JP2020079646A - Automatic self-aligning roller bearing - Google Patents

Abstract

To provide an automatic self-aligning roller bearing excellent in low heat generation for effectively suppressing the skew of rollers while preventing the abnormal wear of a guide ring.SOLUTION: An automatic self-aligning roller bearing 1 includes an inner ring 2, an outer ring 3, a plurality of rollers 4 arranged between double-row raceway surfaces 2a, 3a in a freely rolling manner, and a guide ring 6 arranged between the rows of the rollers 4, 4 for guiding the rollers 4. The side face of the guide ring 6 and the axial end face of each of the rollers 4 are isolated from each other to form a guide clearance, and the size of the guide clearance is equal to or smaller than 1.0% of the maximum diameter size of the roller 4. When the roller 4 skews, an inclination surface 6c of the guide ring 6 and a boundary 4ac between the axial end face 4a and a chamfering part 4c of the roller 4 contact each other.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a spherical roller bearing.

  2. Description of the Related Art Conventionally, as shown in FIG. 4, a self-aligning roller bearing used in an industrial machine or the like has an inner ring 101 having double rows of raceway surfaces 101a and 101a on an outer peripheral surface and a raceway surface 101a of an inner ring 101 on an inner peripheral surface. An outer ring 102 having a spherical raceway surface 102a facing each other, and a plurality of rollers 103 rotatably arranged between the double-row raceway surfaces 101a and 102a of the inner race 101 and the outer race 102.

  In such a self-aligning roller bearing 100, in many cases, the guide wheel 105 that guides the axial end surface of the roller 103 of the rollers 103, 103 allows the double row rollers 103 to roll without skewing. It is located between columns. That is, the guide wheel 105 has a sliding surface 105a that slidably contacts the sliding surface 101b of the inner ring 101. Further, the guide wheel 105 has a side surface 105b slidably in contact with the axial end surfaces 103a and 103a of the rollers 103 and 103, respectively.

In such self-aligning roller bearings, in order to prevent wear of the guide wheels, roller skew is suppressed, sliding friction with the bearing rings is reduced, and low heat generation is achieved. In many cases, a configuration such as forming an oil film between and is adopted. Examples of this type of self-aligning roller bearing include those disclosed in Patent Documents 1 and 2.
For example, Patent Document 1 discloses a configuration in which the "boundary between the axial end surface of the roller and the sloping portion" is rounded to prevent local abrasion with the guide wheel.
Further, in Patent Document 2, for the purpose of reducing wear due to low heat generation of the guide wheel, the contact area with the guide wheel is made small to facilitate formation of an oil film, and the side surface of the guide wheel is provided with an end surface in the axial direction. There is disclosed a self-aligning roller bearing having a configuration of point contact with.

JP, 2007-100934, A Japanese Patent No. 3789698

However, in the technique described in Patent Document 1, since the "boundary between the axial end surface of the roller and the flattened portion" is rounded, the contact point with the guide wheel is not limited, and the accuracy of the guide gap is poor. Therefore, in manufacturing, if the guide gap is excessively large, the skew angle becomes large, and there is a possibility that heat generation cannot be reduced.
Further, in the technique described in Patent Document 2, "the inclined surface of the guide wheel" and "the boundary between the axial end surface of the roller and the sloping portion" are in point contact with each other. There is an angle (opening angle) between the "slope" and the "roller axial end face". Here, if the opening angle is made too large, it becomes difficult for the rollers to come into contact with the guide wheels when the rollers are skewed, and the skew angle becomes large, so it may not be possible to reduce heat generation.
The present invention has been made in view of the above problems, and provides a self-aligning roller bearing excellent in low heat generation that effectively suppresses roller skew while preventing abnormal wear of guide wheels. To aim.

