JP2013061040A - Self-aligning rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a structure that can prevent a guide ring 8b from being axially excessively displaced to suppress or prevent friction between end faces of spherical rollers 4, 4 and the side face of the guide ring 8b.SOLUTION: The outer circumferential surface of a guide ring 8b is formed into a projecting curved surface 14 with an outer diameter at the center in an axial direction made larger than an outer diameter at both ends in the axial direction. The inner circumferential surface of a rim part 9a of a retainer 7b is formed into a recessed curved surface 13 with an inner diameter at the center in an axial direction made larger than an inner diameter at both ends in the axial direction. By engaging the recessed curved surface 13 with the projecting curved surface 14, the guide ring 8b is supported inside the rim part 9a to be relatively rotatable with respect to the retainer 7b, while suppressing displacement of the guide ring in the axial direction of the retainer 7b.

Description

  The present invention relates to an improvement in a self-aligning roller bearing that is incorporated in various mechanical devices and supports a rotating shaft inside a housing, for example. Specifically, it has excellent durability by suppressing or preventing friction between the axial end surface of each spherical roller and the axial side surface of the guide wheel for stabilizing the posture of the cage that holds each spherical roller. It is intended to realize a self-aligning roller bearing having the characteristics.

  For example, a self-aligning roller bearing as described in Patent Documents 1 to 3 is conventionally used to rotatably support a heavy shaft on the inside of a housing. 6 to 7 show a first example of a conventional structure of a self-aligning roller bearing. The self-aligning roller bearing 1 includes a plurality of spherical rollers 4 and 4 arranged in a freely rollable manner between an outer ring 2 and an inner ring 3 that are concentrically combined with each other. An outer ring raceway 5 that is a spherical concave surface having a single center is formed on the inner circumferential surface of the outer ring 2. Further, a pair of inner ring raceways 6 and 6 are formed on both sides of the outer peripheral surface of the inner ring 3 in the width direction (left and right direction in FIGS. 6 to 7) to face the outer ring raceway 5. Each of the spherical rollers 4 and 4 has a symmetric shape in which the respective maximum diameter portions are in the central portion in the axial direction, and extends in two rows between the outer ring raceway 5 and the inner ring raceways 6 and 6. It is arranged so that it can roll freely. The pair of cages 7 and 7 prevent the spherical rollers 4 and 4 from being separated. Further, by bringing the inner peripheral surfaces of the large-diameter side end portions of both the cages 7 and 7 close to the outer peripheral edge of the guide wheel 8 that is rotatably arranged around the intermediate portion of the inner ring 3, the cages 7 and 7 7 is guided (supported so as to be rotatable in a state where radial displacement is suppressed). Further, both side surfaces of the guide wheel 8 are close to and opposed to the inner end surfaces in the axial direction of the spherical rollers 4, 4 to guide the spherical rollers 4, 4, and the rotational centers of the spherical rollers 4, 4. The shaft is prevented from tilting (skewing) from the normal state.

  For example, when the rotating shaft is supported inside the housing by the self-aligning roller bearing 1 having the above-described structure, the outer ring 2 is fitted and fixed to the housing, and the inner ring 3 is fixed to the rotating shaft. To do. When the inner ring 3 rotates together with the rotating shaft, the spherical rollers 4 and 4 roll to allow this rotation. When the axis of the rotating shaft and the axis of the housing do not coincide, the inner ring 3 is aligned inside the outer ring 2 (the central axis of the inner ring 3 is inclined with respect to the central axis of the outer ring 2). To compensate for this discrepancy. In this case, the position where the rolling surfaces of the spherical rollers 4 and 4 are in rolling contact with each other in the outer ring raceway 5 changes. Since the outer ring raceway 5 is formed in a single spherical shape, the rolling of the plurality of spherical rollers 4 and 4 is performed smoothly even after the mismatch compensation (after the change of the position of contact with rolling). .

