Self-aligning roller bearing

Abstract

The utility model provides a self-aligning roller bearing, which has enough strength, can restrain the action of a roller, is easy to process and can be manufactured at low cost, and is provided with a comb-shaped punching retainer. A self-aligning roller bearing (1) is provided with an outer ring (2), an inner ring (3), a plurality of rollers (4) arranged in two rows in a ring shape between the outer ring (2) and the inner ring (3), and a cut cage (5) for holding the plurality of rollers (4), the cut cage (5) being provided with a ring-shaped portion (5a) arranged between the two rows of rollers, and a plurality of column portions (5b) protruding from axial side surfaces on both sides of the ring-shaped portion (5a). Pockets (P) for holding the rollers in a rollable manner are formed by circumferentially adjacent columns (5b) of the plurality of columns (5b), and each pocket (P) has a pocket bottom portion which is continuous with the annular portion and is located on the root side of the corresponding column, and a pocket inlet portion which extends from the axial front end edge of the pocket bottom portion to the front end of the corresponding column. The pocket bottom portion is a partial conical surface whose diameter decreases from the axial front end edge toward the root side of the column portion, and the pocket inlet portion is a partial cylindrical surface.

Description

TECHNICAL FIELD

[0001] The utility model relates to an automatic self-aligning roller bearing. BACKGROUND

[0002] In the automatic self-aligning roller bearing, the retainer that holds the rollers uses a comb-shaped or cage-shaped retainer, and various shapes of retainers have been proposed (Patent Documents 1 and 2).

[0003] The retainer for roller bearing shown in Patent Document 1 is a comb-shaped cutout retainer composed of a ring-shaped portion and a plurality of column portions protruding from the ring-shaped portion, and the rollers are held in pocket portions formed by the column portions adjacent in the circumferential direction. As shown in Figure 8A 、 Figure 8B and Figure 8C , the pocket portion is shaped by machining the side surface 104d of the column portion 104b to have a concave partial cylindrical surface, and the inner surface shape of the pocket portion p is cylindrical up to the root of the column portion 104b.

[0004] The automatic self-aligning roller bearing shown in Patent Document 2 has spherical rollers as rolling elements, and as shown in Figure 9A and Figure 9B , the inner surface shape of the pocket p in the retainer 214 that holds the spherical rollers is set to the concave surface shape along the rolling surface of the spherical roller.

[0005] [Related Art Documents]

[0006] [Patent Documents]

[0007] [Patent Document 1] JP Laid-Open No. 2008-069868

[0008] [Patent Document 2] JP Laid-Open No. 2018-169044 SUMMARY

[0009] [Problems to be Solved by the Invention]

[0010] However, in the comb-shaped retainer, if the side surface shape 104d, 214c, 214d of the column portions 104b, 214b adjacent in the circumferential direction that form each pocket portion is set to the concave cylindrical shape from the leading end portion to the root of the column portion, the cross-sectional area (hereinafter sometimes simply referred to as "sectional area") in the circumferential direction of the root 113, 214d becomes smaller, and therefore the sufficient strength of the column portion cannot be ensured. Moreover, since the gap between the rollers held in the pocket portions p, P and the column portions 104b, 214b becomes larger, there is a problem that the movement of the rollers cannot be sufficiently suppressed, and the position and posture of the rollers become unstable.

[0011] Further, if the inner surface shape of the pocket portion p, P of the holding roller is set to a concave surface shape along the outer diameter surface of the spherical roller, the cross-sectional area of the root portion 113, 214d of the column portion 104b, 214b of the holder 104, 214 becomes large, and the strength can be improved. At the same time, since the gap between the column portion 104b, 214b and the roller becomes uniform in the axial direction of the pocket, the movement of the roller can be suppressed. However, if such a structure is adopted, the shape of the drill for machining the pocket portion p, P needs to be set to a spherical shape along the outer diameter of the roller. Therefore, there is a problem that the molding of the tool takes effort, and the manufacturing cost of the holder becomes high.

