JP2012082844A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing which can improve the rigidity of a pressing member while suppressing the increase of bearing dimensions.SOLUTION: An inner ring 3 at the rotating side is made up of a first inner ring constituting member 3A and a second inner ring constituting member 3B. The pressing member 5 grants the preload to the inside of the bearing. The end surface 13 of the first inner ring constituting member 3A and an opposing surface 15 of the pressing member 5 facing the end surface in the axial direction are made to partially contact each other. An abutting part α is arranged at the outer diameter side, a non-contact part S is arranged at the inner diameter side, and a lubricant is supplied to the non-contact part S at the inner diameter side.

Description

  The present invention relates to a rolling bearing used in various fields including industrial machines, and more particularly to an ultra-thin type rolling bearing used in medical equipment such as a CT scanner device.

  The CT scanner device is a device that diagnoses and analyzes pathological symptoms by irradiating X-rays or the like. An example of this CT scanner device is shown in FIG.

  The CT scanner device includes an inspection unit 200 provided with an opening 200A, and a bed unit 250 on which an inspected object 300 such as a human body is mounted and movable within the opening 200A of the inspection unit 200. The inspection unit 200 is provided with a ring-shaped rotating body 201 (gantry) in which an X-ray irradiation device 211 and a detection unit 212 are arranged to face each other in the diameter direction. The rotating body 201 is rotatably supported by a cylindrical fixing portion 215 via a bearing 51.

  In this CT scanner device, in a state where X-rays are irradiated from the X-ray irradiation device 211, the rotating body 201 is rotated around the bed portion 250, and X-rays transmitted through the object to be inspected 300 are detected by the detector 212. Thus, a cross-sectional image of the inspection object 300 can be obtained.

  In the CT scanner device, the opening 200A of the inspection unit 200 is formed to have a size (approximately a diameter of about 1 m) that allows the inspected object 300 to pass through, and the CT scanner device itself can be miniaturized. It is necessary to reduce the space of the rotation support part 213 in which the bearing 51 is disposed. Therefore, a so-called ultra-thin type rolling bearing having a remarkably small ball diameter with respect to the PCD is used for the bearing 51.

  The ultra-thin type rolling bearing 51 illustrated in FIG. 12 is a double-row angular contact ball bearing, and is disposed inside the outer ring 52, an outer ring 52 having two raceway surfaces 52a and 52b formed on the inner peripheral surface, Main components are an inner ring 53 having two raceway surfaces 53Aa and 53Bb, and a double row of balls 54 (rolling elements) disposed between the raceway surfaces 52a and 52b of the outer ring 52 and the races 53Aa and 53Bb of the inner ring 53. Composed. The inner ring 53 includes two inner ring constituting members 53A and 53B which are adjacent to each other with an axial gap G therebetween, and raceway surfaces 53Aa and 53Bb are formed on the outer peripheral surfaces of both inner ring constituting members 53A and 53B, respectively.

  One inner ring constituent member (second inner ring constituent member) 53B has a small-diameter portion 62 on the outer peripheral surface of one end portion in the axial direction, and the other inner ring constituent member (first inner ring constituent member) on the outer periphery of the small-diameter portion 62. Member) 53A is fitted with an appropriate margin. The end portion on the one axial side of the first inner ring constituting member 53A protrudes in the axial direction from the end surface of the second inner ring constituting member 53B.

  In this double row angular contact ball bearing, a ring-shaped presser member 55 is used to apply a preload to the inside of the bearing. Of the presser member 55, the end faces on the inner ring constituting members 53A and 53B side have a stepped surface shape having steps in the axial direction, and a small-diameter end face 55A and a large-diameter end face 55B having different axial positions are formed. The small diameter end face 55A faces the end face of the second inner ring constituting member 53B, and the entire large diameter end face 55B faces the end face of the first inner ring constituting member 53A. The holding member 55 is fixed to the second inner ring constituting member 53 </ b> B using a bolt 60.