  Next, the self-aligning roller bearing 1a shown in FIG. 8 shows a second example of a conventional structure. In the case of the structure of the second example, the spherical rollers 4 and 4 arranged in both rows are rotatably held by one cage 7a. For this purpose, the retainer 7a is provided on the both sides in the axial direction of the annular rim portion 9 disposed between the spherical rollers 4 and 4 in both rows, and the base ends of the plurality of column portions 10 respectively. Each part is continuous. And the part enclosed by the circumferential side surface of the column part 10 adjacent to the circumferential direction and the axial direction side surface of the said rim | limb part 9 is made into the pocket 11 for holding each said spherical roller 4 and 4 so that rolling is possible. Yes. The guide wheel 8 a is disposed between the inner peripheral surface of the rim portion 9 and the outer peripheral surface of the intermediate portion of the inner ring 3.

  In the case of the self-aligning roller bearings 1 and 1a having the above-described structure, during operation, the end surfaces of the spherical rollers 4 and 4 and the side surfaces of the guide wheels 8 and 8a rotate relative to each other while being in sliding contact. In the case of the conventional structure, the guide wheels 8 and 8a are not particularly restricted in the axial direction and are displaced in the axial direction. For this reason, the surface pressure of the sliding contact portion between the end surface of each of the spherical rollers 4 and 4 and the side surface of the guide wheels 8 and 8a excessively increases, and there is a possibility that remarkable wear may progress at each sliding contact portion. . Such progress of wear increases rattling within the self-aligning roller bearings 1 and 1a and causes damage due to the generated wear powder. Therefore, it is necessary to suppress or prevent such wear.

  In view of such circumstances, Patent Document 1 discloses that a boundary portion existing in a portion in contact with the mating surface of the end surface of each spherical roller and the side surface of the guide wheel is a smooth convex curved surface. A structure that prevents the contact surface pressure from excessively rising (edge load) is described. In Patent Document 2, a circumferential groove is provided on the side surface of the guide wheel, and an oil film is formed on the sliding contact portion between the end surface of each spherical roller and the side surface of the guide wheel by the lubricating oil collected in the circumferential groove. And the structure which reduces the friction of the friction part of each of these surfaces is described. Further, Patent Document 3 describes a structure in which a thrust rolling bearing is installed between the end surface of each spherical roller and the side surface of the guide wheel, and the friction state between these surfaces is changed from sliding friction to rolling friction. Yes.

  Among the conventional structures described in Patent Documents 1 to 3 as described above, in the case of the structure described in Patent Document 1, the excessive displacement due to the edge load can be prevented, but the axial displacement of the guide wheels can be prevented. Therefore, the increase in the surface pressure of the friction surface between the end face of each spherical roller and the side face of the guide wheel cannot be suppressed, and the wear preventing effect is not always sufficient. Further, even with the conventional structure described in Patent Document 2, the effect of preventing wear is not always sufficient for the same reason. Further, in the case of the conventional structure described in Patent Document 3, it is inevitable that the structure is complicated and the cost is increased, and it is difficult to apply to a small self-aligning roller bearing.

Japanese Patent Laid-Open No. 2007-100934 JP 2007-315450 A JP 2009-210078 A

  The present invention has been invented to realize a structure capable of suppressing or preventing the friction between the end face of each spherical roller and the side face of the guide wheel in view of the above-described circumstances.

The self-aligning roller bearing of the present invention includes an outer ring, an inner ring, a plurality of spherical rollers, a cage, and a guide ring.
Of these, the outer ring forms an outer ring raceway, which is a spherical concave surface having a single center, on its inner peripheral surface.
Further, the inner ring forms a pair of inner ring raceways opposed to the outer ring raceway on the outer peripheral surface thereof.
The spherical rollers are provided between the outer ring raceway and the inner ring raceways so as to roll freely in two rows.
Further, the retainer includes an annular rim portion disposed between the spherical rollers in both rows, and both side surfaces in which the respective base end portions are connected to both axial side surfaces of the rim portion. Each column consists of multiple pillars. And the part enclosed by the circumferential side surface of the column part adjacent to the circumferential direction and the axial direction side surface of the said rim | limb part is made into the pocket for hold | maintaining each said spherical roller so that rolling is possible.
Further, the guide wheel has an annular shape, and is provided in an annular gap between the two rows of rollers between the inner peripheral surface of the rim portion and the outer peripheral surface of the inner ring.