[0012] The object of the present application is to provide a self-aligning roller bearing which can suppress the movement of the roller while ensuring the strength of the column portion of the holder, and which can reduce the manufacturing cost.

[0013] [Technical Solution for Solving the Problem]

[0014] To solve the above problem, the self-aligning roller bearing of the present application has an outer ring, an inner ring, a plurality of rollers arranged in two rows in a ring shape between the outer ring and the inner ring, and a cut holder which holds the plurality of rollers. The cut holder is a comb-shaped cut holder which includes a ring portion arranged between the two rows of rollers and a plurality of column portions protruding from the axial side surfaces of both sides of the ring portion. A pocket which freely holds each roller in rolling is formed by the column portions adjacent to each other in the circumferential direction of the plurality of column portions. The pocket has a pocket bottom portion connected to the ring portion and located on the root side of the column portion, and a pocket entrance portion extending from the axial front end edge of the pocket bottom portion to the front end of the column portion, the pocket bottom portion is a local conical shape whose diameter becomes smaller as it goes from the axial front end edge toward the root side of the column portion, and the pocket entrance portion is a local cylindrical shape.

[0015] With this structure, since the cross-sectional area of the root portion of the column portion of the holder can be made larger than the cross-sectional area of the front end portion of the column portion, the strength of the holder can be improved compared to the holder of the existing structure in which the cross-sectional area of the root portion of the column portion is small. Further, in the case where the inclination of the roller occurs, since the root portion of the column portion of the holder comes into contact with the outer diameter portion of the roller, the movement of the roller can be suppressed. In addition, since the shape of the pocket is a simple shape which does not have an R shape, the molding of the drill for machining the pocket is relatively easy, and therefore the holder can be manufactured at a low cost.

[0016] In the self-aligning roller bearing of the present application, the axial length of the pocket bottom portion can be 20 to 40% of the axial length of the roller.

[0017] With this structure, when the bearing rotates, the root of the column portion of the retainer forming the pocket bottom does not come into contact with the maximum diameter portion of the roller, and a force that inclines the rotational axis of the retainer with respect to the retainer is not generated, so the positional relationship between the retainer and the roller can be favorably maintained, and the action of the roller is suppressed. If the axial length of the pocket bottom exceeds 40% of the axial length of the roller, in the rotation of the bearing, the maximum diameter portion of the roller comes into contact with the partial conical surface, and a force that inclines the rotational axis of the retainer can be applied. If the axial length of the pocket bottom is less than 20% of the axial length of the roller, the cross-sectional area of the root of the column portion is sometimes not sufficiently ensured, and there is a problem in terms of strength.

[0018] In the self-aligning roller bearing of the present application, the angle of inclination of the partial conical surface can be the angle of the rolling surface of the roller with respect to the tangent direction of the roller axis at a position that is 10 to 30% of the axial length of the roller from the axial base end edge of the pocket bottom.

[0019] With this structure, since the roller comes into contact with the root of the column portion of the retainer at an appropriate angle of inclination, the action of the roller can be sufficiently controlled, and the root of the column portion of the retainer is difficult to come into contact with the edge between the outer diameter surface and the chamfer on the end surface side of the roller, so reduction in wear of the root of the column portion of the retainer can be achieved. If it exceeds 30% of the axial length of the roller, the angle of inclination when the roller comes into contact with the partial conical surface undesirably becomes large, so the effect of controlling the action of the roller is reduced. If it is less than 10% of the axial length of the roller, the edge between the outer diameter surface and the chamfer on the end surface side of the roller is easily brought into contact, and there is a concern that the partial conical surface will be worn.

[0020] In the present application, any combination of at least two structures disclosed in the claims and / or the description and / or the drawings is included.

[0021] In particular, any combination of the claims is included in the present application. BRIEF DESCRIPTION OF DRAWINGS

[0022] The present application will be more readily understood by referring to the following description of the preferred embodiments in conjunction with the accompanying drawings.

[0023] However, the embodiments and drawings are for illustration and explanation only, and are not to be used to limit the scope of the present application.

[0024] The scope of the present application is defined by the claims.

[0025] In the drawings, like numerals refer to like or corresponding parts throughout the several views.

