X-ray CT apparatus

Abstract

To provide an X-ray CT apparatus that allows abrasion powder to be recovered while a rotary frame is rotating.SOLUTION: An X-ray CT apparatus includes: a fixed frame; a rotary frame that can rotate relative to the fixed frame, and is equipped with an X-ray source and an X-ray detector; a slip ring that rotates in synchronization with the rotary frame; an electric power supply brush and a signal transmission brush brought into contact with the slip ring; a cover for covering the slip ring, the electric power supply brush, and the signal transmission brush; and a collection container with an opening provided in the cover for collecting abrasion powder, the opening being positioned downward in a gravity direction relative to the electric power supply brush, and extending to a side in a progressing direction of an air flow generated by the rotation of the slip ring.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an X-ray CT apparatus, and more particularly to an X-ray CT apparatus equipped with a brush and a slip ring. [Background technology]

[0002] Generally, an X-ray CT scanner has a slip ring unit as a means for supplying power and transmitting signals between a fixed frame and a rotating frame that continuously rotates. The slip ring unit has multiple slip rings that rotate together with the rotating frame and brushes that contact the slip rings.

[0003] Typically, the brushes are in sliding contact with the slip ring to maintain electrical connection, and therefore, when the slip ring rotates, conductive wear particles are generated due to the sliding contact between the slip ring and the brushes.

[0004] Patent Document 1 discloses an X-ray CT device that includes a cover to prevent wear debris from scattering, a collection container disposed below the rotating frame, and a collection container disposed below the brushes to deal with the generation of wear debris. The collection container below the brushes collects falling wear debris, while the collection container below the rotating frame collects wear debris that has flowed down the cover when rotation has stopped. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-027239 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, X-ray CT systems are equipped with two types of brushes: power supply brushes for power supply and signal transmission brushes for signal transmission. The power supply brushes have a larger contact area with the slip ring than the signal transmission brushes. This means that the size of the wear particles from the power supply brushes is larger than that from the signal transmission brushes. For this reason, X-ray CT systems need to collect two types of wear particles of different sizes.

[0007] Furthermore, even if a cover is installed to prevent wear debris from scattering, it can still escape through gaps, so it is preferable to guide and collect the wear debris while the rotating frame is rotating. If the wear debris escapes the cover, it will scatter inside and outside the device, requiring extensive cleaning. It can also accumulate in the filters of the device's cooling fan, reducing cooling efficiency.

[0008] The present invention has been made to solve the above-mentioned problems, and has an object to provide an X-ray CT apparatus that can collect wear debris while the rotating frame is rotating. [Means for solving the problem]

[0009] The X-ray CT device of the first embodiment comprises a fixed frame, a rotating frame rotatable relative to the fixed frame and equipped with an X-ray source and an X-ray detector, a slip ring that rotates in synchronization with the rotating frame, a power supply brush and a signal transmission brush that contact the slip ring, a cover that covers the slip ring, the power supply brush and the signal transmission brush, and a collection container provided in the cover and having an opening for collecting wear powder, the opening being located below the power supply brush in the direction of gravity and extending in the direction of the air flow generated by the rotation of the slip ring.

[0010] In the X-ray CT apparatus of the second aspect, the opening widens toward the cover.

[0011] In the X-ray CT apparatus of the third aspect, the collection container extends in a tangential direction to the outer periphery of the cover.

[0012] The X-ray CT apparatus of the fourth aspect includes a porous member disposed inside the collection container.

[0013] In the X-ray CT apparatus of the fifth aspect, the power supply brush is located below, in the direction of gravity, an imaginary horizontal line passing through the rotation axis of the rotating frame.

[0014] In the X-ray CT apparatus of the sixth aspect, the power supply brush and the signal transmission brush are arranged at different positions in the circumferential direction of the slip ring.

[0015] In the X-ray CT apparatus of the seventh aspect, the power supply brush and the signal transmission brush are arranged at the same position in the circumferential direction of the slip ring.

[0016] In the X-ray CT apparatus of the eighth aspect, the signal transmission brush is disposed upstream of the power supply brush in the rotation direction of the slip ring.

