JP6829522B2 - Self-aligning roller bearing - Google Patents

Description

The present invention relates to self-aligning roller bearings.

Conventionally, as shown in FIG. 4, self-aligning roller bearings used in industrial machinery and the like have an inner ring 101 having a double row of raceway surfaces 101a and 101a on the outer peripheral surface and a raceway surface 101a of the inner ring 101 on the inner peripheral surface. It includes an outer ring 102 having a spherical raceway surface 102a facing the inner ring 101, and a plurality of rollers 103 rotatably arranged between the raceway surfaces 101a and 102a in a double row of the inner ring 101 and the outer ring 102.

In such a self-aligning roller bearing 100, in many cases, the guide wheels 105 that guide the axial end faces of the rollers 103 are the rollers 103, 103 so that the double-row rollers 103 can roll without skewing. Arranged between columns. That is, the guide ring 105 has a sliding surface 105a that is slidably in contact with the sliding surface 101b of the inner ring 101. Further, the guide wheel 105 has a side surface 105b that is slidably contacted with the end faces 103a and 103a in the axial direction of the rollers 103 and 103, respectively.

In such self-aligning roller bearings, in order to prevent wear of the guide wheels, skew of the rollers is suppressed, sliding friction with the raceway wheels is reduced, and heat generation is reduced. In many cases, a configuration such as forming an oil film between the and is adopted. Examples of this type of self-aligning roller bearing are those disclosed in Patent Documents 1 and 2.
For example, Patent Document 1 discloses a configuration in which "the boundary between the end face in the axial direction of the roller and the sloping portion" is rounded to prevent local wear between the guide wheel and the portion.
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 reduced to facilitate the formation of an oil film, and the end face in the axial direction of the side surface of the guide wheel is described. A self-aligning roller bearing having a configuration in which is in point contact is disclosed.

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

However, since the technique described in Patent Document 1 rounds the "boundary between the end face in the axial direction of the roller and the sloping portion", the contact point with the guide wheel is not limited, and the accuracy of the guide gap is poor. Therefore, if the guide gap is excessive in manufacturing, the skew angle becomes large, and there is a risk that the 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 brought into point contact with each other. An angle (opening angle) is given to the "inclined surface" and the "end surface in the axial direction of the roller". Here, if this opening angle is made too large, it becomes difficult to come into contact with the guide wheel when the rollers are skewed, and the skew angle becomes large, so that there is a risk that heat generation cannot be reduced.
The present invention has been made by paying attention to the above problems, and to provide a self-aligning roller bearing having excellent low heat generation that effectively suppresses roller skew while preventing abnormal wear of the guide wheel. The purpose.

Some aspects of self-aligning roller bearings for solving the above problems include an inner ring having a double row of raceway surfaces on the outer peripheral surface, and an outer ring having a spherical raceway surface facing the raceway surface on the inner peripheral surface. It has a plurality of rollers rotatably arranged between the double row of raceway surfaces and a spherical raceway surface, and a guide ring arranged between the rows of the rollers to guide the rollers.
The side surface of the guide wheel and the axial end surface of the roller are separated to form a guide gap, and the dimension of the guide gap is 1.0% or less of the maximum diameter of the roller.
A chamfered portion is provided on the end surface side of the roller, which is chamfered over the entire circumference of the axial end surface of the roller, and an inclined surface is provided inside the side surface of the guide wheel in the radial direction. A chamfer is provided on the inside in the radial direction of the surface.
The side surface of the guide ring has an inclined surface that 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. And
When the roller is skewed, the inclined surface, the axial end surface of the roller, and the boundary between the sloping portion are in point contact, and the opening angle θ is 0.5 ° to 4 °.
Scruffy diameter X (along the radial direction of the roller, the diameter between the boundary between the scruffy portion and the axial end face of the roller) satisfies the following formulas (1) to (3).

In the following formulas (1) to (3), Ze is the radial dimension of the "center of the roller head (the intersection of the center axis of the roller and the axial end face of the roller on the guide wheel side)", and Dmo is the inner ring. Orbital diameter dimension of, Da is the roller maximum diameter dimension, L0 is the roller center dimension (roller shaft from the "roller maximum diameter" to the "roller axial end face" on the side in contact with the guide wheel. Dimension along the direction), Zm is the radial dimension of the "boundary between the inclined surface of the guide wheel and the chamfered part", and δ is the "nominal contact angle" in the Japanese Industrial Standard JIS B 0104-991 "Rolling bearing terminology". The contact angle defined by, Dco is the outer diameter dimension of the inner ring, dmi is the inner diameter dimension of the guide wheel, Rm is the chamfered dimension of the chamfered portion of the guide wheel, and β is the plane orthogonal to the bearing central axis of the guide wheel. It is an inclination angle of the inclined surface with respect to.
X <2 (Ze-Zm) / cosδ ... Equation (1)
Ze = (Dmo + Da / 2) × cosδ + L0sinδ ・ ・ ・ ・ ・ ・ ・ ・ Equation (2)
Zm = Dco / 2 + (dmi-Dco) / 2 + Rm (1-sinβ) ... Equation (3)

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

It is sectional drawing which shows the structure in embodiment of the self-aligning roller bearing of this invention. It is an enlarged view of the main part of FIG. It is an enlarged view of the main part of FIG. 2B. It is sectional drawing which shows the conventional structure of the self-aligning roller bearing.

