WO2024079790A1

WO2024079790A1 - Tapered roller bearing

Info

Publication number: WO2024079790A1
Application number: PCT/JP2022/037915
Authority: WO
Inventors: 陽三谷口
Original assignee: 株式会社ジェイテクト
Priority date: 2022-10-11
Filing date: 2022-10-11
Publication date: 2024-04-18

Abstract

A tapered roller bearing 1 is provided with: an inner ring 2 having an inner ring raceway 21 on the outer circumferential side; an outer ring 3 having an outer ring raceway 31 on the inner circumferential side; a plurality of tapered rollers 4 that have a depression part 44 formed on a roller large end face 42 and are brought into rolling-contact with the inner ring raceway 21 and the outer ring raceway 31; and an annular retainer 5 that includes a small diameter annular body 6, a large diameter annular body 7, and a plurality of columns 8 for connecting the small diameter annular body 6 and the large diameter annular body 7 to each other, and has a plurality of pockets 9 formed in the circumference direction and accommodating the tapered rollers 4, wherein the large diameter annular body 7 includes a large diameter side face 7a that faces the roller large end face 42 of the tapered roller 4 accommodated in the pocket 9, the large diameter side face 7a has a recess 7b for storing a lubricant and a protrusion 11 protruding toward the depression part 44 from at least one of the inner side or the outer side from the recess 7b in the radial direction, and the protrusion 11 faces the depression part 44 with a gap therebetween.

Description

Tapered roller bearings

This disclosure relates to tapered roller bearings.

　Tapered roller bearings have traditionally been used to form the rotational support parts of various mechanical devices. In tapered roller bearings, for example, a sliding part exists between the large end faces of the tapered rollers and the rib end face of the inner ring. The contact state between the large end faces of the rollers and the rib end face in this sliding part is rolling contact accompanied by sliding, so if the lubricating oil supplied to the tapered rollers becomes insufficient or runs out, seizure may occur.

Therefore, it has been proposed to form a recess (circumferential groove) for oil storage in a cage that holds multiple tapered rollers (see, for example, Patent Document 1). The conventional tapered roller bearing described in Patent Document 1 is equipped with a cage in which a recess (circumferential groove) is formed in a position (large diameter side surface) that faces the large end faces of the tapered rollers housed in the pockets. The conventional tapered roller bearing described in Patent Document 1 can alleviate the lack of lubricating oil in the sliding parts by the lubricating oil stored in the recess, thereby suppressing the occurrence of seizure in the sliding parts.

In the conventional tapered roller bearing, the large roller end face faces the recess in the axial direction of the roller, covering the opening of the recess. As a result, the lubricating oil that has entered the recess is held between the large roller end face and the cage by surface tension. In the conventional tapered roller bearing, the large roller end face prevents the outflow of lubricating oil stored in the recess when the machine is stopped.

JP 2015-183804 A

<Problems to be Solved by the Invention of the Present Disclosure>
The tapered rollers that make up a tapered roller bearing may have a recess formed in the center of their large end faces. When a cage with a recess is used with a tapered roller bearing having this recess, a part of the recess that faces the large end face of the roller faces the recess. At the position where the recess faces the recess, the gap between the large end face of the roller and the recess is larger than at a position where the large end face of the roller other than the recess faces the recess. For this reason, with a tapered roller bearing configured in this way, lubricating oil may leak out from the position of the recess that faces the recess when the machine is stopped.

The purpose of this disclosure is to prevent the leakage of lubricating oil from a recess in the cage for storing lubricating oil when the bearing is stopped.

The tapered roller bearing disclosed herein comprises an inner ring having an inner ring raceway on the outer circumferential side, an outer ring having an outer ring raceway on the inner circumferential side, a plurality of tapered rollers having a recess formed on the roller large end face and rollingly contacting the inner ring raceway and the outer ring raceway, a small diameter annular body, a large diameter annular body, and a plurality of pillars connecting the small diameter annular body and the large diameter annular body to each other, and an annular cage having a plurality of pockets formed in the circumferential direction to accommodate the tapered rollers, the large diameter annular body having a large diameter side surface facing the roller large end face of the tapered roller housed in the pocket, the large diameter side surface being formed with a recess for storing lubricating oil and a protrusion protruding from at least one of the radially inner side and the radially outer side of the recess toward the recess, the protrusion facing the recess with a gap therebetween.

