JP2004169806A - Double row tapered roller bearing, and method for assembling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double row tapered roller bearing capable of preventing troubles such as burning caused by heat generation by sufficiently distributing lubricant between a tapered roller and flange portions even at a high-speed rotation. <P>SOLUTION: Tapered outer ring raceway surfaces 3x, 4x, 5x and 6x facing tapered inner ring raceway surfaces 1x, 1y and 2x and 2y are formed on inner circumference of single row outer rings 3, 4, 5 and 6, large diameter side flange portions 3a and 4a, and 5a and 6a in slidable contact with a large diameter side end face 7t of a tapered roller are formed on the center side in the axial direction of inner circumferential surfaces of the pair of outer rings 3 and 4 and on the center side in the axial direction of inner circumferential surfaces of the outer rings 5 and 6. In this configuration, lubricant of sufficient amount is circulated between end faces of the flange portions 3a, 4a, 5a and 6a and the large diameter side end face 7t of a tapered roller 7, and heat generation at the flange portions 3a, 4a, 5a and 6a can be suppressed even at a high-speed rotation. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a double-row tapered roller bearing, and more particularly to a double-row tapered roller bearing suitable for a roll neck bearing for a rolling mill rotating at high speed.
[0002]
[Prior art]
Double row tapered roller bearings are used as bearings for supporting work rolls and the like of a rolling mill, and have a structure that receives loads in both radial loads and thrust (axial) loads. 2. Description of the Related Art In recent years, many sealed four-row tapered roller bearings having oil seals mounted on both sides of a bearing have been used for maintenance-free use (for example, see Patent Document 1).
[0003]
FIG. 3 is an axial cross-sectional view showing the structure of a conventional four-row tapered roller bearing disposed on a work roll neck of a rolling mill.
[0004]
This roll neck bearing is coaxially disposed on an inner ring assembly including two double row inner rings 11 and 12 and an inner ring spacer 21 interposed between the double row inner rings 11 and 12, one double row outer ring 13 and both ends thereof. Outer ring assembly comprising two single-row outer races 14 and 15 and two outer-ring spacers 22 and 22 interposed between the double-row outer races 13 and the single-row outer races 14 and 15, respectively. A plurality of tapered rollers 16 rotatably arranged on each of the four rows of conical tracks formed between the outer ring assemblies, and the respective tapered rollers 16 are circumferentially spaced at predetermined intervals in the respective conical tracks. In this structure, oil seals 23, 23 and seal covers 24, 24 are attached to both ends of the bearing, respectively, with four retainers 17a, 17b, 17c, 17d as main components.
[0005]
A pair of conical inner raceway surfaces 11x, 11y and 12x, 12y having a large diameter at the axial center of the inner races are formed on the outer periphery of the two double-row inner races 11 and 12, respectively. Between 11x and 11y and between 12x and 12y, flange-shaped large-diameter flanges 11a and 12a for receiving a thrust load from the large-diameter end face of each tapered roller 16 are formed.
[0006]
Conical outer raceway surfaces 14x and 15x facing the inner raceway surfaces 11x and 12y are formed on the inner periphery of the single-row outer races 14 and 15, respectively. A pair of conical outer raceway surfaces 13x and 13y facing the inner raceway surfaces 11y and 12x, respectively, are formed. A lubricant (not shown) such as grease is sealed in the conical orbit formed by the inner and outer rings. Further, O-rings 25, 25 are disposed on the outer periphery of the seal covers 24, 24 arranged on the outer side in the axial direction of the single-row outer rings 14, 15, and the inner diameter surfaces of the double-row inner rings 11, 12 are provided. Is formed with a spiral groove 26.
[0007]
On the other hand, assembling such double-row tapered roller bearings usually involves mounting the cages (17a, 17b) on the conical inner ring raceway surfaces (11x, 11y) of the inner ring (11) having the large-diameter flange (11a). After the plurality of tapered rollers (16) fitted in the respective pockets are assembled, the outer rings (14, 13) are assembled from both axial sides of the inner ring (11).
[0008]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2001-105011
[Problems to be solved by the invention]
By the way, in the conventional double-row tapered roller bearing as described above, there is a problem that the flange for receiving the thrust load from the tapered roller becomes hot at the time of high-speed rotation.
[0010]
The problem is that as shown in the enlarged view of FIG. 4, when the inner ring 11 rotates at a high speed, the lubricant (not shown) enclosed therein is biased toward the outer rings (13, 14) due to centrifugal force. It is considered that the reason is that sufficient lubricant does not circulate between the end surface 11t of the flange portion 11a that comes into sliding contact and the large-diameter side end surface 16t of the tapered roller 16.
[0011]
Further, if the heat generation from the flange portion 11a continues, the double row tapered roller bearing may be burned at worst.
