JP2018031408A - Radial rolling bearing and rotation support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To materialize a structure capable of preventing the concentration of stress on a part of a fixed ring, in a structure capable of certainly preventing the generation of creeping of the fixed ring to a fixed side member.SOLUTION: At an axial intermediate portion of an outer peripheral surface of an outer ring 3a, a recessed groove 8 recessed radially inward is provided over the entire circumference. A bottom surface 9 configuring the recessed groove 8 and a pair of side surfaces 10, 10 are continued by a pair of curved surface portions 11, 11 with partially arc-shaped cross sections. A continuing portion of the pair of the side surfaces 10, 10 and the outer peripheral surface of the outer ring 3a is made to be a pair of corner portions 12, 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radial rolling bearing incorporated in a rotational support portion of various mechanical devices such as a transmission for an automobile, and an improvement of a rotational support device incorporating the radial rolling bearing.

  Various structures, such as the structure described in Patent Document 1, are known as radial rolling bearings that are used by being incorporated in the rotation support portion of various rotating machine devices. FIG. 7 shows a ball bearing 1 described in Patent Document 1. The ball bearing 1 includes an outer ring 3 having an outer ring raceway 2 on an inner peripheral surface, an inner ring 5 having an inner ring raceway 4 on an outer peripheral surface, and a rolling element provided between the outer ring raceway 2 and the inner ring raceway 4. And a plurality of balls 6, 6. Each of these balls 6, 6 is held by a cage 7 so as to be able to roll while being arranged at equal intervals in the circumferential direction.

  The ball bearing 1 as described above is, for example, a rotation in which the outer ring 3 is fitted and fixed to a housing which is a stationary member that does not rotate even when used, and the inner ring 5 is provided on the inner diameter side of the housing. The rotary shaft is rotatably supported on the inner diameter side of the housing by being fitted and fixed to the rotary shaft which is a side member. Alternatively, the inner ring 5 is externally fixed to a fixed shaft that is a stationary member that does not rotate during use, and the outer ring 3 is arranged around the fixed shaft (on the outer diameter side) coaxially with the fixed shaft. The rotary cylinder is rotatably supported around the fixed shaft by being fitted and fixed to the rotary cylinder provided as a rotation side member. In any case, along with vibration during use of the ball bearing 1, a force to rotate (creep) is generated in the fixed ring fitted and fixed to the fixed side member.

JP 2014-122378 A

  In view of the circumstances as described above, the present invention has a structure that can reliably prevent creep of a fixed ring with respect to a fixed side member, and can prevent the stress from concentrating on a part of the fixed ring. And it aims at realizing the structure of the rotation support device incorporating this radial rolling bearing.

Among the radial rolling bearing and the rotation support device of the present invention, the radial rolling bearing according to claim 1 includes an outer ring, an inner ring, and a plurality of rolling elements.
Of these, the outer ring has an outer ring raceway on the inner peripheral surface.
The inner ring has an inner ring raceway on an outer peripheral surface.
Each of the rolling elements is provided between the outer ring raceway and the inner ring raceway so as to be freely rollable. As such rolling elements, balls, tapered rollers, cylindrical rollers (including needles), or the like can be used.

  In particular, in the radial rolling bearing of the present invention, radially concave grooves are provided in the circumferential direction in one or more axial directions on the outer peripheral surface of the outer ring or the inner peripheral surface of the inner ring that do not rotate during use. . And the bottom face and side face of this ditch | groove are continuing with the curved surface.

According to a second aspect of the present invention, the rotation support device includes a fixed side member, a rotation side member, and a radial rolling bearing.
Of these, the stationary member does not rotate during use.
The rotation side member is provided coaxially with the fixed side member and rotates during use.
The radial rolling bearing is provided between a circumferential surface of the stationary member and a circumferential surface of the rotating member that face each other.