[0026] Figure 1 is a longitudinal sectional view of a self-aligning roller bearing of the first embodiment of the present application.

[0027] Figure 2 is a cross-sectional view along Figure 1 the line II-II of Fig. 1.

[0028] Figure 3 is a cross-sectional view of a main part of the self-aligning roller bearing according to the second embodiment of the present application (corresponding to Fig. 2). Figure 2

[0029] Figure 4 is a cross-sectional view of a main part of the self-aligning roller bearing according to the third embodiment of the present application.

[0030] Figure 5 is a longitudinal cross-sectional view of the self-aligning roller bearing according to the fourth embodiment of the present application.

[0031] Figure 6 is a longitudinal cross-sectional view of the self-aligning roller bearing according to the fifth embodiment of the present application.

[0032] Figure 7 is a cross-sectional view along Figure 6 the line VII-VII of Fig. 6.

[0033] Figure 8A is an enlarged main view of a main part of an example of a conventional retainer for a roller bearing.

[0034] Figure 8B is an enlarged plan view of a main part of an example of a conventional retainer for a roller bearing.

[0035] Figure 8C is a left side view of a main part of an example of a conventional retainer for a roller bearing.

[0036] Figure 9A is a plan view of an example of a conventional retainer for a self-aligning roller bearing.

[0037] Figure 9B is a cross-sectional view along Figure 9A the line B-B of Fig. 8. DETAILED DESCRIPTION

[0038] [First Embodiment]

[0039] The embodiments of the present application will be described below with reference to the drawings. Figure 1 and Figure 2 are views showing a first embodiment of the self-aligning roller bearing according to the present application. As shown in Figs. 1 and 2, the self-aligning roller bearing according to the present application includes an outer ring 1, an inner ring 2, a plurality of rolling elements 3, and a retainer 4. Figure 1 ​As shown, a spherical roller bearing 1 includes an outer ring 2, an inner ring 3, a plurality of rollers 4, and a cage 5. The plurality of rollers 4 are arranged in two rows between the inner ring 3 and the outer ring 2, and the cage 5 retains the two rows of rollers 4, 4. The bearing space between the inner ring 3 and the outer ring 2 is filled with, for example, grease. In this specification, the spherical roller bearing 1 may be simply referred to as a "bearing."

[0040] A concave spherical raceway 2a is formed on the inner diameter surface of the outer ring 2, and two rows of concave spherical raceway surfaces 3a, 3a are formed on the outer diameter surface of the inner ring 3. Flanges 6, 6 are provided on the axially outer side of the inner ring 3, bulging outward. Two rows of rollers 4, 4 are positioned between the raceway 2a of the outer ring 2 and the raceway 3a, 3a of the inner ring 3. Each row of rollers 4 is a so-called barrel-shaped roller, whose rolling surface is spherically expanded. The subassembly consisting of the inner ring 3, the retainer 5, and the two rows of rollers 4, 4 is configured to be relatively alignable with respect to the outer ring 2. The self-aligning roller bearing 1 is a type of so-called radial roller bearing, in which the outer ring 2 is positioned radially outward of the outer circumference of the inner ring 3. The axial direction of the center axes of the inner ring 3 and the outer ring 2 is referred to as the "axial direction." The direction orthogonal to this "axial direction" is referred to as the "radial direction."

[0041] Retainer

[0042] like Figure 2 As shown, the retainer 5 is a comb-shaped retainer comprising an annular portion 5a and columns 5b protruding axially outward from either side of the annular portion 5a. Circumferentially adjacent columns 5b form pockets P, spaces for retaining the rollers 4. The pockets P are arranged in two rows, circumferentially evenly spaced, on the left and right sides of the annular portion 5a. Each pocket P holds two rows of rollers 4. The pockets P in each row can also be formed differently by staggering the circumferential phases of the columns 5b of the retainer 5 on either side of the annular portion 5a. This arrangement prevents load concentration at circumferentially aligned locations on the annular portion 5a.

