WO2023277098A1 - Tapered roller bearing - Google Patents

Abstract

In the present invention, a retainer has: a large-diameter ring part and a small-diameter ring part disposed so as to be separated from each other in an axial direction; a plurality of column parts disposed at prescribed intervals in the circumferential direction and connecting the large-diameter ring part and the small-diameter ring part; and a plurality of pockets formed between the large-diameter ring part, the small diameter ring part, and the column parts adjacent in the circumferential direction, the pockets respectively holding tapered rollers. Notches are formed in corners on the inner diameter side of an inner surface of the large-diameter ring part forming the pockets.

Description

tapered roller bearing

The present invention relates to tapered roller bearings.

Roller bearings have a greater radial load bearing capacity than ball bearings, and tapered roller bearings, in which truncated conical rollers (tapered rollers) are incorporated as rolling elements, support a combined load of radial load and axial (thrust) load. can do. For this reason, tapered roller bearings are widely used in rotation support parts of various mechanical devices that require high load and high rigidity.

For example, in the tapered roller bearing described in Patent Document 1, the retainer includes a large-diameter side annular portion extending in the circumferential direction along the large end surfaces of the plurality of tapered rollers and a circumferential and a plurality of pillars connecting the large-diameter annular portion and the small-diameter annular portion. The large-diameter side annular portion, the small-diameter side annular portion, and the plurality of column portions define a plurality of pockets that respectively accommodate a plurality of tapered rollers. The large-diameter side annular portion is formed with a large-diameter side pocket surface facing the large end surface of each tapered roller. A non-penetrating oil retaining hole or oil retaining recess for introducing and retaining lubricating oil by capillary action is formed in the large-diameter side pocket surface.

With this configuration, lubricating oil is retained in the oil retaining hole or oil retaining recess formed in the large-diameter side pocket surface, and seizure resistance between the large end surface of the tapered roller and the inner ring large flange is enhanced. It is designed to withstand higher loads.

WO2019/163809

　In tapered roller bearings, tapered rollers are usually incorporated into the retainer from the inside. In the case of tapered roller bearings for robots that require higher load and higher rigidity, tapered rollers longer than normal ones are incorporated. If the rollers have the same name, the size of the rollers becomes larger than the pocket holes of the retainer, making it difficult to insert the rollers into the retainer, resulting in poor assembly. If the rollers are forcibly inserted into the cage in this situation, the cage may be damaged.

The present invention has been made in view of the above circumstances, and its object is to provide a tapered roller bearing in which tapered rollers can be easily incorporated into a retainer.

The above objects of the present invention are achieved by the following configurations.
(1) an outer ring having an outer ring raceway surface on its inner peripheral surface;
an inner ring having an inner ring raceway surface on its outer peripheral surface;
a plurality of tapered rollers rollably arranged between the outer ring raceway surface and the inner ring raceway surface;
a retainer that retains the plurality of tapered rollers in a rollable manner;
A tapered roller bearing comprising
The retainer is
a large-diameter ring portion and a small-diameter ring portion arranged so as to be spaced apart from each other in the axial direction;
a plurality of pillars connecting the large-diameter ring portion and the small-diameter ring portion and arranged at predetermined intervals in the circumferential direction;
a plurality of pockets formed between the large-diameter ring portion, the small-diameter ring portion, and the column portions adjacent in the circumferential direction and holding the tapered rollers;
has
A tapered roller bearing, wherein a notch is formed at an inner diameter side corner of an inner surface of the large-diameter ring portion forming the pocket.
(2) The pocket according to (1), wherein the size of the notch in the circumferentially central portion of the pocket is larger than the size of the notch in the circumferentially outer portion of the pocket. Tapered roller bearing.
(3) Rk>Rs, where Rk is the radius of curvature of the notch and Rs is the radius of the maximum diameter portion of the tapered roller;
A tapered roller bearing according to (1) or (2), characterized in that:
(4) Dw3>Kw>0, where Kw is the length of the notch in the circumferential direction of the retainer, and Dw3 is the maximum diameter of the large-diameter end surface of the tapered roller.
The tapered roller bearing according to any one of (1) to (3), characterized in that:

According to the present invention, it is possible to provide a tapered roller bearing in which tapered rollers can be easily incorporated into the retainer.

