in the CT scanner.

Claims

1. A rotary joint comprising: at least one shielding component made of a SMC material, the SMC material enclosing at least one of an electrically conductive material and a magnetically conductive material.

2. A rotary joint according to claim 1, wherein said shielding component comprises a mixture of a plastic material and glass fibers.

3. A rotary joint according to claim 2, wherein the plastic material is uncured.

4. A rotary joint according to claim 1, further comprising a plastic material, wherein the plastic material comprises carbon nanotubes as fillers.

5. A rotary joint according to claim 1, further comprising a plastic material, wherein at least one of an electrically conductive material and a magnetically conductive material comprises at least one metal in at least one of the following forms: a powder, a granulate, a film, a paste, fiber, and a fabric.

6. A rotary joint according to claim 5, wherein the at least one metal present in a form of a filler comprises at least one of ferrite, copper, aluminum, mu-metal, iron and steel.

7. A rotary joint comprising at least one shielding component that includes a BMC material with at least one of (i) an electrically conductive material and (ii) a magnetically conductive material enclosed therein.

8. A rotary joint according to claim 7, wherein said MBC material includes a molding material containing plastic with glass fibers.

9. A rotary joint according to claim 7, wherein the plastic contains carbon nanotubes as fillers.

10. A rotary joint according to claim 7, wherein said at least one of (i) an electrically conductive material and (ii) a magnetically conductive material comprises at least one metal in at least one of the following forms: a powder, a granulate, a film, a paste, a fiber, and a fabric.

11. A rotary joint according to claim 10, wherein the at least one metal present in a form of a filler comprises at least one of ferrite, copper, aluminum, mu-metal, iron, and steel.

12. A rotary joint according to claim 7, wherein said at least one shielding component constitutes a casting mold and a casting compound, said casting compound being inside the casting mold.

13. A CT scanner comprising a rotary joint according to claim 1, and further comprising at least a gantry, an x-ray source, and an x-ray detector.

14. A CT scanner with a rotary joint according to claim 7, and further comprising at least a gantry, an x-ray source, and an x-ray detector.

15. A method for manufacturing a shielding component of a rotary joint, the method comprising: providing a piece of SMC material having at least one of (i) an electrically conductive material and (ii) a magnetically conductive material enclosed therein, wherein the SMC material comprises a first film, a second film, and a mixture of a plastic material with glass fibers, wherein said mixture together with the at least one of (ii) the electrically conductive material and (ii) the magnetically conductive material is enclosed between the first and second films; removing at least one of the first and second film, and curing the mixture.

16. A method according to claim 12, further comprising inserting additional plastic or metal parts in said mixture prior the curing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In the following, the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment and with reference to the drawings.

[0046] FIG. 1 shows a general structure of a rotary joint for CT scanners with data link, power transmission and shielding.

[0047] FIG. 2 shows a partial section of another rotary joint for CT scanners with a rearward mounted shielding.

[0048] FIG. 3 shows a partial section of another rotary joint for CT scanners with a shielding arranged between data link and power transmission.

[0049] FIG. 4 shows the schematic structure of a CT scanner.

[0050] FIG. 5 shows a detail of a rotary joint for a CT scanner with mounted shield.

[0051] FIG. 6 shows a shell of SMC or BMC for casting and subsequent processing.

[0052] FIG. 7 shows filled SMC material in conjunction with conductive layers.

[0053] FIG. 8 shows a filled SMC or BMC material with carbon nanotubes.

[0054] While embodiments of the invention may be varied or modified, specific embodiments thereof are shown by way of example in the drawings and are further described in detail. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to any particular form disclosed, but to the contrary, the scope of intention is intended to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.

DETAILED DESCRIPTION

[0055] FIG. 1 shows a contactless rotary joint in a CT scanner. It has a first machine part 100 and a second machine part 200 which are supported rotatably against each other and are rotatable about a common axis of rotation 101. The two machine parts 100, 200 being rotatable relative to each other are preferably designed similarly in shape.

[0056] Preferably, the machine parts 100, 200 can have an approximately disk-shaped contour. However, they can also be formed as a drum. Both embodiments preferably have a free inner diameter. This is generally common in CT scanners for bearing the X-rayed object. Objects may be human or animal patients or other items such as luggage or plants.

[0057] The rotary joint comprises a first contactless data link (110, 111, 112, 213, and 214), a second contactless data link (210, 211, 212, 113, and 114) and a rotary transformer 300.

[0058] The first contactless data link comprises a transmission line structure 110 for contactless transmission of the data, a transmitter 111 for feeding the data in the transmission line structure 110, a receiver 213 for receiving the data from the transmission line structure 110, and a holding bracket 214 for guiding the receiver 213 at the transmission line structure 110. The transmission line structure may be, for example, a strip line or other suitable structure.

[0059] The second contactless data link comprises a transmission line structure 210 for the contactless transmission of the data, a transmitter 211 for feeding the data in the transmission line structure 210, a receiver 113 for receiving the data from the transmission line structure 210, and a holding bracket 114 for guiding the receiver 113 at the transmission line structure 210. The holdings 112 and 212 are used for mechanical fixation of the holding bracket 114 as well as the transmission line structures 110 and 210.

[0060] For power transfer, the CT scanner is equipped with a rotary transformer 300. It has a core 120 on the first machine part 100, which may be configured E-shaped in this advantageous embodiment. A first primary-side winding 121, 122 is wound on this E-shaped core. The magnetic core 120 may consist of multiple pieces to improve mounting properties.

[0061] The secondary-side winding of the rotary transformer 221, 222 is arranged on the second machine part, which winding is also wound on an advantageously E-shaped core 220. Other core geometries are conceivable, adapted to the specific requirements. It is obvious for a person skilled in the art to configure the primary and secondary part of the rotary transformer 300 symmetrically.

