Cage for self-aligning roller bearing and self-aligning roller bearing

Abstract

To provide a cage for a self-aligning roller bearing having high rigidity and capable of achieving excellent handleability and assemblability of the bearing.SOLUTION: In a cage (4) for a self-aligning rolling bearing in which a plurality of pockets (8) for accommodating a plurality of rollers (3) are provided in a state of being arranged in a circumferential direction via pillar portions (7), a fall prevention portion (9) for preventing the rollers (3) from falling from the pockets (8) to an outer diameter side is provided between an outer diameter side end 7a and an inner diameter side end 7b of the pillar portion (7) (excluding the outer diameter side end 7a and the inner diameter side end 7b of the pillar portion (7)). Accordingly, even when the outer diameter of the cage 4 is large, the roller falling amount H can be suppressed without increasing the radial width T of the fall preventing portion 9. As a result, it is possible to provide the cage 4 having high rigidity and capable of realizing excellent handleability and assemblability of the bearing.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a retainer for a self-aligning roller bearing, and a self-aligning roller bearing including the retainer. [Background technology]

[0002] BACKGROUND ART Self-aligning roller bearings are known as one type of roller bearing. Patent Document 1 discloses an example of a self-aligning roller bearing (see FIG. 1 and the like in the document).

[0003] The self-aligning roller bearing disclosed in the document has as its main components an outer ring 1 having a concave spherical raceway surface on its inner circumference, an inner ring 2 having two rows of concave curved raceway surfaces on its outer circumference, a plurality of barrel-shaped spherical rollers 3 interposed between the raceway surface of the outer ring 1 and the raceway surface of each row of the inner ring 2, and a pair of retainers (retainers for self-aligning roller bearings) 4, 4 that hold the plurality of spherical rollers 3 in each row so that they can roll freely.

[0004] Self-aligning roller bearings have the advantage of being self-aligning because the center of the raceway surface of the outer ring 1 coincides with the center of the bearing, and can be used even if there is an inclination between the outer ring 1 and the inner ring 2 due to shaft deflection, etc.

[0005] When a self-aligning roller bearing supports a shaft that rotates at high speed, such as the main shaft of a centrifugal separator, or when the self-aligning roller bearing is particularly large, a machined cage formed by cutting metal is often used as the cage 4 in order to ensure the rigidity of the cage 4. One example of a machined cage is a squirrel-cage type cage 4, as shown in Figures 6 and 7.

[0006] The cage-shaped cage 4 has a large-diameter ring 5, a small-diameter ring 6 that is spaced apart from the large-diameter ring 5 in the axial direction (the direction of the bearing's central axis), and a plurality of pillars 7 that connect the two rings 5, 6. The pillars 7 are arranged at equal intervals in the circumferential direction (the circumferential direction around the bearing's central axis). The cage 4 is a so-called inner-ring-guided cage, in which the rotation of the cage 4 is guided by bringing its inner peripheral surface into contact with the guide surface of the inner ring 2.

[0007] The large diameter side ring 5 and small diameter side ring 6 and the two circumferentially adjacent pillar portions 7, 7 form pockets 8 for accommodating spherical rollers 3 (not shown in FIGS. 6 and 7). A plurality of pockets 8 are provided in the cage 4, and the plurality of pockets 8 are arranged in the circumferential direction via the pillar portions 7. The spherical rollers 3 accommodated in the pockets 8 have their circumferential movement restricted by contact with the two pillar portions 7, 7, and their axial movement restricted by contact with both rings 5, 6, thereby suppressing their behavior. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 3538488 Summary of the Invention [Problem to be solved by the invention]

[0009] Although not disclosed in Patent Document 1, the cage 4 is provided with a drop prevention portion 9 for preventing the spherical rollers 3 from falling out of the pocket 8 to the outer diameter side. As can be most easily understood from Figure 8, the drop prevention portion 9 is provided so as to protrude from the outer diameter side end 7a of the column portion 7 towards the pocket 8 side.

[0010] Here, in order to ensure the rigidity of the cage 4, it is advantageous to make the outer diameter of the cage 4 (the outer diameters of the large diameter side ring 5, the small diameter side ring 6, and the column portion 7) as large as possible. This is because as the outer diameter of the cage 4 increases, the cross-sectional areas of both rings 5 ​​and 6 and the column portion 7 also increase.

