JP2002070874A - Rotational supporting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotational supporting apparatus which attains improvement of durability by preventing damage due to galling, seizure, unusual wear and the like, even under high speed operation with severe lubricating conditions. SOLUTION: A driving pinion 5 which is a helical gear having a helix angle of 6 to 25 degrees is supported by cylindrical roller bearings 18a, 18b with collar. The cross-sectional shape of the inside surface of the collar is of straight line type, and further this inside surface is inclined at 15 to 65 minutes as moved off toward the outside diameter side with respect to the direction extending away from an axial direction of a bearing ring upon which the collar is mounted. Moreover, on the portion of the inside surface opposing an axial direction end surface of a cylindrical roller 15, crowning having a radius of curvature of 25 to 100 times of the diameter of the cylindrical roller is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention A rotation supporting device according to the present invention is incorporated in a gear transmission device such as a speed reducer constituting various mechanical devices, and a rotating shaft on which a helical gear constituting the gear transmission device is fixed. , And rotatably supported by a fixed part such as a housing.

[0002]

2. Description of the Related Art FIG. 10 shows a railway vehicle drive device described in Japanese Utility Model Laid-Open Publication No. 64-38351. A driven large gear 3 fixed to an intermediate portion of an axle 2 having wheels 1 and 1 fixed to both ends is engaged with a driving small gear 5 fixed to an intermediate portion of a drive shaft 4. The drive shaft 4 is rotatably driven by an output shaft 7 of a drive motor 6 via a joint 8. During traveling, the axle 2 to which the wheels 1, 1 are fixed is connected to the joint 8,
The drive shaft 4, the drive small gear 5, and the driven large gear 3 are driven to rotate.

[0003] Such a railway vehicle drive device comprises
The drive small gear 5 and the driven large gear 3 use a helical gear for the purpose of reducing noise and vibration generated at the meshing portion, etc., so that at the meshing portion between the two gears 5, 3,
Axial load occurs in addition to radial load. Therefore, the rolling bearing for rotatably supporting the drive shaft 4 rotating with the drive small gear 5 fixed to the housing 9 must be capable of supporting not only a radial load but also an axial load. . For this purpose, conventionally, the drive shaft 4 is supported on the housing 9 by at least one pair of tapered roller bearings having different contact angles from each other. However, when the drive shaft 4 is supported by a tapered roller bearing, the clearance adjustment of the tapered roller bearing becomes very troublesome. In particular, the temperature of the housing 9 changes greatly due to seasonal changes and further due to the influence of heat generated by the drive motor 6 during traveling. Regardless of such a large temperature change, in order to prevent the tapered rollers from seizing or rattling, it is necessary to strictly adjust the internal clearance of the tapered rollers. For this reason, skill is required for the work, and the work time is inevitably prolonged.

In order to solve such a trouble, Japanese Utility Model Laid-Open Publication No. 64-38351 discloses a cylindrical roller bearing and a four-point contact type ball bearing for supporting the drive shaft 4 on the housing 9. The invention relating to the rotation support device, which combines the above, is described. FIG. 11 shows a rotation support device described in the above publication. The drive shaft 4 as a rotary shaft is provided with a drive small gear 5 as a helical gear fixed to the outer peripheral surface of the intermediate portion.
Rotate with. A cylindrical roller bearing 10 and a four-point contact type ball bearing 11 are provided between the housing 9 which is a fixed portion and an intermediate portion and a tip portion (right end portion in FIG. 11) of the drive shaft 4. The drive shaft 4 is rotatably supported on the housing 9. Also, meshing with the driving small gear 5,
An axle 2 to which a driven large gear 3 which is also a helical gear is fixed.
Also, the cylindrical roller bearing 10
a and a four-point contact type ball bearing 11a.

The cylindrical roller bearings 10, 10a and 4 as described above
In the case of a rotary support device combining point contact type ball bearings 11 and 11a, the radial load acting between the drive shaft 4 or the axle 2 and the housing 9 is limited to the cylindrical roller bearings 10 and 1a.
0a and the ball bearings 11 and 11a, and the axial load is similarly supported by the ball bearings 11 and 11a.

[0006]

Problems to be Solved by the Invention
In the case of the rotation support device described in -38351,
Rolling bearings for rotational support are changed from tapered roller bearings to cylindrical roller bearings 10, 10a and four-point contact type ball bearings 11, 11.
By changing to a, you can improve the assembly workability,
It is inevitable that the cost increases and the size increases. The reason is as follows.

First, four-point contact type ball bearings 11, 11a
In the Gothic arch, the inner ring or outer ring (the outer ring in the example of FIG. 11) has a split structure, and the inner ring raceway formed on the outer peripheral surface of the inner ring and the outer ring raceway formed on the inner peripheral surface of the outer ring have the cross-sectional shape of the Gothic arch It is necessary to make such a special shape. Because of this,
The processing of the inner raceway and outer raceway is troublesome, and the ball bearing 1
It is inevitable that the cost of 1 and 11a increases.

