JP2011021743A - Sliding bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sliding bearing low in cost with a small number of components, stable in rotational torque and usable even in a high-load and corrosive atmosphere. <P>SOLUTION: The sliding bearing 1 is made of a combination of an inner ring 2 made of synthetic resin and having a convex outer peripheral surface 2a, and an outer ring 3 made of synthetic resin and having a concave inner peripheral surface 3b corresponding to the outer peripheral surface 2a. The outer ring 3 is formed with inner ring built-in grooves 3a at two opposed parts of the inner peripheral surface 3b. The inner ring built-in grooves 3a are opened to at least one end face of the outer ring 3, and the inner ring 2 is built in the outer ring 3 through the inner ring built-in grooves 3a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sliding bearing, and more particularly to a sliding bearing in which an inner ring and an outer ring are separately manufactured and incorporated.

  A sliding bearing comprising a combination of an inner ring having a convex curved surface on the outer peripheral surface and an outer ring having a concave curved surface corresponding to the outer peripheral surface on the inner peripheral surface is known. For example, a sliding bearing having an outer member having a bearing hole and an inner member inserted into the bearing hole with an annular bearing gap interposed between the outer member and the inner member made of molten resin. A sliding bearing is known which is made of a cured resin composition and in which a bearing gap between an outer member and an inner member is formed by resin shrinkage when the inner member is cured (Patent Document 1). reference).

  Further, in the hydrodynamic bearing unit in which a pair of inner ring and outer ring are coaxially combined, the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring face each other with a minute gap and are parallel to the axial direction. A hydrodynamic bearing unit in which at least one dynamic pressure groove is formed between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring (see Patent Document 2). )It has been known. The inner ring includes a synthetic resin inner ring and a synthetic resin outer ring that supports the inner ring so that the inner ring is rotatable about its axis, and the inner ring rotates with the rotating shaft to be supported. A hole for receiving the shaft, a large-diameter outer peripheral surface disposed in the central portion in the axial direction, and a diameter smaller than the diameter of the large-diameter outer peripheral surface, and sandwiching the large-diameter outer peripheral surface in the axial direction A pair of small-diameter outer peripheral surfaces, and the outer ring is provided integrally with the outer ring main body fitted to the support member so as to be non-rotating around the axis and the inner peripheral surface of the outer ring main body. And a sliding bearing having an annular seal portion that presses each of the pair of small-diameter outer peripheral surfaces of the inner ring and slidably contacts each of the pair of small-diameter outer peripheral surfaces (see Patent Document 3) It has been known.

  In addition, the self-alignment that the inner ring having the spherical outer peripheral surface that is in sliding contact with the inner peripheral surface is assembled inside the outer ring having the spherical inner peripheral surface so that the outer ring and the inner ring can be relatively rotated relative to each other. In the plain bearing, the outer ring is made of synthetic resin, and includes a groove formed along at least one end surface of both end surfaces along the circumferential direction of the end surface, and an inner peripheral portion and an outer peripheral portion divided by the groove. When the inner ring is assembled, the inner ring is pushed by the outer ring surface of the inner ring and is distorted toward the groove. When the inner ring is assembled, the inner ring is automatically adjusted to restore the distortion and hold the outer ring surface of the inner ring. A center slide bearing (see Patent Document 4) is known.

On the other hand, as an anti-corrosion resin ball bearing used in corrosive atmosphere such as in water, chemicals or high humidity atmosphere, the inner ring and outer ring are formed of polyarylene sulfide (PAS) resin having a flexural modulus of 2000 to 6000 MPa. (See Patent Document 5). This resin ball bearing can be increased in a radial load of about 2 kgf / cm ² (1.96 × 10 ⁻¹ MPa), for example, in a # 6000 series deep groove ball bearing by selecting a specific resin material. It is.