[0011] Figure 9 shows a configuration in which the outer diameter of the cage 4 is increased compared to Figure 8. Increasing the outer diameter of the cage 4, as in the configuration shown in Figure 9, can increase the rigidity of the cage 4, but has the drawback of increasing the amount of roller drop H. "Amount of roller drop" refers to the amount of radial movement of the rollers within the cage (radial direction from the central axis of the bearing).

[0012] If the amount of roller dropout H becomes large, when the assembly of the inner ring 2, spherical rollers 3, and cage 4 is aligned and caused to protrude from the outer ring 1 for purposes such as applying grease, the amount of movement of the spherical rollers 3 becomes large, making it difficult to return them to the outer ring 1, which causes a problem with the handling of the bearing. Therefore, one possible solution to this problem is to suppress the amount of roller dropout H by adopting a configuration in which the radial width T of the drop prevention portion 9 is wider than in FIG. 9 in addition to increasing the outer diameter of the cage 4, as shown in FIG. 10.

[0013] However, while widening the width T of the stopper portion 9 as in the form shown in Figure 10 can improve the handleability described above, there is a concern that it may worsen the ease of insertion of the spherical rollers 3 into the pockets 8 of the cage 4 from the outer diameter side during assembly of the bearing, reducing the ease of assembly of the bearing. This is because, when inserting the spherical rollers 3 into the pockets 8, it is necessary to elastically deform the entire stopper portion 9 and the column portions 7, and then have the spherical rollers 3 climb over the stopper portion 9, and if the width T is wide, it becomes that much more difficult for them to climb over it.

[0014] Furthermore, if the width T of the stopper portion 9 is made wider, there is a concern that the spherical rollers 3 may be damaged when they are inserted into the pockets 8 of the cage 4 .

[0015] In view of the above, there has been a demand for a cage that can achieve high rigidity, excellent handling properties of the bearing, and excellent assembly properties of the bearing.

[0016] In view of the above circumstances, a technical problem to be solved is to provide a cage for a self-aligning roller bearing that has high rigidity and allows the bearing to be easily handled and assembled. [Means for solving the problem]

[0017] To solve the above problem, a retainer for a self-aligning roller bearing is provided, which has a pair of rings arranged in parallel, a plurality of pillars connecting the pair of rings and arranged circumferentially of the pair of rings, a pocket formed by the pair of rings and the pillars, and a drop prevention portion that prevents the rollers held in the pocket from falling out to the outer diameter side of the pocket, and is characterized in that the drop prevention portion is provided between the outer diameter side end and inner diameter side end of the pillars, excluding the outer diameter side end and inner diameter side end of the pillars.

[0018] In this cage, the anti-drop portions are provided between the outer diameter end and the inner diameter end of the bar portion, excluding the outer diameter end and the inner diameter end of the bar portion. Therefore, as a first effect, even when the outer diameter of the cage is large to ensure high rigidity, the anti-drop portions are provided between the outer diameter end and the inner diameter end of the bar portion, rather than at the outer diameter end, thereby suppressing the amount of roller drop. Furthermore, as a second effect, since it is sufficient to provide the anti-drop portions between the outer diameter end and the inner diameter end of the bar portion to suppress the amount of roller drop, a radially wide anti-drop portion as shown in FIG. 10 is not required. From the above, with this cage, the first effect suppresses the amount of roller drop even when the outer diameter of the cage is large, thereby achieving high rigidity of the cage and excellent handleability of the bearing. In addition, the second effect eliminates the need for a radially wide anti-drop portion, thereby achieving excellent assemblyability of the bearing.

[0019] A self-aligning roller bearing equipped with the above-mentioned retainer for a self-aligning roller bearing has high retainer rigidity and can be made into a bearing that is easy to handle and assemble. This self-aligning roller bearing comprises an outer ring having a raceway surface on its inner circumference, an inner ring having a raceway surface on its outer circumference, a plurality of rollers interposed between the outer ring and the inner ring, and the above-mentioned retainer for a self-aligning roller bearing.

