JP2004060758A - Rolling bearing and roll supporting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing capable of not deforming a raceway ring when a preload is applied to bearings and easily and suitably assembling a shaft and a housing. <P>SOLUTION: The rolling bearing 10 is comprised of an assembly of single row bearings 10a and 10a, and is assembled into a device in a preloading state. Extension portions 12c and 12d increasing rigidity of raceway rings are arranged on the outside of raceways of the raceway rings of the single row bearings 10a and 10a in a widthwise direction, and both end faces of the extension portions 12c are directly butted against each other. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rolling bearing used in general industrial machines in general, and particularly to a bearing for a cylinder roll support in a commercial offset printing press requiring high precision and high rigidity in a state where a preload is applied to the shaft. And bearings incorporated in housings.
[0002]
[Prior art]
As a rolling bearing used by applying a preload, a combined bearing 80 including a single row tapered roller bearing and a spacer as shown in FIG. 5 may be used. In this combined bearing 80, an outer ring spacer 86 and an inner ring spacer 87 are disposed between a pair of single row tapered roller bearings 80a, 80a. The spacer has an action of determining the width of the entire combined bearing and at the same time determining the internal clearance of the bearing.
The outer races 82, 82 sandwiching the outer race spacer 86 usually have a portion slightly protruding outward in the width direction of a contact portion (outer raceway) 82 a with the roller 83.
[0003]
Further, as a rolling bearing used by applying a preload, there is also a double row bearing 90 having an integral bearing ring as shown in FIG. This double row bearing 90 is provided with a pair of inner rings 91, 91 each having an outer diameter surface provided with a conical outer surface inner raceway 91a, and two conical inner surface outer row raceways 92a, 92a provided on the inner diameter surface. And a single outer ring 92. An inner ring spacer 97 is arranged between the pair of inner rings 91.
[0004]
A typical example of a rolling bearing used under a preload is a bearing for a roll support of a commercial offset printing press. Hereinafter, an example of a commercial offset printing machine will be described. Roll support bearings are required to have extremely high rigidity and rotational accuracy, and are generally used under a preload. As shown in FIG. 2, from the structure of the device, the bearing is mounted on the roll shaft in a state where the preload is adjusted in advance, and thereafter, a mounting hole opened larger than the bearing outer diameter provided on the frame supporting both ends of the roll shaft. Is fixed via a sleeve.
[0005]
[Problems to be solved by the invention]
In the case of a tapered roller bearing for a roll support of an offset printing machine, when a preload is applied in advance while being mounted on a roll shaft, the outer ring is in a state of expanding radially outward due to the preload. In this state, it is difficult to incorporate the roll shaft into the frame because the fit between the sleeve inner diameter and the bearing outer diameter is tight.
In such a case, it is common to loosen the fitting between the sleeve inner diameter and the bearing outer diameter by expanding the sleeve by thermal expansion, but this time, the fitting between the sleeve outer diameter and the inner diameter of the mounting hole of the frame is performed. This also makes it difficult to incorporate the roll shaft into the frame.
[0006]
As a means for suppressing such assembly problems due to deformation of the outer ring due to the preload, it is conceivable to increase the wall thickness of the race such as the outer ring to improve the rigidity. However, in an apparatus in which a plurality of rolls are in contact with each other, such as an offset printing press, it is impossible to increase the outer diameter of the bearing from the body of the roll in order to obtain the thickness of the raceway. . In addition, an increase in the bearing space is not preferable because the rigidity of the frame is reduced. Furthermore, in order to ensure the rigidity of the roll at the same time, the diameter of the bearing mounting portion of the roll must be as large as possible. Therefore, the thickness of the bearing ring cannot be so large, and the method of increasing the thickness of the bearing ring cannot sufficiently suppress deformation of the bearing ring due to preload.
[0007]
The outer ring spacer 86 and the inner ring spacer 87 in the combined bearing 80 as shown in FIG. 5 are ground separately from the bearing ring. However, dimensional errors of the spacer and the contact surface between the spacer and the bearing ring may be reduced. Damaged scratches may cause poor mounting such as the raceway being tilted.
In addition, when the width of each single row tapered roller bearing 80a is short, the single row tapered roller bearing 80a may be inclined with respect to the frame, or may be assembled while being seated badly, thereby causing problems such as poor rotation and early peeling. There is.
[0008]
In the double row bearing 90 having the integrated races as shown in FIG. 6, the left and right outer raceways 92a are separately ground, so that the left and right outer raceways 92a are in different phase positions. If this occurs, the shaft will be misaligned and high rotational accuracy cannot be maintained, and an edge load will occur on the contact surface between the raceway and the rolling element, leading to early separation of the raceway.