Hereinafter, embodiments of the self-aligning roller bearing according to the present invention will be described with reference to the drawings.
(First Embodiment)
FIG. 1 is a cross-sectional view showing a configuration of a self-aligning roller bearing according to the present invention in the first embodiment. 2 (a) is an enlarged view of a main part of FIG. 1, and FIG. 2 (b) is an enlarged view of a main part of FIG. 2 (a). Note that FIGS. 2 (a) and 2 (b) are slightly exaggerated for the sake of understanding the explanation.
As shown in FIG. 1, the self-aligning roller bearing 1 of the present embodiment has an inner ring 2 having a double row of raceway surfaces 2a on the outer peripheral surface and a spherical raceway on the inner peripheral surface facing the raceway surface 2a of the inner ring 2. It includes an outer ring 3 having a surface 3a, and a plurality of rollers 4 rotatably arranged between the raceway surfaces 2a and 3a in a double row.

The rollers 4 of the self-aligning roller bearing 1 are rotatably held for each roller row by the cage 5. Further, an annular guide ring 6 is arranged between the axial central portion 2b 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 ring 6 is in sliding contact with the axially central portion 2b on the outer peripheral surface of the inner ring 2, and the outer peripheral surface 6f is in sliding contact with a part of the inner peripheral surface of the cage 5. It has become like. Then, the lubricating oil is held between the side surface 6b of the guide wheel 6 and the axial end of 4, and a fluid film is formed.

[Guide gap]
The self-aligning roller bearing 1 of the present embodiment has "inclined surface 6c of the guide wheel 6" and "roller 4" in the load area of the self-aligning roller bearing (in a state where there is no gap between the inner ring 2, the outer ring 3, and the roller 4). The dimension s of the gap along the axial direction of the roller 4 (hereinafter, may be referred to as a guide gap) with the end face 4a in the axial direction of the roller 4 is positive, and the upper limit of the dimension s is the maximum diameter dimension Da of the roller 4. It is set to 1.0% or less of (see FIG. 1). 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 dimension s of the guide gap refers to the dimension 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 "axial end face 4a of the roller 4" and the "sloppy portion 4c" described later. Further, the "straight line M" refers to a straight line orthogonal to the "straight line L indicating the direction of the force applied from the roller 4 to the inner ring 2 (see FIGS. 1 and 2)". Further, 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.

In this way, by setting the dimension s of the guide gap to be positive and configuring it so that preload is not applied, abnormal wear of the guide wheel 6 is unlikely to occur, and when the roller 4 is skewed, the roller 4 is the guide wheel. In contact with 6, the skew of the roller 4 can be geometrically suppressed, and low heat generation can be realized.
Here, if the dimension s of the guide gap is excessive, there is a concern that the skew angle of the roller 4 will be large (sliding friction will be large) and the amount of heat generated will be large. Therefore, in the present embodiment, by setting the upper limit value of the dimension 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]
Further, the chamfered portion 4b chamfered on the axial end surface 4a of the roller 4 of the self-aligning roller bearing 1 is provided with a sloppy portion 4c. The sloppy portion 4c refers to a shape cut by the chamfered portion 4b by dimension d in a state where the change in curvature in the radial direction of the chamfered portion 4b is less than or zero. The dimension d is preferably set so that the boundary 4ac of the rollers 4 hits the inclined surface 6c of the guide wheel 6. The dimension d is measured in a direction orthogonal to the central axis of the roller 4.
As described above, in the present embodiment, the roller 4 is subjected to a slacking process to provide a "boundary 4ac between the axial end surface 4a of the roller 4 and the sloping portion 4c", and the contact point with the guide wheel 6 can be accurately limited. , It is possible to prevent the size of the guide gap from becoming excessive. Therefore, even when the roller 4 is skewed, the skew angle can be suppressed to be small, and low heat generation can be realized.

[Processing method for sloppy parts]
The processing method of the slack portion 4c includes turning processing, grinding processing, 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.

[Sloppy dimensions]
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, even when the guide wheel 6 is biased to any one side, abnormal wear of the guide wheel 6 due to contact between the boundary portions 4ac and 6cd can be prevented.