[0017] In the X-ray CT apparatus of the ninth aspect, the cover is disposed on the opposite side of the slip ring from the fixed frame. [Effects of the Invention]

[0018] According to the present invention, wear debris can be collected while the rotating frame is rotating. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view illustrating the overall appearance of an X-ray CT apparatus. [Figure 2] FIG. 2 is a front view of the rotating disk part of the X-ray CT apparatus with the gantry cover removed. [Figure 3] 3 is a front view of the rotary disk unit of FIG. 2 with the rotary frame removed. [Figure 4] 4 is a cross-sectional view of the rotary disk portion of FIG. 2 taken along line 4-4. [Figure 5] FIG. 2 is a diagram illustrating a slip ring and a brush arranged on a gantry. [Figure 6]6 is a cross-sectional view taken along line 6-6 of FIG. 5. [Figure 7] 7 is a cross-sectional view taken along line 7-7 of FIG. 5. [Figure 8] FIG. 2 is an enlarged view of the collection container of the first embodiment. [Figure 9] FIG. 10 is a diagram for explaining a modified example. [Figure 10] FIG. 10 is a diagram for explaining a second embodiment. [Figure 11] 11-11 cross-sectional view of FIG. 10. DETAILED DESCRIPTION OF THE INVENTION

[0020] First Embodiment An X-ray CT (Computed Tomography) apparatus according to one embodiment of the present invention will be described.

[0021] The structure of the X-ray CT device of this embodiment is shown in Figures 1 to 8. Figure 1 is an external perspective view of the X-ray CT device, Figure 2 is a front view of the rotating disk unit with the gantry cover removed, and Figure 3 is a front view of the structure with the rotating frame removed from the rotating disk unit. Figure 4 is a 4-4 cross-sectional view of the rotating disk unit. Figure 5 is a diagram schematically showing slip rings and brushes arranged in the gantry 100 of the X-ray CT device. Figure 6 is a 6-6 cross-sectional view of Figure 5. Figure 7 is a 7-7 cross-sectional view of Figure 5. Figure 8 is an enlarged view of a collection container of this embodiment.

[0022] The three-dimensional coordinate system shown in FIG. 1 shows an example of the definition of directions in the X-ray CT scanner 1. The X-axis, Y-axis, and Z-axis of the three-dimensional coordinate system are an example and are not limited to this. For ease of understanding in the following description, the X-axis, Y-axis, and Z-axis in the X-ray CT scanner 1 are defined in the same direction in all figures. The Z-axis direction is the body axis direction of the subject. The Y-axis direction is the up-down direction of the subject, and is a direction parallel to the direction of gravity. The X-axis direction is the left-right direction of the subject, and is a horizontal direction perpendicular to the direction of gravity.

[0023] The X-ray CT apparatus 1 includes a gantry 100 , a bed 105 , an input device 121 , an image processing device 122 , and a display device 125 .

[0024] The gantry 100 includes a gantry cover 101 and a rotating disk unit 102 (see FIG. 2, etc.) disposed therein. The rotating disk unit 102 includes a rotating frame 40 having an opening 104, a fixed frame 30 that supports the rotating frame 40 from its rear side via bearings 5, a pulley 6 for driving the rotation of the rotating frame 40, and a tilt mechanism that supports the fixed frame 30 in a tiltable manner. The tilt mechanism includes a stand 10, side frames 3 fixed to the fixed frame 30, and bearings 12 that support the side frames 3 on the stand 10 in a tiltable manner. The fixed frame 30 is an example of a fixed frame of the present invention. The rotating frame 40 is an example of a rotating frame of the present invention.

[0025] The rotating frame 40 is equipped with an X-ray tube 51, an X-ray detection unit 56, a cooling device 52, a control unit 55, high-voltage generation units 54 and 53, etc. The rotating frame 40 rotates around the subject 2. The X-ray detection unit 56 is disposed opposite the X-ray tube 51. The X-ray detection unit 56 measures the spatial distribution of the transmitted X-rays by detecting X-rays that have passed through the subject 2. The X-ray tube 51 is an example of an X-ray source of the present invention. The X-ray detection unit 56 is an example of an X-ray detector of the present invention.