[0009]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rolling bearing that can be easily and appropriately incorporated into a shaft or a housing without deforming a bearing ring even when a preload is applied.
[0010]
[Means for Solving the Problems]
The object of the present invention is achieved by the following configurations.
(1) In a rolling bearing which is constructed by combining single-row bearings and is incorporated into a device under a preload, an extension portion for increasing the rigidity of the race is provided outside the raceway of the race of the single-row bearing. And the end faces of the extension portions are directly butted against each other.
(2) The rolling bearing according to (1), wherein the outer ring of the single-row bearing is provided with the extension.
(3) The rolling bearing according to (1) or (2), wherein the extended portions are provided on both outer sides in the width direction of the track of the ring track.
(4) On the outer diameter surface of the extension provided on the thinner side of the raceway in the width direction outside of the raceway of the raceway, the extension is performed toward the axial end of the extension. The rolling bearing according to any one of the above (1) to (3), wherein a rolling part is provided to gradually reduce the outer diameter of the part.
(5) A roll support structure in which a roll is supported by the rolling bearing according to any one of (1) to (4).
[0011]
According to the above configuration, since the rigidity of the bearing ring is improved by the extension, deformation of the bearing ring when preload is applied is significantly suppressed. Therefore, this rolling bearing can be easily and appropriately incorporated into a shaft or a housing (or a frame) under a preloaded state. Since the rolling bearing is not enlarged in the radial direction, it is not necessary to increase the size of the mounting hole of the frame or the like, and the rigidity of the frame or the like can be secured. In addition, since the fitting surface is expanded by the extension portion, the seating in the frame or the like can be improved, and the incorporation of the bearing in an inclined state can be prevented. Since the end faces of the extending portions of the single row bearings are directly abutted with each other, no spacer is used there, and there is no dimensional error of the spacer or mounting failure of the bearing ring due to a scratch. Therefore, problems such as poor rotation and early peeling can be prevented.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing the rolling bearing of the first embodiment. This rolling bearing 10 is a combination bearing of a pair of single row tapered roller bearings 10a, 10a. Each single-row tapered roller bearing 10a includes an inner ring 11 provided with a conical outer surface inner raceway 11a on each outer diameter surface and an outer ring 12 provided with a conical inner surface outer raceway 12a on each inner diameter surface. Have. A plurality of tapered rollers 13 are arranged between the inner and outer raceways 11a and 12a. The plurality of tapered rollers 13 are rotatably held by a retainer 14 at intervals in the circumferential direction. The inner ring 11 is provided with a small flange 11e that supports the small-diameter end face of the tapered roller 13 and a large collar 11f that supports the large-diameter end face of the tapered roller 13.
[0013]
The outer race 12 of each single-row tapered roller bearing 10a has extended portions 12c and 12d on both outer sides in the width direction of the outer raceway 12a. That is, the tapered roller 13 has an extended portion 12c that protrudes axially outward from the small-diameter end surface of the tapered roller 13, and an extended portion 12d that protrudes axially outward from the large-diameter end surface of the tapered roller 13. The extension 12c is provided on the thicker outer ring 12 (back side), and the extension 12d is provided on the thinner outer ring 12 (front side).
[0014]
In the present embodiment, each of the extension portions 12c and 12d slightly protrudes outward in the width direction of the outer raceway 12a as a margin. Further, the extension portions 12c and 12d have outer diameter surfaces flush with the outer diameter surface of the outer race 12.
[0015]
In the pair of single-row tapered roller bearings 10a, the end faces of the extended portions 12c on the small-diameter end face side of the tapered rollers 13 directly abut each other. That is, the outer ring spacer is omitted. An inner ring spacer 17 is arranged between the inner rings 11, 11 of the single row tapered roller bearings 10a, 10a.
Since the rolling bearing 10 has the extended portions 12c and 12d even when a preload is applied thereto, expansion deformation of the outer ring 12 is suppressed.
[0016]
For example, in a tapered roller bearing 32930 (manufactured by Nippon Seiko Co., Ltd.) having no extension, the average value of the amount of radial expansion of the outer ring when a preload of 10,000 N is applied is 7 μm. On the other hand, when the same preload is applied to a bearing having an 8 mm wide extension on the back side and a 4 mm extension on the front side, the average value of the radially outward expansion of the outer ring is 2 μm or less. Can be suppressed.
[0017]
As shown in FIG. 2, the rolling bearing 10 is incorporated into roll shafts 51, 51 projecting from both ends of a roll 50 of an offset printing press. In this state, a preload is applied to the rolling bearing 10. Then, the sleeve 52 is externally fitted to the rolling bearing 10, and the rolling bearing 10 is fixed to the mounting hole 55 a provided in the frame 55 supporting the roll via the sleeve 52.
