X-ray CT apparatus

Abstract

To provide an X-ray CT apparatus that can inhibit a foreign matter from entering the inside of a bearing without much cost.SOLUTION: An X-ray CT apparatus 10 includes a stationary frame 20, a rotary frame 18, and a bearing 30. The bearing 30 includes: an outer ring 42 connected to the stationary frame 20; and an inner ring 44 connected to the rotary frame 18. The stationary frame 20 includes seal parts 100, 110 for sealing the bearing 30.SELECTED DRAWING: Figure 5

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 gantry having a rotating disk portion. [Background technology]

[0002] Patent Document 1 discloses an X-ray CT (Computed Tomography) device that prevents wear powder generated by contact between a slip ring and a brush in an X-ray tomography device equipped with a slip ring from entering the inside of the X-ray tomography device.

[0003] According to Patent Document 1, the rotating side of the X-ray computed tomography device is provided with multiple fins, which rotate together with the rotating side to generate an air flow. This air flow expels wear powder to the outside of the X-ray CT device, preventing the wear powder from scattering toward the X-ray tube, support bearings, etc. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-5319 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the X-ray CT apparatus of Patent Document 1 has a configuration in which a plurality of fins are provided on the rotating side (rotating frame side), which makes the structure of the rotating frame complex, resulting in a problem of increased costs.

[0006] It is also possible to adopt, as the support bearing for the rotating frame, a bearing with a seal structure (for example, a labyrinth seal structure) capable of preventing the intrusion of foreign matter such as wear powder. However, a bearing with such a seal structure is not cheap, and therefore, this also poses the problem of an increase in costs.

[0007] The present invention has been made to solve the above-mentioned problems, and provides an X-ray CT apparatus that can prevent foreign matter from entering the inside of a bearing without incurring additional costs. [Means for solving the problem]

[0008] The first embodiment of the X-ray CT device comprises a fixed frame, a rotating frame on which an payload including an X-ray source and an X-ray detector is mounted, and a bearing that rotatably supports the rotating frame relative to the fixed frame, the bearing including an outer ring connected to the fixed frame and an inner ring connected to the rotating frame, and the fixed frame has a seal portion that seals the bearing.

[0009] In the X-ray CT apparatus of the second aspect, the seal portion is preferably configured integrally with the fixed frame.

[0010] In the X-ray CT apparatus of the third aspect, it is preferable that the sealing portion is an end of a fixed frame connected to the outer ring, and is an end extending opposite at least one of two openings on both sides of the bearing in the rotational axis direction.

[0011] In the X-ray CT device of the fourth aspect, it is preferable that a drive unit having a pulley that rotates and drives the rotating frame is provided, a recess is formed between the inner ring and the pulley, the seal portion is inserted into the recess via a gap, and the seal portion and the recess form a labyrinth seal.

[0012] In the X-ray CT apparatus of the fifth aspect, it is preferable that a recess is provided between the inner ring and the rotating frame, the seal portion is inserted into the recess via a gap, and the seal portion and the recess form a labyrinth seal. Effect of the Invention

[0013] According to the present invention, it is possible to prevent foreign matter from entering the inside of a bearing without incurring any cost. [Brief description of the drawings]

[0014] [Figure 1] 1 is an external perspective view of an X-ray CT apparatus according to an embodiment. [Diagram 2] FIG. 2 is a front view of a rotating disk part of the gantry in FIG. 1 with the cover removed. [Diagram 3] 3 is a front view of the rotating disk unit in FIG. 2 with a rotating frame removed. [Figure 4] 4 is a cross-sectional view taken along line 4-4 of the rotating disk portion in FIG. 2. [Diagram 5] 4 is an enlarged cross-sectional view of a main portion showing a seal structure in a rotation support portion of the rotating frame. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] An X-ray CT apparatus according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

[0016] The structure of the X-ray CT device of the embodiment is shown in Fig. 1 to Fig. 4. Fig. 1 is an external perspective view of the X-ray CT device 10, Fig. 2 is a front view of the rotating disk unit 16 with the front cover 14 removed from the gantry 12 in Fig. 1, and Fig. 3 is a front view of the structure including the fixed frame 20 with the rotating frame 18 removed from the rotating disk unit 16 in Fig. 2. Fig. 4 is a cross-sectional view taken along line 4-4 of the rotating disk unit 16 in Fig. 2. Fig. 5 is an enlarged cross-sectional view of a main part showing the seal structure in the rotation support part of the rotating frame 18.

