X-ray CT device

Abstract

The present invention addresses the problem of providing an X-ray CT device capable of suppressing entry of foreign matter into a bearing without cost. This X-ray CT device (10) is provided with a fixed frame (20), a rotating frame (18), and a bearing (30), the bearing (30) comprising 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) having sealing parts (100, 110) for sealing the bearing (30).

Description

Technical Field

[0001] The present invention relates to an X-ray CT apparatus, and more particularly to an X-ray CT apparatus having a gantry having a rotating disk portion. Background Art

[0002] Patent Document 1 discloses an X-ray CT (Computed Tomography) device which prevents abrasive powder generated by contact between a slip ring and a brush from entering the X-ray tomography device in an X-ray tomography device having a slip ring.

[0003] According to Patent Document 1, a plurality of fins are provided on the rotating side of the X-ray tomography device, and these fins rotate as the rotating side rotates, thereby generating air flow. The air flow releases the abrasive powder to the outside of the X-ray CT device, thereby preventing the abrasive powder from scattering toward the X-ray tube and support bearings.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2010-5319

[0005] However, since the X-ray CT apparatus of Patent Document 1 has a structure in which a plurality of fins are provided on the rotating side (rotating frame side), there is a problem that the structure of the rotating frame becomes complicated, resulting in an increase in cost.

[0006] Furthermore, as the support bearing of the rotating frame, a bearing having a sealing structure (e.g., a labyrinth seal structure) that can prevent the intrusion of foreign matter such as abrasive powder may also be considered. However, a bearing having such a sealing structure is not cheap, and therefore, in this case, there is also a problem of increasing costs. Summary of the invention

[0007] The present invention has been made to solve the above-mentioned problems, and provides an X-ray CT apparatus capable of suppressing the intrusion of foreign matter into the interior of a bearing without increasing costs.

[0008] The first type of X-ray CT device comprises: a fixed frame; a rotating frame equipped with a load including an X-ray source and an X-ray detector; and a bearing that supports the rotating frame so that it can rotate relative to the fixed frame, the bearing comprising: an outer ring connected to the fixed frame; and an inner ring connected to the rotating frame, and the fixed frame has a sealing portion that seals the bearing.

[0009] In the X-ray CT apparatus according to the second aspect, it is preferable that the sealing portion is formed integrally with the fixed frame.

[0010] In the X-ray CT apparatus of the third aspect, the sealing portion is preferably an end portion of the fixed frame connected to the outer ring and extending to face at least one of two opening portions on both sides of the bearing in the rotation axis direction.

[0011] In the X-ray CT apparatus of the fourth aspect, it is preferred that a driving unit is provided, the driving unit has a pulley for rotationally driving the rotating frame, a recess is provided between the inner ring and the pulley, a sealing unit is inserted into the recess via a gap, and a labyrinth seal is formed by the sealing unit and the recess.

[0012] In the X-ray CT apparatus of the fifth aspect, preferably, a recessed portion is provided between the inner ring and the rotating frame, the sealing portion is inserted into the recessed portion via a gap, and a labyrinth seal is formed by the sealing portion and the recessed portion.

[0013] Effects of the Invention

[0014] According to the present invention, it is possible to suppress the intrusion of foreign matter into the interior of the bearing without increasing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a perspective view of the appearance of the X-ray CT apparatus according to the embodiment.

[0016] Figure 2 is from Figure 1 A front view of the rotating disc portion of the frame with the cover removed.

[0017] Figure 3 is from Figure 2 A front view of the rotating disc portion of the embodiment in which the rotating frame is removed.

[0018] Figure 4 It is along Figure 2 A cross-sectional view of the rotating disk portion taken along line 4-4.

[0019] Figure 5 It is an enlarged cross-sectional view of a main part showing a sealing structure in a rotation support portion of a rotating frame.

[0020] Explanation of symbols

[0021] 10-X-ray CT device, 16-rotating disk part, 18-rotating frame, 20-fixed frame, 30-bearing, 32-pulley, 42-outer ring, 44-inner ring, 30A-opening part, 30B-opening part, 64-opening part, 80-slip ring, 84-brush device, 100-sealing part, 110-sealing part. DETAILED DESCRIPTION

[0022] Hereinafter, an X-ray CT apparatus according to an embodiment of the present invention will be described with reference to the drawings.