FIG. 1 is a cross-sectional view showing a tapered roller bearing according to an embodiment of the present disclosure. FIG. FIG. 4 is a partially enlarged perspective view showing the periphery of a recess of the cage. FIG. 2 is a partial cross-sectional view showing the cage according to the first embodiment. 4 is a schematic partial cross-sectional view showing the relationship between a first distance between a roller large end face and a large diameter side surface and a second distance between a recessed portion and a protruding portion. FIG. FIG. 11 is a partial cross-sectional view showing a cage according to a second embodiment.

<Effects of the Invention of the Present Disclosure>
According to the tapered roller bearing of the present disclosure, when the cage is provided with a recess for storing lubricating oil, outflow of the lubricating oil from the recess when the bearing is stopped can be suppressed.

<Overview of the embodiment of the present disclosure>
Below, an overview of the embodiments of the present disclosure will be listed and described.

(1) The tapered roller bearing of the present disclosure comprises an inner ring having an inner ring raceway on its outer periphery, an outer ring having an outer ring raceway on its inner periphery, a plurality of tapered rollers having a recess formed in the roller large end face and rollingly contacting the inner ring raceway and the outer ring raceway, a small diameter annular body, a large diameter annular body, and a plurality of pillars connecting the small diameter annular body and the large diameter annular body to each other, and an annular cage having a plurality of pockets formed in the circumferential direction for accommodating the tapered rollers. The large diameter annular body has a large diameter side surface facing the roller large end surface of the tapered roller accommodated in the pocket. The large diameter side surface is formed with a recess for storing lubricating oil and a protrusion protruding from at least one of the radially inner side and the radially outer side of the recess toward the recess. The protrusion faces the recess with a gap therebetween.

In a tapered roller bearing with this configuration, if a recess for oil collection is provided in the cage, it is possible to prevent lubricating oil from leaking out of the recess when the bearing is stopped.

(2) In the tapered roller bearing disclosed herein, preferably, a surface of the large diameter side surface that is located radially outward from the recess is defined as a first surface, and a surface of the convex portion that faces the recess is defined as a second surface, and a first distance between the first surface and the roller large end surface other than the recess is smaller than a second distance between the second surface and the recess.

A tapered roller bearing with this configuration can prevent contact between the convex and concave portions.

<Details of the embodiment of the present disclosure>
Hereinafter, an embodiment of the present disclosure will be described.

[Configuration of tapered roller bearing]
Fig. 1 is a cross-sectional view showing a tapered roller bearing according to an embodiment of the present disclosure. Fig. 2 is a perspective view showing a cage. Fig. 3 is a partially enlarged perspective view showing the periphery of a recess in the cage. Fig. 4 is a partial cross-sectional view showing a cage according to a first embodiment. Here, the configuration of the tapered roller bearing 1 of the present disclosure will be described based on the tapered roller bearing 1 shown in Fig. 1. The tapered roller bearing 1 shown in Fig. 1 comprises an inner ring 2, an outer ring 3 provided radially outward of the inner ring 2, a plurality of tapered rollers 4 provided between the inner ring 2 and the outer ring 3, and an annular cage 5 that holds the tapered rollers 4.

The "axial direction," "radial direction," and "circumferential direction" in the explanation of the inner ring 2, outer ring 3, and cage 5 are defined below. The "axial direction" is the direction along the center line of each of the inner ring 2, outer ring 3, and cage 5. The axial direction also includes the direction parallel to the center line. The "radial direction" is the direction perpendicular to each center line. The "circumferential direction" is the direction along a circle centered on each center line. In each drawing, the center line of the inner ring 2, outer ring 3, and cage 5 when they are aligned is designated by the symbol "C0." In the following explanation, as shown in FIG. 1, the side above the center line C0 in the radial direction of the tapered roller bearing 1 is referred to as the "upper side" of the tapered roller bearing 1, and the side below the center line C0 is referred to as the "lower side" of the tapered roller bearing 1.