In addition, four-point contact type ball bearings 11, 11a
Can support an axial load in addition to a radial load, but its load capacity is smaller than that of a tapered roller bearing. For this reason, in order to secure a sufficient load capacity, it is necessary to use each of the ball bearings 11 and 11a larger than a tapered roller bearing. As a result,
Each of these ball bearings 11, 11a and the cylindrical roller bearing 10,
The center-to-center distance from the rotation supporting device 10a is larger than when a pair of tapered roller bearings is used, and the size of the rotation support device as a whole increases. The rotation support device of the present invention has been made in view of such circumstances.

[0009]

According to the present invention, there is provided a rotation supporting apparatus comprising: a rotating shaft which rotates together with a helical gear fixed to an outer peripheral surface thereof; and a rolling member which rotatably supports the rotating shaft with respect to a fixed portion. And a bearing. In this rolling bearing, the rolling element is a cylindrical roller, and supports an axial load based on the engagement between the axial end surface of the cylindrical roller and the inner surface of the flange provided at the peripheral end of the bearing ring. It is a cylindrical roller bearing.

The torsion angle of the helical gear is 6 to 2
5 degrees, and the cross-sectional shape of the inner surface of the flange is a straight line. And this inner side surface is inclined in the direction toward the axial direction outward of the bearing ring provided with this flange portion toward the outer diameter side,
Crowning is applied to a portion of the cylindrical roller facing the inner side surface of the flange at the axial end surface. Preferably, the angle at which the inner side surface of the flange portion is inclined with respect to an imaginary plane orthogonal to the center axis of the raceway provided with the flange portion is 15 to 65 minutes, and the axial end surface of the cylindrical roller. Is 25 to 100 times the diameter of this cylindrical roller. More preferably, the inner side surface of the flange portion and the axial end surface of the cylindrical roller contact each other near the radial center of the inner side surface of the flange portion.

[0011]

According to the rotary support device of the present invention constructed as described above, the assembling operation can be easily performed, and the axial load generated due to the meshing of the helical gears can be supported. That is, since cylindrical roller bearings are used as rolling bearings for supporting the rotating shaft with respect to the fixed portion, adjustment work when assembling each of these cylindrical roller bearings between the rotating shaft and the fixed portion is easy. Become. Further, the axial load can be supported by the engagement between the inner side surface of the flange portion and the axial end surface of the cylindrical roller.

In addition, in the case of the rotary support device of the present invention, the rotary support devices come into sliding contact with each other while supporting the axial load.
Since the shapes of the inner side surface of the flange portion and the axial end surface of the cylindrical roller are regulated, damages such as galling and seizure are less likely to occur in the engagement portion between these two surfaces. Accordingly, a large axial load can be supported, and the degree of freedom in designing the helical gear portion is improved.

Next, the reasons for limiting the numerical values that regulate the present invention will be described. First, the torsion angle of the helical gear is 6 to 2
The reason for limiting the range to 5 degrees will be described with reference to FIG. FIG. 1 shows the relationship between the torsion angle β of the helical gear and the ratio η (η = axial load / radial load) between the radial load and the axial load. Note that this ratio η is
It fluctuates to some extent according to the specifications (dimensions, span between a plurality of cylindrical roller bearings provided, pitch diameter of a helical gear, etc.) of the rotary support device. Therefore, FIG. 1 shows the ratio η
To some extent.

A cylindrical roller bearing for supporting an axial load based on engagement between an axial end face of a cylindrical roller and an inner side surface of a flange provided at an end of a peripheral surface of a bearing ring, which constitutes the rotation support device of the present invention. In the case of (a cylindrical roller bearing with a flange for supporting an axial load), generally, under such load conditions that the above-mentioned ratio η becomes 0.2 or more (the ratio of the axial load is large), the inner surface of the flange portion is Based on the sliding friction at the contact portion with the axial end surface of the cylindrical roller, the amount of heat generated at this contact portion is increased, and the damage such as galling and seizure is likely to occur. Therefore, when the above-mentioned ratio η is 0.2 or more and the above-mentioned torsion angle β is 6 degrees or more, special consideration is required for the cylindrical roller bearing with a flange for axial load bearing to be used. Conversely, when the ratio η is less than 0.2, the amount of heat generated during operation is limited, and the above-mentioned damage is unlikely to occur, so that special consideration is not required. Therefore, the lower limit of the torsion angle β of the helical gear is set to 6 degrees.