  By tightening the bolt 60, the first inner ring constituting member 53A is pressed through the presser member 55 in the direction in which the axial gap G is reduced, so that a preload is applied to the bearing. When the small-diameter end surface 55A of the presser member 55 is in contact with the end surface of the second inner ring constituent member 53B and the large-diameter end surface 55B is in contact with the end surface of the first inner ring constituent member 53A, the axial positioning of the first inner ring member 53A is performed. Thus, a prescribed amount of preload is applied inside the bearing.

  An example of a rolling bearing that applies preload using the presser member 55 in this way is disclosed in Patent Document 1 and Patent Document 2 below.

Japanese Patent Laid-Open No. 2005-3152 JP 2004-286116 A

  In the CT scanner device shown in FIG. 13, silence is required in order to reduce organ atrophy caused by anxiety and fear felt by the patient. Accordingly, there is a strong demand for further quietness of the rolling bearings installed in the CT scanner device.

  However, in the conventional rolling bearing shown in FIG. 12, the rigidity of the presser member 55 that is a thin-walled large-diameter component tends to be insufficient. Therefore, the presser member 55 is likely to vibrate during the operation of the bearing, particularly during high-speed operation, and abnormal noise and noise may be generated from the bearing as a result of this vibration, which is contrary to the above requirement. The vibration of the presser member 55 may cause a minute slip at the contact portion between the presser member 55 and the first inner ring constituent member 53A, and there is a possibility that fretting wear may occur at the contact portion. Such progress of wear causes noise promotion and wear powder generation due to preload loss and must be avoided as much as possible. The above problems are particularly prominent in a CT scanner apparatus in which an inner ring rotating type bearing is used as a bearing of the CT scanner apparatus and a gantry portion is provided on the inner ring.

  In order to solve the above problems, it is possible to improve the rigidity by increasing the thickness of the presser member (increasing the dimension in the axial direction), but there is a limitation in expanding the bearing space in the CT scanner device. Therefore, in practice, it is difficult to increase the thickness of the presser member 55.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a rolling bearing capable of improving the rigidity of a pressing member while suppressing an increase in bearing size.

  A rolling bearing according to the present invention for solving the above problems includes an outer ring having a double-row raceway surface on an inner peripheral surface, and a first inner ring constituent member and a second inner ring constituent member that are adjacent to each other via an axial gap. An inner ring in which a raceway surface is formed on the outer peripheral surface of each inner ring constituent member, a double row rolling element disposed between the raceway surface of the outer ring and the raceway surface of the inner ring, In a rolling bearing used for rotating an inner ring, the inner ring component member is provided with a pressing member that applies an axial pressing force that reduces the axial clearance to the bearing and applies a preload inside the bearing. The inner ring constituent member is opposed to the inner ring in the axial direction, and the opposing surfaces in the axial direction of both members are partially brought into contact with each other.

  In the present invention, since the axially opposed surfaces of the presser member and the first inner ring constituent member are partially brought into contact with each other, the contact surface pressure between the presser member and the first inner ring constituent member can be increased. As a result, the presser member is integrated with the first inner ring constituent member, so that the apparent rigidity of the presser member is improved. Therefore, it is possible to avoid a situation in which the presser member becomes a vibration generation source during the operation of the bearing, and the quietness of the bearing is improved. In addition, since the contact surface pressure is increased, a minute slip between the first inner ring constituent member and the presser member is less likely to occur, and preload loss and wear powder generation due to the progress of fretting wear can be suppressed. Since the above effect can be obtained without increasing the required space of the pressing member, it is possible to increase the rigidity of the pressing member even in a situation where the installation space of the bearing is limited.

  The contact portion between the opposing surfaces and the non-contact portion where the opposing surfaces are not in contact with each other can be formed separately in the radial direction. In this case, if a non-contact part is arranged on the inner diameter side of the contact part, the lubricant such as grease accumulated in the non-contact part is scattered by the centrifugal force during rotation of the bearing and supplied to the contact part on the outer diameter side. Therefore, fretting wear of the contact portion can be prevented more reliably. The number of contact portions and non-contact portions provided separately in the radial direction is not limited to one and may be plural.