[0020] Here, a note will be added regarding the excellent handling properties of the above-mentioned bearing. The above-mentioned cage for a self-aligning roller bearing and self-aligning roller bearing offer advantages when performing so-called "belt extrusion" and "belt return." Note that "belt extrusion" refers to an operation in which the axial center of the outer ring is tilted relative to the axial centers of the inner ring and the cage, causing a portion of the inner ring and the cage to protrude beyond the outer ring. "Belt return" refers to an operation in which the axial center of the outer ring is aligned with the axial centers of the inner ring and the cage, returning the rollers to their state before the bet extrusion. The above advantages are as follows. As mentioned above, the amount of roller drop is suppressed by providing the retaining portion of the cage between the outer diameter end and the inner diameter end of the column portion. This makes it possible to limit the amount of movement of the rollers toward the outer diameter inside the cage, even when the bet extrusion is performed. As a result, it is possible to effectively prevent the rollers from interfering with the outer ring when performing the bet return.

[0021] In the above self-aligning roller bearing, it is preferable that the radial width of the stopper portion is more than 0% and not more than 10% of the diameter of the roller.

[0022] If the radial width of the anti-drop portion is 10% or less of the diameter of the roller, the force required to elastically deform the entire anti-drop portion and column portion when inserting the roller into the pocket of the retainer can be reduced, and it becomes easier to prevent the roller from being damaged during insertion. [Effects of the Invention]

[0023] The retainer for a self-aligning roller bearing of the present disclosure can achieve high rigidity, excellent handling properties of the bearing, and excellent assembly properties of the bearing. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a cross-sectional view showing a self-aligning roller bearing. [Figure 2] 1 is a view of a retainer for a self-aligning roller bearing provided in a self-aligning roller bearing, viewed from the outer diameter side. [Figure 3] 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 4] 3 is a cross-sectional view of FIG. 2 taken along line B-B. [Figure 5] FIG. 2 is a cross-sectional view showing an assembled form of a self-aligning roller bearing. [Figure 6] 1 is a view of a retainer for a conventional self-aligning roller bearing, as viewed from the outer diameter side; [Figure 7] 7 is a cross-sectional view taken along CC in FIG. 6. [Figure 8] FIG. 7 is a cross-sectional view taken along the line DD in FIG. 6. [Figure 9] 1 is a cross-sectional view illustrating a problem with a conventional retainer for a self-aligning roller bearing. [Figure 10] 1 is a cross-sectional view illustrating a problem with a conventional retainer for a self-aligning roller bearing. DETAILED DESCRIPTION OF THE INVENTION

[0025] Embodiments of a cage for a self-aligning roller bearing and a self-aligning roller bearing including the cage will be described with reference to the accompanying drawings. Here, in the description of the embodiments, "axial direction" means a direction parallel to the bearing central axis, "radial direction" means a direction radial from the bearing central axis, and "circumferential direction" means a circumferential direction around the bearing central axis.

[0026] The self-aligning roller bearing RB shown in Figure 1 comprises an outer ring 1 having a concave spherical raceway surface 1s on its inner circumference, an inner ring 2 having two rows of concavely curved raceway surfaces 2s, 2s on its outer circumference, a plurality of rollers 3 interposed between the raceway surface 1s of the outer ring 1 and each row of raceway surfaces 2s of the inner ring 2, and a pair of self-aligning roller bearing retainers 4, 4 (hereinafter simply referred to as retainers 4) that hold the plurality of rollers 3 in each row so that they can roll freely.

[0027] In this embodiment, of the outer ring 1 and the inner ring 2, the outer ring 1 is fixed to a stationary member (e.g., a housing), and the inner ring 2 is fixed to a rotating member (e.g., a rotating shaft). Alternatively, the inner ring 2 may be fixed to a stationary member, and the outer ring 1 may be fixed to a rotating member. Alternatively, the outer ring 1 may be fixed to a first rotating member, and the inner ring 2 may be fixed to a second rotating member that rotates relative to the first rotating member.