[0026] The image calculation device 122 performs calculation processing on the measurement data of the X-ray detection unit 56 to reconstruct a CT image. The display device 125 displays the CT image created by the image calculation device 122. The input device 121 accepts input of imaging conditions and the like from the operator.

[0027] 3 and 4, the fixed frame 30 is disposed on the rear side of the rotating frame 40 of the rotating disk unit 102. The fixed frame 30 has, for example, a polygonal shape when viewed from the front. The end of the fixed frame 30 on the rotating frame 40 side is connected to the outer ring 5a, which is the fixed portion side of the bearing 5, and supports the bearing 5.

[0028] A conical pulley 6 is disposed inside the opening 104 of the fixed frame 30, and the end of the pulley 6 on the rotating frame 40 side is connected to the inner ring 5b on the rotating part side of the bearing 5. The inner ring 5b of the bearing 5 is connected to the rotating frame 40.

[0029] A motor (not shown) is disposed, and a drive belt 8 is wound between the motor and the pulley 6. When the pulley 6 is rotated by the motor, the rotating frame 40 is rotated.

[0030] A plate-like, ring-shaped holding member 92 is attached to the tip (open end) of the pulley 6 via a connector 91. A slip ring 9 made up of a plurality of conductors is disposed on the holding member 92. The main plane on which the slip ring 9 of the holding member 92 is disposed is perpendicular to the rotation axis 23 of the rotating frame 40. Although an example has been shown in which the slip ring 9 is disposed on the holding member 92 attached to the rotating frame 40, the slip ring 9 can also be disposed on the rotating frame 40.

[0031] A plurality of cables 13 are connected to each of the slip rings 9. The plurality of cables 13 pass through the inside of the pulley 6 and reach a rotating frame 40 located in front of the bearing 5.

[0032] As shown in FIG. 5, the plurality of conductor rings constituting the slip ring 9 each have a different diameter, and are arranged concentrically with respect to the rotation axis 23 on the main plane of the holding member 92.

[0033] A power supply brush device 15 and a signal transmission brush device 16 are arranged in positions facing the slip ring 9. The power supply brush device 15 and the signal transmission brush device 16 are physically separated from each other. The power supply brush device 15 and the signal transmission brush device 16 are arranged in different positions in the circumferential direction of the slip ring 9, and the signal transmission brush device 16 is arranged upstream of the power supply brush device 15 and spaced apart in the circumferential direction in the rotation direction R of the slip ring 9. Upstream can be defined as when the slip ring 9 is divided into two equal parts by a line passing through the reference object (power supply brush device 15) and the rotation axis 23, and the comparison object (signal transmission brush device 16) is located on the left side in rear view.

[0034] The slip ring 9 is composed of a power supply conductor 9a and a signal transmission conductor 9b. The power supply conductor 9a is arranged on the outer side (opposite side from the rotation shaft 23) of the signal transmission conductor 9b. The power supply conductor 9a is configured to be wider than the signal transmission conductor 9b. Although the example shown is one in which the power supply conductor 9a is arranged on the outer side of the signal transmission conductor 9b, the power supply conductor 9a may also be arranged on the inner side (towards the rotation shaft 23) of the signal transmission conductor 9b.

[0035] A cover 20 for preventing scattering is arranged so as to surround the outer periphery of the slip ring 9. The cover 20 has an overall ring-like shape that matches the shape of the slip ring 9. A collection container 32 for collecting wear debris is provided in part of the cover 20. The collection container 32 will be described later.

[0036] The power supply brush device 15 and the signal transmission brush device 16 are disposed below, in the direction of gravity, an imaginary horizontal line HL that passes through the rotation axis 23 of the rotation frame 40 of the gantry 100 .

[0037] When the rotating frame 40 rotates around the rotating shaft 23, the slip ring 9 rotates in the rotation direction R indicated by the arrow in synchronization with the rotating frame 40. As the slip ring 9 moves in the rotation direction R, an air flow AF indicated by the arrow is generated.