  In particular, in the rotation support device of the present invention, the radial rolling bearing is the radial rolling bearing of the present invention as described above. And, among the outer ring and the inner ring of this radial rolling bearing, a fixed ring that does not rotate during use is fitted and fixed (for example, press-fitted) to the peripheral surface of the fixed side member, and a rotating ring that also rotates during use is also used. It fits and is fixed to the peripheral surface of the said rotation side member (it fits so that rotation synchronizing with this rotation side member is possible). Further, at least a portion of the fixed side member to which the fixed ring is fitted and fixed is formed of a material softer than a material constituting the fixed ring.

  The radial rolling bearing of the present invention as described above is provided with a radially concave groove on the outer peripheral surface of the outer ring or the inner peripheral surface of the inner ring in the circumferential direction. For this reason, when the outer ring or the inner ring is fitted and fixed to the peripheral surface of the stationary member, the side surface of the concave groove and the outer peripheral surface of the outer ring, or the inner peripheral surface of the inner ring (from the concave groove in the axial direction) The contact pressure between the continuous portion and the peripheral surface of the stationary member increases. As a result, the fitting strength of the outer ring or the inner ring with respect to the fixed side member can be increased, and the outer ring or the inner ring can be reliably prevented from creeping with respect to the fixed side member. In addition, since the concave groove is provided, the contact area between the outer peripheral surface of the outer ring or the inner peripheral surface of the inner ring and the peripheral surface of the stationary member is reduced, and between these peripheral surfaces. The acting friction can be increased and the creep can be prevented more effectively.

  In the present invention, the bottom surface and the side surface of the concave groove are continuous with a curved surface. For this reason, it is possible to prevent stress from concentrating on the continuous portion between the bottom surface and the side surface of the concave groove, and to prevent the outer ring or the inner ring from being damaged such as a crack.

Sectional drawing (A) which shows the 1st example of embodiment of this invention, and the X section enlarged view (B) of (A). The figure similar to FIG. 1 which shows the 2nd example. The figure similar to FIG. 1 which shows the 3rd example. The figure similar to FIG. 1 which shows the 4th example. Sectional drawing (A) which shows the 5th example, and the Y section enlarged view (B) of (A). Sectional drawing which shows the 6th-8 examples. The partially cut perspective view which shows an example of a prior art structure.

[First example of embodiment]
FIG. 1 shows a first example of an embodiment of the present invention. As in the ball bearing 1 shown in FIG. 7, the ball bearing 1a of the present example which is a radial rolling bearing has an outer ring 3a having an outer ring raceway 2 on an inner peripheral surface and an inner ring 5 having an inner ring raceway 4 on an outer peripheral surface. And a plurality of balls 6, 6 provided between the outer ring raceway 2 and the inner ring raceway 4, each of which is a rolling element. Each of these balls 6, 6 is held by a cage 7 so as to be able to roll while being arranged at equal intervals in the circumferential direction.

In the case of the ball bearing 1a of this example, a concave groove 8 that is recessed radially inward and having a substantially rectangular cross section is provided over the entire circumference in the axially intermediate portion of the outer peripheral surface of the outer ring 3a. . The bottom surface 9 and the pair of side surfaces 10 and 10 constituting the concave groove 8 are continuous by a pair of curved surface portions 11 and 11 having a partial arc shape (1/4 arc shape). On the other hand, the continuous portion between the pair of side surfaces 10 and 10 and the outer peripheral surface of the outer ring 3a (of which the portion is axially removed from the concave groove 8) is a pair of corner portions 12 that are perpendicular to each other in cross section. , 12. The bottom surface 9 is coaxial with the outer peripheral surface of the outer ring 3a (of which the recessed groove 8a is separated in the axial direction) and except for the continuous portions 11 and 11 provided at both axial ends. The cylindrical surface has a constant outer diameter in the axial direction (a constant groove depth). On the other hand, the pair of side surfaces 10 and 10 are circular rings orthogonal to the outer peripheral surface of the outer ring 3a. In the case of this example, the concave groove 8 is provided at a position that aligns with the outer ring raceway 2 provided on the inner peripheral surface of the outer ring 3a in the axial direction (overlaps in the radial direction). The axial width W ₈ is the same as the axial width w ₂ of the outer ring raceway 2 (W ₈ = w ₂ ). However, the axial width W ₈ of the concave groove 8 can be made larger or smaller than the axial width w ₂ of the outer ring raceway 2. Such a concave groove 8 can be formed at the same time when the outer ring 3a is made by forging or casting, or can be formed by cutting or the like after forging or casting.