On the other hand, in a region where the ratio η of the radial load to the axial load exceeds 0.8, a cylindrical roller bearing with a flange for supporting an axial load cannot be applied (for example, abnormal heat generation, galling, seizure, etc.). Damage cannot be prevented), and a combination with another thrust bearing is required. In such a case, the cylindrical roller bearing does not need to support the axial load, and the special consideration as described above becomes unnecessary. FIG.
As is apparent from the above, when the twist angle β is 25 degrees or more, the ratio η exceeds 0.8 depending on the specifications of the rotation support device. Therefore, the upper limit of the twist angle β of the helical gear is set to 25 degrees.

Next, the sectional shape of the inner surface of the flange is regulated,
The reason for crowning the axial end face of the cylindrical roller will be described. In the case of a railway vehicle incorporating the rotation supporting device of the present invention, the rotation speed of the drive motor 6 (FIG. 10) increases due to the increase in speed, and the use conditions of the cylindrical roller bearings are becoming severer accordingly. The inner surface of the flange portion is inclined toward the outside in the axial direction of the raceway ring provided with the flange portion (with the flange opened outward) toward the outer diameter side, and the axial end surface of the cylindrical roller is The crowning of the part that abuts against the inner surface of the flange part is performed under severe load conditions, saying that not only the radial load but also the axial load is received by the flanged cylindrical roller bearing for axial load bearing. Even when the above-described cylindrical roller bearing with axial load bearing flanges is operated at high speed, it is effective to prevent the occurrence of damage such as galling, seizure and abnormal wear. By forming the inner surface and the axial end surface in such a shape, a wedge-shaped space whose thickness becomes smaller toward the contact portion is formed around the contact portion between these two surfaces. Then, the lubricating oil existing around the contact portion is taken into the space along with the rolling of the cylindrical roller, and a strong oil film is formed at the contact portion.
As a result, it is possible to prevent the metal contact from occurring at the contact portion, and to effectively prevent the above-described damages such as galling, seizure, and abnormal wear.

Further, according to the inner surface of the flange portion having a linear cross section and the crowning provided on the axial end surface of the cylindrical roller, the inclination angle of the inner surface, the radius of the crowning, The position of the contact portion where the two surfaces contact each other can be set to an arbitrary height in the radial direction of the inner side surface. Therefore, there is an advantage that the design for improving the lubrication state of the contact portion is facilitated.

That is, among the driving devices for railway vehicles, the lubrication of the cylindrical roller bearing for rotatably supporting the drive shaft 4 to which the drive pinion 5 is fixed with respect to the housing 9 is lubricated with the drive pinion 5. The driven large gear 3 meshed with the housing 9
(FIGS. 10 and 11) This is performed with the mist-like lubricating oil scattered by splashing up the lubricating oil existing in the inside. Such a lubrication state
It is severe for the above-mentioned cylindrical roller bearing (it cannot be said to be a sufficient lubrication method). In particular, when the vehicle is started in the cold season, the viscosity of the lubricating oil in the housing 9 is high due to the low temperature, and the lubricating oil is not easily scattered. It may not be possible to supply. In consideration of such circumstances, the drive shaft 4 is connected to the housing 9.
On the other hand, in a cylindrical roller bearing for rotatably supporting the cylindrical roller bearing, it is desirable to set the position of the abutting portion where the two surfaces abut to each other at an optimum location in view of lubrication. The present invention can sufficiently respond to such a demand. Therefore, the optimum position of the contact portion will be described with reference to FIG.

As shown in FIG. 2, the inner side surface 14 of the flange 13 formed at the end of the peripheral surface of the race 12 constituting the cylindrical roller bearing is positioned at the center of the race 12 on which the flange 13 is provided. An angle inclined with respect to an imaginary plane (normal to the raceway surface) orthogonal to the axis is defined as θ, and a radius of crowning applied to the axial end face 16 of the cylindrical roller 15 is defined as r. This axial end face 1
A well-known contact ellipse exists at the contact portion between the inner surface 14 and the inner surface 14. The shape and size of the contact ellipse are as follows.
It is determined by the inclination angle θ and the crowning radius r. Therefore, in order to optimize the position, the shape and the size of the contact ellipse, the inclination angle θ and the radius r of the crowning are restricted.

When actually designing the above-mentioned cylindrical roller bearing, it is necessary to determine the above-mentioned inclination angle θ and the radius r of the crowning in consideration of operating conditions. In the case of a cylindrical roller bearing, generally, when calculating the contact point between the inner surface 14 and the axial end surface 16, a state where no axial load is applied, that is, these two surfaces contact very lightly. Calculate position in state. On the other hand, when an axial load is applied, the contact position between the two surfaces is determined by the internal clearance of the cylindrical roller bearing or the cylindrical roller 15.
Due to the influence of the tilt or the like, it changes with respect to the case of no load. Further, the size of the contact ellipse changes according to the magnitude of the axial load.