The "axial direction," "radial direction," and "circumferential direction" in the description of the tapered rollers 4 are defined below. The "axial direction" of the tapered rollers 4 is the direction along the center line C1 of the tapered rollers 4. To distinguish it from the axial direction of the inner ring 2, outer ring 3, and cage 5, the axial direction of the cage 5, etc. is sometimes simply referred to as the "axial direction," and the axial direction of the tapered rollers 4 is sometimes referred to as the "roller axial direction." Note that the roller axial direction also includes a direction parallel to the center line C1. The "radial direction" is the direction perpendicular to the center line C1 of the tapered rollers 4, and may be referred to as the "roller radial direction." The "circumferential direction" is the direction along a circle centered on the center line C1 of the tapered rollers 4, and may be referred to as the "roller circumferential direction."

The inner ring 2 is an annular member formed using bearing steel, steel for mechanical construction, or the like. The inner ring 2 has a tapered inner ring raceway 21 on its outer periphery. The inner ring 2 has a small rib portion 22 provided on one axial side (left side in FIG. 1) of the inner ring raceway 21, and a large rib portion 23 provided on the other axial side (right side in FIG. 1) of the inner ring raceway 21. The small rib portion 22 and the large rib portion 23 each protrude radially outward.

The outer ring 3 is an annular member formed using bearing steel or steel for mechanical construction. The outer ring 3 has a tapered outer ring raceway 31 on its inner circumference.

The tapered roller 4 is a member in the shape of a truncated tapered member formed from bearing steel or the like. The tapered roller 4 has a small-diameter circular roller small end face 41 on one side in the roller axial direction (the left side in FIG. 1), and a large-diameter circular roller large end face 42 on the other side in the roller axial direction (the right side in FIG. 1). The tapered roller 4 is in rolling contact with the inner ring raceway 21 and the outer ring raceway 31. The large roller end face 42 is in rolling contact with the side surface (rib surface) 24 of the large rib portion 23.

The tapered roller 4 has a recess 44 formed in the center of the roller large end face 42. The recess 44 in this embodiment is formed by a forging technique. Therefore, the surface roughness of the recess 44 is greater than the surface roughness of the roller large end face 42 at the other parts than the recess 44. The roller large end face 42 at the other parts than the recess 44 are designed on the assumption that they will come into contact with the retainer 5 (large diameter side surface 7a), and are subjected to a surface treatment (surface finish) that reduces the surface roughness. Therefore, there is no problem even if the retainer 5 comes into contact with the roller large end face 42 except for the recess 44. On the other hand, the recess 44 is not designed on the assumption that it will come into contact with the retainer 5, and is not usually subjected to a surface treatment (surface finish) that reduces the surface roughness. Therefore, it is preferable that the recess 44 in the tapered roller bearing 1 of the present disclosure avoids contact with the retainer 5.

As shown in Figures 1 to 4, the cage 5 has a small diameter annular body 6 on one axial side, a large diameter annular body 7 on the other axial side with an outer diameter larger than that of the small diameter annular body 6, and a number of pillars 8 spaced apart in the circumferential direction. The small diameter annular body 6 and the large diameter annular body 7 are annular and spaced apart in the axial direction. The pillars 8 connect the small diameter annular body 6 and the large diameter annular body 7. The space formed between the two

pillars

8, 8 adjacent to each other in the circumferential direction between the small diameter annular body 6 and the large diameter annular body 7 forms a pocket 9. Each pocket 9 houses one tapered roller 4. The side surfaces 8a, 8a of the two

pillars

8, 8 face each other on the inside of the pocket 9.

The cage 5 has multiple pockets 9 that house the tapered rollers 4, and holds the multiple tapered rollers 4 at equal intervals in the circumferential direction.

The small diameter annular body 6 is formed with a small diameter side surface 6a. The small diameter side surface 6a is the portion that faces the roller small end surface 41 of the tapered roller 4 housed in the pocket 9.

The large diameter annular body 7 is formed with a large diameter side surface 7a. The large diameter side surface 7a is the portion that faces the roller large end surface 42 of the tapered roller 4 housed in the pocket 9.