  In such a ball bearing 1a, the outer ring 3a is fitted and fixed to a fitting inner peripheral surface of a housing (not shown) which is a stationary member that does not rotate during use, and the inner ring 5 is fixed to the housing. On the inner diameter side, it is fitted and fixed to a rotary shaft (not shown) that is a rotation side member provided coaxially with the fitting inner peripheral surface of the housing (externally fitted to enable rotation synchronized with this rotary shaft). Thus, the rotating shaft is rotatably supported on the inner diameter side of the housing. The housing is preferably made of a material such as a light alloy such as an aluminum alloy or a synthetic resin that is softer than a material such as bearing steel constituting the outer ring 3a. In the state where the outer ring 3a is fitted and fixed to the fitting inner peripheral surface of the housing, the fitting inner peripheral surface of the housing and the bottom surface 9 of the concave groove 8 are directly (without intervening other members). ) Opposite.

  In the ball bearing 1a of the present example as described above, the outer circumferential surface of the outer ring 3a is provided with a concave groove 8 that is recessed radially inward over the entire circumference. Therefore, when the outer ring 3a is fitted and fixed to the housing, a sharp point that is a continuous part of the pair of side surfaces 10 and 10 constituting the concave groove 8 and the outer peripheral surface of the outer ring 3a. The fitting inner peripheral surface contact pressure of the housing of the portions 12 and 12 can be increased. As a result, the fitting strength of the outer ring 3a with respect to the housing can be increased, and the outer ring 3a can be reliably prevented from creeping with respect to the housing. Furthermore, if the housing in which the outer ring 3a is fitted and fixed is made of a material softer than the material constituting the outer ring 3a, the corners 12 and 12 can bite into the fitting inner peripheral surface of the housing. And the creep can be more effectively prevented.

  Further, in the case of this example, the bottom surface 9 and the pair of side surfaces 10 and 10 constituting the concave groove 8 are continuous by a pair of curved surface portions 11 and 11 which are curved surfaces having a partial arc shape in cross section. For this reason, it is possible to prevent stress from concentrating on the continuous portion (the pair of curved surface portions 11 and 11) of the bottom surface 9 and the pair of side surfaces 10 and 10, and the outer ring 3a is damaged such as a crack. It can be prevented from occurring.

  The radial depth of the concave groove 8 is determined by design in consideration of the amount of biting of the pair of corner portions 12 and 12 with respect to the housing, the strength of the outer ring 3a, and the like. That is, if the depth of the concave groove 8 in the radial direction is too small, a sufficient amount of biting of the pair of corner portions 12 and 12 with respect to the housing cannot be secured, and the fitting strength of the outer ring 3a with respect to the housing is sufficient. There is a possibility that it will not be able to be large. On the other hand, when the radial depth of the concave groove 8 is too large, the radial thickness of the portion of the outer ring 3a where the concave groove 8 is provided becomes small, and it is difficult to ensure the strength of the outer ring 3a. there is a possibility.

  The radius of curvature of the pair of curved surface portions 11 and 11 is determined by design in consideration of the magnitude of stress applied to the pair of curved surface portions 11 and 11. That is, if the curvature radii of the pair of curved surface portions 11 and 11 are too small, the stress concentration on the pair of curved surface portions 11 and 11 cannot be sufficiently reduced. On the other hand, if the radius of curvature of the pair of curved surface portions 11 and 11 is too large, the cross-sectional shape of the pair of corner portions 12 and 12 becomes an obtuse angle, and the pair of corner portions 12 and 12 with respect to the housing. There is a possibility that the amount of biting cannot be secured sufficiently and the fitting strength of the outer ring 3a with respect to the housing cannot be sufficiently increased.