  In this case, it is preferable to form the outer diameter side portion adjacent to the contact portion in the non-contact portion in a tapered shape in which the outer diameter side is reduced. Thereby, since the lubricant accumulated in the non-contact portion is guided to the tapered portion and smoothly moves to the contact portion, the lubricity at the contact portion can be further improved.

  In this case, it is desirable that the rolling bearing be provided with a radial groove that penetrates the contact portion and communicates the non-contact portion and the bearing internal space.

  In this case, the lubricant accumulated in the non-contact portion flows in the radial groove toward the outer diameter side due to the centrifugal force when the bearing rotates. Therefore, the lubricant can be supplied to the contact portion not only directly from the non-contact portion but also through the radial groove. Therefore, abundant lubricant can be supplied to the contact portion. In this case, by increasing the width of the radial groove toward the outer diameter side, the lubricant can smoothly flow in the radial groove.

  In each of the configurations listed above, it is desirable that the first inner ring constituent member is fitted to the outer periphery of the second inner ring constituent member, and the presser member and the second inner ring constituent member are coupled by the fastening member. In this case, the preload can be applied to the inside of the bearing by tightening the fastening member.

  At this time, if the non-contact portion is provided on the outer diameter side of the contact portion, the contact portion can be provided in a portion close to the fastening member, and the rigidity of the pressing member can be further improved.

  It is desirable to form a plating layer having wear resistance on at least the surface constituting the contact portion of the pressing member. By forming this type of plating layer, the wear resistance of the pressing member is improved, so that the progress of fretting wear at the contact portion can be suppressed.

  The plating is not particularly limited as long as the above-described effects can be obtained, but chromium (Cr) plating is desirable. In this case, copper (Cu) plating is applied to the base of the Cr plating layer. It is desirable to form a layer. In this case, since the surface hardness of the presser member can be increased to the same level of hardness (Hv 800 to 900) as the surface of the first inner ring constituent member by Cr plating, wear of the presser member can be suppressed. . Further, since the Cr plating layer is in close contact with the Cu layer, the Cr plating layer is hardly peeled off.

  In the above invention, it is desirable to interpose an axial groove between the inner peripheral surface of the first inner ring constituent member and the outer peripheral surface of the second inner ring constituent member that are fitted together. As a result, the lubricant accumulated in the axial gap between the first inner ring constituent member and the second inner ring constituent member can be supplied to the non-contact portion and the abutting portion via the axial groove, and the lubricant can be supplied inside the bearing. It becomes possible to circulate.

  The rolling bearing described above can be suitably used for a CT scanner device.

  The rolling bearing of the present invention can prevent the generation of abnormal noise and noise using the presser member as a vibration source. Therefore, silence is high, and when it is incorporated in a CT scanner device, the burden on the patient can be reduced. Further, fretting at the contact portion between the presser member and the first inner ring constituent member can be suppressed, and preload loss and generation of wear powder due to progress of wear can be prevented.

It is sectional drawing of the double row angular contact ball bearing concerning this invention. It is a front view of the pressing member shown in FIG. The other embodiment of the present invention is shown and is a front view of a pressing member. FIG. 2 is an enlarged cross-sectional view of a pressing member and a first inner ring constituent member shown in FIG. 1. The other embodiment of the present invention is shown and it is an expanded sectional view of a pressing member and the 1st inner ring constituent member. The other embodiment of the present invention is shown and it is an expanded sectional view of a pressing member and the 1st inner ring constituent member. The other embodiment of the present invention is shown and it is an expanded sectional view of a pressing member and the 1st inner ring constituent member. It is a front view of the pressing member in the embodiment shown in FIG. It is a top view of the pressing member in embodiment shown in FIG. The other embodiment of the present invention is shown and it is a sectional view of a double row angular contact ball bearing. It is a front view of the pressing member shown in FIG. It is sectional drawing which shows the conventional double row angular contact ball bearing. It is sectional drawing which shows medical CT scanner apparatus.

  Embodiments of the present invention will be described below with reference to FIGS.

