Patent Description:
A conventional inspection apparatus has been known for inspecting a board having a flat plate shape (for example, see Patent Literature <NUM>). An inspection apparatus disclosed in Patent Literature <NUM> includes a radiation generator emitting radiation, such as X-rays, toward a board, a board holder holding the board, and a detector taking an image of the board. The board is held by the board holder, for example, with the thickness direction of the board coinciding with the vertical direction. The radiation generator is disposed above the board holder, and the detector is disposed below the board holder. The inspection apparatus disclosed in Patent Literature <NUM> also includes a board holder driver. The board holder driver includes a horizontal movement mechanism moving the board holder horizontally and a rotation mechanism rotating the board holder.

Furthermore, as a conventional inspection apparatus for inspecting a flat plate shaped board like the inspection apparatus disclosed in Patent Literature <NUM>, for example, an inspection apparatus, as illustrated in <FIG>, is also used which includes a board holder <NUM> holding a board <NUM>, an XY table <NUM> moving the board holder <NUM> in two horizontal directions, and a rotation mechanism <NUM> on which the XY table <NUM> is mounted. In this inspection apparatus, a radiation generator is disposed above the board holder <NUM>, and a detector is disposed below the rotation mechanism <NUM>.

The rotation mechanism <NUM> rotates the XY table <NUM> using the vertical direction as a rotation axis direction. In the board holder <NUM>, the XY table <NUM>, and the rotation mechanism <NUM>, through holes that pass therethrough vertically are formed, and radiation emitted from the radiation generator passes through these through holes. The rotation mechanism <NUM> includes, for example, a table <NUM> to which the XY table <NUM> is fixed, a table holding member <NUM> rotatably holding the table <NUM>, and a driving mechanism rotating the table <NUM>.

Between the table <NUM> and the table holding member <NUM>, a rolling bearing <NUM> having a relatively large inner diameter is disposed. The rolling bearing <NUM> has an outer race fixed to the table holding member <NUM> and an inner race fixed to the table <NUM>. On the table holding member <NUM>, for example, a cylindrical outer race fixer 106a is formed, and the outer race of the rolling bearing <NUM> is press-fitted and fixed on the inner circumferential side of the outer race fixer 106a. In this case, the outer race of the rolling bearing <NUM> can be fixed to the table holding member <NUM> with high accuracy.

<CIT> shows a rotation mechanism for an X-ray inspection apparatus according to the preamble of claim <NUM>.

As illustrated in <FIG>, when the outer race of the rolling bearing <NUM> is press-fitted and fixed on the inner circumferential side of the outer race fixer 106a, the outer race of the rolling bearing <NUM> may deform depending on the shape of the inner circumferential surface of the outer race fixer 106a. If the outer race of the rolling bearing <NUM> deforms, the rotation loci of the inner race of the rolling bearing <NUM> and the table <NUM> rotating along the outer race of the rolling bearing <NUM> may greatly differ from a perfect circle. That is, if the outer race of the rolling bearing <NUM> deforms, the rotation locus of the board <NUM> may greatly differ from a perfect circle. Furthermore, if the rotation locus of the board <NUM> greatly differs from a perfect circle, a reconstructed image reconstructed on the basis of a plurality of images of the board <NUM> acquired by the detector may have reduced accuracy.

Therefore, an object of the present invention is to provide a rotation mechanism for an X-ray inspection apparatus that can bring the rotation locus of a rotating object to be inspected near to a perfect circle in the rotation mechanism for an X-ray inspection apparatus used in an X-ray inspection apparatus. Furthermore, an object of the present invention is to provide an X-ray inspection apparatus including this rotation mechanism for an X-ray inspection apparatus. Moreover, an object of the present invention is to provide a method of adjusting a rotation mechanism for an X-ray inspection apparatus that can bring the rotation locus of a rotating object to be inspected near to a perfect circle in the method of adjusting a rotation mechanism for an X-ray inspection apparatus used in an X-ray inspection apparatus.

To solve the above problems, a rotation mechanism for an X-ray inspection apparatus according to the present invention, used in an X-ray inspection apparatus including an X-ray generator and an X-ray detector disposed with an object to be inspected placed between the X-ray detector and the X-ray generator, includes: a table; a table holding member rotatably holding the table; a rolling bearing including an inner race and an outer race, the inner race having a ring shape and being fixed to either one of the table and the table holding member, the outer race having a ring shape and being fixed to another of the table and the table holding member; and three or more adjustment members configured to adjust a shape of the outer race by deforming the outer race. The adjustment members are arranged in a circumferential direction of the rolling bearing. The table or the table holding member to which the outer race is fixed includes an adjustment member holder movably holding the adjustment members, the adjustment member holder being disposed on an outer circumferential side of the outer race. The adjustment members are movable relative to the adjustment member holder in a diameter direction of the rolling bearing and are contactable with an outer circumferential surface of the outer race. A gap configured to allow deformation of the outer race is formed between the outer circumferential surface of the outer race and the adjustment member holder in the diameter direction of the rolling bearing. According to the present invention, the outer race is fixed, for example, to the table holding member.

