JP2025015986A - Tapered roller bearing - Google Patents

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

The present invention relates to a tapered roller bearing equipped with a comb-type cage.

Tapered roller bearings are ideally used to support the rotation of rotating shafts in various industrial machines, such as railway cars, automobiles, construction machines, and steel rolling mills. In tapered roller bearings, multiple tapered rollers are arranged to roll freely in pockets formed in a cage or comb-type cage.

As shown in Figures 6 and 7, a conventional tapered roller bearing 100 includes 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 number of tapered rollers 130 arranged to roll freely between the outer ring raceway surface 111 and the inner ring raceway surface 121, and a cage-type retainer 140 that holds the tapered rollers 130 rotatably in pockets 147.

The cage-type retainer 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 retainer 140 rotatably retains the tapered roller 130 in a pocket 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 the adjacent pillar portions 143, 143.

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 that is half or more the length of the tapered roller and is less than the full length, and both circumferential sides of the column portion have a curvature approximately equal to that of the tapered roller, and has a snap portion for holding the tapered roller in the radial direction, thereby reducing manufacturing costs.

JP 2009-2377 A JP 2014-231899 A

However, with the conventional cage cage 140 shown in Figures 6 and 7 and the comb cage described in Patent Document 1, it is necessary to crimp the cage when assembling the tapered rollers and cage into the inner ring. Also, with the comb cage described in Patent Document 2, crimping of the cage is not required during assembly, but because it is shaped to hold the tapered rollers, there is a problem that the radial thickness is greater than that of conventional cage cages, resulting in higher material costs. Also, since the center of gravity of a tapered roller is generally located at approximately half the length of the tapered roller, if the length of the column portion is half the length of the tapered roller, the center of gravity of the tapered roller and the tip position of the column portion will coincide, and there is a risk of unstable retention of the tapered roller.

The present invention was made in consideration of the above-mentioned problems, and its purpose is to provide a tapered roller bearing that can stably hold tapered rollers in pockets, can easily assemble the tapered rollers and cage into the inner ring, and can reduce manufacturing costs.

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 an 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.

The tapered roller bearing of the present invention allows the tapered rollers to be stably held in the pockets, and the tapered rollers and cage can be easily assembled into the inner ring, allowing the tapered roller bearing to be manufactured at low cost.

1 is a cross-sectional view of a tapered roller bearing according to a first embodiment of the present invention. FIG. 2 is a perspective view showing the tapered roller bearing of FIG. 1 with an outer ring removed. FIG. 2 is a cross-sectional view showing the tapered roller length and the column length of the cage of the tapered roller bearing of FIG. 1 . FIG. 4 is an enlarged view of a main portion of FIG. 3 . 5 is an enlarged view equivalent to FIG. 4 of a tapered roller bearing according to a second embodiment of the present invention; FIG. 1 is a cross-sectional view of a tapered roller bearing equipped with a conventional cage type retainer. FIG. 7 is a perspective view showing the conventional tapered roller bearing of FIG. 6 with the outer ring removed.

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-type retainer 40 that holds the plurality of tapered rollers 11 rotatably at a predetermined interval in the circumferential direction.

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 flange portion 32 formed on one axial side (right side in FIG. 1) of the inner ring raceway surface 31, and a small diameter flange portion 33 formed on the other axial side (left side in FIG. 1) of the inner ring raceway surface 31.

The large diameter flange 32 and small diameter flange 33 of the inner ring 30 are in sliding contact with the large diameter end face 12 (head face) and small diameter end face 13 (tail face) of the tapered roller 11, respectively, and position the tapered roller 11 in the axial direction. In addition, inner ring escape 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 flange 32, and the inner ring raceway surface 31 and the small diameter flange 33, respectively.

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. The corner connecting the rolling surface 14 and the large diameter side end face 12, and the corner connecting the rolling surface 14 and the small diameter side end face 13 are each formed in a convex spherical shape.

The comb-shaped cage 40, which holds the tapered rollers 11 rotatably, 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 arranged at a predetermined interval in the circumferential direction from the 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 incline 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.

The comb-shaped cage 40 has pockets 45 defined by the opposing circumferential side surfaces 44, 44 of the circumferentially adjacent column sections 43, 43 and the other axial surface 42 of the annular section 41. Each of the pockets 45 holds a tapered roller 11 so that it can roll freely.

It is preferable that the length L2 of the column portion 43 (length along the axis C1 of the tapered roller 11) is 2/3 or more of the axial length L1 of the tapered roller 11 and is less than or equal to the full length. In this embodiment, as shown in Figures 3 and 4, the length L2 of the column portion 43 (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.

The center of gravity G 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 center of gravity G of the tapered roller 11 and the tip position of the column portion 43 will coincide, and there is a risk that the retention of the tapered roller 11 by the pocket portion 45 will become unstable.

However, in this 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.

The length L2 of the column portion 43 is set to 2/3 of the axial length L1 of the tapered roller 11, taking into consideration that in a special tapered roller 11, the center of gravity position G is located 1/3 of the axial length L1 from the large diameter side end face 12 of the tapered roller 11. Even in 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.

In addition, with the above-mentioned comb-type retainer 40, when the tapered rollers 11 and the retainer 40 are assembled to the inner ring 30, the comb-type retainer 40 easily deforms elastically, making assembly easy. Furthermore, with the comb-type retainer 40, the crimping process required after assembly, which was previously required when assembling tapered roller bearings using conventional cage retainers, is not required.

Furthermore, when a conventional cage-type cage and the comb-type cage 40 according to this embodiment, which hold the tapered rollers 11 in the pockets 45, are assembled into the inner ring 30, the displacement that occurs in each cage is the same for both cages. Therefore, the column root stress was analyzed when a forced displacement was 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 column root stress by about 60% compared to the conventional cage-type cage.

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 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.

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

Second Embodiment
Next, a comb-type cage 40 of a second embodiment will be described with reference to Fig. 5. As shown in Fig. 5, in the comb-type cage 40 of 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).

The comb-type cage 40 of this embodiment has a longer length L2 of the column portion 43 than the comb-type cage 40 of the first embodiment, so that the tapered rollers 11 can be held more stably. In addition, 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 portion of the comb-type cage 40 can be reduced by about 60% compared to a conventional cage-type cage.

The rest of the configuration and function are the same as those of the comb-shaped retainer 40 of the first embodiment, so the same or corresponding symbols are used for the same parts and the explanation is omitted.

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

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 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.
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.

(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.

10 Tapered roller bearing 11 Tapered roller 20 Outer ring 21 Outer ring raceway surface 30 Inner ring 31 Inner ring raceway surface 40 Centrifugal retainer (retainer)
41 Annular portion 43 Column portion 44 Circumferential side surface of column portion 45 Pocket portion C1 Axis center of tapered roller L1 Length of tapered roller L2 Length of column portion

Claims (2)

an outer ring having an outer ring raceway on an 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. The cage is a press-formed product of a steel plate.
2. The tapered roller bearing according to claim 1.

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