[0017] The three-dimensional coordinate system shown in Figs. 1 to 5 shows an example of the definition of directions in the X-ray CT device 10. The X-axis, Y-axis, and Z-axis of the three-dimensional coordinate system are just an example, and are not limited to this. For easy understanding in the following description, the X-axis, Y-axis, and Z-axis in the X-ray CT device 10 are defined in the same direction in all figures. The Z-axis direction is the body axis direction of the subject 1 when the subject 1 is placed on the bed 22. The Y-axis direction is the up-down direction of the subject 1, and is parallel to the direction of gravity. The X-axis direction is the left-right direction of the subject 1, and is the horizontal direction perpendicular to the direction of gravity.

[0018] As shown in FIG. 1, the X-ray CT apparatus 10 includes a gantry 12, a bed 22 on which a subject 1 is placed, an input device 24, an image processing device 26, and a display device .

[0019] The gantry 12 includes a front cover 14 and a rotating disk unit 16 arranged inside the front cover 14. The rotating disk unit 16 includes a rotating frame 18, a fixed frame 20 that supports the rotating frame 18 from the rear side via bearings 30, and a pulley 32 for driving the rotating frame 18 to rotate. The rotating disk unit 16 also has a tilt mechanism that rotates the rotating frame 18 while tilting the direction of the rotation axis with respect to the main plane of the tabletop of the bed 22. The rotating disk unit 16 is supported by a stand 36.

[0020] As shown in FIGS. 4 and 5, a ball bearing is used as the bearing 30 that rotatably supports the rotating frame 18 relative to the fixed frame 20 in this embodiment.

[0021] The bearing 30 is composed of an outer ring 42, an inner ring 44, balls 46 which are rolling elements, and a cage 48 (also called a retainer) which holds the balls 46.

[0022] Furthermore, the bearing 30 has two open portions 30A, 30B on both sides in the direction of the rotation axis P of the bearing 30 (the same as the rotation axis of the rotating frame 18). That is, the bearing 30 of this example is a bearing of a basic structure that does not have a seal structure in the bearing 30 itself. Note that in this example, a ball bearing is applied as the bearing 30, but this is not limited thereto, and for example, a roller bearing may also be applied. The bearing 30 is one example of a bearing of the present invention.

[0023] As shown in FIG. 2, the rotating frame 18 is mounted with components such as an X-ray tube 52, an X-ray detection unit 54, a cooling device 56, a control unit 58, and high-voltage generating units 60, 62 along a circumferential direction centered on the rotation axis P.

[0024] The rotating frame 18 rotates around the subject 1 by the power of a drive unit described below. In the rotating frame 18, the X-ray detection unit 54 is disposed opposite the X-ray tube 52. The X-ray detection unit 54 measures the spatial distribution of the transmitted X-rays by detecting the X-rays that have passed through the subject 1. The rotating frame 18 is an example of a rotating frame of the present invention. The X-ray tube 52 is an example of an X-ray source of the present invention. The X-ray detection unit 54 is an example of an X-ray detector of the present invention.

[0025] 1 performs arithmetic processing on the measurement data of the X-ray detection unit 54 to reconstruct a CT image. The display device 28 displays the CT image created by the image processing device 26. The input device 24 accepts input of imaging conditions and the like from an operator.

[0026] 3 and 4, a fixed frame 20 is disposed on the rear side of the rotating frame 18. The fixed frame 20 is configured, for example, in a polygonal shape when viewed from the front when viewed from the Z-axis direction.

[0027] The fixed frame 20 has a circular opening 64 in the center. A cylindrical sleeve 66 of the rotating frame 18 is placed in this opening 64, and this sleeve 66 is attached to the fixed frame 20 via the bearing 30.

[0028] 5, the opening 64 is defined by a circular opening edge 68 which is an end of the fixed frame 20. The outer ring 42 which is the fixed side of the bearing 30 is connected to this opening edge 68, and the sleeve 66 of the rotating frame 18 is connected to the inner ring 44 which is the rotating side of the bearing 30. In this way, the rotating frame 18 is rotatably supported relative to the fixed frame 20 via the bearing 30.

[0029] The fixed frame 20 of this example has a double plate-like body structure in the Z direction. The inner peripheral edge portions of the two plate-like bodies 76, 78 constituting the fixed frame 20 are formed as the opening edge portion 68, and the outer ring 42 is fixed to the two plate-like bodies 76, 78. The fixed frame 20 is one example of the fixed frame of the present invention.

[0030] As shown in FIGS. 4 and 5, a conical pulley 32 is disposed from the inside of the opening 64 of the fixed frame 20 toward the rear side of the fixed frame 20 .