An aspect of a self-aligning roller bearing for solving the above problems is an inner ring having a double row raceway surface on an outer peripheral surface, and an outer ring having a spherical raceway surface facing the raceway surface on an inner peripheral surface, A plurality of rollers rotatably arranged between the double-row raceway surface and a spherical raceway surface, and a guide wheel that is arranged between the rows of the rollers and guides the rollers,
The side surface of the guide wheel and the axial end surface of the roller are spaced apart to form a guide gap, and the size of the guide gap is 1.0% or less of the maximum diameter dimension of the roller,
A chamfered portion that is chamfered over the entire circumference on the axial end surface of the roller is provided with a sloping portion on the end surface side of the roller, and an inclined surface is provided on the inner side in the radial direction of the side surface of the guide wheel. A chamfer is provided inside the surface in the radial direction,
The side surface of the guide wheel has an inclined surface which is inclined toward the outer ring side at an opening angle θ so as to be separated from the axial end surface of the roller with respect to the direction of the force applied from the roller to the inner ring. Then
When the roller is skewed, the inclined surface and the boundary between the axial end surface of the roller and the splayed portion make point contact, and the opening angle θ is 0.5° to 4°,
The flattening diameter X (diameter dimension along the radial direction of the roller between the axial end surface of the roller and the flattened portion) satisfies the following equations (1) to (3).

In the following formulas (1) to (3), Ze is a radial dimension of “the center of the roller head (intersection point between the center axis of the roller and the axial end surface of the roller on the guide wheel side)”, and Dmo is the inner ring. Of the raceway diameter, Da is the maximum diameter dimension of the roller, L0 is the centering dimension of the roller (the axis of the roller from the "maximum diameter of the roller" to the "end surface in the axial direction of the roller" on the side in contact with the guide wheel). (Dimensions along the direction), Zm is the radial dimension of "the boundary between the inclined surface of the guide wheel and the chamfer", and δ is the "nominal contact angle" in the Japanese Industrial Standard JIS B 0104-1991 "Rolling bearing term". Contact angle, Dco is the outer diameter of the inner ring, dmi is the inner diameter of the guide ring, Rm is the chamfered dimension of the chamfer of the guide ring, and β is the surface orthogonal to the bearing center axis of the guide ring. Is an inclination angle of the inclined surface with respect to.
X<2 (Ze−Zm)/cos δ... Equation (1)
Ze=(Dmo+Da)/2×cosδ+L0sinδ... Equation (2)
Zm=Dco/2+(dmi-Dco)/2+Rm(1-sinβ)... Formula (3)

  According to the present invention, it is possible to provide a self-aligning roller bearing which is capable of effectively suppressing roller skew while suppressing abnormal wear of the guide wheel and which is excellent in low heat generation.

It is a sectional view showing composition in an embodiment of a self-aligning roller bearing of the present invention. It is a principal part enlarged view of FIG. It is a principal part enlarged view of FIG.2(b). It is sectional drawing which shows the conventional structure of a self-aligning roller bearing.

  Hereinafter, embodiments of a self-aligning roller bearing according to the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a sectional view showing the structure of a self-aligning roller bearing according to the first embodiment of the present invention. 2A is an enlarged view of a main part of FIG. 1, and FIG. 2B is an enlarged view of a main part of FIG. 2A. 2(a) and 2(b) are slightly exaggerated for understanding of the description.
As shown in FIG. 1, the self-aligning roller bearing 1 of the present embodiment has an inner ring 2 having a double row raceway surface 2a on the outer peripheral surface, and a spherical raceway facing the raceway surface 2a of the inner ring 2 on the inner peripheral surface. An outer ring 3 having a surface 3a and a plurality of rollers 4 rotatably arranged between the double-row raceway surfaces 2a and 3a are provided.

The rollers 4 of the self-aligning roller bearing 1 are held by a cage 5 so as to be rollable for each row of rollers. An annular guide wheel 6 is arranged between the central portion 2b in the axial direction on the outer peripheral surface of the inner ring 2 and the inner peripheral surface of the cage 5.
The inner peripheral surface (sliding surface) 6a of the guide wheel 6 is in sliding contact with the axial center portion 2b of the outer peripheral surface of the inner ring 2, and the outer peripheral surface 6f thereof is in sliding contact with a part of the inner peripheral surface of the cage 5. It is like this. Then, the lubricating oil is retained between the side surface 6b of the guide wheel 6 and the end of the guide wheel 6 in the axial direction to form a fluid film.