Accordingly, in the case of a cylindrical roller bearing in which a large axial load is applied by the meshing of the driving small gear 5 and the driven large gear 3, each of which is a helical gear, the contact point caused by the axial load It is necessary to determine the position of the contact point in consideration of the change in the position and the size of the contact ellipse. In particular, in the case of cylindrical roller bearings incorporated in gear transmissions for driving railway vehicles that require a high degree of reliability, a relatively large axial load must be applied in order to suppress the occurrence of problems such as seizure. Assuming that the inclination angle θ and the radius r of the crowning need to be determined.

When the size of the contact ellipse formed in the contact portion is theoretically obtained, the size of the contact ellipse may protrude from the inner surface 14 of the flange 13 depending on conditions. . Actually, no load is applied to the protruding portion (in fact, there is no portion that should become a contact ellipse in that portion), so not only the surface pressure of the portion that is actually in contact increases, The peripheral portion of the flange portion 13 and the flange portion 13
At the edge portion of the escape groove 17 formed at the base end portion, excessive surface pressure based on the edge load is easily applied. Such excessive surface pressure is not preferable because it causes damage such as abnormal wear and galling. On the other hand, depending on the magnitude of the axial load, a part of the contact ellipse may protrude from the inner surface 14 of the flange portion 13 (about half if the contact ellipse is significant). In order to eliminate the inconvenience that occurs in such a case, it is preferable that the position of the contact point be disposed near the center of the inner side surface 14 of the flange 13 in the radial direction of the flange 13. With this arrangement, even if the contact ellipse protrudes from the inner side surface 14 based on the axial load, the protruding amount can be minimized.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 shows a structure suitable for implementing the rotation supporting device of the present invention.
342 shows a railway vehicle drive device described in Japanese Patent Application Publication No. 342-342. The drive shaft 4, which is a rotating shaft, rotates together with a drive small gear 5, which is a helical gear fixed to the outer peripheral surface of the intermediate portion.
A pair of cylindrical roller bearings 18a and 18b are provided between the housing 9 which is a fixed part and the middle part and the tip part (right end in FIG. 3) of the drive shaft 4, and the drive shaft 4 is connected to the housing 9 It is rotatably supported with respect to. Further, the axle 2 to which the driven large gear 3 which is also a helical gear meshed with the driving small gear 5 is fixed to the housing 9 by a pair of cylindrical roller bearings 18a and 18b.

Each of these cylindrical roller bearings 18a, 18b
The cylindrical rollers 15, 15 are used as rolling elements. In the case of a cylindrical roller bearing, generally, an axial load cannot be supported even if a radial load can be supported. However, in the case of the rotary support device described in the above publication, at least one of the cylindrical roller bearings 18a and 18b ( In the illustrated example, the cylindrical roller bearing 18a (on the right in FIG. 3) is formed based on the engagement between the axial end surface of the cylindrical roller 15 and the inner surface of the flange provided at the peripheral end of the bearing ring. The one that can support the axial load is used. For this reason, in the illustrated example, as shown in FIG. 4A, one cylindrical roller bearing 18a capable of supporting axial loads in both directions is used. That is, 1 is formed at both ends of the inner peripheral surface of the outer ring 19.
The inner surfaces of the pair of inward flange portions 20 and the axially opposite end surfaces of the cylindrical roller 15 are opposed to each other, so that axial loads in both directions can be supported between the cylindrical roller 15 and the outer ring 19. In addition, the inner surface of the outward flange 22 formed at one end (the left end in FIG. 4) of the outer peripheral surface of the inner race 21 and the inner race 2
1, the inner surface of the collar ring 23 abutting against the other end surface (the right end surface in FIG. 4) and both axial end surfaces of the cylindrical roller 15 are opposed to each other. Axial loads in both directions can be freely supported between a member (the drive shaft 4 or the axle 2) to which the outside is fixed. With this configuration, the axial load applied to the drive shaft 4 or the axle 2 can be supported by the housing 9 in which the outer ring 19 is fitted and fixed.

Since the drive shaft 4 and the axle 2 are supported by a pair of cylindrical roller bearings 18a and 18b, respectively, these cylindrical roller bearings 18a and 18b are formed as shown in FIG. It is also possible to use a cylindrical roller bearing 18c that can support only an axial load in one direction. In the illustrated example, one end of the outer peripheral surface (FIG. 10) is used as the inner race 21a.
(The right end of the rim) is provided with an outward flange 22 and is not provided with a flange ring 23 as shown in FIG. When such a structure is used, the axial load directions that can be supported by the pair of cylindrical roller bearings 18c are reversed. Furthermore,
As shown in FIGS. 4 (C) and 4 (D), cylindrical roller bearings 18d and 18e whose inside and outside are reversed in the radial direction can be used for the structure shown in FIGS. 4 (A) and 4 (B).