  In this example, the concave groove 8 is provided on the outer peripheral surface of the outer ring 3a over the entire circumference. However, when the present invention is implemented, the concave groove is related to the circumferential direction of the outer peripheral surface of the outer ring. It can also be provided in part or intermittently in the circumferential direction. In this example, balls 6 and 6 are used as rolling elements, but the present invention can also be implemented by a radial rolling bearing using tapered rollers or cylindrical rollers (needles) as rolling elements. Further, the radial rolling bearing of the present invention is not limited to the structure in which the rolling elements are arranged in a single row, but may have a structure in which the rolling elements are arranged in a double row (two rows or more).

[Second Example of Embodiment]
FIG. 2 shows a second example of the embodiment of the present invention. The ball bearing 1b of this example is provided with concave grooves 8a and 8a that are recessed radially inward at three positions in the axial direction on the outer peripheral surface of the outer ring 3b. The bottom surface 9a and the pair of side surfaces 10a and 10a constituting each concave groove 8a are continuous by curved surface portions 11a and 11a having a circular arc section. On the other hand, the continuous portion between each of the side surfaces 10a and 10a and the outer peripheral surface of the outer ring 3b (of which the portion is axially removed from the concave grooves 8a and 8a) 12a and 12a.

In the case of this example, the axial width of the portion of the outer peripheral surface of the outer ring 3b where the concave grooves 8a and 8a are provided (arranged on both axial sides of the concave grooves 8a and 8a). a pair of grooves 8a, the axially outer edge distance between) W _8a of 8a, is made larger than the axial width w ₂ of the outer ring raceway 2 provided on the inner peripheral surface of the outer ring 3b (W _8a > W ₂ ). However, the axial width W _8a of the portion provided with the concave grooves 8a, 8a may be equal to or less than the axial width w ₂ of the outer ring raceway 2.

According to this example, the number of biting portions (the number of the corner portions 12a and 12a) with respect to the housing can be increased, and the fitting strength of the outer ring 3b with respect to the housing can be further increased. In the case of the present example, the concave grooves 8a and 8a are provided at three positions in the axial direction of the outer peripheral surface of the outer ring 3b. However, when the present invention is implemented, such a concave groove is provided on the outer periphery of the outer ring. It can also be provided at two positions in the axial direction of the surface, or at four positions or more.
The configuration and operation of the other parts are the same as in the first example of the embodiment described above.

[Third example of embodiment]
FIG. 3 shows a third example of the embodiment of the present invention. The ball bearing 1c of this example is provided with a groove 8b that is recessed in the radial direction on the outer peripheral surface of the outer ring 3c over the entire circumference. And in the continuous part of the bottom face 9b and the pair of side faces 10b, 10b constituting the concave groove 8b, it is radially inward of the bottom face 9b and more axially than the pair of side faces 10b, 10b. A pair of relief recesses 13 and 13, which is a curved surface with a partially arcuate cross section (3/4 arc), are provided.

Also in this example, the outer ring 3c is strongly fitted to the housing (increase the tightening allowance) to reliably prevent the outer ring 3c from creeping against the housing. Can do. Further, the corners 12 and 12 which are continuous portions of the pair of side surfaces 10b and 10b and the outer peripheral surface of the outer ring 3c (among the concave groove 8b to a portion removed in the axial direction) are slightly It is possible to prevent the stress from concentrating on the continuous portion (the pair of relief recesses 13 and 13) of the bottom surface 9b and the pair of side surfaces 10b and 10b constituting the concave groove 8b.
The configuration and operation of the other parts are the same as in the first example of the embodiment described above.