  FIG. 1 shows a double-row angular contact ball bearing used in a medical CT scanner apparatus. The ball bearing 1 includes an outer ring 2 having two raceway surfaces 2a and 2b formed on the inner peripheral surface, an inner ring 3 disposed on the inner side of the outer ring 2 and having two raceway surfaces 3Aa and 3Bb on the outer peripheral surface, and an outer ring. A double row of balls 4 (rolling elements) disposed between the two raceway surfaces 2a and 2b and the raceway surfaces 3Aa and 3Bb of the inner ring 3, and a cage 6 that holds the balls 4 in a circumferentially equidistant position. Is used for inner ring rotation. The ball bearing 1 is an ultra-thin type rolling bearing in which the ratio φ between the ball diameter dB and the pitch circle diameter is 0.03 or less (φ = dB / PCD ≦ 0.03).

  The space between the inner ring 3 and the outer ring 2 is sealed with seal members 7 disposed on both sides in the axial direction. A space sealed by the seal member 7 constitutes a bearing internal space. Although FIG. 1 illustrates the case where the seal member 7 is mounted on the inner peripheral surface of the outer ring, the seal member 7 can also be mounted on the outer peripheral surface of the inner ring 2.

  The inner ring 3 includes two inner ring constituent members 3A and 3B that are adjacent to each other via an axial gap G, and raceway surfaces 3Aa and 3Bb are formed on the outer circumferences of the inner ring constituent members 3A and 3B, respectively. One inner ring constituting member 3B (second inner ring constituting member) has a small-diameter portion 12 on the outer peripheral surface of one end portion in the axial direction, and the other inner ring constituting member 3A (first inner ring) on the outer periphery of the small-diameter portion 12. The component members are fitted with a moderate tightening allowance. In this fitted state, the end portion on the one axial side of the first inner ring constituting member 3A protrudes in the axial direction from the end face of the second inner ring constituting member 3B.

  The double-row angular contact ball bearing has a form in which two bearings are combined back to back. In a back-to-back rolling bearing, preload can be applied to the inside of the bearing by causing the inner ring constituent members 3A and 3B to relatively approach each other in the axial direction. In order to apply this preload, a presser member 5 having a thin perforated disk shape is arranged on one side in the axial direction of the first inner ring constituting member 3A and the second inner ring constituting member 3B.

  As shown in FIG. 4, two types of axial steps h <b> 1 and h <b> 2 are formed on the end surface of the presser member 5 facing the inner ring constituent members 3 </ b> A and 3 </ b> B. Due to the steps h1 and h2, a small-diameter end surface 5A, a large-diameter end surface 5B, and an intermediate-diameter end surface 5C having different axial positions are formed on the end surfaces. The axial positions of the end faces 5A to 5C are gradually shifted to the one side in the axial direction in the order of the small-diameter end face 5A, the large-diameter end face 5B, and the intermediate-diameter end face 5C. The large-diameter end surface 5B and the intermediate-diameter end surface 5C form a facing surface 15 that faces the end surface 13 of the first inner ring constituting member 3A in the axial direction. The small-diameter end surface 5A faces the end surface of the second inner ring constituent member 3B in the axial direction. A small-diameter outer peripheral surface 16 between the small-diameter end surface 5A and the intermediate-diameter end surface 5C has the same diameter as the outer peripheral surface of the small-diameter portion 12 of the second inner ring constituting member 3B.

  The pressing member 5 described above is coupled to one side in the axial direction of the second inner ring constituting member 3 </ b> B using a fastening member such as a bolt 11. By tightening the bolt 11, the first inner ring constituent member 3 </ b> A pressed against the large-diameter end surface 5 </ b> B of the presser member 5 moves in the reduction direction of the axial gap G, and preload is applied inside the bearing. The large diameter end surface 5B of the presser member 5 is in contact with the end surface 13 of the first inner ring constituting member 3A, and the small diameter end surface 5A is in contact with the end surface of the second inner ring constituting member 3Bb, whereby the first inner ring constituting member 3A is axially moved. And a predetermined amount of preload is applied inside the bearing. At this time, the inner peripheral surface of the first inner ring constituting member 3A is not only fitted to the small diameter step portion 12 of the second inner ring constituting member 3B but also to the small diameter outer peripheral surface 16 of the presser member 5.