Furthermore, the cage 5 has a recess 7b formed on the large diameter side surface 7a. The recess 7b is a groove-shaped portion formed along the circumferential direction, and serves to retain lubricating oil on the large diameter side surface 7a. As shown in FIG. 4, the recess 7b has a length that is included in the roller large end surface 42 when viewed from the roller axial direction. In other words, in the state shown in FIG. 4, the circumferential length of the roller large end surface 42 at the portion overlapping with the large diameter side surface 7a is greater than the circumferential length of the recess 7b. For this reason, the opening of the recess 7b is covered by the roller large end surface 42. However, the portion of the opening of the recess 7b that faces the recess 44 is not covered by the roller large end surface 42.

As shown in Figures 1 to 4, the pocket 9 is a space surrounded by the opposing

side surfaces

8a, 8a of the pillar 8, the small diameter side surface 6a, and the large diameter side surface 7a. The tapered roller 4 housed in the pocket 9 has a cone-shaped roller rolling surface 43 that faces the side surfaces 8a, 8a. In addition, the tapered roller 4 housed in the pocket 9 has a roller small end surface 41 that faces the small diameter side surface 6a, and a roller large end surface 42 that faces the large diameter side surface 7a.

The retainer 5 is made of synthetic resin and is formed by injection molding. In this embodiment, the retainer 5 is made of, for example, polyphenylene sulfide resin (PPS). The retainer 5 is resistant to lubricating oil (oil resistance), is relatively hard, and is not easily elastically deformed. The retainer 5 may be manufactured by a 3D printer.

In this disclosure, the rotation of the retainer 5 is guided by the tapered rollers 4. In other words, the tapered roller bearing 1 shown in FIG. 1 is a roller-guided type bearing in which the retainer 5 is guided by the tapered rollers 4.

As shown in FIG. 1, the state in which the center line of the cage 5 coincides with the center line of the inner ring 2 and the multiple tapered rollers 4 held by the cage 5 are in proper contact with the inner ring raceway 21 and the side surface 24 of the large flange portion 23 is defined as the "reference state". In the reference state in which the tapered rollers 4 are in contact with the outer ring raceway 31, the tapered rollers 4 cannot be displaced in the roller radial and axial directions. A gap is provided between the roller small end face 41 of the tapered roller 4 and the small diameter annular body 6, and a gap is provided between the roller rolling surface 43 of the tapered roller 4 and each

side surface

8a, 8a of the column 8. For this reason, the cage 5 can be slightly displaced in the radial and axial directions relative to the tapered rollers 4. In the reference state, the imaginary circle connecting the centers of the roller large end faces 42 of the tapered rollers 4 is defined as the pitch circle P1 of the (design) large diameter side of the tapered rollers 4 (see FIG. 4).

(Detailed configuration of the cage (first embodiment))
Fig. 4 shows a first embodiment of a cage 5 constituting a tapered roller bearing 1 according to the present disclosure. Among the circles shown by two-dot chain lines in Fig. 4, the circle marked with reference numeral 42 indicates the outer shape of the roller large end face 42 when viewed from the roller axial direction, and the circle marked with reference numeral 44 indicates the outer shape of the recessed portion 44 when viewed from the roller axial direction. The cage 5 according to the first embodiment is preferably applied when, as shown in Fig. 4, the recessed portion 44 overlaps with the large diameter side surface 7a located radially inside of the recessed portion 7b, but does not overlap with the large diameter side surface 7a located radially outside of the recessed portion 7b, when viewed from the roller axial direction.

As shown in FIG. 4, the retainer 5 according to the first embodiment has a protrusion 11 formed on the large diameter side surface 7a. The protrusion 11 has a shape such that, when the tapered rollers 4 are assembled to the retainer 5, its tip is positioned inside the recessed portion 44. When the tapered rollers 4 are assembled to the retainer 5, the protrusion 11 faces the recessed portion 44 with a gap between them.

In the retainer 5 according to the first embodiment, a protrusion 11 is formed on the large diameter side surface 7a located radially inside the recess 7b. In this case, the protrusion 11 is inserted into the region of the recess 44 that faces the large diameter side surface 7a and is radially inside the recess 7b. Therefore, when the retainer 5 according to the first embodiment is used, the size of the gap between the recess 44 and the retainer 5 (protrusion 11) is reduced, and as a result, the outflow of lubricating oil from the recess 7b facing the recess 44 is suppressed. Note that the protrusion 11 in the retainer 5 according to the first embodiment suppresses the outflow of lubricating oil from the recess 7b located above the central axis C0.