JP-A-9-32856 Japanese Patent Application Laid-Open No. 2004-293685 JP 2007-127225 A JP 2007-100905 A Japanese Patent Laid-Open No. 10-47355

  However, in the sliding bearing described in Patent Document 1, after molding the outer member into a predetermined shape, the bearing hole is filled with molten resin, and the molten resin is cured to mold the inner member. Manufactured by a method (insert molding) in which an annular bearing gap is formed between the member and the outer member by resin shrinkage accompanying the hardening of the molten resin. Due to the variation in shrinkage after molding, the inner ring and the outer ring There is a problem that the clearance fluctuates and the rotational torque is not stable. Further, the sliding bearings described in Patent Document 2 and Patent Document 3 have a problem that the number of parts is large and assembly is complicated.

  Further, the sliding bearing described in Patent Document 4 has a problem that it cannot be used under high load conditions due to the presence of a circumferential groove formed on the end face of the outer ring. Further, the resin ball bearing described in Patent Document 5 has a problem that although it has good load resistance and rotational torque performance, it has a complicated structure and is expensive to manufacture.

  The present invention has been made to cope with such problems, and has an object to provide a slide bearing that has a small number of parts, is low in price, has a stable rotational torque, and can be used even in a high load and corrosive atmosphere. And

  The sliding bearing of the present invention is a sliding bearing comprising a combination of a synthetic resin inner ring having a convex curved outer peripheral surface and a synthetic resin outer ring having a concave curved inner peripheral surface corresponding to the outer peripheral surface. The outer ring has inner ring mounting grooves formed at two opposing locations on the inner peripheral surface thereof, and the inner ring mounting groove is formed by opening at least one end surface of the outer ring. It is incorporated in the outer ring through the inner ring incorporating groove.

  The inner ring is inserted into the outer ring through the inner ring mounting groove in a state in which the axis of the inner ring is shifted from the axis of the outer ring, and then the inner ring and the outer ring are relatively rotated to rotate the inner ring shaft. It is characterized in that it is incorporated in the outer ring by matching the core and the axial center of the outer ring.

  The width of the groove for incorporating the inner ring is the same as the width of the inner ring. Further, the distance between the bottom surfaces of the opposed inner ring incorporating grooves is the same as the outer diameter of the inner ring.

  The convex curved surface is a spherical surface. Further, the outer peripheral surface of the inner ring is characterized in that the entire circumference of the central portion in the axial direction of the convex curved surface is flat. In particular, the flat shape is a shape in which the distance from the apex position of the convex curved surface to the flat surface is 0.05 to 0.1 mm in the axial section of the outer peripheral surface of the inner ring.

  An axial cross-sectional shape of the concave curved surface is a Gothic arch shape formed by inclined surfaces of two circular arcs having different circle centers.

  Lubricating grooves are formed on the outer peripheral surface of the inner ring or the inner peripheral surface of the outer ring.

  The inner ring is an injection molded body of the synthetic resin.

  The synthetic resin is at least one selected from polyether ether ketone (hereinafter referred to as PEEK) resin, polyimide (hereinafter referred to as PI) resin, and polyphenylene sulfide (hereinafter referred to as PPS) resin. Features.

  The slide bearing is used in a corrosive atmosphere such as water, chemicals, or a high humidity atmosphere.

  The sliding bearing according to claim 1 is a combination of an inner ring having a convex curved outer peripheral surface and an outer ring having a concave curved surface corresponding to the outer peripheral surface on the inner peripheral surface. Inner ring incorporating grooves are formed at two opposing positions, and the inner ring incorporating groove is open on at least one end surface of the outer ring, and the inner ring is incorporated into the outer ring through the inner ring incorporating groove. Therefore, it is possible to manufacture the inner ring and the outer ring separately and to incorporate the inner ring into the outer ring, and the number of parts is small, and it can be manufactured at a lower cost and in a shorter time than a resin ball bearing. In addition, it has a simple structure and can be used even under high load conditions. In addition, there is no need to insert-mold the inner ring or the like, the gap between the inner ring and the outer ring can be managed, and the rotational torque is stabilized.