[0062] In this advantageous embodiment, the machine has a data link in each direction. It is obvious that also only one data link for one direction may be provided. Preferably, CT devices comprise at least one data link from a first machine part 100 to a second machine part 200.

[0063] The body of the rotary transformer 300 may preferably be made of plastics, in order to achieve isolating properties. It may be also made of metals, and in this case serves as an electromagnetic shield with good thermal conductivity. The big disadvantage of a metal body lies in high costs and high weight.

[0064] The core of the rotary transformer 300 may at least partially be surrounded by a shield 140, 240. The shield body made of metal or of SMC or BMC materials serves as an electromagnetic shield 140, 240 between the data transmission path 110, 210 and the body of the rotary transformer 300, as well as outwardly. The shield body 140, 240 may additionally be grounded, and may as well be designed as mechanically bearing part. In case of a multi-layer structure of the shield structure 140, 240, it has to be made sure to keep the capacity of the shield structure as low as possible, in order to avoid capacitive currents.

[0065] FIG. 2 shows a further alternative embodiment of a first machine part 100 of a CT scanner with a conductive back plate 140 made of metal, SMC or BMC material, which serves for heat dissipation and as a shield. The shield 140 may additionally be configured grounded. Additionally, in this embodiment a first sliding track 131 and a second sliding track 132 for transmitting electrical signals and/or for providing grounding for the second opposite machine part 200 are shown.

[0066] FIG. 3 shows a shielding 141 of BMC or SMC material which shields the capacitive data link from the rotary transformer and is also rotationally symmetrical about the rotational axis. Here, it is possible to integrate the shielding 141 in the first machine part 100 in the course of the production process.

[0067] FIG. 4 shows a CT scanner in which a contactless rotary joint for data links is used. The CT scanner consists of two mechanical base parts. A fixed part 310 which serves the basis for the rotating part 309. The patient 304 is on a table 307 in a free inner diameter of the rotating machine part 309. An X-ray tube 301 and an associated X-ray detector 303 are mounted opposite to the rotating machine part, wherein the X-ray tube 302 emits the X-rays and the X-ray detector 303 receives them. The rotary transformer 300 ensures the electric power between the rotating machine part 309 and the stationary machine part. A control device 306 is used to control the CT scanner and for evaluation of the transmitted data. The communication between the CT scanner and the control device takes place via a wired data connection 305 or a wireless data connection 305.

[0068] FIG. 5 shows the first machine part 100 of a rotary joint with a shield 143 made of SMC or BMC material mounted on one side by at least one screw connection 153. The body of the rotary joint 100 is preferably equipped with a sliding track 131 which has been molded or glued in directly during production. Furthermore, a groove 109 for receiving the transmission line structure for a capacitive data link is provided.

[0069] The shield 143 may also be glued. The complete slipring is mounted in the device by means of at least one screw connection 153.

[0070] FIG. 6 shows a shield structure at the beginning of manufacturing. The U-shaped shell of BMC or SMC material, which will act as a shield 143, is filled with casting material 104, preferably made of non-conductive plastics, such as for example polyurethane or epoxy resins, in order to provide a higher mechanical strength to the entire shield structure. The casting material may additionally be filled with fillers. The U-shaped shell therefore serves as a mold. After casting with plastics or epoxy resins, the side edges can be cut to the required final size at the cutting lines 102, wherein the cutting edges 102 can be moved in direction 103.

[0071] FIG. 7 shows a composite of SMC material with a first film 400 and second film 410 and conductive layers 420 in a casting compound 460. The casting compound is filled with conductive fibers 430, carbon nanotubes 450 and glass fibers 440, for increasing the mechanical stability. The carbon nanotubes 450 as well as the conductive fibers 430 form percolation paths 470 (electrically conductive paths) between the conductive layers 420 at stochastically distributed locations.

[0072] FIG. 8 shows a detail of an SMC or BMC materials 460 filled with carbon nanotubes 450. One or more percolation paths 470 are generated by the statistical contact of the carbon nanotubes. Thereby, a power transfer inside the material and thus a shielding is effected.

[0073] It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to provide a shielding for a rotary joint or a rotary joint comprising a shielding. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims.

LIST OF REFERENCE NUMERALS

[0074] 100 first machine part [0075] 101 rotation axis [0076] 102 cutting edge [0077] 103 displacement direction [0078] 104 casting material [0079] 109 groove [0080] 110 transmission line structure [0081] 111 transmitter [0082] 112 holding device [0083] 113 receiver [0084] 114 holding bracket [0085] 120 core of the rotary transformer [0086] 121 winding [0087] 122 winding [0088] 131 first sliding track [0089] 132 second sliding track [0090] 140 shield [0091] 141 shield [0092] 143 shield [0093] 153 screw connection [0094] 200 second machine part [0095] 210 transmission line structure [0096] 211 second transmitter [0097] 212 holding device [0098] 213 receiver [0099] 214 holding bracket [0100] 220 core of the rotary transformer [0101] 221 winding [0102] 222 winding [0103] 240 shield [0104] 300 rotary transformer [0105] 301 X-ray tube [0106] 302 X-ray [0107] 303 X-ray detector [0108] 304 patient [0109] 305 data link [0110] 306 control panel [0111] 307 patient table [0112] 308 rotation direction [0113] 309 rotating machine part [0114] 310 stationary machine part [0115] 400 first film [0116] 410 second film [0117] 420 conductive intermediate layer [0118] 430 conductive fiber [0119] 440 glass fiber [0120] 450 carbon nanotubes [0121] 460 mass of SMC or BMC material [0122] 470 percolation path