[Guiding gap]
The self-aligning roller bearing 1 of the present embodiment has the “slope 6c of the guide wheel 6” and the “roller 4” in the load zone of the self-aligning roller bearing (in the state where there is no gap between the inner ring 2, the outer ring 3 and the roller 4). Of the axial end surface 4a of the roller 4 along the axial direction of the roller 4 (hereinafter sometimes referred to as a guide gap) has a positive dimension s, and the upper limit of the dimension s is the maximum diameter dimension Da of the roller 4 ( (See FIG. 1) 1.0% or less. As shown in FIG. 3, the dimension s of the guide gap is orthogonal to the “straight line L (see FIGS. 1 and 2) indicating the direction of the force applied from the roller 4 to the inner ring 2” at the “boundary 4ac of the roller 4”. It is the distance between the roller 4 and the guide wheel 6 along the direction. Specifically, the size s of the guide gap refers to the size of the "boundary 4ac of the roller 4" and the "opposing portion 6e" of the boundary 4ac. Here, the "boundary 4ac" refers to the boundary between the "end face 4a of the roller 4 in the axial direction" and the "drained portion 4c" described later. The “straight line M” refers to a straight line that is orthogonal to the “straight line L (see FIGS. 1 and 2) indicating the direction of the force applied from the roller 4 to the inner ring 2 ”. The “opposing portion 6e” refers to the intersection of the straight line M passing through the boundary 4ac and the inclined surface 6c of the guide wheel 6.

As described above, the dimension s of the guide gap is set to be positive and the preload is not applied, so that abnormal wear of the guide wheel 6 is unlikely to occur, and when the roller 4 is skewed, the roller 4 is guided by the guide wheel. By contacting 6 and geometrically suppressing the skew of the roller 4, low heat generation can be realized.
Here, if the dimension s of the guide gap is excessively large, there is a concern that the skew angle of the roller 4 becomes large (sliding friction becomes large) and the amount of heat generation becomes large. Therefore, in this embodiment, by setting the upper limit value of the size of the guide gap as described above, the skew angle can be suppressed to be small even when the roller 4 is skewed.

[Sloppy part]
A chamfered portion 4b, which is chamfered on the axial end surface 4a of the roller 4 of the self-aligning roller bearing 1, is provided with a flattened portion 4c. The flattened portion 4c indicates a shape which is smaller than the change in the radial curvature of the chamfered portion 4b or is zero in the chamfered portion 4b with a dimension d. The dimension d is preferably such that the boundary 4ac of the roller 4 contacts the inclined surface 6c of the guide wheel 6. The dimension d is measured in the direction orthogonal to the central axis of the roller 4.
As described above, in the present embodiment, the roller 4 is subjected to the flattening process to provide the “boundary 4ac between the axial end surface 4a of the roller 4 and the flattened portion 4c”, and the contact point with the guide wheel 6 can be accurately defined. It is possible to prevent the dimension of the guide gap from becoming excessive. Therefore, even if the rollers 4 are skewed, the skew angle can be suppressed to a small value, and low heat generation can be realized.

[Processing method for sloppy part]
The processing method of the blunt portion 4c includes turning, grinding, hard turning, and the like, but is not particularly limited as long as it is a processing method that maintains accuracy without impairing the effects of the present invention.

[Large size]
Here, the radial position of the self-aligning roller bearing 1 at the “boundary 4ac” is the radial position of the self-aligning roller bearing 1 at the “boundary 6cd between the inclined surface 6c of the guide wheel 6 and the chamfered portion 6d”. Is set larger than. By doing so, it is possible to prevent abnormal wear of the guide wheel 6 due to contact between the boundary portions 4ac and 6cd even when the guide wheel 6 is biased to either side.