[0031] The small diameter end 70 of the pulley 32 is connected to the inner ring 44 of the bearing 30 by a plurality of bolts (not shown). This connects the pulley 32 and the rotating frame 18 via the inner ring 44 of the bearing 30. As a result, when the pulley 32 is driven to rotate, the rotational force is transmitted to the rotating frame 18 via the inner ring 44, and the rotating frame 18 is rotated about the rotation axis P.

[0032] A motor (not shown) is disposed in the X-ray CT device 10. A pulley is attached to the rotating shaft of the motor, and a drive belt 72 is wound between the pulley and the pulley 32. The pulley 32 is rotated by the power of the motor, whereby the rotating frame 18 is rotated about the rotation axis P.

[0033] The drive unit of the present invention is composed of the pulley 32, the motor, the drive belt 72, etc. The pulley 32 is an example of a pulley included in the drive unit.

[0034] 5, the opening edge 68 of the fixed frame 20 has two seal portions 100, 110 that seal the bearing 30. These seal portions 100, 110 are integrally formed with the fixed frame 20 (the two plate-like bodies 76, 78).

[0035] Moreover, these seal portions 100, 110 are configured in a plate shape along the Y direction. Moreover, these seal portions 100, 110 are ends (opening edge portion 68) of the fixed frame 20 connected to the outer ring 42, and are ends that extend in the Y direction so as to face the open portions 30A, 30B of the bearing 30 in the Z direction.

[0036] Of the seal portions 100, 110, the seal portion 100 closer to a slip ring 80 (see FIG. 4) described below has an inner peripheral edge 100A of the seal portion 100 inserted, via a gap, into an L-shaped notch 44A provided in the side portion of the inner ring 44 facing the pulley 32 and an L-shaped notch 70A provided in the end portion 70 of the pulley 32. These notches 44A, 70A form a recess of the present invention.

[0037] That is, the seal portion 100 is inserted, via a gap, into a recess (notch portions 44A, 70A) provided between the inner ring 44 and the pulley 32. As a result, a labyrinth seal is formed by the seal portion 100 and the recess.

[0038] When the inner periphery 100A is inserted into the recess, the gap between the inner periphery 100A and the recess (gaps in the Z and Y directions) is set to about 1 mm, forming an excellent labyrinth seal structure.

[0039] On the other hand, the inner peripheral edge 110A of the seal portion 110 is inserted, via a gap, into a notch 44B provided on the side of the inner ring 44 facing the rotating frame 18 and a notch 66A provided in the sleeve 66 of the rotating frame 18. These notches 44B and 66A form the recess of the present invention.

[0040] That is, the seal portion 110 is inserted, via a gap, into a recess (notch portions 44B, 66A) provided between the inner ring 44 and the rotating frame 18. As a result, a labyrinth seal is formed by the seal portion 110 and the recess.

[0041] When the inner periphery 110A is inserted into the recess, the gap between the inner periphery 110A and the recess (gaps in the Z and Y directions) is set to about 1 mm, forming an excellent labyrinth seal structure.

[0042] The slip ring 80 will now be described.

[0043] 4, a slip ring 80 having multiple conductor rings is fixed to a large diameter end 82 of the pulley 32. Multiple cables (not shown) are connected to the slip ring 80. The multiple cables pass through the inside of the pulley 32 and reach the rotating frame 18 located in front of the bearing 30.

[0044] The multiple conductor rings constituting the slip ring 80 have different diameters and are arranged concentrically about the rotation axis P. The multiple conductor rings have power supply conductors and signal transmission conductors (not shown). As an example, the power supply conductors are arranged on the outer side (opposite the rotation axis P) of the signal transmission conductors. The power supply conductors are configured to be wider than the signal transmission conductors.

[0045] A brush device 84 is disposed at a position facing the slip ring 80 in the Z direction. Power supply brushes of the brush device 84 come into contact with the power supply conductors of the slip ring 80, and signal transmission brushes of the brush device 84 come into contact with the signal transmission conductors of the slip ring 80. The brush device 84 is fixed to a metal fitting (not shown) extending from the fixed frame 20.

[0046] In an X-ray CT device 10 having such a slip ring 80 and brush device 84, in order to prevent malfunction of the rotating frame 18, it is necessary to prevent wear powder generated by contact between the conductor ring and the brush from entering the inside of the bearing 30.

[0047] Possible measures to prevent the intrusion of wear debris include providing multiple fins on the rotating side (see Patent Document 1) or using bearings with a seal structure, but all of these have the problem of increasing the cost of the equipment.

[0048] Therefore, the X-ray CT apparatus 10 of the embodiment employs a configuration that solves the above problem. The above configuration will be described below.