Regarding the positional relationship between the boundary portions 4ac and 6cd, specifically, the dimensions between the boundary portions 4ac and 4ac between the axial end surface 4a of the roller 4 and the slack portion 4c along the radial direction of the roller 4 (hereinafter, sloppy). (Sometimes referred to as dimensions) satisfies the following equations (1) to (3).
X <2 (Ze-Zm) / cosδ ... Equation (1)
Ze = (Dmo + Da / 2) × cosδ + Losinδ ・ ・ ・ ・ ・ ・ ・ ・ Equation (2)
Zm = Dco / 2 + (dmi-Dco) / 2 + Rm (1-sinβ) ... Equation (3)

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

Further, in the above formula (2), "Dmo" indicates the dimension of the track diameter of the inner ring 2. Further, "Da" indicates the dimension of the maximum diameter of the roller 4. Further, "δ" is defined by the contact angle "nominal contact angle" described in Japanese Industrial Standards JIS B 0104-991 "Rolling bearing terminology", and the plane S2 orthogonal to the bearing central axis and the roller 4 It means an angle δ formed by a straight line L indicating the direction of the force applied to the inner ring 2. Further, "L ₀ " is the axial direction of the roller 4 from the center-oriented 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. Dimension along with) 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 axial end surface 4a of the roller 4" and "the inclined surface 6c of the guide wheel 6", and this angle is specified. Is preferable.
[Opening angle]
The side surface 6b of the guide ring 6 of the self-aligning roller bearing 1 has an opening angle θ 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. An inclined surface 6c that is opened and inclined toward the outer ring side is formed. This opening angle θ is defined as an angle formed by a surface S1 including the inclined surface 6c of the guide ring 6 and a 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 °. When 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. The boundary 6 cg is easily damaged. Further, depending on the manufacturing accuracy, the "axial end surface 4a of the roller 4" and the "inclined surface 6c of the guide wheel 6" may come into surface contact, 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 for the roller 4 to come into contact with the guide wheel 6 when the roller 4 is skewed, and the skew angle of the roller 4 tends to be large (sliding friction becomes large), 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" are provided. The axial end surface 4a of 4 and the boundary 4ac between the sloping portion 4c can be brought into point contact with each other. Therefore, even when the roller 4 is skewed, the skew angle can be suppressed to be small, and the guide gap can be managed with high accuracy.

As described above, in the self-aligning roller bearing 1 of the present embodiment, there is an axial gap (guide gap) between the "inclined surface 6c of the guide wheel 6" and the "axial end surface 4a of the roller 4" of the roller 4. ) 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, while preventing abnormal wear of the guide wheel 6, when the roller 4 skews, it contacts the side surface 6b of the guide wheel 6 to geometrically prevent the skew, 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 having excellent low heat generation.

Further, in the self-aligning roller bearing 1 of the present embodiment, the "axial end surface 4a of the roller 4" is subjected to a slanting process to provide a "boundary 4ac between the axial end surface 4a of the roller 4 and the sluggish 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 managed with high accuracy.
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 are made as long as the gist of the present invention is not deviated. Is possible.

1 Self-aligning roller bearing 2 Inner ring 3 Outer ring 4 Roller 4a (Axial) end face 4b Chamfering part 4c Sloppy part 4ac (End face and sloppy 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 (1)

An inner ring having a double row of raceway surfaces on the outer peripheral surface, an outer ring having a spherical raceway surface facing the raceway surface on the inner peripheral surface, and between the double row raceway surface and the spherical raceway surface. It has a plurality of rollers that are rotatably arranged 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 separated to form a guide gap, and the dimension of the guide gap is 1.0% or less of the maximum diameter of the roller.
A chamfered portion is provided on the end surface side of the roller, which is chamfered over the entire circumference of the axial end surface of the roller, and an inclined surface is provided inside the side surface of the guide wheel in the radial direction. A chamfer is provided on the inside in the radial direction of the surface.
The inclined surface in which the side surface of the guide ring 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. Have and
When the roller is skewed, the inclined surface, the axial end surface of the roller, and the boundary between the sloping portion are in point contact, and the opening angle θ is 0.5 ° to 4 °.
A self-aligning roller bearing in which the slack diameter X (diameter dimension between the end face in the axial direction of the roller and the boundary between the slack portion along the radial direction of the roller) satisfies the following equations (1) to (3).
Here, in the following equations (1) to (3), Ze is the radial dimension of the "center of the roller head (the intersection of the center axis of the roller and the axial end face of the roller on the guide wheel side)", Dmo. Is the track diameter dimension of the inner ring, Da is the maximum roller diameter dimension, L0 is the roller center-side dimension, Zm is the radial dimension of the "boundary between the inclined surface of the guide wheel and the chamfered part", and δ is Japan. The contact angle defined by the "nominal contact angle" in the industrial standard JIS B 0104-991 "Rolling bearing terminology", Dco is the outer diameter of the inner ring, dmi is the inner diameter of the guide wheel, and Rm is the chamfer of the guide wheel. The radius of curvature of the chamfer of the arc of the portion, β, is the inclination angle of the inclined surface with respect to the surface orthogonal to the bearing central axis of the guide wheel.
X <2 (Ze-Zm) / cosδ ... Equation (1)
Ze = (Dmo + Da / 2) × cosδ + L0sinδ ・ ・ ・ ・ ・ ・ ・ ・ Equation (2)
Zm = Dco / 2 + (dmi-Dco) / 2 + Rm (1-sinβ) ... Equation (3)

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