  As shown in FIG. 1, in the state where preload application has been completed, the large-diameter end surface 5B of the presser member 5 contacts the end surface 13 of the first inner ring constituting member 3A to form the contact portion α. On the other hand, the intermediate diameter end surface 5C is not in contact with the end surface 13 of the first inner ring constituting member 3A, and a space S (non-contact portion) is formed therebetween. As shown in FIG. 2, the contact part α and the non-contact part S are each annular, and are separated in the radial direction with the contact part α arranged on the outer diameter side and the non-contact part S arranged on the inner diameter side. Is formed.

  According to the above configuration, of the end surface of the presser member 5, the opposing surface 15 (the large diameter end surface 5B and the intermediate diameter end surface 5C) facing the end surface 13 of the first inner ring component 3A in the axial direction is the first inner ring configuration. It partially abuts against the end face 13 of the member 3A. This is different from the conventional configuration in which the end surface 13 of the first inner ring constituting member 3A and the large-diameter end surface 55B (see FIG. 12) corresponding to the facing surface 15 of the pressing member 5 are in full contact. With this configuration, the contact surface pressure between the presser member 5 and the first inner ring constituent member 3A can be made larger than that of the conventional product, and the presser member 5 is integrated with the first inner ring constituent member 3A. . Thereby, since the apparent rigidity of the presser member 5 is improved, it is possible to prevent the generation of noise and noise due to insufficient rigidity of the presser member 5 during operation of the bearing 1, and the quietness of the bearing is improved.

  Further, the contact surface pressure is increased, so that relative micro-slip generated at the contact portion α between the end surface 13 of the first inner ring constituting member 3A and the large-diameter end surface 5B of the pressing member 5 is suppressed, and the fretting of the both surfaces 13 and 5B Wear can be prevented. This makes it possible to avoid problems such as preload loss during long-term use and generation of wear powder.

  Moreover, since the rigidity of the presser member 5 can be increased without increasing the thickness in the axial direction, the presser member 5 can be accommodated in the existing installation space in the bearing, and the bearing dimensions can be maintained. Can do. Therefore, for example, when the bearing 1 is used in a CT scanning device, it is not necessary to modify the CT scanning device side in accordance with the increase in bearing size, and the cost can be reduced.

  Further, as shown in FIG. 2, if a non-contact portion S is provided on the inner diameter side and a contact portion α is provided on the outer diameter side, a lubricant such as grease is supplied to the non-contact portion S in advance. Thus, the lubricant can be scattered to the outer diameter side by the centrifugal force during the bearing operation, and can be sequentially supplied to the contact portion α. For this reason, the lubrication at the contact portion α is good, and fretting wear can be more reliably prevented.

  Furthermore, in this embodiment, since the contact portion α and the space S are formed by providing the step h2 on the end surface of the pressing member 5, the end surface 13A of the first inner ring constituting member 3A is kept flat while the end surface 13 is kept flat. 13 and the opposed surface 15 of the pressing member 5 can be partially brought into contact with each other. Therefore, the existing product can be used as it is as the first inner ring constituting member 3A and further the second inner ring constituting member 3B, and there is no need to separately manufacture the dedicated inner ring 3. Therefore, cost reduction of the rolling bearing 1 can be achieved.

  As described above, in the present embodiment, the contact portion α and the non-contact portion S are formed separately in the radial direction. However, as schematically illustrated in FIG. The radial end surface 5B and the intermediate radial end surface 5C) are formed flush with each other in the radial direction, and the opposing surface 15 of the pressing member 5 is provided with irregularities in the circumferential direction, whereby the contact portion α and the non-contact portion S are circumferentially arranged. It can also be formed separately. Even with this configuration, it is possible to obtain the same functions and effects as those of the embodiments shown in FIGS. 1, 2, and 4.