[0023] The structure of the X-ray CT apparatus of the embodiment is shown in FIG. Figure 1 to Figure 4 middle. Figure 1 is a perspective view of the appearance of the X-ray CT device 10. Figure 2 is from Figure 1 The front view of the rotating disc portion 16 of the frame 12 with the front cover 14 removed, Figure 3 is from Figure 2 The front view of the structure including the fixed frame 20 in which the rotating frame 18 is removed from the rotating disk portion 16 is shown. Figure 4 It is along Figure 2 A cross-sectional view of the rotating disk portion 16 taken along line 4-4. Figure 5 It is an enlarged cross-sectional view of a main part showing a sealing structure in a rotation support portion of the rotating frame 18 .

[0024] in addition, Figures 1 to 5 The three-dimensional coordinate system described in the figure represents 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 examples and are not limited to them. In order to facilitate 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 any figure. 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-and-down direction of the subject 1, and is a direction parallel to the gravity direction. The X-axis direction is the left-right direction of the subject 1, and is a horizontal direction orthogonal to the gravity direction.

[0025] like Figure 1 As shown, the X-ray CT apparatus 10 includes a gantry 12 , a bed 22 on which the subject 1 is placed, an input device 24 , an image computing device 26 , and a display device 28 .

[0026] The frame 12 includes a front cover 14 and a rotating disk unit 16 disposed inside the front cover 14. The rotating disk unit 16 includes: a rotating frame 18; a fixed frame 20 supporting the rotating frame 18 from the back side via a bearing 30; and a pulley 32 for rotating and driving the rotating frame 18. In addition, the rotating disk unit 16 has a tilting mechanism that rotates the rotating axis direction in a state tilted relative to the main plane of the top plate of the bed 22. The rotating disk unit 16 is supported by a bracket 36.

[0027] like Figure 4 and Figure 5 As shown, in this example, a ball bearing is applied as the bearing 30 that supports the rotating frame 18 so as to be rotatable relative to the fixed frame 20 .

[0028] The bearing 30 is composed of an outer ring 42 , an inner ring 44 , balls 46 as rolling elements, and a retainer 48 (also referred to as a retainer ring) for retaining the balls 46 .

[0029] Furthermore, the bearing 30 has two openings 30A and 30B on both sides of the direction of the rotation axis P (the same as the rotation axis of the rotating frame 18) of the bearing 30. That is, the bearing 30 of this example is a bearing of a basic structure in which the bearing 30 itself does not have a sealing structure. In addition, in this example, a ball bearing is used as the bearing 30, but it is not limited to this. For example, a roller bearing may also be used. The bearing 30 is an example of a bearing of the present invention.

[0030] like Figure 2 As shown, an X-ray tube 52 , an X-ray detection unit 54 , a cooling device 56 , a control unit 58 , and high voltage generation units 60 , 62 are mounted on the rotating frame 18 along a circumferential direction around the rotation axis P.

[0031] The rotating frame 18 rotates around the subject 1 using the power of a driving unit described later. In the rotating frame 18, an X-ray detection unit 54 is arranged opposite to 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. In addition, 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.

[0032] Figure 1 The image computing device 26 shown reconstructs a CT image by computing the measurement data of the X-ray detection unit 54. The display device 28 displays the CT image generated by the image computing device 26. The input device 24 receives input of imaging conditions and the like from the operator.

[0033] like Figure 3 and Figure 4 As shown, the fixed frame 20 is disposed on the back side of the rotating frame 18. The fixed frame 20 is configured in a polygonal shape, for example, when viewed from the front when viewed in the Z-axis direction.

[0034] The fixed frame 20 is provided with a circular opening 64 at the center. A cylindrical sleeve 66 of the rotating frame 18 is arranged in the opening 64 , and the sleeve 66 is attached to the fixed frame 20 via the bearing 30 .

[0035] Specifically, if Figure 5 As shown, 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 the 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. Thus, the rotating frame 18 is supported to be rotatable relative to the fixed frame 20 via the bearing 30.

[0036] The fixed frame 20 of this example has a double-layer plate structure in the Z-axis direction. The inner peripheral edges of the two plate-like bodies 76 and 78 constituting the fixed frame 20 are formed as opening edges 68, and the outer ring 42 is fixed to the two plate-like bodies 76 and 78. The fixed frame 20 is an example of the fixed frame of the present invention.

[0037] like Figure 4 and Figure 5 As shown, the conical pulley 32 is arranged from the inside of the opening 64 of the fixed frame 20 toward the back side of the fixed frame 20 .