[Fourth Example of Embodiment]
FIG. 4 shows a fourth example of the embodiment of the present invention. The ball bearing 1d of the present example is provided with concave grooves 8c, 8c that are recessed radially inward at three positions in the axial direction on the outer peripheral surface of the outer ring 3d. Then, in a continuous portion of the bottom surface 9c and the pair of side surfaces 10c, 10c constituting each concave groove 8c, it is more radially inward than the bottom surface 9c and more axial than the pair of side surfaces 10c, 10c. Relief recesses 13a and 13a, which are concave in the direction and have a curved surface with a partial arc shape (3/4 arc shape), are provided.
The configuration and operation of the other parts are the same as in the first to third examples of the above-described embodiment.

[Fifth Example of Embodiment]
FIG. 5 shows a fifth example of the embodiment of the present invention. In the first to fourth examples of the above-described embodiment, a configuration is adopted in which the outer ring is a fixed ring that does not rotate even when used, and the inner ring is a rotating wheel that rotates when used, but the ball bearing 1e of this example has an inner ring 5a. Is a fixed wheel and the outer ring 3 is a rotating wheel. A groove 8d that is recessed radially outward is provided in the axially intermediate portion of the inner peripheral surface of the inner ring 5a over the entire circumference. The bottom surface 9d and the pair of side surfaces 10d and 10d constituting the concave groove 8d are continuous by a pair of curved surface portions 11b and 11b which are curved surfaces having a partial arc shape. On the other hand, the continuous portion between the pair of side surfaces 10d and 10d and the inner peripheral surface of the inner ring 5a (of which the portion is axially removed from the concave groove 8d) is a corner having a right angle and a sharp point. A pair of 12b and 12b is used.

  In the ball bearing 1e as described above, the inner ring 5a is fixed to the fixed shaft (not shown), which is a fixed side member that does not rotate during use, and is fitted and fixed (press-fit) with an interference fit. The rotating cylinder is rotatably supported around the fixed shaft by being fitted and fixed to a rotating cylinder which is a rotation side member provided coaxially with the fixed shaft. The fixed shaft is made of a material such as a light alloy or a synthetic resin that is softer than a material such as bearing steel constituting the inner ring 5a. In the state in which the inner ring 5a is externally fitted and fixed to the fixed shaft, the outer peripheral surface of the fixed shaft and the bottom surface 9d of the concave groove 8d are directly opposed (without interposing other members).

  The ball bearing 1e of this example is provided with a groove 8d that is recessed radially outward on the inner peripheral surface of the inner ring 5a over the entire circumference, and a fixed shaft in which the inner ring 5a is fitted and fixed. Is made of a material softer than the material constituting the inner ring 5a. Therefore, when the inner ring 5a is externally fixed to the fixed shaft by an interference fit, the pair of side surfaces 10d and 10d constituting the recessed groove 8d and the inner peripheral surface of the inner ring 5a are continuous portions. The sharp corners 12b and 12b bite into the outer peripheral surface of the fixed shaft. As a result, the fitting strength of the inner ring 5a with respect to the fixed shaft can be increased, and the inner ring 5a can be reliably prevented from creeping with respect to the fixed shaft.

  Further, the bottom surface 9d and the pair of side surfaces 10d, 10d constituting the concave groove 8d are continuous by a pair of curved surface portions 11b, 11b having a circular arc section. For this reason, it is possible to prevent stress from being concentrated on the pair of both curved surface portions 11b, 11b, and to prevent the inner ring 5a from being damaged such as cracks.

It should be noted that the radial depth of the concave groove 8d is determined by the amount of biting of the pair of corner portions 12b, 12b with respect to the fixed shaft, the strength of the inner ring 5a, and the like, and the radius of curvature of the pair of curved surface portions 11b, 11b. Are designed in consideration of the magnitude of the stress applied to the pair of curved surface portions 11b and 11b, respectively.
The configuration and operation of the other parts are the same as in the first example of the embodiment described above.