In the rotation mechanism for the X-ray inspection apparatus according to the present invention, the three or more adjustment members configured to adjust the shape of the outer race by deforming the outer race are arranged in the circumferential direction of the rolling bearing. Furthermore, according to the present invention, the adjustment members are movable relative to the adjustment member holder in the diameter direction of the rolling bearing and contactable with the outer circumferential surface of the outer race. Moreover, according to the present invention, the gap configured to allow deformation of the outer race is formed between the outer circumferential surface of the outer race and the adjustment member holder in the diameter direction of the rolling bearing. Thus, according to the present invention, with the shape of the outer race adjusted using the adjustment members so that the rotation locus of the object to be inspected rotated by the rotation mechanism for an X-ray inspection apparatus near to a perfect circle, the outer race can be fixed to the table or the table holding member. Therefore, according to the present invention, the rotation locus of the object to be inspected rotated by the rotation mechanism for an X-ray inspection apparatus can be brought near to a perfect circle.

According to the present invention, the adjustment members are preferably adjusting screws composed of screws, and threaded holes are preferably formed in the adjustment member holder, the threaded holes engaging with the adjusting screws and passing through the adjustment member holder in the diameter direction of the rolling bearing. With this configuration, the outer race can be deformed in accordance with the amount of rotation of the adjusting screws. Thus, the shape of the outer race can be readily adjusted.

According to the present invention, the rotation mechanism for an X-ray inspection apparatus preferably includes looseness preventing screws configured to prevent looseness of the adjusting screws, and the looseness preventing screws preferably engage with the threaded holes from outside the adjusting screws in the diameter direction of the rolling bearing. With this configuration, engagement of the looseness preventing screw with the threaded hole engaging with the adjusting screws can prevent looseness of the adjusting screws. Thus, a simple configuration can prevent looseness of the adjusting screws.

According to the present invention, the rolling bearing is, for example, a cross roller bearing. In this case, the rotation accuracy of the object to be inspected rotated by the rotation mechanism for an X-ray inspection apparatus can be improved. Furthermore, according to the present invention, for example, an X-ray inspection apparatus includes the above-described rotation mechanism for an X-ray inspection apparatus.

Furthermore, to solve the above problems, a method of adjusting a rotation mechanism for an X-ray inspection apparatus according to the present invention, used in an X-ray inspection apparatus including an X-ray generator and an X-ray detector disposed with an object to be inspected placed between the X-ray detector and the X-ray generator, the rotation mechanism including a table, a table holding member rotatably holding the table, and a rolling bearing including an inner race and an outer race, the inner race having a ring shape and being fixed to either one of the table and the table holding member, the outer race having a ring shape and being fixed to another of the table and the table holding member, includes: fixing the outer race to the table or the table holding member with a shape of the outer race adjusted by bringing a plurality of adjustment members into contact with an outer circumferential surface of the outer race, the adjustment members being configured to adjust the shape of the outer race by deforming the outer race, the adjustment members being arranged in a circumferential direction of the rolling bearing.

In the method of adjusting the rotation mechanism for an X-ray inspection apparatus according to the present invention, with the shape of the outer race adjusted by bringing the adjustment members that are configured to adjust the shape of the outer race by deforming the outer race and that are arranged in the circumferential direction of the rolling bearing into contact with the outer circumferential surface of the outer race, the outer race is fixed to the table or the table holding member. Thus, according to the present invention, with the shape of the outer race adjusted using the adjustment members so that the rotation locus of the object to be inspected rotated by the rotation mechanism for an X-ray inspection apparatus near to a perfect circle, the outer race can be fixed to the table or the table holding member. Therefore, through adjustment by the method of adjusting the rotation mechanism for an X-ray inspection apparatus according to the present invention, the rotation locus of the object to be inspected rotated by the rotation mechanism for an X-ray inspection apparatus can be brought near to a perfect circle.

As described above, the rotation mechanism for an X-ray inspection apparatus according to the present invention can bring the rotation locus of a rotating object to be inspected near to a perfect circle. Furthermore, through adjustment by the method of adjusting the rotation mechanism for an X-ray inspection apparatus according to the present invention, the rotation locus of a rotating object to be inspected can be brought near to a perfect circle.

