Cage for tapered roller bearing, and tapered roller bearing

Abstract

To provide a cage for a tapered roller bearing and a tapered roller bearing, which improves assemblability when assembling tapered rollers and the cage, allows the tapered rollers and the cage to be handled as a single unit, and provides excellent handling of the tapered rollers and the cage and excellent assembly of the bearing.SOLUTION: A resin cage for a tapered roller bearing has slits that are cut into the tip ends of multiple column portions from axial end faces thereof toward an annular portion and open to the inner diameter side and the outer diameter side, and a pair of claw portions respectively protruding in the circumferential direction from both circumferential side faces of the column portions. The circumferential side surfaces of the multiple column portions have overlapping allowances on at least a portion of the outer diameter side and at least a portion of the inner diameter side so that the circumferential opening widths on the outer diameter side and inner diameter side of a pocket portion are smaller than the diameters of tapered rollers at corresponding axial positions of the tapered rollers.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a cage for a tapered roller bearing and a tapered roller bearing. [Background technology]

[0002] Tapered roller bearings are widely used because they are compact, can support large radial and axial loads, and can be used at high speeds, such as in railroad vehicle axles and automobile transmissions.

[0003] Conventionally, retainers used in tapered roller bearings include so-called cage-type retainers having a pair of annular portions and a plurality of pillar portions connecting the pair of annular portions, and so-called comb-type retainers having a small-diameter annular portion and a plurality of pillar portions extending axially from the annular portion to the large-diameter side (see, for example, Patent Documents 1 to 3).

[0004] For example, the comb-type cage described in Patent Document 1 does not have an annular portion on the large-diameter side, so the flow of lubricating oil is not impeded on the large-diameter side, and stirring resistance can be reduced. Furthermore, in this comb-type cage, any adjacent bar portions are provided with a connecting portion that connects the tips of both bar portions, and this connecting portion engages with the axial ends of the tapered rollers, thereby preventing the inner ring, tapered rollers, and cage from coming apart after assembly. This prevents the inner ring, tapered rollers, and cage from coming apart while reducing stirring resistance. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-14187 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-29522 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-91007 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, Patent Document 1 mentions preventing the inner ring, tapered rollers, and cage from coming apart when the tapered rollers housed in the cage are assembled into the inner ring, but it does not mention ease of assembly when assembling the tapered rollers to the cage. With the tapered roller bearing described in Patent Document 1, the cage and tapered rollers cannot be handled as a single unit before being assembled into the inner ring, leaving room for improvement in ease of assembly and handling. Similar issues exist with the tapered roller bearings described in Patent Documents 2 and 3, which use a cage-type cage.

[0007] The present invention has been made in view of the above-mentioned problems, and its object is to provide a retainer for a tapered roller bearing and a tapered roller bearing which improves the ease of assembly when assembling the tapered rollers and the retainer, enables the tapered rollers and the retainer to be handled as a single unit, and provides excellent ease of handling of the tapered rollers and the retainer and excellent assembly of the bearing. [Means for solving the problem]

[0008] The above object of the present invention can be achieved by the following configuration. (1) an annular portion; a plurality of pillar portions protruding from an axial end surface of the annular portion toward a tip end thereof so as to gradually increase in diameter, and provided at equal intervals in a circumferential direction; a plurality of pocket portions formed by adjacent column portions and the annular portion and holding tapered rollers; A resin-made tapered roller bearing cage comprising: The tip ends of the plurality of columnar portions have slits that are cut from their axial end faces toward the annular portion and open to the inner diameter side and the outer diameter side, and a pair of claw portions that protrude circumferentially from both circumferential side surfaces of the columnar portions, the circumferential side surfaces of the plurality of column portions are provided with overlapping allowances on at least a portion of the outer diameter side and at least a portion of the inner diameter side such that the circumferential opening widths on the outer diameter side and the inner diameter side of the pocket portion are smaller than the diameters of the tapered rollers at corresponding axial positions of the tapered rollers; Cage for tapered roller bearings. [Effects of the Invention]