[0049] As shown in FIG. 5, the X-ray CT device 10 of the embodiment includes a fixed frame 20, a rotating frame 18, and a bearing 30, the bearing 30 including an outer ring 42 connected to the fixed frame 20 and an inner ring 44 connected to the rotating frame 18, and the fixed frame 20 has seal portions 100, 110 that seal the bearing 30.

[0050] That is, the X-ray CT device 10 of the embodiment employs a configuration in which the fixed frame 20 has seal portions 100, 110. As a result, compared to X-ray CT devices that are provided with multiple fins on the rotating side or that employ bearings with a seal structure, the X-ray CT device 10 of the embodiment can prevent foreign matter from entering the inside of the bearing 30 without incurring additional costs.

[0051] Furthermore, in the X-ray CT apparatus 10 of the embodiment, the seal parts 100, 110 are configured integrally with the fixed frame 20. As a result, compared to a configuration in which the seal parts are separate and are later attached to the fixed frame, the X-ray CT apparatus 10 of the embodiment can save on parts management costs, later attachment work costs, etc. As a result, it is possible to reduce the manufacturing costs of the X-ray CT apparatus 10.

[0052] Furthermore, in the X-ray CT device 10 of the embodiment, the seal parts 100, 110 are disposed opposite each other in both of the two openings 30A, 30B, so that it is possible to prevent wear powder from entering the inside of the bearing 30 from the openings 30A, 30B.

[0053] In the embodiment, the configuration in which both of the two openings 30A, 30B are sealed by the seal portions 100, 110 has been exemplified, but the present invention is not limited thereto. For example, one of the two openings 30A, 30B may be sealed by a seal portion. In this case, a configuration in which the opening 30A, which is closer to the slip ring 80, is sealed by the seal portion 100 is preferable from the viewpoint of preventing the intrusion of wear powder.

[0054] Further, the seal portion 100 that seals the open portion 30A is inserted into recesses (notches 44A, 70A) provided in the inner ring 44 and the pulley 32, respectively, via a gap.

[0055] That is, in the X-ray CT device 10 of the embodiment, the seal portion 100 is inserted into the recessed portion (cutout portion 44A, 70A) via a gap, thereby forming a labyrinth seal by the seal portion 100 and the recessed portion (cutout portion 44A, 70A). This makes it possible to prevent foreign matter such as wear powder from entering the inside of the bearing 30 from the open portion 30A, and to prevent the bearing lubricant (grease) filled inside the bearing 30 from leaking from the open portion 30A.

[0056] Further, the seal portion 110 that seals the open portion 30B is inserted into recesses (notches 44B, 66A) provided in the inner ring 44 and the rotating frame 18, respectively, via a gap.

[0057] That is, in the X-ray CT device 10 of the embodiment, the seal portion 110 is inserted into the recess (cutout portion 44B, 66A) via a gap, thereby forming a labyrinth seal by the seal portion 110 and the recess (cutout portion 44B, 66A). This makes it possible to prevent foreign matter such as wear powder from entering the inside of the bearing 30 from the open portion 30B, and to prevent the bearing lubricant (grease) filled inside the bearing 30 from leaking from the open portion 30B.

[0058] Although the embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to the above-described embodiment, and various modifications are possible. [Explanation of symbols]

[0059] 10...X-ray CT device, 16...rotating disk portion, 18...rotating frame, 20...fixed frame, 30...bearing, 32...pulley, 42...outer ring, 44...inner ring, 30A...open portion, 30B...open portion, 64...opening, 80...slip ring, 84...brush device, 100...seal portion, 110...seal portion

Claims

1. A fixed frame and a rotating frame on which a payload including an X-ray source and an X-ray detector is mounted; a bearing that rotatably supports the rotating frame relative to the fixed frame; Equipped with The bearing includes an outer ring connected to the fixed frame and an inner ring connected to the rotating frame, The fixed frame has a seal portion that seals the bearing. X-ray CT device.

2. The seal portion is integrally formed with the fixed frame. The X-ray CT apparatus according to claim 1 .

3. the seal portion is an end portion of the fixed frame connected to the outer ring, and is an end portion extending to face at least one of two open portions on both sides in the rotation axis direction of the bearing.

3. The X-ray CT apparatus according to claim 1 or 2.

4. A drive unit having a pulley for rotating the rotating frame is provided, A recess is provided between the inner ring and the pulley. The seal portion is inserted into the recess via a gap, and the seal portion and the recess form a labyrinth seal. The X-ray CT apparatus according to claim 3.

5. A recess is provided between the inner ring and the rotating frame, The seal portion is inserted into the recess via a gap, and the seal portion and the recess form a labyrinth seal. The X-ray CT apparatus according to claim 3.

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