Therefore, in the tapered roller bearing 1 disclosed herein, the convex portion 11 can prevent the outflow of lubricating oil from the concave portion 7b during stoppage. As a result, even after the tapered roller bearing 1 has been stopped for a long period of time, the lubricating oil can be maintained in a stored state in the concave portion 7b. As a result, even when the tapered roller bearing 1 is restarted after being stopped for a long period of time, the occurrence of seizure due to a lack or depletion of lubricating oil can be prevented.

(Gaps between depressions and protrusions)
5 is a partial cross-sectional schematic diagram showing the relationship between a first distance between the roller large end face and the large diameter side surface and a second distance between the recessed portion and the protruding portion. As shown in Fig. 4 and Fig. 5, in the tapered roller bearing 1 of the present disclosure, when the surface (cross-hatched area) of the large diameter side surface 7a located radially outward from the recessed portion 7b of the cage 5 is defined as a first surface S1 and the surface (cross-hatched area) of the surface constituting the protruding portion 11 facing the recessed portion 44 is defined as a second surface S2, a first distance D1 between the first surface S1 and a portion of the roller large end face 42 other than the recessed portion 44 is smaller than a second distance D2 between the second surface S2 and the recessed portion 44 (D1 < D2).

In a tapered roller bearing 1 having such a retainer 5, when the retainer 5 is displaced in the axial and radial directions, the first surface S1 (large diameter side surface 7a) comes into contact with the roller large end surface 42 before the convex portion 11 (second surface S2) comes into contact with the recessed portion 44. Therefore, in the tapered roller bearing 1 of the present disclosure, it is possible to prevent the second surface S2 (convex portion 11) from coming into contact with the recessed portion 44, thereby suppressing wear of the convex portion 11.

(Regarding another embodiment of the cage)
Fig. 6 is a partial cross-sectional view showing a cage according to a second embodiment. Fig. 6 shows a second embodiment of a cage 5 constituting a tapered roller bearing 1. In the tapered roller bearing 1 of the present disclosure, the cage 5 shown in Fig. 6 may be adopted. The cage 5 according to the second embodiment is preferably applied when, as shown in Fig. 6, the recessed portion 44 overlaps with the large diameter side surface 7a located radially inside of the recess 7b and also overlaps with the large diameter side surface 7a located radially outside of the recess 7b when viewed from the roller axial direction.

As shown in FIG. 6, in the retainer 5 according to the second embodiment, the convex portion 11 formed on the large diameter side surface 7a is composed of a first convex portion 11a and a second convex portion 11b. The first convex portion 11a is the convex portion 11 formed on the large diameter side surface 7a located radially inside the recessed portion 7b. The second convex portion 11b is the convex portion 11 formed on the large diameter side surface 7a located radially outside the recessed portion 7b.

In the retainer 5 according to the second embodiment, the first protrusion 11a is inserted into a region facing the large diameter side surface 7a of the recess 44, which is radially inward of the recess 7b. The first protrusion 11a suppresses the outflow of lubricating oil from the recess 7b located above the central axis C0 (in other words, when the first protrusion 11a is located below the recess 7b). Therefore, when the retainer 5 according to the second embodiment is used, the size of the gap between the recess 44 and the retainer 5 (first protrusion 11a) is reduced, and as a result, the outflow of lubricating oil from the recess 7b facing the recess 44 is suppressed.

Furthermore, in the retainer 5 according to the second embodiment, the second protrusion 11b is inserted into a region facing the large diameter side surface 7a of the recess 44, which is radially outward of the recess 7b. The second protrusion 11b suppresses the outflow of lubricating oil from the recess 7b located below the central axis C0 (in other words, when the second protrusion 11b is located above the recess 7b). Therefore, when the retainer 5 according to the second embodiment is used, the size of the gap between the recess 44 and the retainer 5 (second protrusion 11b) is reduced, and as a result, the outflow of lubricating oil from the recess 7b facing the recess 44 is suppressed.

