Tapered roller bearing

Abstract

To provide a tapered roller bearing which enables tapered rollers to be stably held in pockets, enables easy assembly of the tapered rollers and a retainer into an inner ring, and enables reduction of manufacturing costs.SOLUTION: A comb-like retainer 40 of a tapered roller bearing 10 includes: an annulus part 41 disposed at one side in an axial direction; a plurality of column parts 43 which are provided from the other axial side surface 42 of the annulus part 41, spaced apart from each other by a predetermined space in a circumferential direction; pocket parts 45 each defined by circumferential direction side surfaces 44 of the column parts 43 located adjacent to each other in the circumferential direction and the other axial side surface 42 of the annulus part 41. A length L2 of the column part 43 is longer than or equal to two-thirds of a length L1 of a tapered roller 11 and is shorter than the entire length.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a tapered roller bearing equipped with a comb-type cage. [Background technology]

[0002] Tapered roller bearings are suitably used to support the rotation of rotating shafts in various industrial machines such as railway cars, automobiles, construction machines, steel rolling machines, etc. In tapered roller bearings, a plurality of tapered rollers are rollably disposed in pockets formed mainly in a cage type or comb type cage.

[0003] As shown in Figures 6 and 7, a conventional tapered roller bearing 100 comprises an outer ring 110 having an outer ring raceway surface 111 on its inner peripheral surface, an inner ring 120 having an inner ring raceway surface 121 on its outer peripheral surface, a plurality of tapered rollers 130 arranged so as to roll freely between the outer ring raceway surface 111 and the inner ring raceway surface 121, and a cage retainer 140 that holds the plurality of tapered rollers 130 each rotatably within a pocket 147.

[0004] The cage-type cage 140 has a large diameter annular portion 142 formed on one axial side, a small diameter annular portion 141 formed on the other axial side, and a plurality of pillar portions 143 that axially connect the large diameter annular portion 142 and the small diameter annular portion 141 and are formed spaced apart from each other in the circumferential direction. The cage-type cage 140 rotatably holds the tapered rollers 130 in pockets 147 defined by a surface 144 on one axial side of the small diameter annular portion 141, a surface 145 on the other axial side of the large diameter annular portion 142, and circumferential side surfaces 146, 146 of adjacent pillar portions 143, 143.

[0005] Patent Document 1 and Patent Document 2 disclose tapered roller bearings equipped with a comb-type cage. The comb-type cage described in Patent Document 1 is formed by pressing steel, has an annular portion on the small diameter side, and has a bent portion facing radially inward of the bearing at the small diameter side end. An annular protrusion that regulates the axial position of the bent portion is formed on the inner ring small flange, thereby reducing the stirring resistance of the lubricant. The comb-type cage described in Patent Document 2 is formed by molding or cutting resin, or casting or cutting metal, has a column portion having a length that is half or more the length of the tapered roller and is less than the entire length, and both circumferential faces of the column portion have a curvature that is approximately equal to the curvature of the tapered roller, and has a snap portion for holding the tapered roller in the radial direction, thereby reducing manufacturing costs. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2009-2377 A [Patent Document 2] JP 2014-231899 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the conventional cage cage 140 shown in Figures 6 and 7 and the comb-type cage described in Patent Document 1, it is necessary to crimp the cage when assembling the tapered rollers and the cage to the inner ring. In addition, the comb-type cage described in Patent Document 2 does not require crimping of the cage during assembly, but since it has a shape that holds the tapered rollers, there is a problem that the radial thickness is larger than that of the conventional cage cage, which increases the cost of materials. In addition, since the center of gravity of the tapered roller is generally located at a position approximately half the length of the tapered roller, if the length of the column part is half the length of the tapered roller, the center of gravity of the tapered roller and the tip position of the column part will coincide, and there is a risk that the retention of the tapered roller will become unstable.