[0038] 6, the slip ring 9 is disposed on the main plane opposite the fixed frame 30, with the holding member 92 sandwiched therebetween. The power supply brush device 15 includes a power supply brush 15a, and the power supply brush 15a comes into contact with the power supply conductor 9a of the slip ring 9.

[0039] As shown in FIG. 7, the signal transmission brush device 16 includes a signal transmission brush 16 a, and the signal transmission brush 16 a comes into contact with the signal transmission conductor 9 b of the slip ring 9.

[0040] As shown in Figures 6 and 7, the power supply brush 15a has a larger contact area with the slip ring 9 than the signal transmission brush 16a, corresponding to the respective widths of the power supply conductor 9a and the signal transmission conductor 9b.

[0041] In a cross-sectional view, a shatterproof cover 20 is arranged to cover the slip ring 9, the power supply brush device 15 (power supply brushes 15a), and the signal transmission brush device 16 (signal transmission brushes 16a). The cover 20 is located on the opposite side of the slip ring 9 from the fixed frame 30.

[0042] The cover 20 has a generally U-shape in cross section, with the side facing the fixed frame 30 being open. The two corners of the cover 20 may be rounded or angular (for example, right-angled) in cross section. The cover 20 covers the slip ring 9, the power supply brush device 15 (the power supply brushes 15a), and the signal transmission brush device 16 (the signal transmission brushes 16a), and therefore conductive wear powder generated by sliding contact between the slip ring 9 and the power supply brushes 15a and the signal transmission brushes 16a can be kept inside the cover 20.

[0043] The slip ring 9 is an example of a slip ring of the present invention. The power supply brush 15a is an example of a power supply brush of the present invention, and the signal transmission brush 16a is an example of a signal transmission brush of the present invention. The cover 20 is an example of a cover of the present invention.

[0044] 8, in the gantry 100 of the X-ray CT apparatus 1, a collection container 32 for collecting conductive wear particles is provided on the cover 20. The collection container 32 includes an opening 33 for receiving the wear particles D1 and D2, and a cylindrical container body 34 inside which the wear particles D1 and D2 are accumulated.

[0045] The opening 33 is connected to the cover 20 and serves as a receiving port for guiding the wear debris D1 and D2 that falls or scatters inside the cover 20 into the container body 34. The opening 33 is located below the power supply brush 15a in the direction of gravity and is arranged on the cover 20. If there are multiple power supply brushes 15a, it is sufficient that at least one opening 33 is located below the power supply brush 15a in the direction of gravity. The opening 33 has a shape that widens toward the cover 20. The widened shape means that the length L1 of the opening 33 is greater than the gap length L2 between the slip ring 9 and the cover 20. The shape of the opening 33 is not limited to this, and various shapes can be used.

[0046] The container body 34 has a cylindrical shape with an internal space, such as a cylindrical or rectangular pillar shape, and extends from the opening 33 in the direction FW of the airflow AF generated by the rotation of the slip ring 9. Here, the airflow AF is generated upstream of the opening 33 in the direction of rotation R, and the collection container 32 simply extends in the direction FW of the airflow AF. The extension direction of the collection container 32 and the direction FW of the airflow AF may be parallel, or they do not have to be parallel as long as the wear debris D1 and D2 can be collected in the collection container 32 by the airflow AF. The shape and size of the container body 34 can be changed as appropriate, as long as it has a space for accumulating the wear debris D1 and D2.

[0047] The container body 34 is preferably provided with a porous member 35 inside. The porous member 35 is made of a porous substance such as an open-cell sponge, and is preferably made of a synthetic resin such as polyurethane, polyethylene, or polyvinyl alcohol. The porous member 35 is one example of the porous member of the present invention.

[0048] <effect> The operation of the collection container 32 will be described with reference to Figure 8. The collection container 32 is positioned so that its opening 33 is located below the power supply brush 15a (not shown) of the power supply brush device 15 in the direction of gravity. The wear debris D1 generated by sliding contact between the power supply brush 15a and the power supply conductor 9a is large in size, and even when the slip ring 9 is rotating and airflow AF is being generated, the wear debris D1 often falls in the direction of gravity rather than scattering. Because the opening 33 of the collection container 32 is located below the power supply brush 15a in the direction of gravity, the collection container 32 can collect the wear debris D1 falling in the direction of gravity, even when the slip ring 9 is rotating.