  FIG. 5 shows another embodiment of the present invention. As in the embodiment shown in FIGS. 1, 2, and 4, this embodiment has two steps h1 on the facing surface 15 of the presser member 5 facing the first inner ring constituting member 3A and the second inner ring constituting member 3B. , H2 are formed. On the other hand, unlike the embodiment shown in FIG. 4, the axial positions of the three end faces 5A to 5C formed by the two steps h1 and h2 are the order of the small-diameter end face 5A, the intermediate-diameter end face 5C, and the large-diameter end face 5B. Is displaced to one side in the axial direction. With this configuration, the contact portion α formed by the intermediate diameter end surface 5C of the presser member 5 and the end surface 13 of the first inner ring constituent member 3A is disposed on the inner diameter side, and the presser member 5 is disposed on the outer diameter side thereof. The non-contact portion S formed by the small-diameter end surface 5B and the end surface 13 of the first inner ring constituting member 3A can be disposed.

  In this case, since the contact portion α is provided in the vicinity of the coupling portion between the pressing member 5 and the second inner ring constituting member 3B by the fastening member (bolt 11 in FIG. 1), the small diameter end surface 5A of the pressing member 5 and the first Adhesion with the end surface 13 of the inner ring constituting member 3A is improved. Therefore, the apparent rigidity of the pressing member 5 can be further increased.

  FIG. 6 shows another embodiment of the present invention. In this embodiment, in the first embodiment shown in FIGS. 1, 2, and 4, the outer diameter side region of the non-contact portion S adjacent to the contact portion α is tapered so as to decrease toward the outer diameter side. Formed. In the example of illustration, the case where it forms in the taper shape by connecting the large diameter end surface 5B and the intermediate diameter end surface 5C of the pressing member 5 with the taper surface 5D is illustrated.

  With such a configuration, the lubricant accumulated in the non-contact portion S can be moved to the contact portion α more smoothly by the guide action of the tapered surface 5D, and the lubricity of the contact portion α is further improved.

  7 to 9 show another embodiment of the present invention. In the basic structure of the bearing according to the present embodiment, in comparison with the bearing of the embodiment shown in FIG. 6, a radial groove 20 that connects the non-contact portion S and the bearing internal space is formed through the contact portion α. The point is different.

  As shown in FIG. 8, the radial groove 20 can be formed, for example, on the large-diameter end surface 5 </ b> B of the pressing member 5. The radial groove 20 is formed in, for example, a V-shaped cross section (see FIG. 9) formed intermittently in the circumferential direction.

  In the bearing of the present embodiment, the lubricant (not shown) accumulated in the non-contact portion S flows into the radial groove 20 due to the centrifugal force during the bearing operation, and enters the bearing internal space via the radial groove 20. Moving. Therefore, since the lubricant is directly supplied from the non-contact portion S to the outer diameter direction from the non-contact portion S and is also supplied from the circumferential direction through the radial groove 20, lubrication at the contact portion α is performed. The nature is further improved.

  In particular, as shown in FIG. 8, if the circumferential width of the radial groove 20 is increased toward the outer diameter side, the lubricant can easily pass through the radial groove 20. We can supply abundantly.

  10 and 11 show a double-row angular contact ball bearing according to another embodiment of the present invention. In this bearing 31, axial grooves 40 that open to both end surfaces are formed at one or a plurality of locations (for example, four locations) on the inner peripheral surface of the first inner ring constituting member 3A. By forming such an axial groove 40, for example, in the configuration in which the non-contact portion S is disposed on the inner diameter side as shown in FIG. 4, the axial gap G and the non-contact portion S can be communicated. (FIG. 10) In the configuration in which the contact portion α is arranged on the inner diameter side as shown in FIG. 5, the axial gap G and the contact portion α can be communicated (not shown). Therefore, in the former example, a circulation cycle of the lubricant returning to the bearing internal space sequentially through the axial gap G → the axial groove 40 → the non-contact portion S → the contact portion α is formed, and in the latter example In other words, a circulation cycle of the lubricant that returns to the bearing internal space through the axial gap G → the axial groove 40 → the contact portion α → the non-contact portion S is formed. Therefore, the lubricant can be stably supplied to the contact portion α, and the lubricity of the contact portion α is improved.