[0038] The end 70 on the small diameter side of the pulley 32 is connected to the inner ring 44 of the bearing 30 by a plurality of bolts (not shown). As a result, the pulley 32 and the rotating frame 18 are connected 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 rotates around the rotation axis P.

[0039] The X-ray CT apparatus 10 is provided with a motor (not shown). A pulley is mounted on the rotating shaft of the motor, and a driving belt 72 is wound between the pulley and the pulley 32. The rotating frame 18 is driven to rotate about the rotating axis P by rotating the pulley 32 using the power of the motor.

[0040] The pulley 32, the motor, the drive belt 72, and the like constitute a driving unit of the present invention. The pulley 32 is an example of a pulley included in the driving unit.

[0041] On the other hand, Figure 5 As shown, the opening edge portion 68 of the fixed frame 20 has two seal portions 100 and 110 for sealing the bearing 30. These seal portions 100 and 110 are formed integrally with the fixed frame 20 (two plate-like bodies 76 and 78).

[0042] Furthermore, these sealing portions 100, 110 are formed in a plate shape along the Y-axis direction. Furthermore, these sealing portions 100, 110 are ends (opening edge portions 68) of the fixed frame 20 connected to the outer ring 42, and are ends extending in the Y-axis direction in a manner opposite to the opening portions 30A, 30B of the bearing 30 in the Z-axis direction.

[0043] Furthermore, in the sealing parts 100 and 110, the sliding ring 80 (see Figure 4 ), the inner peripheral edge 100A of the sealing portion 100 is inserted through a gap into the L-shaped cutout portion 44A provided on the side of the inner ring 44 on the pulley 32 side and the L-shaped cutout portion 70A provided on the end 70 of the pulley 32. These cutout portions 44A and 70A constitute the recessed portion of the present invention.

[0044] That is, the seal portion 100 is inserted through the gap into the recessed portion (the notched portion 44A, 70A) provided between the inner ring 44 and the pulley 32. As a result, the seal portion 100 and the recessed portion constitute a labyrinth seal.

[0045] When the inner peripheral edge 100A is inserted into the above-mentioned recessed portion, the gap between the inner peripheral edge 100A and the recessed portion (the gap in the Z-axis direction and the Y-axis direction) is set to about 1 mm, thereby forming a good labyrinth seal structure.

[0046] On the other hand, in the seal portion 110, the inner peripheral edge 110A of the seal portion 110 is inserted through a gap into the cutout portion 44B provided on the side of the inner ring 44 on the rotating frame 18 side and the cutout portion 66A provided in the sleeve 66 of the rotating frame 18. These cutout portions 44B and 66A constitute the recess of the present invention.

[0047] That is, the seal portion 110 is inserted through the gap into the recessed portion (the notched portion 44B, 66A) provided between the inner ring 44 and the rotating frame 18. As a result, the seal portion 110 and the recessed portion constitute a labyrinth seal.

[0048] When the inner peripheral edge 110A is inserted into the above-mentioned recessed portion, the gap between the inner peripheral edge 110A and the recessed portion (the gap in the Z-axis direction and the Y-axis direction) is set to about 1 mm, thereby forming a good labyrinth seal structure.

[0049] Next, the slip ring 80 will be described.

[0050] like Figure 4 As shown, a slip ring 80 having a plurality of conductor rings is fixed to the end 82 on the large diameter side of the pulley 32. A plurality of cables (not shown) are connected to the slip ring 80. The plurality of cables pass through the inner side of the pulley 32 and reach the rotating frame 18 located on the front side of the bearing 30.

[0051] The plurality of conductor rings constituting the slip ring 80 have different diameters and are arranged in a concentric circle shape relative to the rotation axis P. The plurality of conductor rings have a power supply conductor and a signal transmission conductor (not shown). As an example, the power supply conductor is arranged on the outside (the side opposite to the rotation axis P) relative to the signal transmission conductor. The power supply conductor is configured to be wider than the signal transmission conductor.

[0052] Brush devices 84 are arranged at positions opposite to each other in the Z-axis direction in the slip ring 80. The power supply brush of the brush device 84 contacts the power supply conductor of the slip ring 80, and the signal transmission brush of the brush device 84 contacts the signal transmission conductor of the slip ring 80. The brush device 84 is fixed to a metal part (not shown) extending from the fixed frame 20.

[0053] In the X-ray CT apparatus 10 having such a slip ring 80 and a brush device 84 , in order to prevent rotation failure of the rotating frame 18 , it is necessary to prevent abrasive powder generated by contact between the conductor ring and the brush from entering into the bearing 30 .