[0049] Furthermore, in consideration of the fact that wear debris D1 falls in the direction of gravity, it is preferable that power supply brush 15a be located below an imaginary horizontal line HL passing through rotation shaft 23 in the direction of gravity, that is, in the lower half of gantry 100.

[0050] The signal transmission brush 16a (not shown) of the signal transmission brush device 16 is disposed upstream of the power supply brush 15a of the power supply brush device 15 in the rotation direction R. The collection container 32 is disposed downstream of the signal transmission brush 16a in the rotation direction R, and on the downwind side of the airflow AF as seen from the signal transmission brush 16a.

[0051] The size of the wear particles D2 generated by sliding contact between the signal transmission brush 16a and the signal transmission conductor 9b is small. When the slip ring 9 rotates and an air flow AF is generated, the wear particles D2 are carried by the air flow AF inside the cover 20 and move in the rotation direction R. The cover 20 is provided with a collection container 32 having a container body 34 that extends from an opening 33 in the direction of the air flow AF. The wear particles D2 carried downwind by the air flow AF move into the container body 34 through the opening 33, and the wear particles D2 can be collected in the collection container 32.

[0052] Even if the wear debris D1 scatters, it can be collected in the collection container 32 by the air flow AF.

[0053] Furthermore, the opening 33 of the collection container 32 has a structure that widens toward the cover 20, which makes it easier to reduce the pressure of the airflow AF while the slip ring 9 is rotating. As a result, scattering of the wear powder D2 by the airflow AF is suppressed. A downward force due to gravity is more likely to act on the wear powder D2, which makes it easier to guide the wear powder D2 into the collection container 32 and collect it.

[0054] According to the embodiment, the two types of wear debris D1 and D2 can be collected in the collection container 32 even while the slip ring 9 is rotating.

[0055] The porous member 35 disposed in the collection container 32 can capture the wear particles D1 and D2. This prevents the wear particles D1 and D2 from being scattered again even if turbulence occurs in the collection container 32 due to the airflow AF.

[0056] Even if the collection container 32 does not have a porous member 35, the wear powder D1 and D2 can be prevented from being re-scattered by increasing the size of the collection container 32 or by suctioning the collection container 32 from the side opposite the opening 33.

[0057] Furthermore, it is preferable that the collection container 32 extend in a tangential direction relative to the outer periphery of the cover 20. In other words, if the tangential direction and the extension direction of the container body 34 (the forward direction FW) are substantially parallel (including parallel), the wear powder D2 can be effectively collected in the collection container 32 by the air flow AF.

[0058] (Variation) 9 is a diagram for explaining a modified example of the first embodiment. The same reference numerals are used to designate parts common to the first embodiment described above, and the description thereof will be omitted.

[0059] The modified example shown in Figure 9 differs from the present embodiment shown in Figure 5 in terms of the positions of the power supply brush device 15 (including the power supply brush 15a), the signal transmission brush device 16 (including the signal transmission brush 16a) (not shown), and the collection container 32.

[0060] In the modified gantry 100a shown in Figure 9, the power supply brush device 15, the signal transmission brush device 16, and the collection container 32 are rotated approximately 30° in the clockwise direction (opposite to the rotation direction R) relative to the modified gantry 100 shown in Figure 5.

[0061] In the modified example shown in Figure 9, the opening 33 of the collection container 32 is located below the power supply brush device 15 (including the power supply brush 15a) in the direction of gravity, so even when the slip ring 9 is rotating, the wear powder D1 falling in the direction of gravity can be collected in the collection container 32 through the opening 33.

[0062] Furthermore, the signal transmission brush device 16 is disposed upstream of the power supply brush device 15 in the rotation direction R, and the collection container 32 is disposed downwind of the air flow AF from the signal transmission brush device 16. The container body 34 of the collection container 32 extends in the traveling direction FW of the air flow AF, so that the wear powder D2 carried by the air flow AF can be collected in the collection container 32 through the opening 33.