In any case, cylindrical roller bearings 18a, 18b (or 18c, 18d, 18) are used as rolling bearings for supporting the drive shaft 4 and the axle 2 with respect to the housing 9.
e. same as below. ), The adjustment work when assembling these cylindrical roller bearings 18a, 18b between the drive shaft 4 and the axle 2 and the housing 9 becomes easy. or,
The axial load generated by the meshing of the driving pinion 5 and the driven pinion 3 is applied to the axial end faces of the cylindrical rollers 15, 15 constituting the cylindrical roller bearing 18b, the inner surface of the inward flange 20 and the outward flange. It can be supported based on engagement with the inner surface of the collar 22 or the collar ring 23.

Further, in the case of the present invention, as described above, the drive shaft 4 (or the axle 2, hereinafter the same) having the drive small gear 5 (or the driven large gear 3, hereinafter the same) fixed to the outer peripheral surface thereof is housed. 9, the inner surface 14 of the flange portion 13 (a generic name of the inward flange portion 20 and the outward flange portion 22) is rotatably supported by cylindrical roller bearings 18 a and 18 b, as shown in FIG. The outer ring 19 is inclined toward the outside in the axial direction toward the outside of the raceway ring (general term for the outer ring 19 and the inner rings 21 and 21a) provided with the flange portion 13 and is formed on the axial end face 16 of the cylindrical roller 15. By performing the crowning, the lubricating property of the rubbed portion between the axial end surface 16 and the inner side surface 14 is improved.

In order to improve the lubrication of the rubbed portion, the inclination angle θ of the inner surface 14 of the flange 13 is determined.
The case where the optimum value of the crowning radius r of the axial end face 16 of the cylindrical roller 15 is calculated will be described. As a premise of the calculation, it was assumed that the torsion angle of the drive small gear 5 which is a helical gear was 20 degrees. In this case, the ratio η between the radial load and the axial load is about 0.5, as is clear from FIG. In addition, the radius r of the crowning was made dimensionless as a ratio to the diameter D of the cylindrical roller 15. That is, the absolute value of the crowning radius is expressed as R
, R = R / D. The center of the radius of curvature of the crowning is assumed to be on the central axis α of the cylindrical roller 15 (FIG. 2). In the case of a rotation supporting device incorporated in a gear transmission for driving a railway vehicle, the rotation speed of the inner ring 21 (21a) of the cylindrical roller bearing 18a (18b) differs depending on the railway vehicle. Was set to about 4000 min ^-1 .

Under the above-described conditions, the inclination angle θ and the radius r of the crowning are different.
In the three cases, the contact position and the like between the inner surface 14 and the axial end surface 16 in each case were obtained by calculation. θ = 20 minutes, r = 75 θ = 20 minutes, r = 90 θ = 20 minutes, r = 60

The contact position between the two surfaces 14, 16 in the above case is shown in FIG. 5 (A), and the contact position in the above case is also shown in FIG. 5 (B). As,
Similarly, the contact positions in the above case are respectively as shown in FIG. 5A to 5C, a chain line on the outer diameter side is a flange line 1
The inner diameter side end of the chamfer formed on the outer peripheral edge of the inner side surface 14 of FIG. 3 and the chain line on the inner diameter side represent the outer diameter end of the clearance groove 17 (see FIG. 2). Also, FIG.
Is an outward flange formed at the end of the outer peripheral surface of the inner ring 21 (21a), but the same applies to the case of an inward flange formed at the end of the inner peripheral surface of the outer ring 19.

Considering the above cases (1) to (4), the following is obtained. First, in the case, as shown in FIG.
The contact point is located near the center in the radial direction of the inner surface 14 of the flange portion 13, and the center of the contact ellipse 24 indicated by the oblique lattice in FIG. As a result, most of the contact ellipse 24 is contained in the inner side surface 14. Conversely, the amount by which the contact ellipse 24 protrudes from the inner side surface 14 is small, and the edge load generated at the base end of the protruding portion can be suppressed to be small. That is, since the contact pressure at the contact ellipse 24 is large at the center and small at the peripheral edge, the edge load is small when the protruding portion is located at the end of the contact ellipse 24. For this reason, even under severe use conditions, such as a rotation support device incorporated in a gear transmission device for driving a railway vehicle, galling,
Damage such as seizure and abnormal wear hardly occurs.

On the other hand, in the above case, FIG.
As shown in (B), the contact point is located near the base end of the inner surface 14 of the flange portion 13, and the center of the contact ellipse 24 is also located near the base end of the inner surface 14. That is, the contact ellipse 24 is located near the base end of the inner side surface 14, and the amount of the contact ellipse 24 protruding from the inner side surface 14 is larger than in the case described above. To the center of the For this reason, in the above case, the edge load generated at the base end of the protruding portion is larger than that in the above-described case, and galling, seizure, damage such as abnormal wear is more likely to occur than in the above-described case. It is considered to be.