[0054] As a measure to prevent the intrusion of grinding powder, it is conceivable to provide a plurality of fins on the rotating side (see Patent Document 1) or to adopt a bearing having a sealing structure, but these both have the problem of increasing the cost of the device.

[0055] Therefore, in the X-ray CT apparatus 10 of the embodiment, a configuration for solving the above-mentioned problem is adopted. The above-mentioned configuration will be described below.

[0056] like Figure 5 As shown, the X-ray CT apparatus 10 of the embodiment includes a fixed frame 20 , a rotating frame 18 , and a bearing 30 . The bearing 30 includes an outer ring 42 connected to the fixed frame 20 and an inner ring 44 connected to the rotating frame 18 . The fixed frame 20 has seals 100 , 110 for sealing the bearing 30 .

[0057] That is, the X-ray CT apparatus 10 of the embodiment adopts a structure having the sealing parts 100 and 110 on the fixed frame 20. Therefore, compared with an X-ray CT apparatus having a plurality of fins on the rotating side or adopting a bearing having a sealing structure, the X-ray CT apparatus 10 of the embodiment can suppress the intrusion of foreign matter into the inside of the bearing 30 without incurring any cost.

[0058] Furthermore, the X-ray CT apparatus 10 of the embodiment has the sealing parts 100 and 110 integrally formed with the fixed frame 20. Thus, compared with an apparatus having a structure in which the sealing part is a separate body and is installed on the fixed frame later, the X-ray CT apparatus 10 of the embodiment can save parts management costs, after-installation operation costs, etc. As a result, the manufacturing cost of the X-ray CT apparatus 10 can be suppressed.

[0059] Furthermore, the X-ray CT apparatus 10 of the embodiment has the seal portions 100 and 110 disposed opposite to each other in both the openings 30A and 30B, and thus can suppress the intrusion of abrasive particles from the openings 30A and 30B into the bearing 30 .

[0060] In addition, in the embodiment, the structure in which the two openings 30A and 30B are sealed by the sealing parts 100 and 110 is illustrated, but it is not limited to this. For example, it is also possible to have a structure in which the opening of one side of the two openings 30A and 30B is sealed by the sealing part. In this case, from the viewpoint of preventing the intrusion of abrasive powder, it is preferable to have a structure in which the opening 30A on the side close to the slide ring 80 of the openings 30A and 30B is sealed by the sealing part 100.

[0061] Furthermore, the seal portion 100 that seals the open portion 30A is inserted into the recessed portions (the cutout portions 44A and 70A) provided in the inner ring 44 and the pulley 32 , respectively, via a gap.

[0062] That is, the X-ray CT apparatus 10 of the embodiment inserts the seal 100 into the recess (cutout 44A, 70A) via a gap, so that the seal 100 and the recess (cutout 44A, 70A) form a labyrinth seal. This can prevent foreign matter such as abrasive powder from entering the inside of the bearing 30 from the opening 30A and prevent the bearing lubricant (grease) filled in the bearing 30 from leaking from the opening 30A.

[0063] Furthermore, the seal portion 110 that seals the open portion 30B is inserted into the recessed portions (the cutout portions 44B and 66A) provided in the inner ring 44 and the rotating frame 18 respectively via the gap.

[0064] That is, the X-ray CT apparatus 10 of the embodiment inserts the seal 110 into the recess (cutout 44B, 66A) via a gap, so that the seal 110 and the recess (cutout 44B, 66A) form a labyrinth seal. This can prevent foreign matter such as abrasive powder from entering the inside of the bearing 30 from the opening 30B and prevent the bearing lubricant (grease) filled in the bearing 30 from leaking from the opening 30B.

[0065] As mentioned above, although embodiment which concerns on this invention was demonstrated, this invention is not limited to the said embodiment, Of course, various deformation|transformation is possible.

Claims

1. An X-ray CT device, comprising: Fixed frame; A rotating frame carrying a payload including an X-ray source and an X-ray detector; and a bearing that supports the rotating frame so as to be rotatable relative to the fixed frame, The bearing comprises: An outer ring connected to the fixed frame; and an inner ring connected to the rotating frame, The fixing frame has a sealing portion that seals the bearing.

2. The X-ray CT apparatus according to claim 1, wherein: The sealing portion is formed integrally with the fixing frame.

3. The X-ray CT apparatus according to claim 1 or 2, wherein: The sealing 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 opening portions on both sides of the bearing in the rotation axis direction.

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

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

Images