[0028] The rollers 3 are barrel-shaped spherical rollers formed so that the diameter is larger at the center than at both ends of the rollers 3. The outer peripheral surfaces 3a of the rollers 3 are arc-shaped. The curvature of the outer peripheral surfaces 3a of the rollers 3 is slightly larger than the curvature of the raceway surfaces 1s of the outer ring 1 and the raceway surfaces 2s of the inner ring 2.

[0029] 2 and 3 (each of the pair of cages 4, 4) is a machined cage formed by cutting metal, and is a cage-shaped cage. The cage 4 is provided with a plurality of pockets 8 for accommodating a plurality of rollers 3 (not shown in FIGS. 2 and 3), which are arranged at equal intervals in the circumferential direction.

[0030] The cage 4 has a large diameter side ring 5, a small diameter side ring 6 arranged at an interval in the axial direction from the large diameter side ring 5, a plurality of pillar portions 7 connecting the rings 5, 6 and positioned between adjacent pockets 8, 8, and drop prevention portions 9 provided so as to protrude from each of the plurality of pillar portions 7 toward the pocket 8 and prevent the rollers 3 from falling out from the pocket 8 to the outer diameter side. In this embodiment, the large diameter side ring 5 and the small diameter side ring 6 form a pair of rings arranged in parallel. In this cage 4, the inner circumferential surfaces 5a, 6a of the large diameter side ring 5 and the small diameter side ring 6 are brought into contact with the guide surfaces 2a, 2b of the inner ring 2, respectively, to guide the rotation of the cage 4.

[0031] Each of the plurality of pockets 8 is formed by being surrounded by the large diameter side ring 5, the small diameter side ring 6, and two circumferentially adjacent pillar portions 7, 7. One roller 3 is accommodated in each pocket 8. The pockets 8 provided in one of the pair of cages 4, 4 may be circumferentially offset from the pockets 8 provided in the other cage 4 (for example, offset by half a pitch), or may be circumferentially aligned.

[0032] The inner surfaces 5b, 6b of the large diameter side ring 5 and the small diameter side ring 6 that face the pocket 8 are each formed as surfaces that are substantially parallel to the end surfaces 3b of the rollers 3. On the other hand, the side surfaces 7c, 7c of the pair of pillar portions 7, 7 that face the pocket 8 are each formed as surfaces that follow the shape of the outer peripheral surfaces 3a of the rollers 3.

[0033] Each of the multiple pillar portions 7 has a first portion 7X extending in the axial direction and a second portion 7Y extending in a direction inclined relative to the axial direction. The second portion 7Y extends substantially parallel to the center line of the roller 3. The stopper portion 9 is provided on the second portion 7Y of the first portion 7X and the second portion 7Y, and is formed substantially parallel to the direction in which the second portion 7Y extends (the center line of the roller 3). In this embodiment, the stopper portion 9 is provided at a midpoint between the large diameter side ring 5 and the small diameter side ring 6 in the axial direction. Of course, this is not the only option, and the stopper portion 9 may be provided closer to the large diameter side ring 5 or closer to the small diameter side ring 6.

[0034] As can be most easily understood from Figure 4, the stopper portion 9 is provided in the radial direction between the outer diameter side end 7a and the inner diameter side end 7b of the column portion 7, excluding the outer diameter side end 7a and the inner diameter side end 7b. In this embodiment, the stopper portion 9 is provided closer to the outer diameter side end 7a than the inner diameter side end 7b. Of course, this is not limited to this, and the stopper portion 9 may be provided closer to the inner diameter side end 7b or at a midpoint between the outer diameter side end 7a and the inner diameter side end 7b. The radial width T of the stopper portion 9 is set to be more than 0% and 10% or less of the diameter Dw of the roller 3.

[0035] Methods for providing the anti-drop portion 9 on the column portion 7 of the retainer 4 include a method of forming the anti-drop portion 9 on the column portion 7 when cutting the pocket 8 into the retainer 4, and a method of adding the anti-drop portion 9 to the column portion 7 by welding, bonding, fitting, etc.

[0036] The above-described squirrel-cage cage 4 is preferably applied to a self-aligning roller bearing RB that has a narrow bearing width and a high cross-sectional height in the radial direction. Specifically, it is preferable to apply the squirrel-cage cage 4 to a self-aligning roller bearing RB that satisfies the following formula (1), where the bearing outer diameter is D1, the bearing inner diameter is D2, and the bearing width is W (D1, D2, and W are shown in FIG. 1).