1A is a cross-sectional view of a tapered roller bearing according to a first embodiment of the present invention, and FIG. 1B is a diagram showing a tapered roller; FIG. It is a figure which shows a general-purpose tapered roller. 2 is a perspective view of the retainer of FIG. 1; FIG. (a) is an enlarged perspective view of a main part of the retainer of FIG. 3, and (b) is an enlarged cross-sectional view of the main part of the retainer. (a) is a cross-sectional view for explaining a preferred position of a protrusion, and (b) is a cross-sectional view taken along a line perpendicular to the rotation axis of tapered rollers. (a) is a cross-sectional view taken along a line perpendicular to the axis of rotation of tapered rollers on the large diameter side of the cage, and (b) is a cross-sectional view of the cage on the small diameter side of the cage perpendicular to the axis of rotation of the tapered rollers. FIG. 4 is a cross-sectional view taken along a vertical line; FIG. 4 is a cross-sectional view showing a state in which tapered rollers are incorporated into pockets of a retainer; (a) is a perspective view before incorporating the tapered rollers into the retainer, and (b) is a perspective view after incorporating the tapered rollers into the retainer. FIG. 4 is a perspective view of a main part for explaining the dimensional relationship between the notch of the retainer and tapered rollers;

The tapered roller bearings according to each embodiment of the present invention will be described in detail below with reference to the drawings.

(First embodiment)
As shown in FIGS. 1(a) and 1(b), the tapered roller bearing 1 of this embodiment includes an outer ring 2 having an outer ring raceway surface 2a on its inner peripheral surface and an inner ring 3 having an inner ring raceway surface 3a on its outer peripheral surface. a plurality of tapered rollers 4 disposed between the outer ring raceway surface 2a and the inner ring raceway surface 3a so as to be free to roll; , has

The inner diameter of the outer ring raceway surface 2a gradually increases from the small diameter side to the large diameter side.

In addition, the inner ring 3 is provided with a large flange 3b formed at the large-diameter end portion so as to protrude radially outward. The inner ring raceway surface 3a continues to the small diameter side end surface 3c. The outer diameter of the inner ring raceway surface 3a gradually increases from the small diameter side end surface 3c toward the large flange 3b. That is, the inner ring 3 has a flange (large flange 3b) only at the large diameter end of the large diameter end and the small diameter end.

A cross-sectional view of a general-purpose tapered roller bearing 100 is shown in FIG. The tapered roller bearing 100 includes an outer ring 102 having an outer ring raceway surface 102a on its inner peripheral surface, an inner ring 103 having an inner ring raceway surface 103a on its outer peripheral surface, and rolling freely between the outer ring raceway surface 102a and the inner ring raceway surface 103a. It has a plurality of arranged tapered rollers 104 and a resin retainer 110 that holds the plurality of tapered rollers 104 rollably at predetermined intervals. The inner diameter of the outer ring raceway surface 102a gradually increases from the small diameter side toward the large diameter side. In addition, the inner ring 103 is provided with a large flange 103b and a small flange 103d protruding radially outward at the large diameter side end and the small diameter side end, respectively.

Compared to the tapered roller bearing 100 shown in FIG. 2 where the inner ring 103 is provided with the small rib 103d, in the tapered roller bearing 1 of the present embodiment, the inner ring 3 does not have the small rib 103d. Lw can be increased, and as a result, rigidity and load capacity are increased, and service life can be extended.