  In the sliding bearing according to claim 2, after the inner ring is inserted into the outer ring through the inner ring mounting groove with the inner and outer rings being displaced, the inner and outer rings are relatively rotated. Since it is done by aligning the shaft center, it can be incorporated without elastic deformation of the inner and outer rings. Particularly, as described in claim 3 and claim 4, the width of the inner ring built-in groove is the same as the width of the inner ring, and the distance between the bottom surfaces of the opposed inner ring built-in grooves is the same as the outer diameter of the inner ring. Thus, when the inner ring is assembled into the outer ring, the inner ring can be easily assembled into the outer ring by aligning both ends of the inner ring width with both ends of the inner ring assembling groove of the outer ring in a state where the outer ring axis and the inner ring axis are orthogonal to each other. .

  Since the convex curved surface of the outer peripheral surface of the inner ring is a spherical surface, the sliding bearing according to the fifth aspect can be used for the swinging motion part.

  Since the entire circumference of the axially central portion of the convex curved surface of the inner ring outer peripheral surface is a flat shape, the sliding bearing according to claim 6 and claim 7 has a parting line (hereinafter referred to as PL). ) Can be finished only by injection molding without machining the inner ring. In addition, the gap between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring formed by this flat shape facilitates circulation of water, chemicals, and the like over the entire sliding surface, thereby improving lubricity. Also, the incorporation of the inner ring into the outer ring can be improved.

  In the plain bearing according to the eighth aspect, since the lubricating groove is formed on the outer peripheral surface of the inner ring or the inner peripheral surface of the outer ring, water, chemicals, etc. are easily circulated over the entire sliding surface, and the lubricity can be improved. .

  In the sliding bearing according to claim 9, since the axial cross-sectional shape of the concave curved surface of the inner peripheral surface of the outer ring is a Gothic arch shape formed by two inclined surfaces of different circular arcs, the rotational torque is reduced. can do.

  Since the inner ring is an injection-molded body made of the above synthetic resin, the slide bearing according to claim 10 is lightweight, can be easily molded, and matching by the built-in gap is easy.

  In the sliding bearing according to claim 11, since the synthetic resin is at least one selected from PEEK resin, PI resin, and PPS resin, it has excellent load resistance and is in a corrosive atmosphere of water, chemicals, or high humidity. Can be used.

Fig.1 (a) is a front view which shows the sliding bearing of this invention, FIG.1 (b) is sectional drawing cut | disconnected by the AA line of Fig.1 (a). It is the fragmentary sectional view which cut | disconnected the sliding bearing of this invention to the axial direction. It is the fragmentary sectional view which cut | disconnected the inner ring | wheel of the slide bearing of this invention to the axial direction. It is the fragmentary sectional view which cut | disconnected the outer ring | wheel of the slide bearing of this invention to the axial direction. FIG. 5A and FIG. 5B are partial cross-sectional views of the inner ring formed with the lubricating grooves cut in the axial direction. It is a perspective view which shows the aspect at the time of the assembly of the slide bearing of this invention. It is the schematic of an underwater radial test apparatus.