Further, in the above case, as shown in FIG. 5C, the contact point is located near the tip of the inner surface 14 of the flange portion 13, and the center of the contact ellipse 24 is 14 is located near the tip. That is, the contact ellipse 24 is located near the front end of the inner side surface 14, and the amount of the contact ellipse 24 protruding from the inner side surface 14 is larger than in the case described above, as in the above case. For this reason, also in the above case, the edge load generated at the base end of the protruding portion is larger than in the above-described case, and galling, seizure, damage such as abnormal wear is more likely to occur than in the above case. It is considered to be.

As described above, the inner surface 14 of the flange 13
Paying attention to the protrusion of the contact ellipse 24 from
When verifying the case of (1), it is preferable that the center of the contact ellipse 24 is positioned at the radial center of the inner side surface 14 as shown in FIG. It is generally known that it is preferable to lower the PV value in order to prevent damages such as image sticking, galling and abnormal wear. Therefore, in the above case,
Inner surface 14 of flange 13 and axial end surface 16 of cylindrical roller 15
Were obtained by calculation. The calculation result is shown in FIG.
Shown in

As is apparent from FIG. 6, the PV value is smallest when the center of the contact ellipse 24 is located at the radial center of the inner side surface 14 of the flange portion 13, and then the peripheral speed (V)
The contact ellipse 24 exists near the base end of the inner side surface 14 where is smaller. When the contact ellipse 24 exists near the tip of the inner surface 14 where the peripheral speed is high, the PV value becomes the largest. As described above, even in consideration of the PV value, the combination of the inclination angle θ of the inner side surface 14 of the flange portion 13 and the crowning radius r of the axial end surface 16 of the cylindrical roller 15 is as follows.
The above can be said to be the most preferable.

In this way, as is clear from comparison of the protrusion of the contact ellipse 24 from the inner side surface 14 of the flange portion 13 and the PV value in the above three cases, as shown in FIG. By arranging the contact point at the radial center of the inner side surface 14, the protrusion of the contact ellipse 24 can be minimized and the PV value can be reduced, thereby effectively preventing the occurrence of damage such as galling, seizure and abnormal wear. it can. Specifically, when the inclination angle θ of the inner side surface 14 is set to 20 minutes, if the radius r of the crowning of the axial end surface 16 is set to about 75, the contact points of the two surfaces 14 and 16 will Located at the center in the radial direction of the side surface 14, the protrusion of the contact ellipse 24 can be minimized, and the PV value can be reduced.

There are many combinations in which the position of the contact point between the two surfaces 14, 16 is located at the center in the radial direction of the inner side surface 14. Of these, there are many combinations. In order to be located at the center in the direction, the inclination angle θ and the radius r may not be selected from any range. The inclination angle θ and the radius r are also restricted in relation to other parts and the like. This will be described below.

First, FIG. 7 shows the position of the contact point between the two surfaces 14, 16 in relation to the inclination angle θ and the radius r. The position of the contact point is expressed as a contact point height h, which is a radial distance from a track surface existing on the base end side of the inner side surface 14. The height h of the contact point is made dimensionless by dividing the absolute value by the outer diameter D of the cylindrical roller 15 (FIG. 2). The calculation shown in FIG. 7 takes into account the radial load and the axial load that are considered to act when the rotation support device of the present invention is incorporated in a gear transmission for driving a railway vehicle. is there.

In the case of the cylindrical roller bearings 18a and 18b constituting the rotary support device to which the present invention is applied, the height H (FIG. 2) of the flange 13 is generally 20% of the diameter D of the cylindrical roller 15.
(H ≒ 0.2D). Therefore, in order to minimize the protrusion of the contact ellipse 24, the two-sided 1
In order to arrange the positions of the contact points 4 and 16 near the center of the height H of the flange 13, it is necessary to set the contact point height h to about 0.1. If it is determined that the contact height h is set to about 0.1, the value of the radius of curvature r of the crowning according to the inclination angle θ can be obtained from FIG. For example, assuming that the inclination angle θ is 60 minutes, the optimal value of the radius of curvature r of the crowning is 25. On the other hand, assuming that the inclination angle θ is 70 minutes, if the contact points of the both surfaces 14 and 16 are to be located at the radial center of the inner surface 14 of the flange portion 13, The curvature radius r becomes a value smaller than 25. Too small a value of the radius of curvature r is not preferable from the viewpoint of reducing the PV value. This point will be described with reference to FIG.

In FIG. 8, the horizontal axis represents the radius of curvature r of the crowning, and the vertical axis represents the contact pressure between the two surfaces 14 and 16. The solid line shows the relationship when the inclination angle θ is 10 minutes, and the broken line shows the relationship when the inclination angle θ is also 60 minutes. As is apparent from FIG. 8, when the radius of curvature r of the crowning is reduced, the surface pressure of the abutting portions of the two surfaces 14 and 16 increases.
It causes an increase in the PV value. Accordingly, the above-mentioned radius of curvature r is set so as to suppress the increase in the surface pressure and, consequently, the PV value.
It is preferably 25 or more. As described above, the radius of curvature r of 25 is an optimum value when the inclination angle θ is 60 minutes. Conversely, when the radius of curvature r is 25, the optimum value of the inclination angle θ is 60 minutes. Therefore, a value of 60 minutes or more is not necessary as the inclination angle θ, but in an actual case, a processing error inevitable in processing is estimated to be a maximum of 5 minutes, and the upper limit value of the inclination angle θ is set to 65 minutes. I do.