  In particular, in the self-aligning roller bearing of the present invention, the outer peripheral surface of the guide wheel is a convex curved surface in which the outer diameter of the central portion in the axial direction is larger than the outer diameters of both end portions in the axial direction. The inner peripheral surface of the rim portion is a concave curved surface in which the inner diameter at the central portion in the axial direction is larger than the inner diameters at both end portions in the axial direction. Then, by engaging the concave curved surface with the convex curved surface, the guide wheel is moved toward the inner diameter side of the rim portion, and the relative rotation with respect to the cage is suppressed in a state where displacement in the axial direction of the cage is suppressed. I support it as possible.

When the self-aligning roller bearing of the present invention configured as described above is implemented, for example, as in the invention described in claim 2, the concave curved surface is a point on the central axis of the cage as the center of curvature. The partial spherical concave surface. The convex curved surface is a partially spherical convex surface having a center of curvature at a point on the central axis of the guide wheel.
When carrying out the invention described in claim 2, it is preferable that, as in the invention described in claim 3, linear edges parallel to each other are provided at two positions on the radially opposite side of the outer peripheral surface of the guide wheel. Forming part. Further, the interval between the two straight edge portions is set to be equal to or smaller than the inner diameter of both end portions in the axial direction of the partial spherical concave surface.

According to the self-aligning roller bearing of the present invention configured as described above, the guide wheel is prevented from being excessively displaced in the axial direction, and the friction between the end surface of each spherical roller and the side surface of the guide wheel is suppressed. Or it can be prevented.
That is, according to the structure of the present invention, the guide to the cage is based on the engagement between the convex curved surface existing on the outer peripheral surface of the guide wheel and the concave curved surface existing on the inner peripheral surface of the rim portion of the cage. The amount of axial displacement of the wheel is regulated. Since each spherical roller is held in a pocket of the cage in a state in which axial displacement is restricted, the relative displacement in the axial direction between each spherical roller and the guide wheel is restricted, and Rubbing between the end surface of the spherical roller and the side surface of the guide wheel can be suppressed or prevented.
In particular, if the structure of the invention described in claims 2 and 3 is adopted, the guide wheel can be easily assembled without applying an excessive force, and the axial displacement of the guide wheel relative to the cage is small. A structure that can be suppressed to a low level can be realized.

The fragmentary sectional view which shows the 1st example of embodiment of this invention. The center part enlarged view of FIG. 1 for demonstrating the dimensional relationship of each part. The front view which looked at the guide wheel from the axial direction which is the side of FIGS. FIG. 5 is a schematic cross-sectional view for explaining an operation for incorporating this guide wheel into the inner diameter side of the rim portion of the cage. The fragmentary sectional view which shows the 2nd example of embodiment of this invention. The partial cutaway perspective view of the self-aligning roller bearing which shows the 1st example of conventional structure. Similarly partial sectional view. The fragmentary sectional view of the self-aligning roller bearing which shows the 2nd example of conventional structure.

[First example of embodiment]
1 to 4 show a first example of an embodiment of the present invention corresponding to all claims. The self-aligning roller bearing 1b of this example includes an outer ring 2, an inner ring 3, a plurality of spherical rollers 4, 4, a cage 7b, and a guide ring 8b. Among these components, the configuration of the outer ring 2, the inner ring 3, and the spherical rollers 4, 4 has been widely known in the past, including the structures shown in FIGS. Since it is the same as the self-aligning roller bearing, the illustration and description will be omitted or simplified, and the retainer 7b and the guide wheel 8b, which are features of this example, will be described below.

  This cage 7b is formed by cutting a metal material having self-lubricating properties such as brass, or by injection molding a polymer material having the required strength, rigidity and oil resistance, such as a high-performance resin. By doing so, it is built in one. Regardless of which method is used, the cage 7b includes a rim portion 9a and a plurality of column portions 10a and 10a. Of these, the rim portion 9a is in the assembled state of the self-aligning roller bearing 1b, and is radially outside the axial intermediate portion of the annular space 12 between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the inner ring 3. A rotation with respect to the outer ring 2 and the inner ring 3 is freely arranged in a state of being sandwiched between the spherical rollers 4 and 4 in both rows at the side portion. Further, each of the pillar portions 10a and 10a is formed to protrude from both side surfaces in the axial direction of the rim portion 9a toward both end openings of the annular space 12 at equal intervals in the circumferential direction. The spherical rollers 4 and 4 are rotatably held in pockets surrounded by the circumferential side surfaces of the column portions 10a and 10a adjacent in the circumferential direction and the axial side surface of the rim portion 9a. Yes.