[0043] like Figure 1 As shown, the outer diameter surface 5bc of the column portion 5b may have a shape whose outer diameter decreases toward the outside in the direction of the rotation axis of the retainer 5. This configuration allows the roller to be guided approximately along the radial midpoint between the outer diameter surface 5bc of the column portion 5b and the inner diameter surface 5bd formed by the annular surface. Therefore, the force acting on the column portion 5b due to contact with the roller 4 can be absorbed near the radial center of the column portion 5b. This improves the rigidity of the column portion 5b.

[0044] like Figure 1As shown, the column portion 5b of the retainer 5 can also have a length exceeding 50% of the axial length of the roller 4. Thereby, in the state where the roller 4 is held in the pocket P, since the front end of the column portion 5b of the retainer 5 extends to a position axially outward of the maximum diameter position of the roller 4, the roller 4 can be more stably held by holding the roller across the maximum diameter of the roller 4.

[0045] As Figure 2 shown, the retainer 5 is a cut retainer in which each pocket P is made by cutting machining using a drill bit, and is a retainer of a rolling body guide form in which a plurality of rollers 4 are guided. The retainer 5 uses an iron-based material, a brass-based material, or a resin-based material.

[0046] <Shape of Pocket>

[0047] The pocket P has a pocket bottom Pb which is continuous with the annular portion 5a and which is located at the root side of the column portion 5b, and a pocket entrance portion Pa which extends from the axial front end edge 7 of the pocket bottom Pb to the front end of the column portion 5b. The pocket entrance portion Pa is a partial cylindrical surface, and the pocket bottom Pb is a partial conical surface whose diameter decreases as it goes from the axial front end edge 7 toward the root side of the column portion 5b. Since the pockets P are formed by the adjacent column portions 5b, 5b, the circumferential side surface of the column portion 5b has a shape corresponding to the pocket P. In the case where the pocket P has the above-described shape, the circumferential side surface of the front end portion 5ba of the column portion 5b corresponding to the entrance portion of the pocket P is a concave partial cylindrical surface. The circumferential side surface of the root portion 5bb of the column portion 5b corresponding to the bottom portion of the pocket P is a concave partial conical surface.

[0048] <Effects>

[0049] According to the above-described Figure 1 and Figure 2The automatic aligning roller bearing shown, the comb-shaped cutout retainer 5 provided in the automatic aligning roller bearing 1 is provided with a ring-shaped portion 5a arranged between the two rows of rollers 4, 4 and a plurality of column portions 5b protruding from the axial sides of both sides of the ring-shaped portion. A pocket P, which is a space in which each roller 4 is freely rotatably held, is formed by the column portions 5b, 5b adjacent to each other in the circumferential direction of the plurality of column portions 5b. The pocket P has a pocket bottom Pb connected to the ring-shaped portion 5a and located on the root side of the column portion 5b, and a pocket entrance portion Pa extending from an axial front end edge 7 of the pocket bottom Pb to the front end of the column portion 5b, the pocket bottom Pb being a local conical surface whose diameter decreases toward the root side of the column portion 5b from the axial front end edge 7. Thus, the cross-sectional area of the root of the column portion 5b of the retainer 5 is made larger than the cross-sectional area of the front end portion of the column portion 5b, and the movement of the roller 4 can be suppressed while sufficiently ensuring the strength of the column portion 5b. Moreover, since the shape of the pocket P in which the roller 4 is held in the retainer 5 is a simple shape that is easy to machine compared to a spherical shape, the shape of the drill bit used for the cutout machining of the retainer 5 is a shape that is relatively easy to form, and the retainer can be manufactured more inexpensively.

[0050] [Other Embodiments]

[0051] [Second Embodiment]

[0052] Figure 3 The second embodiment of the present application is shown. Figure 3 is a cross-sectional view of the comb-shaped cutout retainer provided in the automatic aligning roller bearing of the present application. Figure 2 In this embodiment, the axial length L1 of the pocket bottom Pb is in a range of 20% or more and 40% or less of the roller length L of the roller 4 held in the pocket P.