[0012]
The present invention has been made in order to address the above-described problem, and even during high-speed rotation, by sufficiently spreading the lubricant between the tapered rollers and the flange, troubles such as burning due to heat generation can be prevented. It is an object of the present invention to provide a double-row tapered roller bearing that can prevent occurrence of the occurrence.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 includes an inner ring provided with a pair of conical inner ring raceway surfaces having a large diameter in an axial center portion, and a pair of inner ring raceway surfaces facing the inner ring raceway surfaces. An outer ring assembly having a conical outer ring raceway surface, a plurality of tapered rollers arranged between the raceway surfaces of the inner and outer rings with the large-diameter end face facing the center in the axial direction, and these tapered rollers being arranged in the circumferential direction. In a double row tapered roller bearing provided with a pair of retainers that hold at predetermined intervals, a large-diameter side flange portion slidingly contacting a large-diameter side end surface of each of the tapered rollers is provided on an inner peripheral surface of the outer ring assembly. It is characterized by being provided.
[0014]
According to a second aspect of the present invention, there is provided a method of assembling the double-row tapered roller bearing according to the first aspect, wherein the conical outer ring of each outer ring forming the outer ring assembly having the large-diameter flange portion. After the tapered rollers are fitted into the raceway surface and integrated by the retainer, these outer rings are assembled from both axial sides of the inner ring.
[0015]
The present invention seeks to achieve the intended object by forming a flange portion on the outer ring side for receiving a thrust load from a tapered roller in a double-row tapered roller bearing rotating at a high speed such as a roll neck bearing for a rolling mill. Is what you do.
[0016]
That is, according to the double-row tapered roller bearing of the present invention, the large-diameter side flange portion that slides on the large-diameter side end face of each tapered roller is provided on the inner peripheral surface of the outer ring assembly, so that it is sealed inside. Even if the lubricant is biased to the outer ring side due to the rotation of the bearing, a sufficient amount of lubricant circulates in this flange, and the gap between the end face of the flange that comes into sliding contact and the large diameter end face of the tapered roller. Will be kept in a low friction state. Therefore, the double-row tapered roller bearing of the present invention can suppress heat generation at the flange even at the time of high-speed rotation, and can prevent troubles such as burnout from occurring.
[0017]
Further, the method of assembling the double-row tapered roller bearing of the present invention is such that the tapered rollers are fitted on a conical outer ring raceway surface of an outer ring having the large-diameter side flange portion, and these tapered rollers and the outer ring are held using a retainer. After that, the outer rings are assembled from both sides of the inner ring in the axial direction. By this assembling method, the double-row tapered roller bearing of the present invention can be easily assembled similarly to the conventional double-row tapered roller bearing having a flange portion on the inner ring side.
[0018]
The type of the cage used in the double-row tapered roller bearing of the present invention is not particularly limited, and a machined cage or a pin-type cage can be adopted depending on the roller diameter used. . In the case of the machined cage, a cut-out type with blades or the like is suitably employed in order to prevent the rollers from falling off during the operation.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an axial sectional view showing a structure of a double-row tapered roller bearing according to this embodiment, and FIG. 2 is an explanatory view showing an assembling method thereof.
[0020]
The double-row tapered roller bearing in the present embodiment is also a bearing used for a work roll neck of a rolling mill, as in the conventional example, and includes two double-row tapered roller bearings arranged coaxially. This roll neck bearing includes an inner ring assembly composed of two double-row inner races 1 and 2 and an inner race spacer 9 interposed between the double-row inner races 1 and 2 and two pairs of mating outer races 3, 4, and 5, 6. The outer ring assembly, the plurality of tapered rollers 7 formed in combination, and the four retainers 8a, 8b, 8c, 8d that hold the respective tapered rollers 7 in the respective tracks in the circumferential direction at regular intervals are mainly used. The oil seals (labyrinth seals) 10, 10 are attached to both ends of the bearing, respectively. As in the conventional example, O-rings 25 and 25 are provided on the outer peripheral surfaces of the oil seals 10 and 10, and a spiral groove 26 is formed on the inner diameter surface of each of the double row inner rings 1 and 2. I have.
[0021]
A feature of the double row tapered roller bearing in the present embodiment is that a flange-shaped large-diameter flange portion (3a, 4a, 5a, 6a) that receives a thrust load from a large-diameter end surface of each tapered roller 7 is a conventional example. Is provided on the outer ring side opposite to the above.
[0022]
On the outer periphery of the two double-row inner races 1 and 2, only a pair of conical inner raceway surfaces 1x, 1y and 2x, 2y each having a large diameter at the axial center of these inner races are formed. Further, conical outer ring raceway surfaces 3x, 4x, 5x, 6x facing the inner raceway surfaces 1x, 1y and 2x, 2y are formed on the inner periphery of each single row outer race 3, 4, 5, 6, respectively. Large-diameter flanges 3a, 4a and 5a, 6a are provided on the axially central side of the inner peripheral surfaces of the pair of outer rings 3, 4 and on the axially central side of the inner peripheral surfaces of the outer rings 5, 6, respectively. Is formed. Further, a plurality of tapered rollers 7 are respectively arranged in the four rows of conical tracks formed between these inner / outer ring assemblies so as to roll freely, and are circumferentially moved by retainers 8a, 8b, 8c, 8d. It is held at predetermined intervals in the direction, and a lubricant (not shown) such as grease is enclosed.