As shown in FIG. 1, in the tapered roller bearing 1 of this embodiment, the contact angle α, which is the angle between the tangent to the outer ring raceway surface 2a and the rotation axis of the tapered roller bearing 1, is set to 45°. Directional stiffness is improved.

By setting the contact angle α in the range of 35° to 55°, the rigidity in the axial direction can be improved. When a pair of tapered roller bearings 1 are arranged axially and used, if the distance between the bearings is short (specifically, if the distance between the bearings is four times or less than the assembly width T of the bearings), the contact angle When α is in the range of 35° to 55°, the distance between the points of action can be lengthened, which is particularly effective in improving the rigidity of the bearing in the axial direction.

Further, the tapered roller bearing 1 of the present embodiment is suitable for bearings having an inner diameter of 30 to 500 mm and an outer diameter of 33 to 650 mm.

As also shown in FIG. 3, the retainer 10 connects a large-diameter ring portion 11 and a small-diameter ring portion 12 which are arranged so as to be spaced apart from each other in the axial direction. , and a plurality of pillars 13 arranged at predetermined intervals in the circumferential direction. The column portion 13 is in sliding contact with the outer peripheral surface of the tapered roller 4 which is a rolling element. In the resin retainer 10, a plurality of pockets P for accommodating and holding the tapered rollers 4 are equally divided in the circumferential direction between the large-diameter ring portion 11, the small-diameter ring portion 12, and the column portions 13 adjacent in the circumferential direction. are formed respectively.

The resin retainer 10 is manufactured by injection molding, and in this embodiment, is injection molded by an axial draw mold that is advantageous in terms of cost.

As shown in FIGS. 4A and 4B, the center portion in the radial direction of the column portion 13 having the pocket P is defined as the mold dividing line, that is, the parting line A′. Together with the side cavities, a pocket P is formed.

As shown in FIGS. 4(a) and 4(b), on the facing surfaces (circumferential side surfaces) of the adjacent columnar portions 13, 13, a plurality of tapered rollers 4 are provided on the outer diameter side of the mold parting line A'. An inner diameter side conical surface 15A that slides on the outer peripheral surface of the tapered roller 4 is formed in a portion on the inner diameter side of the virtual conical surface C connecting each rotation axis X (central axis) of the tapered roller 4. A radial flat surface 16A continuous with the inner diameter side conical surface 15A is formed on the side portion.

In addition, on the facing surfaces (circumferential side surfaces) of the adjacent columnar portions 13, 13, the outer peripheral surface of the tapered roller 4 is formed on the inner diameter side of the mold parting line A' on the outer diameter side of the virtual conical surface C. An outer diameter side conical surface 15B is formed in sliding contact with the outer diameter side conical surface 15B, and a radial plane 16B continuous with the outer diameter side conical surface 15B is formed in a portion on the inner diameter side of the virtual conical surface C.

The curvature of the conical surfaces 15A, 15B is set slightly larger than the curvature of the tapered rollers 4.

Also, as shown in FIG. 5(a), a projecting portion 17A is provided at the end of the inner diameter side conical surface 15A formed in the portion of the column portion 13 near the large-diameter ring portion 11. As shown in FIG. As shown in FIG. 5(b), a projecting portion 17B is provided at the end of an outer diameter side conical surface 15B formed in a portion of the column portion 13 near the small-diameter ring portion 12. As shown in FIG.

In other words, in the present embodiment, the column portion 13 includes the protruding portion 17A forming the first protruding portion that holds the tapered rollers 4 on the inner diameter side of the pocket P and the tapered roller 4 on the outer diameter side of the pocket P. and a projecting portion 17B constituting a second projecting portion.

In order to integrate the tapered rollers 4 and the resin retainer 10, the inner diameter side opening width W1 of the pocket at the projecting portion 17A near the large diameter ring portion 11 of the column portion 13 is equal to the large roller diameter Dw1 (Fig. 1(b) )), and in the projecting portion 17B near the small-diameter ring portion 12 of the column portion 13, the outer diameter side opening width W2 of the pocket is narrower than the roller small diameter Dw2 (see FIG. 1(b)).