  An embodiment of the slide bearing of the present invention will be described with reference to FIG. Fig.1 (a) is a front view which shows the sliding bearing of this invention, FIG.1 (b) is sectional drawing cut | disconnected by the AA line of Fig.1 (a). As shown in FIGS. 1 (a) and 1 (b), a plain bearing 1 of the present invention includes an inner ring 2 having a convex outer peripheral surface 2a and a concave curved surface corresponding to the outer peripheral surface 2a. The outer ring 3 and the inner ring 2 can be rotated relative to each other. A bearing hole 4 is formed in the inner ring 2. The outer ring 3 is formed with an inner ring incorporating groove 3 a at two opposing positions on the inner peripheral surface 3 b, and the inner ring incorporating groove 3 a is open at one end face of the outer ring 3. Here, the inner ring incorporating groove 3a may be formed at two locations facing each other on the end face side of the inner peripheral face 3b so as to open at least one end face of the outer ring 3, and the inner peripheral face so as to open at both end faces. You may form in 2 places which opposes in the both end surface side in 3b, respectively. In the case where the inner ring incorporating groove 3a is formed on both end faces, the inner ring incorporating groove 3a on the other end face is arranged with the inner ring incorporating groove 3a on the other end face as a central axis (two opposed inner rings on the one end face). If the inner ring 2 is assembled into the outer ring 3, the inner ring 2 can be prevented from accidentally dropping from the other inner ring incorporating groove 3a. . The angle of shifting the inner ring incorporating groove 3a is preferably 45 ° to 90 °, but most preferably 90 °. The inner ring 2 is incorporated into the outer ring 3 via an inner ring incorporating groove 3a. After the inner ring 2 and the outer ring 3 are manufactured separately, the fitting gap can be managed by combining them as described above.

  FIG. 2 is a partial cross-sectional view of the sliding bearing of the present invention cut in the axial direction. As shown in FIG. 2, the plain bearing 1 includes an inner ring 2 having an outer peripheral surface 2 a having a convex R shape (convex curved surface) with respect to an axis, and an inner peripheral surface having a corresponding concave R shape (concave curved surface). It is comprised with the outer ring | wheel 3 which has 3b. In particular, the outer peripheral surface 2a of the inner ring 2 is preferably a spherical surface. In this case, the inner peripheral surface 3b of the outer ring 3 is a corresponding spherical surface.

  FIG. 3 is a partial cross-sectional view of the inner ring of the slide bearing of the present invention cut in the axial direction. As shown in FIG. 3, it is preferable that the inner ring | wheel 2 of the side rotated in a slide bearing makes the axial direction center part of the convex curve of the outer peripheral surface 2a flat shape. Moreover, it is preferable to provide this flat shape over the perimeter of the circumferential direction of the outer peripheral surface 2a. When the inner ring 2 is a resin injection-molded body, the PL mark deletion process can be omitted by setting the PL in this flat portion. Further, the gap between the outer ring inner peripheral surface and the inner ring outer peripheral surface 2a formed by this flat shape makes it easy to circulate water, chemicals, and the like over the entire sliding surface, thereby improving the lubricity.

  The flat shape is preferably a shape in which the distance d from the apex position of the convex curved surface to the flat surface in the axial section of the outer peripheral surface 2a of the inner ring 2 is 0.05 to 0.1 mm. If the distance d to the flat surface is less than 0.05 mm, the gap is too small, and there is concern about an increase in rotational torque due to the PL mark being caught, and water and chemicals are less likely to circulate in this gap. Lubricity is not improved. On the other hand, if the distance d to the flat surface exceeds 0.1 mm, the flat surface becomes too wide and a sufficient swing angle cannot be secured, which is not preferable.

  FIG. 4 is a partial cross-sectional view of the outer ring of the slide bearing of the present invention cut in the axial direction. As shown in FIG. 4, the outer ring 3 on the side to be fixed in the sliding bearing has a Gothic arch shape in which the axial cross-sectional shape of the concave curved surface of the inner peripheral surface 3b is formed by inclined surfaces of two circular arcs having different circle centers. It can be. By using a Gothic arch shape, the rotational torque of the sliding bearing can be reduced. It is particularly preferable to use the outer ring 3 having the Gothic arch shape and the inner ring 2 having the flat shape described above in combination.