[0023]
On the other hand, as shown in FIG. 2, the method of assembling the double-row tapered roller bearing is such that the tapered rollers 7 are fitted into the tapered outer ring raceway surfaces of the single-row outer rings (3, 4), and the tapered rollers 7 and the respective After integrating the single row outer ring with the cages (8a, 8b), the outer rings are assembled from both axial sides of the double row inner ring (1). In the case of a four-row tapered roller bearing as shown in FIG. 1 using two sets of double-row tapered roller bearings, after assembling each double-row tapered roller bearing, they are integrated with an inner ring spacer 9 interposed therebetween. The oil seals 10, 10 and the O-rings 25, 25 may be provided at both axial ends of the bearing.
[0024]
With the above-described configuration, the double-row tapered roller bearing according to the present embodiment allows these flange portions 3a, 4a, 4a, 4a, 4a to slide in contact with each other even when the lubricant enclosed therein is biased toward the outer ring assembly due to the rotation of the bearing. A sufficient amount of lubricant circulates between the end faces 5a and 6a and the large-diameter end face 7t of the tapered roller 7 to maintain a low friction state. Therefore, the double-row tapered roller bearing according to the present embodiment can suppress heat generation at the flanges 3a, 4a, 5a, and 6a even during high-speed rotation and the like, and can prevent troubles such as burnout.
[0025]
In addition, by integrating the tapered rollers 7 in the tracks of the single-row outer rings 3, 4, 5, 6, using the cages 8a, 8b, 8c, 8d, as in the conventional example, the double-row tapered rollers are provided. The bearing can be easily assembled.
[0026]
The present invention is not limited to the above-described embodiment, and various modifications and improvements can be made in accordance with the required bearing performance. For example, in the present embodiment, an example is shown in which the small-diameter side flange portion slidingly contacting the small-diameter side end surface 7s of the tapered roller is not provided, but the small-diameter side flange portion is provided axially outside each single-row outer ring inner peripheral surface. May be provided. Further, in this example, two sets of double-row tapered roller bearings have the same structure, and one of them is combined by inverting 180 °. Of course, one set of double-row tapered roller bearings may be used. Needless to say.
[0027]
【The invention's effect】
As described above in detail, according to the double-row tapered roller bearing of the present invention, even at the time of high-speed rotation, the lubricant can be sufficiently spread between the tapered roller end face and the flange end face that are in sliding contact with each other, and heat is generated. Can prevent the occurrence of troubles such as burning.
[Brief description of the drawings]
FIG. 1 is an axial sectional view showing a structure of a double-row tapered roller bearing according to an embodiment of the present invention.
FIG. 2 is an explanatory view showing a method for assembling a double-row tapered roller bearing according to an embodiment of the present invention.
FIG. 3 is an axial sectional view showing the structure of a conventional double-row tapered roller bearing.
FIG. 4 is an enlarged view of a part P in FIG. 3;
[Explanation of symbols]
1, 2 Double row inner ring 1x, 1y, 2x, 2y Inner ring raceway surface 3, 4, 5, 6 Single row outer ring 3x, 4x, 5x, 6x Outer ring raceway surface 3a, 4a, 5a, 6a Large diameter side flange 7 Roller 7s Small diameter side end face 7t Large diameter side end face 8a, 8b, 8c, 8d Cage 9 Inner ring spacer 10 Oil seal 11, 12 Double row inner ring 11a, 12a Large diameter flange 11b, 12b Small diameter flange 11t Collar End face 13 Double row outer ring 14, 15 Single row outer ring 16 Tapered roller 16t Large diameter side end face 17a, 17b, 17c, 17d Cage 21 Inner ring spacer 22 Outer ring spacer 23 Oil seal 24 Seal cover 25 O-ring 26 Spiral groove

Claims (2)

An inner ring provided with a pair of conical inner ring raceway surfaces having a large diameter at an axial center portion, an outer ring assembly having a pair of conical outer ring raceway surfaces opposed to these inner ring raceway surfaces, and a raceway surface of the inner and outer rings In between, a double row cone comprising a plurality of tapered rollers arranged with their large-diameter end faces toward the center in the axial direction, and a pair of retainers for holding these tapered rollers at predetermined intervals in the circumferential direction. In roller bearings,
A double-row tapered roller bearing, wherein a large-diameter flange portion slidingly contacting the large-diameter end surface of each of the tapered rollers is provided on the inner peripheral surface of the outer ring assembly. A method for assembling a double-row tapered roller bearing according to claim 1, wherein the tapered rollers are fitted into the conical outer ring raceway surfaces of each outer ring forming an outer ring assembly having the large-diameter flange portion, A method for assembling a double-row tapered roller bearing, wherein the outer races are assembled from both axial sides of the inner race after being integrated by a retainer.

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