  In the embodiments described so far, it is desirable to form a plating layer on the surface of the pressing member 5 for improving the wear resistance at the contact portion α. As this type of plating, chromium (Cr) plating can be considered. If it is chrome plating, the surface hardness of the presser member 5 can be easily increased to the same degree of hardness (Hv 800 to 900) as the surface of the first inner ring constituting member 3A, and the fretting wear of the contact portion α can be reduced. It can be surely suppressed. Furthermore, if a copper (Cu) plating layer is formed on the base of the chromium plating, the adhesion of the chromium plating layer can be improved and the peeling of the chromium plating layer can be prevented over a long period of time.

  If each plating layer described above is formed on the entire surface of the pressing member 5, masking at the time of plating becomes unnecessary, so that the production efficiency can be improved. If this point is not particularly problematic, masking is appropriately performed, and the surface constituting the contact portion α of the presser member 5 (the presser member 5 in FIG. 4 has the large-diameter end surface 5B and the presser member 5 in FIG. 5). If there is, each plating layer may be formed only on the intermediate diameter end face 5C).

  Various embodiments of the bearing according to the present invention have been described so far. However, the present invention is not limited to the embodiments described herein, and may be appropriately selected within the scope not departing from the technical idea described in the claims. It can be changed.

  For example, in the embodiment described here, the present invention is applied to a double-row angular contact ball bearing, but the present invention can also be applied to various types of rolling bearings such as a double-row tapered roller bearing.

DESCRIPTION OF SYMBOLS 1, 31 Double row angular contact ball bearing 2 Outer ring 2a, 2b Raceway surface 3 Inner ring 3A First inner ring constituent member 3Aa Raceway surface 3B Second inner ring constituent member 3Bb Raceway surface 4 Ball (rolling element)
5 Presser member 5A Small diameter end surface 5B Large diameter end surface 5C Intermediate diameter end surface 5D Tapered surface 13 End surface (first inner ring constituting member 3A)
15 Opposing surface (presser member 5)
20 radial groove 40 axial groove α contact part G axial gap S non-contact part (space)

Claims (12)

An outer ring having a double-row raceway surface on the inner peripheral surface, and a first inner ring constituent member and a second inner ring constituent member that are adjacent to each other via an axial clearance, and a track on each outer peripheral surface of each inner ring constituent member An inner ring formed with a surface, a double-row rolling element disposed between the raceway surface of the outer ring and the raceway surface of the inner ring, and an axial pusher that reduces the axial clearance in the first inner ring constituent member. In a rolling bearing having a presser member that applies pressure to apply a preload inside the bearing, and is used in inner ring rotation,
A rolling bearing characterized in that the pressing member and the first inner ring constituting member are opposed to each other in the axial direction, and axially opposed surfaces of both members are partially brought into contact with each other.   The rolling bearing according to claim 1, wherein a contact portion between the facing surfaces and a non-contact portion where the facing surfaces are not in contact with each other are separated in the radial direction.   The rolling bearing according to claim 2, wherein the non-contact portion is provided on an inner diameter side of the contact portion.   The rolling bearing according to claim 3, wherein, of the non-contact portion, an outer diameter side portion adjacent to the abutting portion is formed in a tapered shape in which the outer diameter side is reduced.   The rolling bearing according to claim 3 or 4, further comprising a radial groove that penetrates the contact portion and communicates the non-contact portion and the bearing internal space.   The rolling bearing according to claim 5, wherein a width of the radial groove is increased toward an outer diameter side.   The rolling bearing according to claim 1 or 2, wherein the first inner ring constituent member is fitted to the outer periphery of the second inner ring constituent member, and the presser member and the second inner ring constituent member are coupled by a fastening member.   The rolling bearing according to claim 7, wherein the non-contact portion is provided on the outer diameter side of the contact portion.   The rolling bearing as described in any one of Claims 1-8 which formed the plating layer which has abrasion resistance in the surface which comprises the said contact part among the said holding members.   The rolling bearing according to claim 9, wherein the plating layer is formed by Cr plating, and a Cu plating layer is formed on an underlayer thereof.   The rolling bearing according to any one of claims 1 to 10, wherein an axial groove is interposed between the inner peripheral surface of the first inner ring constituent member and the outer peripheral surface of the second inner ring constituent member that are fitted to each other.   The rolling bearing as described in any one of Claims 1-11 used for CT scanner apparatus.

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