  An example of the lubricating groove formed in the inner ring of the slide bearing of the present invention is shown in FIG. FIG. 5A and FIG. 5B are partial cross-sectional views of the inner ring cut in the axial direction. In the example shown in FIG. 5A, axial lubrication grooves 2 b are formed on the outer peripheral surface 2 a and the end surface of the inner ring 2. In addition, the axial direction lubricating groove 2b should just be formed in the outer peripheral surface 2a of the inner ring | wheel 2 at least. The axial direction lubricating grooves 2b are formed in the outer peripheral surface 2a at at least 10 locations at equal intervals in the circumferential direction. The axial lubricating groove 2b preferably has a width of 1 to 2 mm and a depth of about 0.5 mm. If the width of the lubricating groove 2b exceeds 2 mm, the pressure receiving area is reduced, which is not preferable. If the width is less than 1 mm, water and chemicals are not easily circulated.

  In the example shown in FIG. 5B, in addition to the axial lubrication groove 2 b formed on the outer circumferential surface 2 a and the end surface of the inner ring 2, the circumferential lubrication groove 2 c is the center in the axial direction of the outer circumferential surface 2 a of the inner ring 2. It is formed in the part. The lubricating groove 2c is preferably a circumferential groove having a width of about 0.5 to 2.5 mm and a depth of about 0.5 mm. If the width of the lubricating groove 2c exceeds 2.5 mm, the pressure receiving area is reduced, which is not preferable. If the width is less than 0.5 mm, water and chemicals are not easily circulated.

  The axial lubrication groove and the circumferential lubrication groove may be provided on the inner circumferential surface of the outer ring. In this case, at least ten lubricating grooves in the axial direction are formed at equal intervals in the circumferential direction on the inner circumferential surface of the outer ring, and the circumferential lubricating grooves are formed in the central portion in the axial direction of the inner circumferential surface of the outer ring. About the width | variety, depth, etc. of these lubrication grooves, it is the same as that of the case where it forms in the outer peripheral surface of the said inner ring | wheel. These lubrication grooves may be formed on both the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring.

  FIG. 6 is a perspective view showing an aspect when the slide bearing of the present invention is assembled. First, in a state where the axis of the inner ring 2 and the axis of the outer ring 3 are shifted (orthogonalized), the inner ring 2 is advanced in the axial direction of the outer ring 3, and the inner ring 2 is inserted into the outer ring 3. At this time, as shown in FIG. 1 (b), the inner peripheral surface 3b of the outer ring 3 has a small diameter after the midpoint in the width direction when viewed from the insertion direction, and cannot proceed any further. Next, from this state, the inner ring 2 and the outer ring 3 are rotated relative to each other (by 90 °) so that the axis of the inner ring 2 and the axis of the outer ring 3 are aligned with each other, whereby the inner ring 2 as shown in FIG. The sliding bearing 1 in which is inserted into the outer ring 3 can be obtained.

  The width of the inner ring incorporating groove 3a is preferably the same as the width of the inner ring 2. Moreover, it is preferable that the distance between the bottom surfaces of the opposed inner ring incorporating grooves 3 a is the same as the maximum outer diameter of the inner ring 2. By setting the dimensions of the inner ring mounting groove 3a to the above dimensions, when the inner ring 2 is assembled to the outer ring 3, both ends of the width of the inner ring 2 are connected to the inner ring of the outer ring 3 in a state where the outer ring axis and the inner ring axis are orthogonal to each other. The inner ring 2 can be easily assembled into the outer ring 3 in accordance with both ends of the incorporating groove 3a.

  In the sliding bearing of the present invention, the outer ring and the inner ring are preferably formed of a synthetic resin. The type of the synthetic resin is not particularly limited, but it is necessary that the synthetic resin has characteristics that meet at least the usage conditions (heat resistance, mechanical strength, etc.) of the bearing. Moreover, if it is a synthetic resin which can be injection-molded, it can be manufactured easily and the dimensional accuracy can be made uniform, which is preferable in managing the fitting gap.