The upper limit of the inclination angle θ is set to 65 minutes as described above, and the lower limit of the inclination angle θ is determined by the contact ellipse 24 (FIG. 5) existing at the contact portions of the two surfaces 14 and 16. It is regulated from the aspect of suppressing the amount of protrusion. In this regard,
This will be described with reference to FIGS. When the inclination angle θ is reduced, as is clear from FIG. 7, when the position of the contact portion between the two surfaces 14 and 16 is to be positioned within the inner surface 14 of the flange portion 13 (the contact contact height h Is set to 0.2 or less, more preferably about 0.1), it is necessary to increase the radius of curvature r. However, this radius of curvature r
Is increased, the contact pressure of the contact portion between the two surfaces 14 and 16 is reduced, but the contact ellipse 24 existing in the contact portion is reduced.
Becomes large, and the contact ellipse 24 protrudes from both the inner and outer peripheral edges of the inner side surface 14, so that the protruding amount increases.

FIG. 9 shows the ratio ε of the protruding amount to the area of the contact ellipse 24 (the protruding amount / the area of the contact ellipse 24 assuming that the protruding amount is zero and the protruding amount is zero. ) And the above-mentioned crowning radius of curvature r. In the case of FIG. 9 as well, as in the case of FIG. 8 described above, the solid line represents the relationship when the inclination angle θ is 10 minutes, and the broken line represents the relationship when the inclination angle is also 60 minutes. I have. In order to suppress the surface pressure of the contact portion between the two surfaces 14 and 16 and the rise of the edge load,
Generally, the upper limit of the ratio ε of the protruding amount should be 0.5. When the curvature radius r is 100 or more, when the inclination angle θ is set to the upper limit of about 65 minutes,
The ratio ε of the protruding amount exceeds 0.5. Therefore, the upper limit of the curvature radius r is set to 100.

When the radius of curvature r increases, the change in the shape of the crowning portion of the axial end face 16 of the cylindrical roller 15 becomes gentle, and the amount of change is small, making measurement difficult. Such a situation is not preferable in the process control. When the radius of curvature r is set to 100, the amount of change in the shape of the axial end face 16 is on the order of several micrometers when converted from the specifications of the actually used cylindrical roller bearing. In a region where the radius of curvature r exceeds 100, the amount of change is on the order of μm or less, and the influence of the measurement error increases. Therefore, it is not preferable to adopt a value exceeding 100 as the radius of curvature r of the crowning.

Next, the lower limit value of the inclination angle θ will be described. When a value slightly exceeding the upper limit value 100 of the curvature radius r is adopted, for example, in FIG.
08, when the inclination angle θ is set to 15 minutes, the abutting portion between the two surfaces 14 and 16 is
Near the center of the inner surface 14 in the radial direction (h = approximately 0.1). However, when the inclination angle θ is set to 10 minutes or less, the position of the contact point between the two surfaces 14 and 16 is displaced from the inner side surface 14 of the flange portion 13 (the contact point height h is set to 0.2. Will exceed). Therefore, the inclination angle θ
Cannot be less than 10 minutes. In addition, the radius of curvature r does not exceed 100 in view of reducing the ratio ε of the amount of protrusion to the area of the contact ellipse 24 to 0.5 or less. Therefore, focusing on the straight line of r = 100 in FIG. 7, when the inclination angle θ is about 16 minutes, the position of the contact point between the two surfaces 14 and 16 is determined by the diameter of the inner surface 14 of the flange portion 13. It will be arranged at the center in the direction. Further, in order to arrange the contact point between the two surfaces 14 and 16 in the inner surface 14, the inclination angle θ needs to be 12 minutes or more. In consideration of these facts, similarly to the case of the maximum value, the processing error inevitable in processing is estimated to be about 5 minutes at the maximum, and the lower limit value of the inclination angle θ is set to 15 minutes.