[0008] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a tapered roller bearing that can stably hold tapered rollers in pockets, can easily assemble the tapered rollers and retainer into the inner ring, and can reduce manufacturing costs. [Means for solving the problem]

[0009] Therefore, the above object of the present invention is achieved by the following configuration [1] relating to a tapered roller bearing. [1] An outer ring having an outer ring raceway on its inner circumferential surface; an inner ring having an inner ring raceway surface on an outer circumferential surface; a plurality of tapered rollers rollably disposed between the outer ring raceway surface and the inner ring raceway surface; a cage that rotatably holds the tapered rollers at predetermined intervals in a circumferential direction; A tapered roller bearing comprising: The retainer is a circular ring portion disposed on one axial side of the tapered roller; a plurality of column portions provided at predetermined intervals in a circumferential direction from a surface on the other axial side of the annular portion; pocket portions each defined by a circumferential side surface of one of the column portions adjacent to the other in the axial direction and a surface on the other side of the annular portion, the pocket portions each holding one of the tapered rollers; A comb-type cage having The length of the base portion is 2 / 3 or more of the length of the tapered roller and is not more than the full length of the tapered roller. Tapered roller bearing. Effect of the Invention

[0010] According to the tapered roller bearing of the present invention, the tapered rollers can be stably held in the pockets, the tapered rollers and the cage can be easily assembled into the inner ring, and the tapered roller bearing can be manufactured at low cost. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view of a tapered roller bearing according to a first embodiment of the present invention. [Diagram 2] 2 is a perspective view showing the tapered roller bearing in FIG. 1 with the outer ring removed. FIG. [Diagram 3] 2 is a cross-sectional view showing the length of a tapered roller and the length of a pillar of a cage in the tapered roller bearing of FIG. 1. [Figure 4] FIG. 4 is an enlarged view of a main part of FIG. [Diagram 5] 5 is an enlarged view equivalent to FIG. 4 of a tapered roller bearing according to a second embodiment of the present invention. [Figure 6] FIG. 1 is a cross-sectional view of a tapered roller bearing equipped with a conventional cage type retainer. [Figure 7] FIG. 7 is a perspective view showing the conventional tapered roller bearing of FIG. 6 with the outer ring removed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (First embodiment) As shown in Figures 1 and 2, the tapered roller bearing 10 of this embodiment comprises an outer ring 20 having an outer ring raceway surface 21 on its inner peripheral surface, an inner ring 30 having an inner ring raceway surface 31 on its outer peripheral surface, a plurality of tapered rollers 11 arranged so as to roll freely between the outer ring raceway surface 21 and the inner ring raceway surface 31, and a comb-shaped retainer 40 that holds the plurality of tapered rollers 11 rotatably at a predetermined interval in the circumferential direction.

[0013] The outer ring raceway surface 21 and the inner ring raceway surface 31 are formed in a conical shape inclined with respect to the axis C of the tapered roller bearing 10. The inner ring 30 has a large diameter rib portion 32 formed on one axial side (right side in FIG. 1) of the inner ring raceway surface 31, and a small diameter rib portion 33 formed on the other axial side (left side in FIG. 1) of the inner ring raceway surface 31.

[0014] The large diameter rib 32 and small diameter rib 33 of the inner ring 30 come into sliding contact with the large diameter side end face 12 (head surface) and small diameter side end face 13 (tail surface) of the tapered roller 11, respectively, and position the tapered roller 11 in the axial direction. Also, inner ring relief grooves 34, 35 are recessed along the circumferential direction at a pair of corners connecting the inner ring raceway surface 31 and the large diameter rib 32, and the inner ring raceway surface 31 and the small diameter rib 33, respectively.

[0015] The tapered roller 11 is formed in a conical shape and has a conical rolling surface 14 on the circumferential surface. A circular recess 15 is formed in the large diameter side end face 12 of the tapered roller 11. A corner portion connecting the rolling surface 14 and the large diameter side end face 12, and a corner portion connecting the rolling surface 14 and the small diameter side end face 13 are each formed in a convex spherical shape.