  For the inner ring and the outer ring, it is preferable to use a synthetic resin excellent in lubrication characteristics and mechanical strength. For example, polyacetal (POM) resin, nylon resin (nylon 6, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 46, semi-aromatic nylon having an aromatic ring in the molecular chain, etc.), polytetra Fluoropolymers that can be injection molded such as fluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) resin, tetrafluoroethylene / hexafluoropropylene copolymer (FEP) resin, ethylene-tetrafluoroethylene copolymer (ETFE) resin , Injection-moldable PI resin, PPS resin, wholly aromatic polyester resin, PEEK resin, polyamideimide resin, and the like. Each of these synthetic resins may be used alone or may be a polymer alloy in which two or more kinds are mixed. Or the polymer alloy which mix | blended said synthetic resin with the synthetic resin with low lubrication characteristics other than the above may be sufficient.

  Among these synthetic resins, PEEK resin, PI resin, and PPS resin are preferably used because they have excellent load resistance and excellent corrosion resistance in a corrosive atmosphere in water, chemicals, or high humidity. By using these resins, the sliding bearing of the present invention can be suitably used even in a corrosive atmosphere.

  Moreover, glass fiber, carbon fiber, and various mineral fibers (whiskers) may be blended with these synthetic resins to increase the strength. Furthermore, you may use together with a solid lubricant. Moreover, it is possible to improve a lubrication characteristic by adding a solid lubricant and lubricating oil to these synthetic resins. Examples of the solid lubricant include polytetrafluoroethylene (PTFE) resin, graphite, and molybdenum disulfide.

Example 1
An inner ring was manufactured by injection molding using a slidable resin material made of PEEK resin containing 30% by weight of PTFE resin. The outer ring was manufactured by using PEEK material with special filler (Bearly PK5031), molding the material by injection molding, and then finishing the entire surface by machining. A test bearing (see FIG. 1) was obtained by combining these inner and outer rings. The obtained test bearing was measured for the amount of wear after a certain period of operation in an underwater radial test shown below. The results are also shown in Table 1.

Example 2
After manufacturing the same inner ring as in Example 1, lubricating grooves were formed in the circumferential direction and the axial direction of the inner ring outer peripheral surface. The circumferential lubricating groove has a width of 2 mm and a depth of 0.5 mm in the entire circumference of the central portion in the width direction, and the axial lubricating groove has a width of 1.5 mm and a depth of 0.5 mm of the lubricating groove in the circumferential direction, etc. Ten locations were formed at intervals. The same outer ring as in Example 1 was used, and a test bearing was obtained by combining the inner ring (see FIG. 5B) and the outer ring (see the outer ring 3 in FIGS. 1 and 2). The obtained test bearing was measured for the amount of wear after a certain period of operation in an underwater radial test shown below. The results are also shown in Table 1.

Comparative Example 1
For comparison, NTN Precision Resin Co., Ltd. resin rolling bearings (ball bearings) having the same inner ring inner diameter, outer ring outer diameter, and the same width were used as test bearings. This resin rolling bearing is manufactured by using a BEAREE PK5031 for inner and outer rings, molding a material by injection molding, and then finishing the entire surface by machining. The cage is an injection-molded product of PPS resin, and the balls (11 pieces) are made of alumina ceramics. The results are also shown in Table 1.

<Underwater radial test>
The test was carried out in water 5 using an underwater radial tester shown in FIG. A load was applied to a test bearing (sliding bearing) 1 assembled to the housing 6 with an air cylinder 7. The shaft 8 was rotated by the motor 10 through the coupling 9, and the initial rotational torque was measured, and the amount of increase in the gap in 50 hours was confirmed. The test conditions were a SUS304 turning product (surface roughness Ra 0.8 μm) on the mating material, a load of 200 N, a roller rotation speed of 800 rpm, an atmosphere of water, and a test time of 50 hours (hours). As for the evaluation method, those having an increase in gap of less than 0.02 mm are particularly excellent in high load resistance in liquid, and “◎” is 0.02 to 0.1 mm. “○” is recorded as being excellent in high load resistance.