<FIG> is an explanatory diagram of a schematic configuration of an X-ray inspection apparatus <NUM> according to an embodiment of the present invention.

The X-ray inspection apparatus <NUM> of this embodiment is an apparatus for nondestructively inspecting an object <NUM> to be inspected, such as an industrial product. The object <NUM> to be inspected of this embodiment is a board (circuit board), such as a glass epoxy board shaped into a flat plate. Thus, hereinafter, the object <NUM> to be inspected is referred to as a "board <NUM>". On the board <NUM>, an electronic component, such as an IC chip, is mounted. The X-ray inspection apparatus <NUM> inspects a joint between the board <NUM> and the electronic component through so-called oblique CT. Inspection with the X-ray inspection apparatus <NUM> thus requires high inspection accuracy, for example, in micron units.

The X-ray inspection apparatus <NUM> includes an X-ray generator <NUM> that emits X-rays toward the board <NUM>, an X-ray detector <NUM> that is disposed with the board <NUM> placed between the X-ray detector <NUM> and the X-ray generator <NUM> and acquires an X-ray image of the board <NUM>, a placing stand <NUM> on which the board <NUM> is placed, an XY table <NUM> to which the placing stand <NUM> is attached, and a rotation mechanism (rotation mechanism for an X-ray inspection apparatus) <NUM> on which the XY table <NUM> is mounted. The board <NUM> is placed on the placing stand <NUM> with the thickness direction of the board <NUM> coinciding with the vertical direction.

The X-ray generator <NUM> emits conical X-rays toward the board <NUM>. The X-ray detector <NUM> is a two-dimensional X-ray detector (area sensor). The X-ray detector <NUM> is disposed with a light-receiving surface of the X-ray detector <NUM> facing the X-ray generator <NUM>, and a fluoroscopic image of the board <NUM> is projected on the X-ray detector <NUM>. The X-ray generator <NUM> and the X-ray detector <NUM> are disposed with the board <NUM> placed therebetween in the vertical direction. A portion of the board <NUM> is placed between the X-ray generator <NUM> and the X-ray detector <NUM>. The placing stand <NUM> is detachably attached to an upper end portion of the XY table <NUM>. The XY table <NUM> is attached to an upper end of the rotation mechanism <NUM> and disposed above the rotation mechanism <NUM>. The X-ray generator <NUM> is disposed above the board <NUM>. The X-ray detector <NUM> is disposed below the rotation mechanism <NUM>.

The XY table <NUM> includes a first movable table to which the placing stand <NUM> is attached, a first table driving mechanism moving the first movable table in an X direction orthogonal to the vertical direction, a second movable table on which the first movable table and the first table driving mechanism are mounted, a second table driving mechanism moving the second movable table in a Y direction orthogonal to the vertical direction and the X direction, and a stationary table on which the second movable table and the second table driving mechanism are mounted. In the placing stand <NUM>, the first movable table, the second movable table, and the stationary table, through holes are formed for transmitting X-rays emitted from the X-ray generator <NUM>.

The rotation mechanism <NUM> includes a table <NUM> to which the stationary table of the XY table <NUM> is attached, a table holding member <NUM> rotatably holding the table <NUM>, and a rolling bearing <NUM> disposed between the table <NUM> and the table holding member <NUM>. The rotation mechanism <NUM> rotates the XY table <NUM> using the vertical direction as a rotation axis direction. That is, the rotation mechanism <NUM> rotates the board <NUM> placed on the placing stand <NUM> using the vertical direction as the rotation axis direction. A specific configuration of the rotation mechanism <NUM> will be described later.

When the X-ray inspection apparatus <NUM> inspects the board <NUM>, the X-ray generator <NUM> emits X-rays toward the board <NUM> rotated by the rotation mechanism <NUM> at a constant speed. The X-ray detector <NUM> sequentially acquires a plurality of two-dimensional X-ray images depicting the fluoroscopic image of the board <NUM>. Specifically, the X-ray detector <NUM> continuously acquires the X-ray image every time the board <NUM> is rotated by a certain angle. The X-ray images acquired by the X-ray detector <NUM> are captured into, for example, a personal computer (PC). The PC performs predetermined arithmetic processing to generate a CT image of the board <NUM> on the basis of the X-ray images. Note that, when the X-ray inspection apparatus <NUM> inspects the board <NUM>, the X-ray detector <NUM> may sequentially acquire two-dimensional X-ray images depicting the fluoroscopic image of the board <NUM> while the table <NUM> is paused in positions obtained by equally dividing <NUM>°.