As shown in FIGS. 1A and 3, in the pocket P, a protrusion 21 is formed on the inner surface 12a of the small-diameter ring portion 12 (the surface facing the small-diameter side end surface 4a of the tapered roller 4). there is On the other hand, the small-diameter side end surface 4a of the tapered roller 4 facing the protrusion 21 is substantially flat.

The apex of the protrusion 21 may be located on the rotation axis X of the tapered roller 4, but may be offset from the rotation axis X of the tapered roller 4. As shown in FIGS. 5(a) and 5(b), when the protrusion 21 is provided at the intersection D1 between the inner surface 12a of the small-diameter ring portion 12 and the rotation axis X (central axis) of the tapered roller 4, the bearing rotation is At this time, since the protrusion 21 does not interfere with the rotational motion of the tapered roller 4, the torque is small.

In addition, when the protruding portion 21 is provided at the position D2, the effect of preventing the tapered rollers 4 from falling off from the retainer 10 is the best. The position D2 is when the tapered roller 4 falls off from the retainer 10 and the intersection point E between the small-diameter end surface 4a of the tapered roller 4 and the outer peripheral surface of the tapered roller 4 comes closest to the inner surface 12a of the small-diameter ring portion 12. This is the facing position of the small-diameter ring portion 12 facing the intersection point E in the rotation axis X direction. The intersection point E rotates along the trajectory EA around the vertex F of the ridgeline of the first engagement margin (that is, the vertex where the ridgeline of the protrusion 17A and the inner diameter side conical surface 15A intersects the groove 14). do.

Therefore, considering both bearing rotation and assembly, the apex of the protrusion 21 is closer to the inner diameter side opening 19 of the pocket P than the position through which the rotation axis X of the tapered roller 4 passes on the inner surface 12a of the small-diameter ring portion 12. is preferably provided in Furthermore, the apex of the protrusion 21 is provided on the inner surface 12a of the small-diameter ring portion 12 between the intersection point D1 and the opposing position D2 facing the intersection point E (that is, on the straight line G connecting D1 and D2). more preferably.

Further, as shown in FIG. 1 , an annular recess 20 is formed on the inner peripheral surface of the large-diameter ring portion 11 so that the thickness of the large-diameter ring portion 11 is thinner than the thickness of the column portion 13 . , the inner peripheral surface of the retainer 10 is formed in a stepped shape from the column portion 13 to the large-diameter ring portion 11 . Further, the thinned portion 20 cuts out a part of the column portion 13 along the radial direction. As a result, the wall thickness of the large-diameter ring portion 11 is reduced, so that the amount of elastic deformation of the column portion 13 on the side of the large-diameter ring portion is increased, making it easier to insert the tapered rollers 4 from the inside of the retainer 10 .

In addition, the large flange 3b of the inner ring 3 can be inserted into the annular recess 20, and the axial load can be increased by increasing the large flange 3b accordingly. Furthermore, since the thinning portion 20 cuts out a part of the column portion 13 along the radial direction, it is possible to avoid interference with the large brim 3b.

The inclination angle α ₂ ( FIG. 1( a )) of the outer peripheral surface of the retainer 10 with respect to the rotation axis of the tapered roller bearing 1 corresponds to the contact angle α of the tapered roller bearing 1 and ranges from 32° to 30′ and less than 55°. Preferably, it is set to 32°30' or more and 54° or less.

In addition, in the pocket P, a notch 11b is formed at the corner on the inner diameter side of the inner surface 11a of the large-diameter ring portion 11 (the surface facing the large-diameter end surface 4b of the tapered roller). The notch 11 b is formed by chamfering the inner diameter side corner of the inner surface 11 a of the large-diameter ring portion 11 . The notch 11b is formed in a range where the pocket P is provided. That is, the notch 11b is formed between the circumferentially adjacent pillars 13 apart from the circumferentially opposite end portions P1 and P2 of the pocket P (see FIG. 4A).

