JP2002089553A - Rolling bearing for continuous casting machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing for a continuous casting machine capable of enhancing the bearing life by preventing wear and damage, and also of permitting a guide roller and a pinch roller or the like installed in the casting machine to be tilted by the deflection of a rotating shaft. SOLUTION: The rolling bearing 21 for a continuous casting machine includes an outer ring 25 provided with a raceway surface 25a on its inner peripheral surface; an inner ring 27 provided with a raceway surface 27a on its outer peripheral surface; and a plurality of approximately tapered rollers 29 positioned between the raceway surfaces 25a and 27a, with the rolling surface 29a of each roller being formed by means of projecting generating lines. Each of the raceway surfaces 25a and 27a is formed by a first generating line 34 with a certain radius of curvature and by second generating lines 36 and 37 each with a radius of curvature such that a small diameter part and a large diameter part adjacent to the center part extend away from the rolling surface 29a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller bearing for a continuous casting machine which is used for supporting a rotating shaft such as a guide roll or a pinch roll installed in a continuous casting machine and which can tolerate an inclination due to the bending of the rotating shaft. Things.

[0002]

2. Description of the Related Art Rotary shafts such as guide rolls and pinch rolls installed in a continuous casting machine are used in an environment where the temperature is high and the temperature changes greatly. Largely, a bearing device that supports these rotary shafts requires a mechanism that allows a tilt due to the bending of the rotary shaft.

Therefore, as a bearing device for supporting a rotating shaft such as a guide roll or a pinch roll installed in a continuous casting machine, a bearing device 2 as shown in FIG. 4 is conventionally known. As shown in FIG. 4, the bearing device 2 includes a roller bearing 5 mounted on a bearing box 3 and a shaft end 1 of a guide roll 1.
a.

The roller bearing 5 includes a roller (spherical roller) 7 having a rolling surface as a rolling element between an inner race 9 having two rows of raceways and an outer race 8 having a spherical raceway 8a. A self-aligning roller bearing incorporated therein, in which the spherical roller 7 rolls while sliding on the raceway surface 8a of the outer ring 8 (differential sliding), thereby causing the inclination between the inner ring 9 and the outer ring 8 (hereinafter, relative to the inner and outer rings). Tilt) can be tolerated.
The inclination of the rotating shaft caused by the deflection of the guide roll 1 can be tolerated.

However, in a bearing device that supports a rotating shaft such as a guide roll or a pinch roll of a continuous casting machine, the bearing load is large and the rotation speed is extremely low (several rpm).
m), it is difficult to form an oil film between the rolling elements (rollers) and the raceway surfaces of the inner and outer rings, and the rolling surface of the rollers and each raceway surface of the inner and outer rings are in direct contact with each other without passing through the oil film. Is easy to occur.

In the case of a self-aligning roller bearing such as the above-described roller bearing 5, the rolling surface of the spherical roller 7 and the inner and outer rings 9,
8 continues to rotate in a state of direct contact (metal contact) with each raceway surface of FIG. 8, a differential sliding phenomenon in which the spherical roller 7 rolls while sliding with respect to each raceway surface is caused by the differential sliding phenomenon shown in FIGS. Following the progress shown, the raceway surfaces of the inner and outer rings 9 and 8 and the rolling surface of the spherical roller 7 are greatly worn and the life of the bearing is reduced, so that the bearing clearance becomes excessive and the guide roll 1 is There is a problem that the guide roll 1 cannot be maintained at the position or the guide roll 1 cannot be rotated due to damage (crack) of the inner and outer rings 9 and 8.

First, at the stage shown in FIG.
Although the local wear 100 occurs from the bearing end face side E of the raceway surface 8a to the bearing center side C, the pure rolling portion 1
01 is left on the track surface 8a. The spherical roller 7
Rolls while sliding on portions other than the pure rolling portion 101 of the raceway surface 8a, and abrasion proceeds. And gradually, FIG.
As shown in (b), the pure rolling portion 10 is formed by stress concentration.
As a result, the positioning accuracy of the rotating shaft decreases due to an increase in the bearing gap due to an increase in wear. As the use proceeds further, as shown in FIG. 5C, the expansion of the peeling and the generation of the bending stress 102 cause the vertical crack 103 to be generated and the outer ring 8 to be broken, so that the proper support of the guide roll 1 is not achieved. Becomes impossible.