[0009] According to the present invention, the assembly of the tapered rollers and the retainer is improved, the tapered rollers and the retainer can be handled as a single unit, and a retainer and tapered roller bearing can be provided that are excellent in handleability of the tapered rollers and the retainer and in assemblyability of the bearing. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view of a tapered roller bearing according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of a cage for a tapered roller bearing according to an embodiment of the present invention. [Figure 3] FIG. 3 is a partially enlarged view of FIG. [Figure 4] FIG. 4 is a diagram showing the process of incorporating tapered rollers into a cage for a tapered roller bearing according to an embodiment of the present invention. [Figure 5] FIG. 5 is a diagram showing a state in which tapered rollers are incorporated into a cage for a tapered roller bearing according to an embodiment of the present invention. [Figure 6] 6 is a cross-sectional view taken along the line VI-VI in FIG. [Figure 7] FIG. 7 is a diagram schematically showing the shape of a column portion according to a modified example of this embodiment as viewed from the outer diameter side. [Figure 8] 8(a) to 8(c) are diagrams schematically showing the shape of a column portion according to a modified example of this embodiment, as viewed from the outer diameter side. [Figure 9] FIG. 9 is a cross-sectional view corresponding to FIG. 6, showing a base portion and tapered rollers according to a modified example of this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a cross-sectional view of a tapered roller bearing according to an embodiment of the present invention, Fig. 2 is a perspective view of a cage for a tapered roller bearing according to an embodiment of the present invention, Fig. 3 is a partially enlarged view of Fig. 2, Fig. 4 is a diagram showing the process of assembling tapered rollers into a cage for a tapered roller bearing according to an embodiment of the present invention, Fig. 5 is a diagram showing the state in which tapered rollers have been assembled into a cage for a tapered roller bearing according to an embodiment of the present invention, and Fig. 6 is a cross-sectional view taken from the direction of arrows VI-VI in Fig. 5. Note that Fig. 2 shows a state in which tapered rollers are housed in only one pocket portion. In addition, in this embodiment, the side to which the small diameter side of the tapered roller faces in the axial direction is also referred to as one axial side, and the side to which the large diameter side of the tapered roller faces is also referred to as the other axial side.

[0012] As shown in Figure 1, the tapered roller bearing 100 of this embodiment comprises an outer ring 50 having an outer ring raceway surface 51 on its inner peripheral surface, an inner ring 60 having an inner ring raceway surface 61 on its outer peripheral surface, a plurality of tapered rollers 40 arranged so as to be able to roll freely between the outer ring raceway surface 51 and the inner ring raceway surface 61, and a resin tapered roller bearing retainer (hereinafter simply referred to as "retainer") 10 that holds the tapered rollers 40 at equal intervals circumferentially.

[0013] The outer ring raceway surface 51 is formed in a generally truncated cone shape that widens in diameter from one axial side to the other axial side, and the inner ring raceway surface 61 is also formed in a generally truncated cone shape that widens in diameter from one axial side to the other axial side. In this embodiment, the inner ring 60 does not have a small rib portion, but has a large rib portion 62 on the other axial side that supports the large-diameter-side end faces 41 of the tapered rollers 40.

[0014] Referring also to Figures 2 to 4, the retainer 10 comprises an annular portion 11 arranged on one axial side of the tapered rollers 40, a plurality of pillar portions 12 protruding from the axial end face of the annular portion 11 so as to gradually increase in diameter toward the tip end and arranged at equal intervals in the circumferential direction, and a plurality of pocket portions 13 formed by adjacent pillar portions 12 and the annular portion 11 and holding the tapered rollers 40.

[0015] The axial end faces of the annular portion 11 that form the pocket portions 13 are formed approximately perpendicular to the longitudinal direction of the base portion 12, and support the small diameter side end faces 42 of the tapered rollers 40. Furthermore, as shown in Figures 5 and 6, both circumferential side faces of the base portion 12 have an arc shape in a cross section perpendicular to the longitudinal direction of the base portion 12, that is, they form recesses 27 that are recessed so as to fit along the rolling surfaces of the tapered rollers 40. Furthermore, the radius of curvature of the arc shape in a cross section perpendicular to the longitudinal direction of the base portion 12 increases as it approaches the tip of the base portion 12.

[0016] The tapered rollers 40 housed in the pockets 13 are surrounded by the outer diameter side and inner diameter side of the column portions 12 by the opposing recesses 27 of the adjacent column portions 12 that form the pockets 13, preventing them from falling out to the outer diameter side or inner diameter side. In other words, the circumferential side surfaces of the multiple column portions 12 are provided with overlapping allowances so that the circumferential opening widths on the outer diameter side and inner diameter side of the pockets 13 are smaller than the diameters of the tapered rollers 40 at the corresponding axial positions of the tapered rollers 40.

[0017] 6 is a diagram showing a cross section perpendicular to the longitudinal direction of the base portion 12 at an arbitrary axial position of the tapered roller 40. In other words, if the circumferential opening width on the outer diameter side of the base portion 12 is W1, the circumferential opening width on the inner diameter side is W2, and the diameter of the tapered roller 40 is D1, then at any axial position of the tapered roller 40, W1 and W2 are smaller than D1.

[0018] Furthermore, the tip portions of the multiple pillar portions 12 have slits 21 cut from their axial end faces toward the annular portion 11 and opening to the inner diameter side and the outer diameter side, and a pair of claw portions 25 protruding circumferentially from both circumferential side surfaces of the pillar portions 12, respectively.