<FIG> is a plan view of the table holding member <NUM> illustrated in <FIG>, and <FIG> is an enlarged view of a portion E in <FIG>. <FIG> is an enlarged view for describing a configuration of a portion F in <FIG>.

The rotation mechanism <NUM> includes a driving mechanism (not illustrated) rotating the table <NUM> in addition to the table <NUM>, the table holding member <NUM>, and the rolling bearing <NUM> described above. The driving mechanism includes, for example, a motor as a driving source and a power transmission mechanism transmitting power of the motor to the table <NUM>. The motor is fixed to the table holding member <NUM>. The power transmission mechanism includes, for example, a driving gear fixed an output shaft of the motor and a driven gear having a ring shape and a large diameter and fixed to the table <NUM>.

The rolling bearing <NUM> (hereinafter referred to as a "bearing <NUM>") is a cross roller bearing. The bearing <NUM> includes a ring-shaped inner race <NUM> fixed to the table <NUM>, a ring-shaped outer race <NUM> fixed to the table holding member <NUM>, and a plurality of rollers <NUM> disposed between the inner race <NUM> and the outer race <NUM>. The bearing <NUM> is a relatively large bearing, and the inner race <NUM> has an inner diameter of, for example, <NUM>. The outer race <NUM> is composed of two outer race members divided vertically. The two outer race members are fixed to each other with a screw, which is not illustrated. Note that the outer race <NUM> does not have to be divided into two outer race members. That is, the outer race <NUM> may be composed of a single member. In this case, the inner race <NUM> may be composed of two inner race members divided vertically.

The rotation mechanism <NUM> also includes three or more adjustment members <NUM> configured to adjust the shape of the outer race <NUM> by deforming the outer race <NUM> in assembly of the rotation mechanism <NUM>. The adjustment members <NUM> of this embodiment are adjusting screws composed of screws. Thus, hereinafter, the adjustment members <NUM> are referred to as "adjusting screws <NUM>". The rotation mechanism <NUM> of this embodiment includes, for example, <NUM> adjusting screws <NUM>. The rotation mechanism <NUM> also includes looseness preventing screws <NUM> configured to prevent looseness of the adjusting screws <NUM>. The rotation mechanism <NUM> includes the same number of the looseness preventing screws <NUM> as that of the adjusting screws <NUM>. That is, the rotation mechanism <NUM> includes <NUM> looseness preventing screws <NUM>.

The table <NUM> is disposed on the inner circumferential side of the inner race <NUM>. The table <NUM> is composed of a ring-shaped first table member <NUM> to which the inner race <NUM> is fixed and a ring-shaped second table member <NUM> to which the first table member <NUM> and the stationary table of the XY table <NUM> are fixed. X-rays emitted from the X-ray generator <NUM> pass through the inner circumferential side of the first table member <NUM> and the second table member <NUM> formed into ring shapes. The inner race <NUM> is fixed to the first table member <NUM> with a fixing screw (not illustrated). The first table member <NUM> is fixed to the second table member <NUM> with a fixing screw (not illustrated). The stationary table of the XY table <NUM> is fixed to the second table member <NUM> with a fixing screw (not illustrated).

The table holding member <NUM> is formed into a ring shape. X-rays emitted from the X-ray generator <NUM> pass through the inner circumferential side of the table holding member <NUM> formed into the ring shape. On the table holding member <NUM>, a placing surface 11a on which the outer race <NUM> is placed is formed. The placing surface 11a is formed into a ring shape having the center of curvature being the center of the table holding member <NUM> formed into the ring shape. Furthermore, the placing surface 11a is a flat surface orthogonal to the vertical direction. The outer race <NUM> placed on the placing surface 11a is fixed to the table holding member <NUM> with a plurality of fixing screws <NUM> arranged in the circumferential direction of the bearing <NUM>.

The outer race <NUM> is fixed to the table holding member <NUM> with, for example, <NUM> fixing screws <NUM>. The <NUM> fixing screws <NUM> are arranged at regular pitches in the circumferential direction of the bearing <NUM>. That is, the <NUM> fixing screws <NUM> are arranged at pitches of an equal angle (pitches of <NUM>°) relative to the center of the table holding member <NUM>. In the table holding member <NUM>, threaded holes 11b engaging with male threads formed on shanks of the fixing screws <NUM> are formed. The threaded holes 11b are recessed downward from the placing surface 11a.