[0053] The strength of the column portion 5b of the retainer 5 protruding from the ring-shaped portion 5a is related to the axial length L1 of the pocket bottom Pb having a local conical surface in the pocket P. The longer the axial length L1 of the pocket bottom Pb, the thicker the wall of the column portion 5b of the retainer 5 in the circumferential direction, and thus the rigidity increases, and the cross-sectional area of the root of the column portion 5b connected to the ring-shaped portion 5a increases, and thus the strength of the column portion 5b improves. On the other hand, when the axial length L1 of the pocket bottom Pb approaches 50% with respect to the roller length L of the roller held in the pocket P, the maximum diameter portion of the roller 4 contacts the column portion 5b of the retainer 5 in the rotation of the bearing. In this case, since a force in a direction that tilts the rotation axis of the retainer 5 is applied, the movement of the roller 4 cannot be sufficiently suppressed in the pocket P, and the strength of the column portion 5b decreases.

[0054] The axial length LI of the bottom Pb of the pocket P having the local conical surface was changed, and the relationship with the strength of the column portion was investigated, and the results shown in Table 1 were obtained. The value in the "Pocket Bottom Length" column in the table indicates the proportion of the axial length LI of the pocket bottom Pb to the length L of the retained roller. In the column of the strength of the column in the table, the symbol "O" indicates that the column portion of the retainer has sufficient strength, the symbol "Δ" indicates that the column portion of the retainer has no problem in strength, and the symbol "X" indicates that the column portion of the retainer has a problem in strength.

[0055] [Table 1]

[0056] Pocket bottom length 0％ 10％ 20％ 30％ 40％ 50％ Column strength × △ 〇 〇 〇 △

[0057] In view of the above, it was decided that in the comb-shaped cut retainer provided in the self-aligning roller bearing of the present application, the axial length LI of the bottom of the pocket P is preferably in the range of 20% or more and 40% or less of the length L of the roller 4 retained in the pocket P. In this way, by setting the axial length LI of the pocket bottom Pb having the local conical surface in the pocket P of the retainer 5 to be in an appropriate numerical range, the strength of the column portion 5b of the retainer 5 can be ensured, and the movement of the roller 4 retained in the pocket P of the retainer 5 can be sufficiently suppressed.

[0058] [Third Embodiment] (Technical Solution 3 Figure 4 of Embodiment)

[0059] Figure 4 The third embodiment of the present application is shown. In the self-aligning roller bearing of the present application, the inclination angle of the local conical surface of the pocket bottom Pb is the angle of the tangent direction of the roller rolling surface of the roller 4 retained in the pocket P with respect to the roller axis at a position of 10% or more and 30% or less of the axial length of the roller from the axial base end edge 8 of the pocket bottom Pb.

[0060] In the pocket P of the retainer 5, whether or not the movement of the retained roller 4 is suppressed depends on the relationship between the shape of the roller 4 and the conical inclination angle of the local conical surface Pb possessed by the bottom of the pocket P. The results of investigating this relationship are shown in Table 2. The value in the "Tangent Position" column in the table, for example, 10%, indicates that the inclination angle of the local conical surface of the pocket bottom is equal to the tangent angle of the rolling surface of the roller 4 retained in the pocket P at a position of 10% of the axial length L2 of the roller length L from the axial base end edge 8 of the pocket bottom Pb. In the column of the movement suppression effect of the roller in the table, the symbol "O" indicates that the movement of the roller 4 is sufficiently suppressed by the retainer 5, the symbol "Δ" indicates that the suppression of the movement of the roller is not a problem, and the symbol "X" indicates that the suppression of the movement of the roller is a problem.

[0061] [Table 2]

[0062] Tangent position 0％ 10％ 20％ 30％ 40％ 50％ Roller action suppression effect × 〇 〇 〇 △ ×

[0063] In view of the above, it is known that in the comb-shaped cut retainer of the self-aligning roller bearing of the present application, the conical inclination angle of the partial conical surface of the bottom of the pocket P is preferably an angle of the rolling surface of the roller 4 with respect to the tangent direction of the axial direction of the roller 4 at a position of 10% or more and 30% or less of the roller length L of the roller 4 held in the pocket P.