[0016] The comb-shaped cage 40, which rotatably holds the tapered rollers 11, is formed by pressing a steel plate, and has an annular portion 41 arranged on one axial side of the tapered rollers 11 (the right side in Figs. 1 and 2; the large diameter side), and a plurality of columnar portions 43 provided at a predetermined interval in the circumferential direction from a surface 42 on the other axial side of the annular portion 41. The columnar portions 43 are located radially outward of the axis C1 of the tapered rollers 11. The columnar portions 43 are inclined so as to approach the radially inner side (the axis C side of the tapered roller bearing 10) as they move from the surface 42 toward the other axial side. In the illustrated example, the columnar portions 43 extend parallel to the axis C1 of the tapered rollers 11, but they do not necessarily have to be parallel to the axis C1.

[0017] In the comb-shaped cage 40, pocket portions 45 are defined by mutually opposing circumferential side surfaces 44, 44 of circumferentially adjacent column portions 43, 43 and the other axial side surface 42 of the annular portion 41. Tapered rollers 11 are respectively held in the pocket portions 45 so as to be able to roll freely.

[0018] It is preferable that the length L2 of the column portion 43 (the length along the axis C1 of the tapered roller 11) is 2 / 3 or more of the axial length L1 and not more than the full length of the tapered roller 11. In this embodiment, as shown in Figures 3 and 4, the length L2 of the column portion 43 (the length along the axis C1 of the tapered roller 11) is set to 2 / 3 of the axial length L1 of the tapered roller 11.

[0019] The position G of the center of gravity of the tapered roller 11 held in the pocket portion 45 of the comb-shaped cage 40 is half the axial length L1 of the tapered roller 11 or a position on the larger diameter side (one axial side) than half, and the load of the tapered roller 11 acts on this position. Here, if the length L2 of the column portion 43 is half the axial length L1 of the tapered roller 11, the position G of the center of gravity of the tapered roller 11 and the tip position of the column portion 43 will coincide, and there is a risk that the holding of the tapered roller 11 by the pocket portion 45 will become unstable.

[0020] However, in the present embodiment, the comb-shaped retainer 40 has the length L2 of the column portion 43 set to 2 / 3 of the axial length L1 of the tapered roller 11, so that the tapered roller 11 can be held up to a portion beyond the center of gravity position G, and the tapered roller 11 is held stably.

[0021] The reason why the length L2 of the column portion 43 is set to 2 / 3 of the axial length L1 of the tapered roller 11 is because it is taken into consideration that, with a special tapered roller 11, the center of gravity position G is located at 1 / 3 of the axial length L1 from the large diameter side end face 12 of the tapered roller 11. Even with such a special tapered roller 11, the tapered roller 11 can be stably held by making the length L2 of the column portion 43 at least twice the distance from the large diameter side end face 12 of the tapered roller 11 to the center of gravity position G.

[0022] Moreover, with the above-described comb-type cage 40, assembly is facilitated because the comb-type cage 40 easily elastically deforms when assembling the tapered rollers 11 and the cage 40 to the inner ring 30. Furthermore, with the comb-type cage 40, there is no need for crimping after assembly, which was necessary when assembling a tapered roller bearing using a conventional cage-type cage.

[0023] Furthermore, since the displacement generated in each cage is the same for both cages when the conventional cage type cage and the comb type cage 40 according to this embodiment, which hold the tapered rollers 11 in the pocket portions 45, are assembled into the inner ring 30, an analysis was conducted on the stress at the base of the columns when a forced displacement is applied to a position halfway along the axial length L1 of the tapered rollers 11. As a result, it was found that the comb type cage 40 can reduce the stress at the base of the columns by approximately 60% compared to the conventional cage type cage.

[0024] In the above analysis, a comparison was made between a conventional cage-type cage and a comb-type cage 40 which has a plate thickness 10 to 20% thicker than that of the cage-type cage, has the same circumferential width W of the column portion 43, and has a length L2 of the column portion 43 that is 2 / 3 of the axial length L1 of the tapered roller 11.