In the outer race <NUM>, insertion holes 15a into which the shanks of the fixing screws <NUM> are inserted are formed. The insertion holes 15a are circular holes passing through the outer race <NUM> vertically. In this embodiment, to allow deformation of the outer race <NUM> by the adjusting screws <NUM>, the insertion holes 15a have an inner diameter greater than the outer diameter of the shanks of the fixing screws <NUM>. That is, the insertion holes 15a are so-called clearance holes. The shanks of the fixing screws <NUM> are inserted into the insertion holes 15a from the upper side of the outer race <NUM>, and heads of the fixing screws <NUM> are disposed on the upper side of the outer race <NUM>.

On the outer circumferential side of the placing surface 11a of the table holding member <NUM>, a screw holder 11c being an adjustment member holder movably holdirig the adjusting screws <NUM> is formed. That is, the table holding member <NUM> includes the screw holder 11c disposed on the outer circumferential side of the outer race <NUM>. The screw holder 11c is formed into a cylindrical shape protruding upward from the placing surface 11a. Furthermore, the screw holder 11c is formed into a cylindrical shape centered around the center of the table holding member <NUM>. Note that, the screw holder 11c of this embodiment is formed, integrated with a main body of the table holding member <NUM> on which the placing surface 11a is formed; however, the screw holder 11c formed separately from the main body of the table holding member <NUM> may be fixed to the main body of the table holding member <NUM>.

In the screw holder 11c, threaded holes 11d engaging with the adjusting screws <NUM> are formed. In this embodiment, <NUM> threaded holes 11d are formed in the screw holder 11c. The threaded holes 11d pass through the screw holder 11c in the diameter direction of the screw holder 11c. That is, the threaded holes 11d pass through the screw holder 11c in the diameter direction of the bearing <NUM>. The <NUM> threaded holes 11d are arranged at regular pitches in the circumferential direction of the bearing <NUM>. That is, the <NUM> threaded holes 11d are arranged at pitches of an equal angle (pitches of <NUM>°) relative to the center of the table holding member <NUM>. The threaded holes 11d are formed in positions slightly misaligned from the threaded holes 11b in the circumferential direction of the bearing <NUM> and are formed in the vicinities of the threaded holes 11b in the circumferential direction of the bearing <NUM>.

As illustrated in <FIG>, between the outer race <NUM> and the screw holder 11c in the diameter direction of the bearing <NUM>, a gap S configured to allow deformation of the outer race <NUM> is formed. That is, between an outer circumferential surface of the outer race <NUM> and an inner circumferential surface of the screw holder 11c in the diameter direction of the bearing <NUM>, the gap S configured to allow deformation of the outer race <NUM> is formed. The gap S is formed in the entire region in the circumferential direction of the bearing <NUM>. The gap S is, for example, a gap of less than <NUM>.

The adjusting screws <NUM> are, for example, hexagon socket set screws with no heads. The adjusting screws <NUM> engage with the threaded holes 11d and are disposed on the outer circumferential side of the outer race <NUM>. The <NUM> adjusting screws <NUM> are arranged in the circumferential direction of the bearing <NUM>. Specifically, the <NUM> adjusting screws <NUM> are arranged at regular pitches in the circumferential direction of the bearing <NUM> and are arranged at pitches of an equal angle (pitches of <NUM>°) relative to the center of the table holding member <NUM>. Furthermore, the adjusting screws <NUM> are movable relative to the screw holder 11c in the diameter direction of the bearing <NUM>. That is, the <NUM> adjusting screws <NUM> are disposed radially relative to the center of the table holding member <NUM>. The adjusting screws <NUM> each have one end contactable with the outer circumferential surface of the outer race <NUM>.

Similar to the adjusting screws <NUM>, the looseness preventing screws <NUM> are hexagon socket set screws. The looseness preventing screws <NUM> engage with the threaded holes 11d. Specifically, the looseness preventing screws <NUM> engage with the threaded holes 11d from outside of the adjusting screws <NUM> in the diameter direction of the bearing <NUM>. The looseness preventing screws <NUM> come into contact with the other ends of the adjusting screws <NUM> with predetermined contact pressure to prevent looseness of the adjusting screws <NUM>.