  Further, the guide wheel 8b is formed in an annular shape as a whole by a low friction material such as a metal material, a high-functional resin, or an oil-impregnated metal which is the same as that constituting the cage 7b, and the rim portion 9a Between the inner peripheral surface and the outer peripheral surface of the intermediate portion of the inner ring 3, rotation with respect to the rim portion 9a and the inner ring 3 is freely arranged. Further, in this state, the outer peripheral surface and the inner peripheral surface of the guide wheel 8b are brought close to or in sliding contact with the inner peripheral surface of the rim portion 9a and the outer peripheral surface of the intermediate portion of the inner ring 3, respectively. The container 7b is guided (supported rotatably in a state in which radial displacement is suppressed). In the case of this example, the width of the guide wheel 8b in the axial direction becomes narrower toward the inner diameter side, so that the shafts of the guide wheel 8b facing each other in the neutral state shown in FIGS. Both side surfaces in the direction and the end surfaces of the spherical rollers 4 and 4 are sufficiently separated in a parallel state.

  In particular, in the case of the self-aligning roller bearing 1b of the present example, a protruding portion 13 that protrudes toward the inner diameter side is formed over the entire circumference in the axially intermediate portion of the inner peripheral surface of the rim portion 9a. At the same time, the inner peripheral surface of the projecting portion 13 is formed over the entire circumference to form a partially spherical concave curved surface 14 in which the inner diameter of the central portion in the axial direction is larger than the inner diameters of both end portions in the axial direction. Further, the outer peripheral surface of the guide wheel 8b includes a partially spherical convex curved surface 15 in which the outer diameter of the central portion in the axial direction is larger than the outer diameter of both end portions in the axial direction. It is composed of a pair of flat surfaces 16 and 16 corresponding to straight edge portions. Then, by engaging the concave curved surface 14 and the convex curved surface 15, axial displacement of the guide wheel 8 b with respect to the cage 7 b is suppressed.

That is, in the case of this example, the center of the radius of curvature R of the concave curved surface 14 exists on the central axis of the rim portion 9a and in the axial center of the rim portion 9a. Further, the center of the radius of curvature r of the convex curved surface 15 exists on the central axis of the guide wheel 8b and at the center in the axial direction of the guide wheel 8b. The curvature radius r of the convex curved surface 15 is slightly smaller than the curvature radius R of the concave curved surface 14 (r <R). Specifically, the outer diameter D ₁₅ (= 2r = maximum outer diameter of the guide wheel 8b) of the portion corresponding to the convex curved surface 15 of the guide wheel 8b is set at the axial end portions of the concave curved surface 14. It is smaller (r <R) than the inner diameter d ₁₄ (= the minimum inner diameter of the rim portion 9a) (D ₁₅ > d ₁₄ ). By adopting such a dimensional relationship, the axial displacement of the guide wheel 8b relative to the cage 7b can be suppressed based on the engagement between the concave curved surface 14 and the convex curved surface 15. .

In the case of this example, the flat surfaces 16, 16 are formed in parallel with each other at two positions on the outer peripheral surface of the guide wheel 8b on the radially opposite side. The width W16 of the guide wheel 8b, which is the distance between the flat surfaces 16 and _16, is larger than the inner diameter d14 of the both ends in the axial direction of the concave curved surface ₁₄ (= the minimum inner diameter of the rim portion 9a). It is small (W ₁₆ <d ₁₄ ).

  The rim portion 9a of the cage 7b and the guide wheel 8b, each having the above-described configuration, are combined with each other as shown in FIG. That is, with the both flat surfaces 16 and 16 being arranged in the diameter direction of the rim portion 9a (both sides in the front and back direction in FIG. 4), the guide wheel 8b is connected to the rim portion 9a as shown by a chain line in FIG. Insert on the inner diameter side. This insertion operation is performed in a state where the central axes of the guide wheel 8b and the rim portion 9a are orthogonal to each other. Then, if the guide wheel 8b is inserted into the inner diameter side of the rim portion 9a until the center points of both the members 8b and 9a coincide with each other, as shown by an arrow α in FIG. Rotate until the central axes of 9a coincide. As a result, the guide wheel 8b can be freely rotated relative to the inner diameter side of the rim portion 9a with the axial displacement suppressed. Such assembling work can be easily performed without applying an excessive force to the guide wheel 8b.