[0025] Furthermore, since equivalent analysis results were obtained even when the circumferential width W of column portion 43 was narrowed, it is also possible to increase the basic dynamic load rating of tapered roller bearing 10 by increasing the number of rollers in tapered roller 11. Furthermore, comb-type cage 40 of this embodiment can be manufactured in almost the same process as a conventional cage-type cage, and therefore can be manufactured inexpensively.

[0026] Second embodiment Next, a comb-type cage 40 according to a second embodiment will be described with reference to Fig. 5. As shown in Fig. 5, in the comb-type cage 40 according to this embodiment, the length L2 of the column portion 43 (the length along the axis C1 of the tapered roller 11) is set to be the same as the axial length L1 of the tapered roller 11 (L2 = L1).

[0027] According to the comb type cage 40 of this embodiment, the length L2 of the column portions 43 is longer than that of the comb type cage 40 of the first embodiment, and therefore the tapered rollers 11 can be more stably held. Also, not only is it easy to assemble the tapered rollers 11 and the comb type cage 40 to the inner ring 30, but the stress at the base of the column portions of the comb type cage 40 can be reduced by about 60% compared to a conventional cage type cage.

[0028] Other configurations and functions are similar to those of the comb-type cage 40 of the first embodiment, so the same or corresponding reference numerals are used for the same parts and the description thereof will be omitted.

[0029] The present invention is not limited to the above-described embodiment, and can be modified, improved, etc. as appropriate.

[0030] As described above, the present specification discloses the following: (1) an outer ring having an outer ring raceway on its inner circumferential surface; an inner ring having an inner ring raceway surface on an outer circumferential surface; a plurality of tapered rollers rollably disposed between the outer ring raceway surface and the inner ring raceway surface; a cage that rotatably holds the tapered rollers at predetermined intervals in a circumferential direction; A tapered roller bearing comprising: The retainer is a circular ring portion disposed on one axial side of the tapered roller; a plurality of column portions provided at predetermined intervals in a circumferential direction from a surface on the other axial side of the annular portion; pocket portions each defined by a circumferential side surface of one of the column portions adjacent to the other in the axial direction and a surface on the other side of the annular portion, the pocket portions each holding one of the tapered rollers; A comb-type cage having The length of the base portion is 2 / 3 or more of the length of the tapered roller and is not more than the full length of the tapered roller. Tapered roller bearing. With this configuration, the tapered rollers can be stably held by the pockets, the tapered rollers and the cage can be easily assembled into the inner ring, and the tapered roller bearing can be manufactured at low cost.

[0031] (2) The cage is a press-formed product of a steel plate. A tapered roller bearing as described in (1). According to this configuration, the cage can be manufactured inexpensively by pressing a steel plate. [Explanation of symbols]

[0032] 10 Tapered roller bearings 11 Tapered roller 20 Outer ring 21 Outer ring raceway 30 Inner Circle 31 Inner ring raceway surface 40 Comb type retainer (retainer) 41 Circular Ring 43 Pillar section 44 Circumferential side of column 45 Pocket section C1 Tapered roller shaft center L1 Tapered roller length L2 Length of column

Claims

1. an outer ring having an outer ring raceway on its inner circumferential surface; an inner ring having an inner ring raceway surface on an outer circumferential surface; a plurality of tapered rollers rollably disposed between the outer ring raceway surface and the inner ring raceway surface; a cage that rotatably holds the tapered rollers at predetermined intervals in a circumferential direction; A tapered roller bearing comprising: The retainer is a circular ring portion disposed on one axial side of the tapered roller; a plurality of column portions provided at predetermined intervals in a circumferential direction from a surface on the other axial side of the annular portion; pocket portions each defined by a circumferential side surface of one of the column portions adjacent to the other in the axial direction and a surface on the other side of the annular portion, the pocket portions each holding one of the tapered rollers; A comb-type cage having The length of the base portion is equal to or greater than 2 / 3 of the length of the tapered roller and equal to or less than the entire length of the tapered roller. Tapered roller bearing.

2. The cage is a press-formed product of a steel plate.

2. The tapered roller bearing according to claim 1.

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