[0064] Thus, by setting the conical inclination angle of the partial conical surface of the pocket P of the retainer 5 within an appropriate numerical range, the action of the roller 4 held in the pocket P of the retainer 5 can be sufficiently suppressed.

[0065] [Fourth Embodiment]

[0066] Figure 5 The fourth embodiment of the present application is shown. Figure 5 is a longitudinal sectional view of the self-aligning roller bearing. In the comb-shaped cut retainer, by making the outer diameter of the annular portion 5a of the retainer 5 larger than the outer diameter of the column portion 5b of the retainer 5, the retainer 5 is set to slide rotate with the inner peripheral surface of the outer ring 2, thereby becoming a retainer of the outer ring guide type. Thereby, even in an environment in which the outer ring rotates or vibration is applied, the roller can be guided while the action of the roller is sufficiently suppressed.

[0067] [Fifth Embodiment]

[0068] Figure 6 and Figure 7 The fifth embodiment of the present application is shown. In the comb-shaped cut retainer, as shown in Figure 6 , with respect to the left and right roller rows CL, CR, comb-shaped cut retainers 5L, 5R are respectively provided as separate bodies. In Figure 7 , a sectional view of the comb-shaped cut retainer 5R along the VII-VII line of Figure 6 is shown. The pocket P is formed by a plurality of column portions 5Rb protruding from the annular portion 5Ra of the comb-shaped cut retainer 5R, and the roller 4 is held in the pocket P. The same also applies to the other comb-shaped cut retainer 5L. Thereby, for example, even in a case where a difference occurs in the revolution speed of the left and right roller rows CL, CR due to a load being generated on one of the roller rows, since the retainers 5L, 5R with respect to the left and right respective roller rows CL, CR can independently rotate, it is difficult for the roller 4 to come into contact with the retainers 5L, 5R due to the difference in the revolution speed of the left and right roller rows CL, CR, and the occurrence of abnormality and wear of the retainers due to the contact and abnormality can be reduced.

[0069] As described above, the preferred embodiments are explained with reference to the accompanying drawings, but various additions, changes, deletions can be made within the scope of the gist of the present application.

[0070] Therefore, such a case is also included in the scope of the present application.

[0071] [Symbol explanation]

[0072] 1 …… self-aligning roller bearing

[0073] 2 …… outer ring

[0074] 3 …… inner ring

[0075] 4 …… roller

[0076] 5 …… retainer

[0077] 5a …… ring portion

[0078] 5b …… column portion

[0079] 7 …… axial front end edge

[0080] 8 …… axial base end edge

[0081] Pa …… partial cylindrical surface

[0082] Pb …… partial conical surface

[0083] P …… pocket

Claims

1. A self-aligning roller bearing having an outer ring, an inner ring, a plurality of rollers arranged in two rows of annular shape between the outer ring and the inner ring, and a cutout retainer that retains the plurality of rollers, characterized in that, the cutout retainer is a comb-shaped cutout retainer that includes an annular portion arranged between the two rows of roller rows and a plurality of column portions that protrude from axial sides of the annular portion, and that a pocket that freely rotatably retains each roller is formed by column portions adjacent in a circumferential direction of the plurality of column portions from each other, the pocket has a pocket bottom that is continuous with the annular portion and is located at a root side of the column portion, and a pocket entrance portion that extends from an axial front end edge of the pocket bottom to a front end of the column portion, the pocket bottom is a local conical shape in which a diameter decreases as it goes from the axial front end edge toward the root side of the column portion, and the pocket entrance portion is a local cylindrical shape.

2. The self-aligning roller bearing according to claim 1, characterized in that, an axial length of the pocket bottom is 20 to 40% of an axial length of the roller.

3. The self-aligning roller bearing according to claim 1 or 2, characterized in that, an inclination angle of a local conical surface of the local conical shape is an angle of a rolling surface of the roller with respect to a tangent direction of a roller shaft center at a position that is 10 to 30% of an axial length of the roller from an axial base end edge of the pocket bottom.

Images