  Further, in the case of this example, during the operation of the assembled self-aligning roller bearing 1b shown in FIGS. 1 and 2, the amount of alignment of the self-aligning roller bearing 1b (the center axis of the outer ring 2 and the inner ring) 3) so that the end surfaces of the spherical rollers 4 and 4 and the side surfaces of the guide wheels 8b can always be prevented from rubbing even when the inclination angle with respect to the central axis 3 is appropriately changed within an assumed range. The dimensions of each part are regulated. This point will be described in detail below.

  In the case of this example, when viewed relatively, the end surfaces of the spherical rollers 4 and 4 can move toward the guide wheel 8b in the axial direction to a position where they contact the side surface of the rim portion 9a. On the other hand, the side surface of the guide wheel 8b can move toward the spherical rollers 4 and 4 in the axial direction until the concave curved surface 14 and the convex curved surface 15 are engaged with each other in the axial direction. Further, the guide wheel 8b is in the direction of curvature of the concave curved surface 14 until the inner peripheral surface of the guide wheel 8b and the outer peripheral surface of the intermediate portion of the inner ring 3 are engaged with the rim portion 9a (see FIG. 1 β direction). Therefore, the side surface of the guide wheel 8b can move toward the spherical surfaces 4 and 4 with respect to the β direction within a rotatable range with respect to the β direction. Therefore, in the case of this example, even when each movement as described above occurs, each part can be prevented so that the end surfaces of the spherical rollers 4 and 4 and the side surface of the guide wheel 8b can be prevented from rubbing. The dimensions of the are regulated.

Specifically, by making the radius of curvature r of the convex curved surface 15 sufficiently close to the radius of curvature R of the concave curved surface 14 (making “R−r” sufficiently small), the concave curved surface 14 and the convex curved surface 15. The function of restricting the displacement of the guide wheel 8b in the axial direction based on the engagement is enhanced. Thus, the amount of movement of the side surface of the guide wheel 8b toward the spherical rollers 4 and 4 in the axial direction is sufficiently suppressed. Further, by making the inner diameter d _8b of the guide wheel 8b sufficiently close to the outer diameter D ₃ of the intermediate portion of the inner ring 3 (“D ₃ -d _8b ” is made sufficiently small), these guide wheels 8b The rotation restricting function of the guide wheel 8b in the β direction based on the engagement between the inner peripheral surface and the outer peripheral surface of the inner ring 3 is enhanced. Thereby, the amount of movement of the side surface of the guide wheel 8b toward the spherical rollers 4 and 4 in the β direction is sufficiently suppressed. Furthermore, the width W ₁₅ in the axial direction of the convex curved surface 15, by less than the width W ₁₄ in the axial direction of the concave curved surface _{14 (W 15 <W 14)} , shown in Figures 1-2 neutral In this state, the axial dimension of the gap existing between the side surface of the guide wheel 8b and the end surfaces of the spherical rollers 4 and 4 is sufficiently secured. By performing the above dimensional regulation, this gap is not always lost even when each of the above movements occurs.

  As described above, according to the self-aligning roller bearing 1b of this example, it is possible to prevent the side surface of the guide wheel 8b and the end surfaces of the spherical rollers 4 and 4 from rubbing during operation. For this reason, it is possible to prevent the facing portions between the side surfaces of the guide wheels 8b and the end surfaces of the spherical rollers 4 and 4 from being worn, thereby extending the life of the self-aligning roller bearing 1b. The spherical rollers 4 and 4 are prevented from skewing by engaging the rolling surfaces or axial end surfaces of the spherical rollers 4 and 4 with the inner surfaces of the pockets 11a and 11a of the cage 7b.