[0063] Second Embodiment 10 and 11 are diagrams for explaining the second embodiment. The same reference numerals are used to designate parts common to the first embodiment, and the description thereof will be omitted.

[0064] A gantry 100b of the second embodiment shown in FIG. 10 differs from the first embodiment in that it includes one brush device 14. As shown in FIG. 11, the brush device 14 includes a power supply brush 14a and a signal transmission brush 14b. The power supply brush 14a contacts the power supply conductor 9a. The signal transmission brush 14b contacts the signal transmission conductor 9b. As shown in FIGS. 10 and 11, in the second embodiment, the power supply brush 14a and the signal transmission brush 14b are arranged at the same position in the circumferential direction of the slip ring 9. The power supply brush 14a and the signal transmission brush 14b being at the same position in the circumferential direction means that the power supply brush 14a and the signal transmission brush 14b are included in a common brush device 14.

[0065] 10, the opening 33 of the collection container 32 is located below the power supply brush 14a of the brush device 14 in the direction of gravity. The container body 34 of the collection container 32 extends in the traveling direction FW of the airflow AF.

[0066] As in the first embodiment, even when the slip ring 9 is rotating, the wear particles D1 falling in the direction of gravity can be collected in the collection container 32 through the opening 33. Because the container body 34 of the collection container 32 extends in the direction FW of the air flow AF, the wear particles D2 carried by the air flow AF can be collected in the collection container 32 through the opening 33. Even when the slip ring 9 is rotating, the wear particles D1 and D2 can be collected in the collection container 32.

[0067] Furthermore, the signal transmission brush 14b is disposed upstream of the collection container 32 in the rotation direction R, and the collection container 32 is disposed downwind of the air flow AF from the signal transmission brush 14b. The container body 34 of the collection container 32 extends in the traveling direction FW of the air flow AF, so that the wear powder D2 carried by the air flow AF can be collected in the collection container 32 through the opening 33.

[0068] Furthermore, it goes without saying that the present invention is not limited to the above-described embodiment, and various modifications are possible. [Explanation of symbols]

[0069] 1 X-ray CT device, 15 power supply brush device, 15a power supply brush, 16 signal transmission brush device, 16a signal transmission brush, 20 cover, 23 rotating shaft, 32 collection container, 33 opening, 34 container body, 35 porous member, D1 wear powder, D2 wear powder, AF air flow, FW direction of travel, HL virtual horizontal line, R direction of rotation

Claims

1. A fixed frame and a rotating frame rotatable relative to the fixed frame and including an X-ray source and an X-ray detector; a slip ring that rotates in synchronization with the rotating frame; a power supply brush and a signal transmission brush that contact the slip ring; a cover that covers the slip ring, the power supply brush, and the signal transmission brush; a collection container provided in the cover and having an opening for collecting wear powder, the collection container having the opening positioned below the power supply brush in the direction of gravity and extending in the direction of the flow of air generated by the rotation of the slip ring; An X-ray CT device comprising:

2. The X-ray CT apparatus according to claim 1 , wherein the opening is widened toward the cover.

3. 3. The X-ray CT apparatus according to claim 1, wherein the collection vessel extends in a tangential direction to an outer periphery of the cover.

4. The X-ray CT apparatus according to claim 1 , further comprising a porous member disposed inside the collection container.

5. 3. The X-ray CT apparatus according to claim 1, wherein the power supply brush is positioned below, in the direction of gravity, an imaginary horizontal line passing through the rotation axis of the rotating frame.

6. 6. The X-ray CT apparatus according to claim 5, wherein the power supply brush and the signal transmission brush are disposed at different positions in the circumferential direction of the slip ring.

7. 7. The X-ray CT apparatus according to claim 6, wherein the signal transmission brush is disposed upstream of the power supply brush in the rotation direction of the slip ring.

8. 6. The X-ray CT apparatus according to claim 5, wherein the power supply brush and the signal transmission brush are arranged at the same position in the circumferential direction of the slip ring.

9. The X-ray CT apparatus according to claim 1 , wherein the cover is disposed on an opposite side of the slip ring from the fixed frame.

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