The notch 11b is preferably formed such that the size of the notch 11b at the circumferentially central portion P3 of the pocket P is larger than the size of the notch 11b at the circumferentially outer portion of the pocket P.
As shown in FIG. 4A, the notch 11b is formed by chamfering an inner diameter side corner of the inner surface 11a of the large-diameter ring portion 11 with an arc-shaped curved surface. The notches 11b are not formed at the circumferential ends P1 and P2 of the pocket P, and the chamfering starts between the circumferential ends P1 and P2 of the pocket P and the circumferential central portion P3. The chamfering increases toward the central portion P3, and the chamfering is maximum at the circumferential central portion P3. In order to facilitate assembly of the tapered rollers 4 into the retainer 10, the shape of the notch 11b is preferably an arc-shaped curved surface. It is preferably larger than the radius of the side end surface 4b.

According to this, it is possible to easily incorporate the tapered rollers 4 from the inside of the cage 10 while suppressing a decrease in the strength of the large-diameter ring portion 11 of the cage 10 .

Specifically, Rk>Rs, where Rk is the radius of curvature of the notch 11b (see FIG. 4(a)) and Rs is the radius of the maximum diameter portion of the tapered roller 4 (see FIG. 6(a)). As a result, as shown in FIG. 7, the tapered rollers 4 rotate from the position indicated by the solid line to the position indicated by the two-dot chain line into the pocket P of the retainer 10 as shown in FIGS. 8(a) and 8(b). incorporated. At this time, the tapered rollers 4 are less likely to come into contact with the notches 11b, and the tapered rollers 4 are easily assembled.

The radius of curvature Rk of the arc is 1.2 times or more, preferably 1.4 times or more, the radius Rs of the maximum diameter portion of the tapered rollers 4, so that the tapered rollers 4 are incorporated into the retainer 10. At this time, it is possible to allow the tapered rollers 4 to be incorporated into the notches 11b while being somewhat displaced in the circumferential direction, so that the tapered rollers 4 can be incorporated more easily from the inside of the retainer 19 .

Further, when Rk is 2.0 times or less, preferably 1.8 times or less, Rs, the width of the notch 11b in the circumferential direction can be suppressed, and the strength of the large-diameter ring portion 11 of the retainer 10 can be increased. Decrease can be suppressed.

Further, as shown in FIG. 9, when the length of the notch 11b in the circumferential direction of the retainer 10 is Kw, and the maximum diameter of the large-diameter end surface 4b of the tapered roller 4 is Dw3, Dw3>Kw>0. .
Setting Kw>0 makes it easier to incorporate the tapered rollers 4 into the retainer 10 from the inside.
Further, by setting Dw3>Kw, the tapered rollers 4 are likely to drop from the cage 10 due to their own weight before the cage and roller in which the tapered rollers 4 are incorporated in the cage 10 is incorporated into the inner ring 3. Even in such a case, contact between the large-diameter side end surface 4b of the tapered roller 4 and the corner portion 11B of the inner surface 11a of the large-diameter ring portion 11 of the retainer 10 where the inner diameter side is not notched causes the conical It is possible to make it difficult for the rollers 4 to fall from the retainer 10 .