[0037]

number

[0038] The following steps are taken to assemble the above-mentioned self-aligning roller bearing RB.

[0039] First, the cage 4, with rollers 3 not yet inserted in each pocket 8, is assembled with the inner ring 2. Specifically, the inner peripheral surface of the cage 4 (the inner peripheral surfaces 5a, 6a of the large diameter side ring 5 and the small diameter side ring 6) is fitted with the outer peripheral surface (guide surfaces 2a, 2b) of the inner ring 2. After that, the outer ring 1 is placed on the outer peripheral side (outer diameter side) of the cage 4 assembled with the inner ring 2. At this time, the axis of the outer ring 1 is aligned with the axis of the inner ring 2 and the cage 4.

[0040] Next, what is called "belly exposing" is performed. In this process, the axis of the outer ring 1 is tilted relative to the axis of the inner ring 2 and the cage 4. This exposes some of the multiple pockets 8 in the cage 4 from the outer ring 1, as shown in Figure 5. Then, as indicated by the white arrows in the figure, rollers 3 are inserted into the exposed pockets 8 from the outer periphery (outer diameter side). At this time, the entire stopper portions 9 and pillar portions 7 are elastically deformed, and the rollers 3 are made to climb over the stopper portions 9. The cage 4 is then rotated to expose a different pocket 8 (the pocket 8 before the rollers 3 were inserted), and rollers 3 are inserted into that pocket 8 in the same way. In this way, rollers 3 are inserted into all of the pockets 8.

[0041] Finally, what is called "belly return" is performed. In this return, the axis of the outer ring 1 is aligned with the axis of the inner ring 2 and cage 4, returning it to the state it was in before the belly extrusion. In this way, the self-aligning roller bearing RB is assembled. Note that the above-mentioned "belt extrusion" and "belt return" are performed not only when assembling the self-aligning roller bearing RB, but also when, for example, applying grease to the self-aligning roller bearing RB.

[0042] In the cage 4 of the self-aligning roller bearing RB described above, the anti-drop portions 9 are provided between the outer diameter side ends 7a and inner diameter side ends 7b of the bar portions 7, excluding the outer diameter side ends 7a and inner diameter side ends 7b of the bar portions 7. This makes it possible to suppress the amount of roller drop H without increasing the radial width T of the anti-drop portions 9, even if the outer diameter of the cage 4 (the outer diameters of the large diameter side ring 5, the small diameter side ring 6, and the bar portions 7) is large to ensure high rigidity. As a result, it is possible to achieve all of the high rigidity of the cage 4, the excellent handleability of the self-aligning roller bearing RB, and the excellent assembly ease of the self-aligning roller bearing RB. [Explanation of symbols]

[0043] 1 outer ring 1s Outer ring raceway 2. Inner circle 2s Inner ring raceway 3 4. Cage for spherical roller bearing 5 Large diameter side ring 5 6 Small diameter side ring 6 7 Pillar part 7a Outer diameter end of column 7b Inner diameter end of column 8 pockets 9 Stopper Dw Roller diameter RB spherical roller bearings T Width of stopper

Claims

1. A pair of rings arranged in parallel; a plurality of pillar portions that connect the pair of rings and are arranged in a circumferential direction of the pair of rings; a pocket formed by the pair of rings and the column; a retainer for a self-aligning roller bearing, the retainer comprising: a retaining portion for preventing the rollers held by the pockets from falling out to an outer diameter side of the pockets; A retainer for a self-aligning roller bearing, characterized in that the anti-drop portion is provided between the outer diameter side end and the inner diameter side end of the column portion, excluding the outer diameter side end and the inner diameter side end of the column portion.

2. 2. A self-aligning roller bearing comprising: an outer ring having a raceway surface on its inner periphery; an inner ring having a raceway surface on its outer periphery; a plurality of rollers interposed between the outer ring and the inner ring; and the retainer for a self-aligning roller bearing according to claim 1.

3. 3. The self-aligning roller bearing according to claim 2, wherein the radial width of the stopper portion is greater than 0% and not greater than 10% of the diameter of the roller.

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