On the other hand, in a normal tapered roller bearing, the above-mentioned "differential sliding phenomenon" hardly occurs, but since the relative inclination of the inner and outer rings cannot be tolerated, a continuous casting machine is simply used instead of the roller bearing 5. When it is used for the bearing device of the above, an edge load occurs in which the contact pressure sharply increases at the contact point between the raceway surface and the end of the inner and outer rings, and the edge load decreases the bearing performance, damages the raceway surface of the inner and outer rings, Serious problems such as breakage of the rollers may occur.

Therefore, a tapered roller bearing 11 as shown in FIG. 6 has been proposed so that only the advantage of the tapered roller bearing that "differential sliding does not occur" can be utilized. The tapered roller bearing 11 shown in FIG.
This is a double row tapered roller bearing in which a conical trapezoidal roller 16 is incorporated as a rolling element between an outer ring 13 having two orbital raceways. An outer ring 13 having an outer ring and an outer ring spacer integrated with the outer ring of the back combination bearing is provided with an aligning seat 15 for allowing the inclination of the outer ring 13 on the outer peripheral portion. The relative inclination between them makes it possible to absorb the inclination of the rotating shaft, thereby preventing the occurrence of an edge load inside the tapered roller bearing 11.

[0010]

However, in the tapered roller bearing 11 shown in FIG. 6, the bearing installation space in the bearing housing is reduced by the centering seat 15, and as a result, the roller 16 to be used is reduced. Is inevitable. And
The reduction in the size of the rollers 16 causes a reduction in the load capacity of the tapered roller bearing 11, and as a result, the life of the bearing is shortened accordingly.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, to improve the life of a bearing by preventing abrasion and damage, and to deflect a rotating shaft such as a guide roll or a pinch roll installed in a continuous casting machine. It is an object of the present invention to provide a roller bearing for a continuous casting machine, which can tolerate the inclination due to the inclination.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an outer race having an inner peripheral surface provided with a raceway surface, an inner race having an outer peripheral surface provided with a raceway surface, and a rolling surface formed by a convex bus bar. And a plurality of substantially conical rolling elements arranged between the respective raceway surfaces, and a roller bearing for a continuous casting machine that rotatably supports a rotating shaft installed in the continuous casting machine, A central portion of any one of the raceway surfaces or the rolling surfaces of the rolling elements is formed by a first bus bar having a constant radius of curvature, and both end portions adjacent to the central portion have the respective raceway surfaces. This is achieved by a roller bearing for a continuous casting machine, which is formed by a second bus bar having a radius of curvature separated from the other of the rolling surfaces of the rolling elements.

According to the above configuration, since the basic configuration is a tapered roller bearing, almost no differential slip occurs between the raceway surface of the inner and outer rings and the rolling surface of the rolling element. Also, since both end sides of each of the raceway surfaces or both end sides of the rolling surface are formed by the second bus bar having a radius of curvature separated from the other, the inner race and the outer race are caused by bending of the rotating shaft or the like. Even if there is a relative inclination between the inner and outer rings, both ends of the substantially conical rolling element do not locally contact the raceway surfaces of the inner and outer rings,
The relative inclination between the inner and outer rings can be tolerated, and edge load is hardly generated. That is, the center of the radius of curvature of the first bus bar is located farther from the axis of the bearing, but the edge load can be remarkably reduced.

Further, since each raceway surface and the rolling surface come into contact with the convex bus line shape and the corresponding concave bus line shape, when the axis deviation angle of the outer ring and the inner ring is small, or when the axis deviation is small. Even in a case where there is no contact pressure, it is possible to suppress an increase in surface pressure between each of the raceway surfaces and the rolling surface.

Further, a special aligning seat for allowing the relative inclination of the inner and outer rings is not required, and when mounted on a bearing housing, the bearing itself does not need to be downsized to secure an installation space for the aligning seat. Also, it is not necessary to reduce the size of the rolling elements, which causes a reduction in the load capacity of the bearing. Therefore, it is possible to prevent wear and damage on the rolling surfaces of the rolling elements and the raceway surfaces of the inner and outer races, and without shortening the life of the bearing, and to rotate the rotating shaft such as a guide roll or a pinch roll installed in the continuous casting machine. Can be stably supported over a long period of time.