[Sixth to eighth examples of embodiment]
FIG. 6 shows sixth to eighth examples of the embodiment of the present invention. The ball bearing 1f of the sixth example of the embodiment shown in FIG. 6 (A) has grooves 8e and 8e that are recessed radially outward at all three axial positions on the inner peripheral surface of the inner ring 5b. It is provided over. The bottom surface 9e and the pair of side surfaces 10e and 10e constituting each concave groove 8e are continuous by curved surface portions 11c and 11c which are curved surfaces having a partial arc shape. On the other hand, the continuous portion between each of the side surfaces 10e and 10e and the inner peripheral surface of the inner ring 5b (of which the portion is axially deviated from the concave grooves 8e and 8e) 12c and 12c.

  In the ball bearing 1g of the seventh example of the embodiment shown in FIG. 6B, a groove 8f that is recessed radially outward is provided on the inner circumferential surface of the inner ring 5c over the entire circumference. Then, a continuous portion of the bottom surface 9f and the pair of side surfaces 10f, 10f constituting the concave groove 8f is radially outward from the bottom surface 9f and more axial than the pair of side surfaces 10f, 10f. Relief recesses 13b and 13b, which are concave and have a curved surface with a partial arc shape (3/4 arc shape), are provided.

  The ball bearing 1h of the eighth example of the embodiment shown in FIG. 6 (C) has grooves 8g and 8g that are recessed radially outward at all three axial positions on the inner peripheral surface of the inner ring 5d. It is provided over. And in the continuous part of the bottom face 9g and the pair of side faces 10g, 10g constituting each concave groove 8g, it is more radially outward than the bottom face 9g and more axial than the pair of side faces 10g, 10g. Relief recesses 13c and 13c having a partial arc shape (3/4 arc shape) that are recessed in the direction are provided.

In the sixth to eighth examples of the embodiment as described above, the inner ring 5b to 5d is made to creep with respect to the fixed shaft by increasing the fitting strength of the inner rings 5b to 5d with respect to the fixed shaft. It is possible to prevent stress from concentrating on the continuous portion of the bottom surfaces 9e to 9g and the pair of side surfaces 10e to 10g constituting the concave grooves 8e to 8g.
The configuration and operation of the other parts are the same as those in the first to fifth examples of the embodiment described above.

DESCRIPTION OF SYMBOLS 1, 1a-1h Ball bearing 2 Outer ring track 3, 3a-3d Outer ring 4 Inner ring track 5, 5a-5d Inner ring 6 Ball 7 Cage 8, 8a-8g Groove 9, 9, 9a-9g Bottom 10, 10, 10a-10g Side 11 , 11a to 11c Curved surface portion 12, 12a to 12c Corner portion 13, 13a to 13c Relief recess

Claims (2)

An outer ring having an outer ring raceway on the inner peripheral surface;
An inner ring having an inner ring raceway on the outer peripheral surface;
A radial rolling bearing comprising a plurality of rolling elements provided between the outer ring raceway and the inner ring raceway so as to be freely rollable,
In the outer circumferential surface of the outer ring that does not rotate during use, or in one or more axial directions on the inner circumferential surface of the inner ring, radially recessed grooves are provided in the circumferential direction. Is a radial rolling bearing characterized in that is continuous by a curved surface. A stationary member that does not rotate during use;
A rotating side member that rotates when in use;
A rotation support device comprising a radial rolling bearing provided between a circumferential surface of the fixed side member and a circumferential surface of the rotation side member facing each other,
This radial rolling bearing is the radial rolling bearing according to claim 1,
Of the outer ring and the inner ring of the radial rolling bearing, a fixed ring that does not rotate during use is fitted and fixed to the peripheral surface of the fixed side member, and a rotating ring that is also rotated during use is connected to the periphery of the rotary side member. It is fitted and fixed to the surface,
A rotation support device, wherein at least a portion of the fixed side member to which the fixed ring is fitted and fixed is made of a material softer than a material constituting the fixed ring.

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