  As a result of the underwater radial test, the sliding bearings of Example 1 and Example 2 had an initial rotational torque increase of about 20% as compared with the resin rolling bearing of Comparative Example 1, and were at a level with no problem. Further, the durability test results of the sliding bearings of Example 1 and Example 2 were good as compared with the resin rolling bearing of Comparative Example 1 without abnormal wear at 50 hr. As is clear from the results in Table 1, the sliding bearings of Example 1 and Example 2 are functionally comparable to the resin rolling bearing of Comparative Example 1, and structurally because there are few components and manufacturing processes. It can be seen that it is far superior and advantageous in terms of quality and cost.

  The slide bearing according to the present invention can be manufactured separately with an inner ring and an outer ring, and the inner ring can be incorporated into the outer ring. The number of parts is small, and it can be manufactured at a lower price than a plastic rolling bearing (ball bearing). Since the torque is stable and can be used even under high loads and corrosive atmospheres, it can be suitably used in place of resin rolling bearings in various applications including special environments.

DESCRIPTION OF SYMBOLS 1 Sliding bearing 2 Inner ring 2a Inner ring outer peripheral surface 2b Axial lubrication groove 2c Circumferential lubrication groove 3 Outer ring 3a Built-in groove 3b Outer ring inner circumferential surface 4 Bearing hole 5 Water 6 Housing 7 Air cylinder 8 Shaft 9 Coupling 10 Motor

Claims (12)

A slide bearing comprising a combination of a synthetic resin inner ring having a convex curved outer peripheral surface and a synthetic resin outer ring having a concave curved inner peripheral surface corresponding to the outer peripheral surface,
The outer ring is formed with an inner ring incorporating groove at two opposing positions on the inner peripheral surface thereof, and the inner ring incorporating groove is formed to open at least one end surface of the outer ring,
The sliding bearing, wherein the inner ring is incorporated in the outer ring through the inner ring incorporating groove.   The inner ring is inserted into the outer ring through the inner ring incorporating groove in a state in which the axis of the inner ring is shifted from the axis of the outer ring, and then the inner ring and the outer ring are rotated relative to each other to rotate the shaft of the inner ring. The plain bearing according to claim 1, wherein the bearing is incorporated in the outer ring by aligning the core with the axis of the outer ring.   The sliding bearing according to claim 1 or 2, wherein a width of the inner ring incorporating groove is the same as a width of the inner ring.   The slide bearing according to claim 1, 2 or 3, wherein a distance between the bottom surfaces of the opposed inner ring incorporating grooves is the same as an outer diameter of the inner ring.   The sliding bearing according to any one of claims 1 to 4, wherein the convex curved surface is a spherical surface.   The sliding bearing according to any one of claims 1 to 5, wherein the outer peripheral surface of the inner ring has a flat shape in the entire circumference of the central portion in the axial direction of the convex curved surface.   The flat shape is a shape in which a distance from a vertex position of the convex curved surface to the flat surface is 0.05 to 0.1 mm in an axial cross section of the outer peripheral surface of the inner ring. Plain bearing.   The sliding bearing according to any one of claims 1 to 5, wherein a lubricating groove is formed on an outer peripheral surface of the inner ring or an inner peripheral surface of the outer ring.   9. The slip according to claim 1, wherein an axial cross-sectional shape of the concave curved surface is a Gothic arch shape formed by inclined surfaces of two circular arcs having different circle centers. bearing.   The plain bearing according to any one of claims 1 to 9, wherein the inner ring is an injection-molded body of the synthetic resin.   The sliding bearing according to any one of claims 1 to 10, wherein the synthetic resin is at least one selected from a polyether ether ketone resin, a polyimide resin, and a polyphenylene sulfide resin.   The sliding bearing according to claim 11, wherein the sliding bearing is used in a corrosive atmosphere.

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