[0019] In addition, the circumferential length of the claw portions 25 is formed so that the circumferential gap between the opposing claw portions 25 of adjacent column portions 12 is smaller than the large diameter of the tapered roller 40, while the circumferential width of the slit 21 is designed so that when the split portion 29, which is bifurcated by the slit 21, elastically deforms and moves into the slit 21, the circumferential gap between the opposing claw portions 25 becomes equal to or larger than the large diameter of the tapered roller 40.

[0020] Furthermore, chamfered portions 39 are formed on the claw portions 25 between the axial end faces 31 of the tips of the column portions 12 and the circumferential end faces 35 of the claw portions 25. When the tapered rollers 40 are assembled into the cage 10, the chamfered portions 39 come into contact with the edges of the small diameter side end faces 42 of the tapered rollers 40, and guide the tapered rollers 40 into the pocket portions 13 while elastically deforming the divided portions 29.

[0021] Furthermore, an inclined surface 37 is provided on the inner peripheral surface of the tip of the column portion 12, inclined so that the diameter increases from the middle of the slit 21 to the axial end face. This inclined surface 37 facilitates elastic deformation of the divided portion 29. This inclined surface 37 may be formed on the outer peripheral surface of the tip of the column portion 12.

[0022] Therefore, in this embodiment, the tapered rollers 40 are assembled into the cage 10 in the direction of arrow IV in Figure 4, i.e., with the central axis of the pocket portion 13 and the central axis of the tapered rollers 40 aligned. At this time, the tapered rollers 40 press the divided portions 29 of the column portions 12 via the claw portions 25, causing the divided portions 29 to elastically deform and the tapered rollers 40 to be inserted between the adjacent column portions 12. After the tapered rollers 40 are assembled, the opposing claw portions 25 of the adjacent column portions 12 elastically return to their original position and engage with the large-diameter side end faces 41 of the tapered rollers 40, preventing the tapered rollers 40 from falling out of the pocket portion 13 in the axial direction. Furthermore, as described above, the opposing recesses 27 also prevent the tapered rollers 40 from falling out in the radial direction, so the tapered rollers 40 are held in the pocket portion 13 and the tapered rollers 40 and the cage 10 can be handled as a unit. This makes it possible to obtain a cage 10 that is excellent in ease of handling the tapered rollers 40 and the cage 10 and in assembling the tapered roller bearing.

[0023] Furthermore, in the retainer 10 of this embodiment, the slit 21 provided at the tip of the column portion 12 allows a pair of claw portions 25 on both sides of the slit 21 to elastically deform, making it possible to insert multiple tapered rollers 40 into the pocket portion 13 at the same time, thereby improving the ease of assembly of the tapered rollers 40 and the retainer 10.

[0024] The present invention is not limited to the above-described embodiment, and modifications and improvements are possible as appropriate. For example, as shown in FIG. 7, the shape of the slit 21 may be such that the inner surface 21b gradually widens in the circumferential direction from the bottom 21a toward the opening, and the divided portion 29 is tapered to facilitate elastic deformation.

[0025] Alternatively, when it is difficult to process the slit 21 into the above-described substantially rectangular cross section, the shape of the slit 21 may be formed into a V shape in which the inner side surface 21b meets at the tip, as shown in Fig. 8(a), in consideration of ease of processing. In this case, the slit 21 does not have a corner between the inner side surface 21b and the bottom 21a as in the case of a substantially rectangular cross section, so that it is possible to alleviate the stress acting on the slit 21 when the tapered roller 40 is inserted, and it is possible to prevent damage to the slit 21.

[0026] Furthermore, as shown in FIG. 8(b), corners 21c between the inner side surface 21b and the bottom 21a of the slit 21 may be curved, in which case stress at the corners 21c can be alleviated.

[0027] 8(c), the bottom 21a of the slit 21 may be rounded to have an arc-shaped cross section, thereby reducing stress on the bottom 21a. In this case, the inner surface 21b coincides with a tangent 21b1 of the bottom 21a at the point where the inner surface 21b and the bottom 21a meet.

[0028] Furthermore, the recess 27 may also have any shape that can prevent the tapered roller 40 from falling off to the inner diameter side or the outer diameter side, and may be formed, for example, in a roughly U-shaped shape by multiple straight lines in a cross section perpendicular to the longitudinal direction of the column portion 12, as shown in Figure 9.

[0029] Furthermore, in the above embodiment, the recess 27 is formed along the entire longitudinal direction of the column portion 12, but the present invention is not limited to this, and as long as the tapered roller 40 does not fall off from the outer diameter side and inner diameter side of the pocket portion 13, it is sufficient that the configuration has an overlapping allowance on at least a portion of the outer diameter side and at least a portion of the inner diameter side of the circumferential side of the column portion 12.