The upper limit value and the lower limit value of the inclination angle θ of the inner surface 14 of the flange portion 13 and the radius of curvature r of the crowning of the axial end surface 16 of the cylindrical roller 15 described above are summarized as follows. become. Range of the inclination angle θ: 15 to 65 minutes Range of the radius of curvature r of the crowning: 25 to 100 In addition, as is clear from FIG.
The value of the inclination angle θ is not limited to 20 minutes as described above, but may be 30 to 40 minutes, or even about 60 minutes.
By appropriately regulating the value of the radius of curvature r of the crowning, the contact point between the two surfaces 14 and 16 can be changed to the flange portion 13.
Can be located near the center in the radial direction of the inner side surface 14. The same contact state as described above can be realized, and even if the axial load applied to the cylindrical roller bearings 18a (18b) is relatively large, the contact ellipse 2
4 can be minimized. That is,
When the inclination angle θ is 30 minutes, the radius of curvature r is about 50, and when the inclination angle θ is 40 minutes, the radius of curvature r is 3
By setting the radius of curvature r to about 25 when the inclination angle θ is 60 minutes, the position of the contact point between the two surfaces 14 and 16 is adjusted to the radial center of the inner side surface 14 of the flange 13. Can be placed nearby. Even when the contact ellipse 24 protrudes from the inner side surface 14, the amount of the protruding ellipse 24 can be minimized.

[0046]

Since the present invention is constructed and operates as described above, it can be operated at a high speed under severe lubrication conditions like a rotary support device incorporated in a gear transmission for driving a railway vehicle. Even in such a case, it is possible to prevent damage such as galling, seizure, and abnormal wear, and to improve the durability of the rotation support device.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a torsion angle of a helical gear and an generated axial load.

FIG. 2 is a schematic diagram showing an inclination angle θ of an inner side surface of a flange portion and a radius of curvature r of crowning of an axial end surface of a cylindrical roller.

FIG. 3 is an enlarged view of a part A in FIG. 10 showing an example of a rotation support device to which the embodiment of the present invention is applied.

FIG. 4 is a partial cross-sectional view showing four examples of a cylindrical roller bearing to be incorporated in a rotation support device to which the present invention is applied.

FIG. 5 shows three examples of a state in which the position of a contact ellipse existing at the contact portion between the inner side surface of the flange portion and the axial end surface of the cylindrical roller changes according to the inclination angle θ and the radius of curvature r. The figure shown in the state seen from the left.

FIG. 6 is a graph showing the influence of the inclination angle θ and the radius of curvature r on the PV value of the contact portion.

FIG. 7 is a diagram showing a relationship among the inclination angle θ, the radius of curvature r, and the contact point height h.

FIG. 8 is a diagram showing the relationship between the radius of curvature r of crowning and the surface pressure.

FIG. 9 is a diagram showing a relationship between a ratio ε of a protrusion amount of a contact ellipse and a radius of curvature r of crowning.

FIG. 10 is a schematic cross-sectional view showing an example of a gear transmission device for driving a railway vehicle, which incorporates a rotation support device to which the present invention is applied.

FIG. 11 is an enlarged view of a part A of FIG. 10 showing one example of a conventional structure.

[Explanation of symbols]

Reference Signs List 1 wheel 2 axle 3 driven large gear 4 driven shaft 5 drive small gear 6 drive motor 7 output shaft 8 joint 9 housing 10, 10a cylindrical roller bearing 11, 11a ball bearing 12 raceway ring 13 flange portion 14 inner surface 15 cylindrical roller 16 shaft Direction end face 17 Escape groove 18a, 18b, 18c, 18d, 18e Cylindrical roller bearing 19 Outer ring 20 Inward flange 21, 21a Inner ring 22 Outward flange 23 Collar ring 24 Contact ellipse

 ────────────────────────────────────────────────── ─── Continued from the front page F term (reference) 3J009 DA16 DA17 EA04 EA05 EA12 EA21 EA32 EB23 FA03 3J101 AA13 AA42 AA54 AA62 BA53 BA54 BA57 CA04 FA32 FA33 FA44 GA02

Claims (3)

[Claims] A rotating shaft fixed to an outer peripheral surface thereof and rotating together with a helical gear; and a rolling bearing for rotatably supporting the rotating shaft with respect to a fixed portion, wherein the rolling bearing comprises a rolling element. Is a cylindrical roller, is a cylindrical roller bearing that supports an axial load based on the engagement between the axial end surface of the cylindrical roller and the inner surface of the flange provided at the end of the peripheral surface of the bearing ring. The torsion angle of the helical gear is 6 to 25 degrees, the cross-sectional shape of the inner surface of the flange is a straight line, and the inner surface of the shaft of the bearing ring provided with the flange toward the outer diameter side. A rotary support device, which is inclined in a direction outward in a direction, wherein a portion facing an inner side surface of the flange portion at an axial end surface of the cylindrical roller is crowned. 2. The angle between the inner side surface of the flange portion and an imaginary plane orthogonal to the center axis of the raceway provided with the flange portion is 15 to 65 minutes, and the axial end surface of the cylindrical roller is provided. Radius of the cylindrical roller is 25 to 10
The rotation support device according to claim 1, wherein the rotation support device has 0 times. 3. The rotation according to claim 1, wherein the inner surface of the flange portion and the axial end surface of the cylindrical roller contact each other near the radial center of the inner surface of the flange portion. Support device.