In the roller bearing for a continuous casting machine according to the present invention, the raceway surfaces or the rolling surfaces of the rolling elements are formed by a first bus and a second bus which are continuous with each other and have different radii of curvature. Good. More specifically, each track surface is
When formed by the bus and the second bus, the central portion of each raceway is formed by a concave first bus corresponding to the bus of the rolling surface of the rolling element, and both end faces of each raceway are formed. What is necessary is just to form by the convex 2nd generatrix. On the other hand, when the rolling surface of each rolling element is formed by the first bus and the second bus, the central portion of the rolling surface is formed by the convex first bus corresponding to the bus of the concave raceway surface. In addition, both ends of the rolling surface may be formed by a convex second bus bar having a smaller radius of curvature than the first bus bar.

The boundary between the first bus and the second bus may be made smoothly continuous, or chamfering may be performed along the boundary between the first bus and the second bus. That is, the first bus and the second bus having different radii of curvature are used.
In order to suppress the increase in surface pressure at the boundary of the bus, a mode in which both buses share a tangent at the boundary of the first bus and the second bus,
Alternatively, the third bus is provided so as to straddle the boundary between the first bus and the second bus.
A mode in which a bus bar is formed can be adopted.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a roller bearing for a continuous casting machine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view of a bearing device provided with a roller bearing for a continuous casting machine according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a main part of the roller bearing for a continuous casting machine shown in FIG.

As shown in FIG. 1, the bearing device 20 of this embodiment supports the shaft end 1a of a guide roll 1 which is a rotating shaft installed in a continuous casting machine. So that the two bearings 21 and 21 for the continuous casting machine can be back-to-back so that
Is mounted inside. The bearing clearance is the outer ring spacer 23.
And the inner ring spacer 24.

As shown in FIG. 2, the roller bearing 21 for a continuous casting machine includes an outer race 25 having a raceway surface 25a on the inner peripheral surface and an inner race 27 having a raceway surface 27a on the outer peripheral surface.
And a plurality of substantially conical rolling elements 29 each having a rolling surface formed by a convex busbar and arranged between the raceway surfaces 25a and 27a. The shaft end 1 a is fitted and fixed to the inner peripheral surface of the inner ring 27.

The rolling surface 29a of the rolling element 29 is formed by a generatrix having a constant radius of curvature over substantially the entire area.
And, the respective raceway surfaces 27a, 25 of the inner and outer rings 27, 25
a first bus bar 34 having a constant radius of curvature at the central portion in a
The small-diameter portion side (left side in FIG. 2) and the large-diameter portion side (right side in FIG. 2) as both end portions adjacent to the center portion are formed on the rolling surface 29a of the rolling element 29. Second busbars 36, 3 having a convex radius of curvature away from the second busbars 36, 3
7.

Here, the radius of curvature of the first generatrix 34 of each of the raceway surfaces 27a, 25a of the inner and outer rings 27, 25 is set to be slightly larger than the radius of curvature of the generatrix of the rolling surface 29a of the rolling element 29. Have been.

Since the first bus 34 and the second bus 36, 37 are formed so as to share a tangent line at the boundary, the boundary is smoothly continuous, so that the surface pressure is reduced at the boundary. There is no fear of becoming high. In order to further prevent an increase in surface pressure at the boundary, a track surface formed by a third bus between the first bus 34 and each of the second buses 36 and 37 may be used.

That is, in the roller bearing 21 for a continuous casting machine of the present embodiment, since the basic form is a tapered roller bearing, the raceway surfaces 27a and 25a of the inner and outer rings 27 and 25 and the rolling surface 29a of the rolling element 29 There is almost no differential slip between them. For example, the outer diameter of the outer ring 25 is 150 mm,
7 has an inner diameter of 85 mm and a central part diameter of the rolling element 29 of about 17 mm.
A comparison was made between the degree of occurrence of differential slip and a spherical roller bearing 40 which is a self-aligning roller bearing as shown in FIG.