In the X-ray inspection apparatus <NUM>, to bring the rotation locus of the board <NUM> rotated by the rotation mechanism <NUM> near to a perfect circle, in assembly of the rotation mechanism <NUM>, the adjusting screws <NUM> are brought into contact with the outer circumferential surface of the outer race <NUM> to adjust the shape of the outer race <NUM>, and in that state, the outer race <NUM> is fixed to the table holding member <NUM>. Specifically, first, a placing stand on which a cylindrical square is placed is fixed to a top surface of the second table member <NUM>, and the cylindrical square is placed on the placing stand. While the table <NUM> is rotated in that state, displacement of an outer circumferential surface of the cylindrical square is detected with a dial gauge or the like, and the position of the cylindrical square placed on the placing stand is adjusted so that the center of rotation of the table <NUM> substantially coincides with the axis of the cylindrical square on the basis of a result of the detection of displacement of the outer circumferential surface of the cylindrical square. At this time, the adjusting screws <NUM> are not in contact with the outer circumferential surface of the outer race <NUM>. Furthermore, the looseness preventing screws <NUM> are removed.

Then, while the table <NUM> is rotated, displacement of the outer circumferential surface of the cylindrical square is detected, and the outer race <NUM> is deformed to adjust the shape of the outer race <NUM> so that the rotation locus of the cylindrical square is near to a perfect circle on the basis of the detection result of displacement of the outer circumferential surface of the cylindrical square. Specifically, on the basis of the detection result of displacement of the outer circumferential surface of the cylindrical square, the fixing screw <NUM> closest to a portion of the outer race <NUM> to be deformed is loosened, and the adjusting screw <NUM> closest to this fixing screw <NUM> is turned to move inward in the diameter direction of the bearing <NUM>, so as to be pressed against the outer circumferential surface of the outer race <NUM>. Since the gap S is formed between the outer circumferential surface of the outer race <NUM> and the inner circumferential surface of the screw holder 11c, the outer race <NUM> deforms in accordance with the amount of rotation of the adjusting screw <NUM>.

Then, after the loosened fixing screw <NUM> is tightened, displacement of the outer circumferential surface of the cylindrical square is detected again while the table <NUM> is rotated. Furthermore, on the basis of the detection result of displacement of the outer circumferential surface of the cylindrical square, the fixing screw <NUM> closest to a portion of the outer race <NUM> to be deformed is loosened, and the adjusting screw <NUM> closest to this fixing screw <NUM> is turned to be pressed against the outer circumferential surface of the outer race <NUM>. Then, the loosened fixing screw <NUM> is tightened.

These operations are repeated to adjust the shape of the outer race <NUM> so that the rotation locus of the cylindrical square is near to a perfect circle. When the shape of the outer race <NUM> is adjusted, the adjusting screw <NUM> coming into contact with the outer circumferential surface of the outer race <NUM> may be turned to move outward in the diameter direction of the bearing <NUM> on the basis of the detection result of displacement of the outer circumferential surface of the cylindrical square. After the shape of the outer race <NUM> is adjusted, the looseness preventing screws <NUM> are attached to prevent looseness of the adjusting screws <NUM>. Furthermore, after the shape of the outer race <NUM> is adjusted, all the fixing screws <NUM> are tightened firmly, and the outer race <NUM> is properly fixed to the table holding member <NUM> with the fixing screws <NUM>.

With the shape of the outer race <NUM> adjusted so that the rotation locus of the cylindrical square is near to a perfect circle, the rotation locus of the board <NUM> rotated by the rotation mechanism <NUM> is also near to a perfect circle. Note that there may be a case where, after the shape of the outer race <NUM> is adjusted, some adjusting screw <NUM> are not in contact with the outer circumferential surface of the outer race <NUM>. In this case, before the looseness preventing screws <NUM> are attached, the adjusting screw <NUM> that is not in contact with the outer circumferential surface of the outer race <NUM> is also brought into slight contact with the outer circumferential surface of the outer race <NUM>.

As described above, in this embodiment, the <NUM> adjusting screws <NUM> are arranged in the circumferential direction of the bearing <NUM> and are contactable with the outer circumferential surface of the outer race <NUM> from the outer circumferential side of the outer race <NUM>. Furthermore, in this embodiment, the gap S configured to allow deformation of the outer race <NUM> is formed between the outer circumferential surface of the outer race <NUM> and the inner circumferential surface of the screw holder 11c. Thus, in this embodiment, as described above, with the shape of the outer race <NUM> adjusted using the adjusting screws <NUM> so that the rotation locus of the board <NUM> rotated by the rotation mechanism <NUM> is near to a perfect circle, the outer race <NUM> can be fixed to the table holding member <NUM>. Therefore, in this embodiment, the rotation locus of the board <NUM> rotated by the rotation mechanism <NUM> can be brought near to a perfect circle.