[0030] As described above, the present specification discloses the following: (1) an annular portion; a plurality of pillar portions protruding from an axial end surface of the annular portion toward a tip end thereof so as to gradually increase in diameter, and provided at equal intervals in a circumferential direction; a plurality of pocket portions formed by adjacent column portions and the annular portion and holding tapered rollers; A resin-made tapered roller bearing cage comprising: The tip ends of the plurality of columnar portions have slits that are cut from their axial end faces toward the annular portion and open to the inner diameter side and the outer diameter side, and a pair of claw portions that protrude circumferentially from both circumferential side surfaces of the columnar portions, the circumferential side surfaces of the plurality of column portions are provided with overlapping allowances on at least a portion of the outer diameter side and at least a portion of the inner diameter side such that the circumferential opening widths on the outer diameter side and the inner diameter side of the pocket portion are smaller than the diameters of the tapered rollers at corresponding axial positions of the tapered rollers; Cage for tapered roller bearings. This configuration improves assembly when assembling the tapered rollers and retainer, allowing the tapered rollers and retainer to be handled as a single unit, resulting in excellent handling of the tapered rollers and retainer and excellent assembly of the bearing.

[0031] (2) A chamfered portion is formed on the claw portion between an axial end surface of the tip of the column portion and a circumferential end surface of the claw portion. (1) A retainer for a tapered roller bearing according to the present invention. According to this configuration, when the tapered rollers are inserted into the pockets of the cage, the tapered rollers come into contact with the chamfered portions, which encourages elastic deformation of the column portions, allowing the tapered rollers to be inserted smoothly.

[0032] (3) The circumferential side surfaces of the plurality of column portions have recesses extending along the longitudinal direction of the column portions. A retainer for a tapered roller bearing according to (1) or (2). According to this configuration, the overlapping allowances on the outer diameter side and inner diameter side of the column portion can be easily configured.

[0033] (4) The recess has an arc shape in a cross section perpendicular to the longitudinal direction of the column portion. (3) A retainer for a tapered roller bearing according to (3). This configuration allows the rotation of the tapered rollers to be guided smoothly.

[0034] (5) an outer ring having an outer ring raceway on its inner circumferential surface; an inner ring having an inner ring raceway surface on its outer circumferential surface; a plurality of tapered rollers rollably disposed between the outer ring raceway surface and the inner ring raceway surface; A tapered roller bearing cage according to any one of (1) to (4), A tapered roller bearing having This configuration improves assembly when assembling the tapered rollers and retainer, allowing the tapered rollers and retainer to be handled as a single unit, resulting in excellent handling of the tapered rollers and retainer and excellent assembly of the bearing. [Explanation of symbols]

[0035] 10. Tapered roller bearing cage 11 Annular section 12 Pillar section 13 Pocket 21 Slit 25 Claw 27 Recess 31 Axial end face 35 Circumferential end face 39 Chamfered part 40 Tapered roller 41 Large diameter side end face 42 Small diameter side end face 43 Rolling surface 50 outer ring 51 outer ring raceway 60 Inner Circle 61 Inner ring raceway surface 100 Tapered roller bearing

Claims

1. an annular portion; a plurality of pillar portions protruding from an axial end surface of the annular portion toward a tip end thereof so as to gradually increase in diameter, and provided at equal intervals in a circumferential direction; a plurality of pocket portions formed by adjacent column portions and the annular portion and holding tapered rollers; A resin-made tapered roller bearing cage comprising: The tip ends of the plurality of columnar portions have slits that are cut from their axial end faces toward the annular portion and open to the inner diameter side and the outer diameter side, and a pair of claw portions that protrude circumferentially from both circumferential side surfaces of the columnar portions, the circumferential side surfaces of the plurality of column portions are provided with overlapping allowances on at least a portion of the outer diameter side and at least a portion of the inner diameter side such that the circumferential opening widths on the outer diameter side and the inner diameter side of the pocket portion are smaller than the diameters of the tapered rollers at corresponding axial positions of the tapered rollers; Cage for tapered roller bearings.

2. The claw portion has a chamfered portion formed between an axial end surface of the tip of the column portion and a circumferential end surface of the claw portion.

2. The cage for a tapered roller bearing according to claim 1.

3. The circumferential side surfaces of the plurality of pillar portions have recesses extending along the longitudinal direction of the pillar portions.

3. The cage for a tapered roller bearing according to claim 1 or 2.

4. The recess has an arc shape in a cross section perpendicular to the longitudinal direction of the column portion.

4. The cage for a tapered roller bearing according to claim 3.

5. an outer ring having an outer ring raceway surface on its inner circumferential surface; an inner ring having an inner ring raceway surface on its outer circumferential surface; a plurality of tapered rollers rollably disposed between the outer ring raceway surface and the inner ring raceway surface; The cage for a tapered roller bearing according to claim 1 or 2; A tapered roller bearing having

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