Regarding the positional relationship between the boundary portions 4ac and 6cd, specifically, the dimension between the boundaries 4ac and 4ac between the axial end surface 4a of the roller 4 and the sloping portion 4c along the radial direction of the roller 4 (hereinafter, slack) May be referred to as dimensions) satisfy the following formulas (1) to (3).
X<2 (Ze-Zm)/cos δ...Equation (1)
Ze=(Dmo+Da)/2×cos δ+L ₀ sin δ... Equation (2)
Zm=Dco/2+(dmi-Dco)/2+Rm(1-sinβ)... Formula (3)

  In the above formula (1), “X” indicates “rolling diameter”, and a force applied from the roller 4 to the inner ring 2 between the boundaries 4ac and 4ac between the axial end surface 4a of the roller 4 and the rolling portion 4c. The dimension along the straight line L indicating the direction of is shown. Further, “Ze” is the center of the roller 4 (the intersection of the central axis of the roller 4 and the axial end surface 4a of the roller 4 on the guide wheel 6 side) S0 ( (See FIG. 1), the dimension along the radial direction is shown (“Ze” in the above formula (2) is also the same). Further, "Zm" indicates the dimension of the "boundary 6cd between the inclined surface 6c of the guide wheel 6 and the chamfered portion 6d" along the radial direction from the rotation axis S0 of the self-aligning roller bearing (the above formula (3)). "Zm" is the same). Further, “β” indicates the inclination angle with respect to the surface S2 orthogonal to the bearing center axis of the guide wheel 6.

Further, in the above formula (2), “Dmo” indicates the dimension of the raceway diameter of the inner ring 2. Further, “Da” indicates the maximum diameter of the roller 4. Further, “δ” is defined by the contact angle “nominal contact angle” described in Japanese Industrial Standard JIS B 0104-1991 “Rolling bearing term”, and the surface S2 orthogonal to the bearing center axis and the roller 4 Means an angle δ formed by the straight line L indicating the direction of the force applied to the inner ring 2. Further, “L ₀ ”is the axial dimension of the roller 4 from the center-side dimension of the roller 4 (from “the maximum diameter Da of the roller 4” to “the axial end surface 4a of the roller 4” on the side in contact with the guide wheel 6”. ) Is shown.
Further, in the above formula (3), “Dco” indicates the outer diameter dimension of the inner ring 2. Further, “dmi” indicates the inner diameter dimension of the guide wheel 6. Further, “Rm” indicates the chamfered dimension of the chamfered portion 6d of the guide wheel 6.

(Other embodiments)
As another embodiment of the self-aligning roller bearing, an angle (opening angle) is provided between the "end face 4a of the roller 4 in the axial direction" and the "sloping face 6c of the guide wheel 6" and the angle is defined. Is preferred.
[Open angle]
On the side surface 6b of the guide wheel 6 of the self-aligning roller bearing 1, an opening angle θ is set so as to be separated from the axial end surface 4a of the roller 4 with respect to the straight line L indicating the direction of the force applied from the roller 4 to the inner ring 2. The inclined surface 6c is formed so as to be opened and inclined toward the outer ring side. The opening angle θ is defined as an angle formed by the surface S1 including the inclined surface 6c of the guide wheel 6 and the straight line L indicating the direction of the force applied from the roller 4 to the inner ring 2 with respect to the contact angle δ. ..

  The opening angle θ is preferably 0.5° to 4.0°. If the opening angle θ is smaller than 0.5°, the axial end surface 4a of the roller 4 and the "boundary 6cg between the parallel portion 6g of the guide wheel 6 and the inclined surface 6c" are likely to hit when the roller 4 is skewed. As a result, the boundary 6cg is easily damaged. Further, depending on the manufacturing accuracy, the "end surface 4a of the roller 4 in the axial direction" and the "sloping surface 6c of the guide wheel 6" may come into surface contact with each other, and the guide wheel 6 may be easily worn due to insufficient lubrication. Further, if the opening angle θ exceeds 4.0°, it is difficult to contact the guide wheel 6 when the roller 4 is skewed, and the skew angle of the roller 4 tends to increase (sliding friction increases), which is not preferable. The opening angle θ is more preferably 1.5°.