In such a roll support structure, the rolling bearing 10 can suppress the expansion of the outer ring due to the preload, so that the sleeve 52 can be smoothly fitted, and the sleeve 52 can be smoothly incorporated into the mounting hole 55 a of the frame 55. The assembly work is easy.
Since the rolling bearing 10 is not enlarged in the radial direction, it is not necessary to enlarge the mounting hole 55a of the frame 55, and the rigidity of the frame 55 can be secured. In addition, since the fitting surface with the inner surface of the mounting hole 55a is expanded by the extension portions 12c and 12d, the rolling bearing 10 is well seated in the sleeve 52, and the incorporation of the bearing 10 in an inclined state can be prevented.
[0018]
In the present invention, the effect of suppressing the incorporation of the bearing into the housing in an inclined state will be described based on FIG. 3 by comparing a conventional bearing with the bearing of the present embodiment. When the outer ring spacer 86 is arranged between the pair of outer rings 82 as in the conventional example shown in FIG. 3A, the inclination angle θ1 is the same as in the present embodiment shown in FIG. It is larger than the inclination angle θ2 when the end faces of the extended portions of the pair of outer rings 12, 12 are directly butted. That is, the present embodiment shown in FIG. 3B has higher mounting accuracy.
In addition, in the present embodiment shown in FIG. 3B, by omitting the outer ring spacer, it is possible to avoid the influence of the dimensional error of the outer ring spacer, the scratch on the contact surface, the entry of foreign matter, and the like. In addition, by omitting the outer ring spacer, the number of parts can be reduced, thereby reducing costs.
[0019]
FIG. 4 shows a rolling bearing 20 according to the second embodiment. Note that members having the same configuration and operation as the members already described are denoted by the same reference numerals or corresponding reference numerals in the drawings to simplify or omit the description.
In the present embodiment, the outer race 22 of each single-row tapered roller bearing 20a has an extension 22c on the back side and an extension 22d on the front side. The outer diameter surface of the rear extension 22 c is flush with the outer diameter surface of the outer race 22. On the other hand, the outer diameter surface of the extension 22d on the front side has a slender portion 29 that gradually reduces the outer diameter of the extension 22d toward the axial end of the extension 22d.
The extension 22c has a substantially constant inner diameter over the entire area in the width direction. The extension 22d also has a substantially constant inner diameter over the entire area in the width direction.
[0020]
When a preload is applied to the outer races 22, 22, the thinner front portion tends to expand and deform significantly. The expansion deformation can be suppressed by the extension 22d. However, when the width (dimension in the width direction) of the extension 22d increases, the amount of deformation of the distal end of the extension 22d increases even when the outer ring 22 is slightly expanded and deformed. Therefore, by providing the slender portion 29 on the extension portion 22d, the extension portion 22d is prevented from protruding radially outward from the outer diameter surface of the outer ring 22.
[0021]
Note that the present invention is not limited to the above-described embodiment, and appropriate modifications and improvements can be made.
For example, the extension may be provided only on the front side or the rear side of the outer race. Further, the extension may be provided on the inner race.
[0022]
【The invention's effect】
As described above, according to the present invention, a rolling bearing that does not deform a bearing ring even when a preload is applied and can be easily and appropriately incorporated into a shaft or a housing, and a roll support structure using the same are provided. .
[Brief description of the drawings]
FIG. 1 is a sectional view of a rolling bearing according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a state where a roll is supported by a rolling bearing.
FIG. 3 is a diagram illustrating a state in which a rolling bearing inclines.
FIG. 4 is a cross-sectional view of the rolling bearing according to the first embodiment of the present invention.
FIG. 5 is a sectional view showing a conventional rolling bearing.
FIG. 6 is a sectional view showing a conventional rolling bearing.
[Explanation of symbols]
10, 20 Rolling bearings 10a, 20a Single row bearing 11 Inner ring 12, 22 Outer ring 12c, 22c Extension 12d, 22d Extension

Claims (5)

Rolling bearings that are configured by combining single-row bearings and that are incorporated into equipment under a preload
A rolling bearing, characterized in that an extension for increasing the rigidity of the race is provided on the outer side in the width direction of the race of the race of the single row bearing, and end faces of the extensions are directly butted against each other. The rolling bearing according to claim 1, wherein the extension is provided on an outer ring of the single-row bearing. The rolling bearing according to claim 1, wherein the extension portion is provided on both outer sides in the width direction of the track of the wheel track. On the outer diameter surface of the extension provided on the thinner side of the raceway in the width direction outside of the raceway of the raceway, the outer side of the extension toward the axial end of the extension is provided. The rolling bearing according to any one of claims 1 to 3, wherein a rolling portion that gradually reduces the diameter is provided. A roll supporting structure in which a roll is supported by the rolling bearing according to claim 1.

Images