  In the case of the first example of the above-described embodiment, the side surfaces of the guide wheels 8b and the spherical rollers 4 are controlled by restricting the dimensions of the members constituting the self-aligning roller bearing 1b. 4 so that the gap between the end faces of the guide member 8 and the end faces of the spherical rollers 4 and 4 are not lost even when movement between the members occurs. Adopted a configuration that can completely prevent rubbing. However, when the present invention is implemented, as a modification of the first example described above, the side surface of the guide wheel 8b and the end surfaces of the spherical rollers 4 and 4 are relaxed by relaxing the dimensional restriction between the members. It is also possible to adopt a configuration that allows a slight amount of friction (so that the surface pressure of the rubbing portion does not become excessive). In the case of adopting such a configuration, it is possible to suppress wear of the facing portion between the side surface of the guide wheel 8b and the end surfaces of the spherical rollers 4 and 4, and the life of the self-aligning roller bearing 1b is also maintained. Can be extended.

[Second Example of Embodiment]
FIG. 5 shows a second example of the embodiment of the present invention, which corresponds only to claim 1. In the case of this example, the inner peripheral surface of the projecting portion 13a provided at the axially intermediate portion of the inner peripheral surface of the rim portion 9b constituting the cage 7c extends over the entire circumference and has a concave curved surface 14a having a V-shaped cross section. It is said. On the other hand, the outer peripheral surface of the guide wheel 8c is a convex curved surface 15a having a V-shaped cross section. In order to be able to incorporate the guide wheel 8c into the inner diameter side of the rim portion 9b, the angle of the cross-sectional shape (V-shape) of the convex curved surface 15a and the concave curved surface 14a is restricted. Since the configuration and operation of the other parts are the same as those in the first example (and the modifications thereof) of the above-described embodiment, a duplicate description is omitted.

1, 1a, 1b Spherical roller bearing 2 Outer ring 3 Inner ring 4 Spherical roller 5 Outer ring raceway 6 Inner ring raceway 7, 7a, 7b, 7c Cage 8, 8a, 8b, 8c Guide wheel 9, 9a, 9b Rim part 10, 10a Pillar part 11, 11a Pocket 12 Annular space 13, 13a Protruding part 14, 14a Concave surface 15, 15a Convex surface 16 Flat surface

Claims (3)

An outer ring raceway that is a spherical concave surface having a single center, an outer ring formed on an inner circumferential surface thereof, a pair of inner ring raceways opposed to the outer ring raceway, an inner ring formed on an outer circumferential surface thereof, and the outer ring raceway, A plurality of spherical rollers provided so as to be able to roll in two rows between the inner ring raceways, an annular rim portion disposed between the spherical rollers in both rows, and the rim portion The base end portions are connected to both side surfaces in the axial direction, and each side surface includes a plurality of column portions, the circumferential side surfaces of the column portions adjacent to each other in the circumferential direction, and the axial side surfaces of the rim portion. And a roller surrounded by a roller for holding the spherical rollers in a rollable manner, and the rollers in both rows between the inner peripheral surface of the rim portion and the outer peripheral surface of the inner ring. In a self-aligning roller bearing provided with an annular guide wheel provided in an annular gap between them ,
The outer peripheral surface of the guide wheel is a convex curved surface in which the outer diameter of the axial central portion is larger than the outer diameters of both axial end portions, and the inner peripheral surface of the rim portion is the inner diameter of the axial central portion. A concave curved surface that is larger than the inner diameter at both axial ends, and by engaging the concave curved surface with the convex curved surface, the guide wheel is displaced toward the inner diameter side of the rim portion in the axial direction of the cage. A self-aligning roller bearing characterized by being supported so as to be capable of relative rotation with respect to the cage in a state where pressure is suppressed.   The concave curved surface is a partial spherical concave surface having a point on the central axis of the cage as a center of curvature, and the convex curved surface is a partial spherical convex surface having a point on the central axis of the guide wheel as a center of curvature. The self-aligning roller bearing according to claim 1. Straight edge portions parallel to each other are formed at two positions on the outer circumferential surface of the guide wheel on the opposite side in the radial direction, and the distance between the two straight edge portions is smaller than the inner diameters of both end portions in the axial direction of the partial spherical concave surface. A self-aligning roller bearing according to claim 2.

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