  In this way, by providing an angle (opening angle) between the "axial end surface 4a of the roller 4" and the "inclined surface 6c of the guide wheel 6", the "inclined surface 6c of the guide wheel 6" and the "roller roller 6" It is possible to make a point contact between the axial end surface 4a of 4 and the boundary 4ac" between the flattened portion 4c. Therefore, even if the roller 4 is skewed, the skew angle can be suppressed to a small value, and the guide gap can be accurately managed.

  As described above, in the self-aligning roller bearing 1 of the present embodiment, the axial gap (guide gap) of the roller 4 between the “inclined surface 6c of the guide wheel 6” and the “axial end surface 4a of the roller 4” is provided. ) Is a positive value, and the upper limit of the gap size is 1.0% or less of the maximum diameter of the roller 4. Therefore, when the roller 4 is skewed while preventing abnormal wear of the guide wheel 6, geometrical skew is prevented by contacting the side surface 6b of the guide wheel 6, and the skew angle of the roller 4 is suppressed to be small. As a result, it is possible to provide a self-aligning roller bearing excellent in low heat generation.

Further, in the self-aligning roller bearing 1 of the present embodiment, the "end face 4a of the roller 4 in the axial direction" is subjected to a shaving process to provide a "boundary 4ac between the end face 4a of the roller 4 in the axial direction and the flattened portion 4c". As a result, the contact point with the “inclined surface 6c of the guide wheel 6” can be limited, and the guide gap can be accurately managed.
Although the self-aligning roller bearing according to the present invention has been described above, the self-aligning roller bearing according to the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. Is possible.

1 Spherical roller bearing 2 Inner ring 3 Outer ring 4 Roller 4a (Axial direction) end face 4b Chamfering part 4c Rolling part 4ac (End face and rolling part) boundary 5 Cage 6 Guide wheel 6a Sliding surface 6b Side surface 6c Inclined surface 6d chamfered part 6cd boundary (between inclined surface and chamfered part) 6g parallel part 6cg boundary

Claims (2)

Between the inner ring having a double-row raceway surface on the outer peripheral surface, the outer ring having a spherical raceway surface on the inner circumferential surface facing the raceway surface, and between the double-row raceway surface and the spherical raceway surface A plurality of rollers rotatably arranged, and a guide wheel arranged between the rows of the rollers and guiding the rollers,
The side surface of the guide wheel and the axial end surface of the roller are spaced apart to form a guide gap, and the size of the guide gap is 1.0% or less of the maximum diameter dimension of the roller, A chamfered portion that is chamfered over the entire circumference at the end face in the direction is provided with a sloping portion on the end face side of the roller, and an inclined surface is provided inside the side surface of the guide wheel in the radial direction, and the diameter of the inclined surface is A chamfer is provided on the inner side in the direction, and the radial position of the boundary between the end face and the flattened part in the axial direction of the roller is larger than the radial position of the boundary between the inclined surface of the guide wheel and the chamfer. Outside the direction, the side surface of the guide wheel is inclined toward the outer ring side so as to be separated from the end surface in the axial direction of the roller with respect to the direction of the force applied from the roller to the inner ring. A self-aligning roller bearing having the inclined surface, wherein when the roller is skewed, the inclined surface and a boundary between the end surface in the axial direction of the roller and the sloping portion are in contact with each other. The inclination in which the side surface of the guide wheel is opened and inclined toward the outer ring side at an opening angle θ so as to be separated from the end surface in the axial direction of the roller with respect to the direction of the force applied from the roller to the inner ring. Has a face,
When the rollers are skewed, the inclined surface and the boundary between the end surface of the roller in the axial direction and the splayed portion are in point contact with each other,
The spherical roller bearing according to claim 1, wherein the opening angle θ is 0.5° to 4°.

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