As described above, this specification discloses the following configurations.
(1) an outer ring having an outer ring raceway surface on its inner peripheral surface;
an inner ring having an inner ring raceway surface on its outer peripheral surface;
a plurality of tapered rollers rollably arranged between the outer ring raceway surface and the inner ring raceway surface;
a retainer that retains the plurality of tapered rollers in a rollable manner;
A tapered roller bearing comprising
The retainer is
a large-diameter ring portion and a small-diameter ring portion arranged so as to be spaced apart from each other in the axial direction;
a plurality of pillars connecting the large-diameter ring portion and the small-diameter ring portion and arranged at predetermined intervals in the circumferential direction;
a plurality of pockets formed between the large-diameter ring portion, the small-diameter ring portion, and the column portions adjacent in the circumferential direction and holding the tapered rollers;
has
A tapered roller bearing, wherein a notch is formed at an inner diameter side corner of an inner surface of the large-diameter ring portion forming the pocket.
(2) The pocket according to (1), wherein the size of the notch in the circumferentially central portion of the pocket is larger than the size of the notch in the circumferentially outer portion of the pocket. Tapered roller bearing.
(3) Rk>Rs, where Rk is the radius of curvature of the notch and Rs is the radius of the maximum diameter portion of the tapered roller;
A tapered roller bearing according to (1) or (2), characterized in that:
(4) Dw3>Kw>0, where Kw is the length of the notch in the circumferential direction of the retainer, and Dw3 is the maximum diameter of the large-diameter end surface of the tapered roller.
The tapered roller bearing according to any one of (1) to (3), characterized in that

The invention of the present application is not limited to each embodiment, and can be implemented and variously modified within the scope of the invention.

This application is based on a Japanese patent application (Japanese Patent Application No. 2021-109392) filed on June 30, 2021, the contents of which are incorporated herein by reference.

1 Tapered roller bearing 2 Outer ring 2a Outer ring raceway surface 3 Inner ring 3a Inner ring raceway surface 3b Large flange (flange portion)
3c small diameter side end face 4 tapered roller 4a small diameter side end face 4b large diameter side end face 10 retainer 11 large diameter ring portion 11a inner surface 11b notch 12 small diameter ring portion 12a inner surface 13 column portion 14 concave groove 15A inner diameter side conical surface 15B outer diameter side Conical surface 16A Radial flat surface 16B Radial flat surface 17A Protruding portion 17B Protruding portion 20 Thinning 21 Protruding portion A' Mold parting line C Virtual conical surface Dw3 connecting the rotational axes of the tapered rollers Large-diameter end faces of the tapered rollers Maximum diameter Kw Notch retainer circumferential length Lw Roller length P Pockets P1, P2 Circumferential both ends P3 Circumferential center Rk Notch curvature radius Rs Tapered roller maximum diameter radius T Assembled width X Axis of rotation α Contact angle α ₂ Cage inclination angle

Claims (4)

an outer ring having an outer ring raceway surface on its inner peripheral surface;
an inner ring having an inner ring raceway surface on its outer peripheral surface;
a plurality of tapered rollers rollably arranged between the outer ring raceway surface and the inner ring raceway surface;
a retainer that retains the plurality of tapered rollers in a rollable manner;
A tapered roller bearing comprising
The retainer is
a large-diameter ring portion and a small-diameter ring portion arranged so as to be spaced apart from each other in the axial direction;
a plurality of pillars connecting the large-diameter ring portion and the small-diameter ring portion and arranged at predetermined intervals in the circumferential direction;
a plurality of pockets formed between the large-diameter ring portion, the small-diameter ring portion, and the column portions adjacent in the circumferential direction and holding the tapered rollers;
has
A tapered roller bearing, wherein a notch is formed at an inner diameter side corner of an inner surface of the large-diameter ring portion forming the pocket. 2. The tapered roller bearing according to claim 1, wherein in the pocket, the size of the notch in the circumferentially central portion of the pocket is larger than the size of the notch in the circumferentially outer portion of the pocket. . Rk>Rs, where Rk is the radius of curvature of the notch and Rs is the radius of the maximum diameter portion of the tapered roller.
The tapered roller bearing according to claim 1 or 2, characterized in that: Dw3>Kw>0, where Kw is the length of the notch in the circumferential direction of the retainer, and Dw3 is the maximum diameter of the large-diameter side end surface of the tapered roller.
The tapered roller bearing according to claim 1 or 2, characterized in that:

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