Therefore, in the tapered roller bearing 1 disclosed herein, the first convex portion 11a and the second convex portion 11b can suppress the outflow of lubricating oil from the concave portion 7b when stopped. As a result, even after the tapered roller bearing 1 has been stopped for a long period of time, the lubricating oil can be maintained in a stored state in the concave portion 7b. As a result, even when the tapered roller bearing 1 is restarted after being stopped for a long period of time, the occurrence of seizure due to a lack or depletion of lubricating oil can be suppressed.

<Actions and Effects of the Embodiments>
(1) The tapered roller bearing 1 of the above embodiment comprises an inner ring 2 having an inner ring raceway 21 on its outer circumferential side, an outer ring 3 having an outer ring raceway 31 on its inner circumferential side, a plurality of tapered rollers 4 having recesses 44 formed in roller large end faces 42 and in rolling contact with the inner ring raceway 21 and the outer ring raceway 31, and an annular cage 5 having a small diameter annular body 6, a large diameter annular body 7, and a plurality of pillars 8 connecting the small diameter annular body 6 and the large diameter annular body 7 to each other, and having a plurality of pockets 9 formed in the circumferential direction for accommodating the tapered rollers 4. The large diameter annular body 7 has a large diameter side surface 7a facing the roller large end faces 42 of the tapered rollers 4 accommodated in the pockets 9. The large diameter side surface 7a is formed with a recess 7b for storing lubricating oil, and a protrusion 11 protruding from at least one of the radially inner side and the radially outer side of the recess 7b toward the recess 44. In the tapered roller bearing 1 of the above embodiment, the convex portion 11 faces the concave portion 44 with a gap therebetween.

In a tapered roller bearing 1 configured in this way, if a recess 7b for storing lubricating oil is provided in the retainer 5, it is possible to prevent the outflow of lubricating oil from the recess 7b when the bearing is stopped.

(2) In the tapered roller bearing 1 of the above embodiment, when the surface of the large diameter side surface 7a located radially outward from the recess 7b is defined as the first surface S1, and the surface of the surfaces constituting the protrusion 11 that faces the recess 44 is defined as the second surface S2, the first distance D1 between the first surface S1 and the roller large end surface 42 other than the recess 44 is smaller than the second distance D2 between the second surface S2 and the recess 44.

A tapered roller bearing 1 configured in this way can prevent contact between the protrusions 11 and the recesses 44.

The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the invention is not limited to the above-described embodiments, but includes all modifications within the scope of equivalence to the configurations described in the claims.

1: Tapered roller bearing 2: Inner ring 3: Outer ring 4: Tapered roller 5: Cage 6: Small diameter annular body 6a: Small diameter side surface 7: Large diameter annular body 7a: Large diameter side surface 7b: Recess 8: Pillar 9: Pocket 11: Convex portion 11a: First convex portion (convex portion)
11b: second protrusion (protrusion)
21: Inner ring raceway 31: Outer ring raceway 41: Roller small end face 42: Roller large end face 44: Depression S1: First surface S2: Second surface D1: First distance D2: Second distance

Claims

an inner ring having an inner ring raceway on an outer circumferential side;
an outer ring having an outer ring raceway on an inner circumferential side;
a plurality of tapered rollers each having a recess formed on a roller large end surface and in rolling contact with the inner ring raceway and the outer ring raceway;
an annular cage having a small diameter annular body, a large diameter annular body, and a plurality of pillars connecting the small diameter annular body and the large diameter annular body to each other, and having a plurality of pockets formed in the circumferential direction for accommodating the tapered rollers;
the large diameter annular body has a large diameter side surface facing the roller large end surface of the tapered roller housed in the pocket,
The large diameter side surface is formed with a recess for storing lubricating oil and a protrusion protruding from at least one of a radial inner side and a radial outer side of the recess toward the recessed portion,
the protruding portion faces the recessed portion with a gap therebetween.
In the case where a surface of the large diameter side surface that is located radially outward from the recess is defined as a first surface, and a surface of the protrusion that faces the recess is defined as a second surface,
2. The tapered roller bearing according to claim 1, wherein a first distance between said first surface and said roller large end surface other than said recessed portion is smaller than a second distance between said second surface and said recessed portion.