In this embodiment, the shape of the outer race <NUM> is adjusted with the adjusting screws <NUM>, and the outer race <NUM> deforms in accordance with the amount of rotation of the adjusting screws <NUM>. Thus, in this embodiment, the shape of the outer race <NUM> can be readily adjusted. Furthermore, in this embodiment, engagement of the looseness preventing screws <NUM> with the threaded holes 11d engaging with the adjusting screws <NUM> prevents looseness of the adjusting screws <NUM>, so that a simple configuration can prevent looseness of the adjusting screws <NUM>.

<FIG> is an explanatory diagram of a configuration of the table holding member <NUM> and the bearing <NUM> according to another embodiment of the present invention. Note that, in <FIG>, constituents similar to those in the above-described embodiment are denoted by the same reference signs.

In the above-described embodiment, as illustrated in <FIG>, the table holding member <NUM> may be composed of two members, a ring-shaped first holding member <NUM> and a ring-shaped second holding member <NUM>. In this modification, the placing surface 11a is formed on the first holding member <NUM>. On the outer circumferential side of the placing surface 11a, a cylindrical portion 25a is formed that is shaped into a cylinder and protrudes upward from the placing surface 11a. The first holding member <NUM> and the second holding member <NUM> are fixed to each other with fixing screws <NUM>. For example, the first holding member <NUM> and the second holding member <NUM> are fixed to each other with <NUM> fixing screws <NUM> arranged at regular pitches in the circumferential direction of the bearing <NUM>.

In this modification, the outer race <NUM> is fixed to the table holding member <NUM> with fixing screws <NUM> coming into contact with an upper end surface of the outer race <NUM>. Specifically, by pressing the outer race <NUM> against the placing surface 11a with the fixing screws <NUM>, the outer race <NUM> is fixed to the table holding member <NUM>. The outer race <NUM> is fixed to the table holding member <NUM>, for example, with <NUM> fixing screws <NUM> arranged at regular pitches in the circumferential direction of the bearing <NUM>. The fixing screws <NUM> are disposed further inward than the fixing screws <NUM> in the diameter direction of the bearing <NUM>. Furthermore, the fixing screws <NUM> are disposed, for example, in the same positions as those of the fixing screws <NUM> in the circumferential direction of the bearing <NUM>. In this modification, no insertion hole 15a is formed in the outer race <NUM>, and the outer race <NUM> has an outer diameter smaller than the outer diameter of the outer race <NUM> of the above-described embodiment.

The fixing screws <NUM> are, for example, hexagon socket set screws. In the second holding member <NUM>, threaded holes 26a engaging with the fixing screws <NUM> are formed. In the second holding member <NUM>, the threaded holes 11d engaging with the adjusting screws <NUM> and the looseness preventing screws <NUM> are also formed. The threaded holes 26a are formed in the vicinities of the threaded holes 11d in the circumferential direction of the bearing <NUM>. The second holding member <NUM> is composed of a cylindrical portion 26b that is shaped into a cylinder and in which the threaded holes 11d are formed and a ring portion 26c that is shaped into a ring and in which the threaded holes 26a are formed. The ring portion 26c protrudes from an upper end portion of the cylindrical portion 26b toward the inner circumferential side of the cylindrical portion 26b. The cylindrical portion 26b has a lower end surface coming into contact with an upper end surface of the cylindrical portion 25a.

In this modification, the cylindrical portion 25a and the cylindrical portion 26b compose the screw holder 11c as the adjustment member holder movably holding the adjusting screws <NUM> and disposed on the outer circumferential side of the outer race <NUM>. In this modification, the gap S configured to allow deformation of the outer race <NUM> is also formed between the outer race <NUM> and the screw holder 11c in the diameter direction of the bearing <NUM>. That is, the gap S configured to allow deformation of the outer race <NUM> is formed between the outer circumferential surface of the outer race <NUM> and inner circumferential surfaces of the cylindrical portions 25a and 26b in the diameter direction of the bearing <NUM>. The gap S is formed in the entire region in the circumferential direction of the bearing <NUM>.

In this modification, when the outer race <NUM> is deformed to adjust the shape of the outer race <NUM>, the fixing screw <NUM> closest to a portion of the outer race <NUM> to be deformed is loosened, and the adjusting screw <NUM> closest to this fixing screw <NUM> is turned to be pressed against the outer circumferential surface of the outer race <NUM>. Then, the loosened fixing screw <NUM> is tightened. This modification can also achieve effects similar to those of the above-described embodiment.