As shown in FIG. 3, in the case of the spherical roller bearing 40, each of the raceway surfaces 43a, 42 on the inner and outer rings 43, 42.
a radius of curvature is about 70 mm, rolling the length of the body 41 is approximately 14 mm, height difference S ₂ between the raceway surface 42a and the rolling surface becomes 0.35 mm. On the other hand, in the case of the roller bearing 21 for a continuous casting machine, since the length of the rolling surface of the rolling element 29 is about 25 mm, as shown in FIG. Height difference S ₁ is 0.028
mm.

In general, the sliding speed between the rolling surface of the rolling element (roller) and the raceway surface of the inner and outer rings is proportional to the difference between the diameters of the rollers. Therefore, the sliding speed of the roller bearing 21 for the continuous casting machine is: 0.0 compared to the sliding speed of the spherical roller bearing 40
It is eight times, which indicates that the differential sliding of the roller bearing 21 for the continuous casting machine is greatly reduced as compared with the spherical roller bearing 40.

Even if the relative inclination of the inner ring 27 to the outer ring 25 is caused between the inner ring 27 and the outer ring 25 due to the bending of the guide roll 1 which is the rotating shaft supported by the roller bearing 21 for the continuous casting machine, the inner and outer rings Both ends of each of the raceway surfaces 27a, 25a of the rolling elements 29 are formed by second busbars 36, 37 having a radius of curvature separated from both end surfaces of the rolling surface a of the rolling element 29. Therefore, the both ends of the substantially conical rolling element 29 do not locally contact the raceway surfaces 27a, 25a, the relative inclination of the inner and outer rings can be allowed, and edge load hardly occurs. That is, the center of the radius of curvature of the first bus bar 34 of each of the raceway surfaces 27a, 25a of the inner and outer rings 27, 25 is located farther from the axis of the bearing, but the edge load can be relieved very effectively. According to the experiment of the inventor of the present application, it has been confirmed that, in the roller bearing 21 for a continuous casting machine of the present embodiment, even when the relative inclination of the inner and outer rings is, for example, about 7/1000, edge load does not occur. .

Further, the raceway surfaces 27a, 25a and the rolling surface 29a come into contact with the convex generatrix of the rolling element 29 and the corresponding concave generatrix of the raceway surfaces 27a, 25a. Even when the axis deviation angle between the outer ring 25 and the inner ring 27 is small or when there is no axis deviation, it is possible to suppress an increase in the surface pressure between each of the raceway surfaces 27a, 25a and the rolling surface.

In addition, the roller bearing 21 for a continuous casting machine according to the present embodiment does not require a dedicated aligning seat for allowing the relative inclination of the inner and outer rings as in the tapered roller bearing 11 shown in FIG. When mounting on 22, the bearing itself is not required to be downsized to secure the installation space for the centering seat.
It is not necessary to reduce the size of the rolling element 29 which causes a reduction in the load capacity of the bearing. Therefore, the rolling surface of the rolling element 29 and the inner and outer rings 27,
The bearing device 20 including the roller bearing 21 for a continuous casting machine, which can prevent wear and damage on the raceway surfaces 27a, 25a of the 25 and does not shorten the bearing life,
The guide roll 1 installed in the continuous casting machine can be stably supported for a long period of time.

The configuration of the inner and outer races and rolling elements in the roller bearing for a continuous casting machine of the present invention is not limited to the configuration of the above-described embodiment, but may employ various configurations based on the spirit of the present invention. Needless to say. For example, in the above embodiment, the raceway surfaces 25a, 2 of the inner and outer rings 27, 25
The intermediate portion 7a and both end portions are formed by a first bus bar 34 and second bus bars 36 and 37 having different radii of curvature.
Instead of the respective raceway surfaces 25a, 27a of 7, 25, the intermediate portion and both end surfaces of the rolling surface 29a of the rolling element 29 are formed by a first bus and a second bus having different radii of curvature from each other. Is also good.