In the above-described embodiment, the looseness preventing screws <NUM> may prevent looseness of the adjusting screws <NUM> by coming into contact with outer circumferential surfaces of the adjusting screws <NUM> from a direction orthogonal to the axial direction of the adjusting screws <NUM>. In this case, in addition to the threaded holes 11d, threaded holes engaging with the looseness preventing screws <NUM> are formed in the screw holder 11c. Furthermore, in this case, the adjusting screws <NUM> may be headed screws having heads. Furthermore, the rotation mechanism <NUM> may include no looseness preventing screw <NUM>. In this case, for example, looseness of the adjusting screws <NUM> may be prevented by an adhesive poured into the threaded holes 11d after the shape of the outer race <NUM> is adjusted.

In the above-described embodiment, the number of the adjusting screws <NUM> of the rotation mechanism <NUM> may be <NUM> or more and <NUM> or less, or <NUM> or more. For example, the number of the adjusting screws <NUM> of the rotation mechanism <NUM> may be <NUM>. If the number of the adjusting screws <NUM> of the rotation mechanism <NUM> is relatively small, the screw holder 11c may not be formed into a cylindrical shape. For example, the screw holder 11c may be an arc-shaped curved plate in which one threaded hole 11d is formed. In this case, a plurality of the screw holders 11c are arranged at regular pitches in the circumferential direction of the bearing <NUM>. Furthermore, in this case, the screw holders 11c may be formed, integrated with the main body of the table holding member <NUM> on which the placing surface 11a is formed, or the screw holders 11c formed separately from the main body of the table holding member <NUM> may be fixed to the main body of the table holding member <NUM>.

In the above-described embodiment, insertion holes through which the shanks of the fixing screws <NUM> are inserted may be formed in the table holding member <NUM>, and threaded holes engaging with the male threads formed on the shanks of the fixing screws <NUM> may be formed in the outer race <NUM>. Furthermore, in the above-described embodiment, the inner race <NUM> may be fixed to the table holding member <NUM>, and the outer race <NUM> may be fixed to the table <NUM>. In this case, the table <NUM> includes a screw holder corresponding to the screw holder 11c, and in this screw holder, the threaded holes 11d are formed.

In the above-described embodiment, the adjustment members <NUM> configured to adjust the shape of the outer race <NUM> by deforming the outer race <NUM> may be members shaped into rods, tubes, or the like, other than the adjusting screws. For example, the adjustment members <NUM> may be rods of oil-hydraulic cylinders. In this case, the table holding member <NUM> includes a cylinder holder to which main bodies of the oil-hydraulic cylinders are fixed. This cylinder holder is an adjustment member holder movably holding the rods of the oil-hydraulic cylinders being the adjustment members <NUM>.

Moreover, in the above-described embodiment, the adjustment member <NUM> may be eccentric cams. In this case, the table holding member <NUM> includes a cam holder as an adjustment member holder rotatably holding the eccentric cams. The eccentric cams are movable relative to the cam holder in the diameter direction of the bearing <NUM>. Specifically, outer circumferential surfaces of the eccentric cams are movable relative to the cam holder in the diameter direction of the bearing <NUM>, when viewed vertically.

In the above-described embodiment, as long as the shape of the outer race <NUM> can be maintained after shape adjustment, the adjusting screws <NUM> may be removed after the shape of the outer race <NUM> is adjusted. For example, if the shape of the outer race <NUM> can be maintained by pouring an adhesive into the gap S after shape adjustment, the adhesive may be poured into the gap S with the shape of the outer race <NUM> adjusted, and then the adjusting screws <NUM> may be removed from the threaded holes 11d. That is, the completed rotation mechanism <NUM> may include no adjusting screw <NUM>.

Claim 1:
A rotation mechanism for an X-ray inspection apparatus used in an X-ray inspection apparatus including an X-ray generator and an X-ray detector disposed with an object to be inspected placed between the X-ray detector and the X-ray generator, the rotation mechanism comprising:
a table;
a table holding member rotatably holding the table;
a rolling bearing including an inner race and an outer race, the inner race having a ring shape and being fixed to either one of the table and the table holding member, the outer race having a ring shape and being fixed to another of the table and the table holding member; characterized in that the rotation mechanism further comprises
three or more adjustment members configured to adjust a shape of the outer race by deforming the outer race,
the adjustment members being arranged in a circumferential direction of the rolling bearing,
the table or the table holding member to which the outer race is fixed including an adjustment member holder movably holding the adjustment members, the adjustment member holder being disposed on an outer circumferential side of the outer race,
the adjustment members being movable relative to the adjustment member holder in a diameter direction of the rolling bearing and being contactable with an outer circumferential surface of the outer race, and
a gap configured to allow deformation of the outer race being formed between the outer circumferential surface of the outer race and the adjustment member holder in the diameter direction of the rolling bearing.