Further, in the bearing device 20 of the above embodiment, 2
Although the individual roller bearings 21 and 21 for the continuous casting machine are mounted in the bearing box 22 in a back-to-back combination, they may be in a front-to-back combination. Further, in the roller bearing 21 for a continuous casting machine, the inner ring collar portion of the inner ring 27 is provided. However, the same effect can be obtained by a configuration in which the inner ring collar portion is omitted.
In the configuration without the collar portion, the rolling element can move freely in the axial direction, so that the moment rigidity is reduced, but the rolling element can swing.

[0032]

According to the roller bearing for a continuous casting machine of the present invention, since the basic form is a tapered roller bearing, there is almost no differential slip between the raceway surface of the inner and outer rings and the rolling surface of the rolling element. Does not occur. Also, since both end sides of each of the raceway surfaces or both end sides of the rolling surface are formed by the second bus bar having a radius of curvature separated from the other, the inner race and the outer race are caused by bending of the rotating shaft or the like. Between the inner and outer rings,
Both ends of the substantially conical rolling element do not locally contact the raceway surfaces of the inner and outer races, the relative inclination of the inner and outer races can be allowed, and edge load hardly occurs. That is, the center of the radius of curvature of the first bus bar is located farther from the axis of the bearing, but the edge load can be remarkably reduced.

Further, since each of the raceway surfaces and the rolling surfaces come into contact with the convex busbar shape and the corresponding concave busbar shape, when the axis deviation angle of the outer ring and the inner ring is small, or when the axis deviation is small. Even in a case where there is no contact pressure, it is possible to suppress an increase in surface pressure between each of the raceway surfaces and the rolling surface.

Also, a special aligning seat for allowing the relative inclination of the inner and outer rings is not required, and when mounted on the bearing housing, the bearing itself does not need to be downsized to secure an installation space for the aligning seat. Also, it is not necessary to reduce the size of the rolling elements, which causes a reduction in the load capacity of the bearing. Therefore, it is possible to prevent wear and damage on the rolling surfaces of the rolling elements and the raceway surfaces of the inner and outer races, and without shortening the life of the bearing, and to rotate the rotating shaft such as a guide roll or a pinch roll installed in the continuous casting machine. Can be stably supported over a long period of time.

[Brief description of the drawings]

FIG. 1 is a sectional view of a bearing device provided with a roller bearing for a continuous casting machine according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the roller bearing for a continuous casting machine shown in FIG.

FIG. 3 is a longitudinal sectional view showing a height difference between a raceway surface and a rolling surface in a spherical roller bearing having the same inner and outer diameters and rolling element diameters as the roller bearing for a continuous casting machine shown in FIG. 2;

FIG. 4 is a longitudinal sectional view of a conventional bearing device provided with a self-aligning roller bearing that supports a guide roll installed in a continuous casting machine.

FIG. 5 is a view for explaining a progress process in which a raceway surface of an outer ring is worn by differential sliding in the self-aligning roller bearing shown in FIG. 4;

FIG. 6 is a longitudinal sectional view of a conventional double-row tapered roller bearing provided with an alignment seat.

[Explanation of symbols]

 Reference Signs List 20 bearing device 21 roller bearing for continuous casting machine 25 outer ring 25a raceway surface 27 inner race 27a raceway surface 29 rolling element 34 first bus 36, 37 second bus

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J012 AB01 BB03 DB02 EB01 FB20 3J101 AA16 AA25 AA43 AA54 AA62 BA06 BA53 BA54 FA31 GA35 3J103 AA02 CA05 CA42 CA62 CA78 DA05 DA07 FA12 FA13 FA26 GA02 GA17

Claims (1)

[Claims] 1. An outer ring having a raceway surface provided on an inner peripheral surface, an inner ring having a raceway surface provided on an outer peripheral surface, and a plurality of rolling surfaces formed by a convex busbar, and a plurality of rolling surfaces arranged between the raceway surfaces. A rolling element having a substantially conical shape, and a roller bearing for a continuous casting machine rotatably supporting a rotating shaft installed in the continuous casting machine, wherein the rolling of each raceway surface or each rolling element is provided. A central portion of one of the surfaces is formed by a first generatrix having a constant radius of curvature, and both end portions adjacent to the central portion are formed of the raceway surfaces and the rolling surfaces of the rolling elements. A roller bearing for a continuous casting machine, wherein the roller bearing is formed by a second bus bar having a radius of curvature away from the other.