Bearing with sealing device

Abstract

To provide a bearing with a sealing device capable of improving sealability inexpensively.SOLUTION: A bearing with a sealing device comprises a metal shield plate mounted to an axially open end part between an inner ring and an outer ring of the bearing. The shield plate is composed of: a cylindrical mounting part that is fitted internally to an inner diameter surface of the outer ring; a body part that extends radially from an axially outer edge of the mounting part, and covers the axially open end part; and an extension part that extends axially inward from a radial edge of the body part. An additional member is arranged on an outer diameter surface of the inner ring of the bearing facing the extension part to prevent foreign matter from entering a gap between the extension part and an outer diameter surface of the inner ring of the bearing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bearing with a sealing device. [Background technology]

[0002] As shown in Figure 12, the main components of a bearing with a sealed device are an inner ring 1, an outer ring 2, double-row rolling elements 3 (cylindrical rollers), and a cage 4. A raceway is formed on the outer surface of the inner ring 1, and it is fitted onto the end of an axle (not shown) serving as a rotating member. A flange 1a is formed integrally with the inner ring 1 at the rear end of the axle, while a flange ring 5, separate from the inner ring 1, is disposed on the front end of the axle as an inner member. The outer ring 2 has double-row raceways formed on its inner surface, and is incorporated into an axle box (not shown) serving as a stationary member. The rolling elements 3 are interposed between the raceways of the inner ring 1 and the outer ring 2 so that they can roll freely. The cage 4 is interposed between the inner ring 1 and the outer ring 2, and holds the rolling elements 3 of each row at a predetermined interval in the circumferential direction. The inner ring 1 and flange ring 5 are fitted onto an axle (not shown), and the bearing is fixed to the axle by bolting a front cover (not shown) to the end of the axle via a nut.

[0003] Sealing devices 9 are provided at both ends of the bearing configured as described above, i.e., at the axial open ends of the inner ring 1 and outer ring 2, to prevent the intrusion of water and dust from the outside and the leakage of internal grease. These sealing devices 9 are double non-contact labyrinth seals consisting of a first sealing member 10 and a second sealing member 11, with the first sealing member 10 attached to both ends of the outer ring 2 and the second sealing member 11 attached to the rib ring 5 and the rib portion 1a of the inner ring 1.

[0004] That is, the bearing described in Patent Document 1 is provided with a pair of seal members 10, 11, which form a labyrinth seal, thereby preventing the intrusion of water and dust from the outside and the leakage of internal grease. Furthermore, by sealing grease between the labyrinths, it is possible to exert the effect of a grease seal.

[0005] However, when two seal members 10, 11 are used, each seal member 10, 11 must be formed by press working, which requires the production of a molding die and the cost of the molding die, resulting in poor productivity.

[0006] Therefore, a sealing device can be proposed that can be manufactured inexpensively using one seal member (shield plate) for each sealing device. In this case, the sealing device shown in Figure 11 can be considered.

[0007] That is, the bearing with sealing device shown in Figure 11 constitutes a double-row bearing device having a pair of bearings 18A, 18B, and each bearing 18 (18A, 18B) is equipped with a bearing inner ring 20 having a raceway surface 20a formed on its outer diameter surface 19, a bearing outer ring 22 having a raceway surface 22a formed on its inner diameter surface 21, rolling elements 23 interposed between the raceway surface 20a of the bearing inner ring 20 and the raceway surface 22a of the bearing outer ring 22, a retainer 24 that holds the rolling elements 23 between the outer diameter surface 19 of the bearing inner ring 20 and the inner diameter surface 21 of the bearing outer ring 22, and a sealing device S that seals the axial opening between the bearing inner ring 20 and the bearing outer ring 22.

[0008] A flange 19a is provided on one axial end (axial outer end) of the outer diameter surface 19 of the inner ring 20 of one bearing 18A, while the inner ring 20 of the other bearing is provided with a flange ring 25 without being provided with a flange ring 19a. That is, in this case, the inner ring 20 of the other bearing 18B has an inner ring main body 26 having a raceway surface 20a, and a flange ring 25 provided alongside the inner ring main body 26. Furthermore, flanges 21a, 21b are provided on both axial ends of the inner diameter surface 21 of each outer ring 22.

[0009] The sealing device S is composed of a single metal seal member (shield plate) 30. In this case, the shield plate 30 is composed of a cylindrical mounting portion 30a that is fitted and fixed to the axially outer flange portion 21a of the outer ring 21, a ring-shaped main body portion 30b that extends radially inward from the axially outer end portion of this mounting portion 30a and covers the axial opening between the inner ring 20 and the outer ring 22, and an extension portion 30c that extends axially inward from the radially inner end portion of this main body portion 30b.

[0010] In this case, the sealing device S on one bearing 18A side has the extension portion 30c facing the flange portion 19a of the inner ring 20, and the sealing device S on the other bearing 18B side has the extension portion 30c facing the flange ring 25. That is, the extension portion 30c of one sealing device S and the flange portion 19a of the inner ring 20 face each other with a predetermined gap between them, and the extension portion 30c of the other sealing device S and the flange ring 25 face each other with a predetermined gap between them. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-316884 Summary of the Invention [Problem to be solved by the invention]

[0012] 11 is excellent in productivity, but the extension portion 30c of one sealing device S and the flange portion 19a of the inner ring 20 face closely with a predetermined gap therebetween, and the extension portion 30c of the other sealing device S and the flange ring 25 face closely with a predetermined gap therebetween. Therefore, gaps extending in the axial direction are formed at the portions where the extension portions 30c and the flange ring 25 face closely with a predetermined gap therebetween.

[0013] Therefore, there is a risk that foreign matter may enter the inside of the bearing through such gaps, resulting in poor sealing performance.

[0014] In view of the above, the present invention provides a bearing with a sealing device that can improve sealing performance at low cost. [Means for solving the problem]

[0015] The first sealing device-equipped bearing of the present invention includes an inner ring, an outer ring, rolling elements interposed between raceways formed on the outer diameter surface of the inner ring and raceways formed on the inner diameter surface of the outer ring, a cage that holds the rolling elements between the outer diameter surface of the inner ring and the inner diameter surface of the outer ring, and a sealing device that seals an axial opening between the inner ring and the outer ring, and a metal shield plate attached to the axial opening end between the inner ring and the outer ring, the shield plate comprising a cylindrical mounting portion that fits within the inner diameter surface of the outer ring, a main body that extends radially from the axial outer edge of the mounting portion and covers the axial opening end, and an extension portion that extends axially inward from the radial edge of the main body, and an additional member is arranged on the outer diameter surface of the inner ring facing the extension portion to prevent foreign matter from entering the gap between the outer diameter surface of the inner ring. Here, the axial direction is defined as the axial direction of the central axes of the inner ring and the outer ring. The direction perpendicular to the "axial direction" is defined as the "radial direction." The "circumferential direction" refers to the direction along the circumference that goes around the center of the central axis of the inner and outer rings. The definitions of these directions remain the same throughout the following explanation. Additionally, "axially inward" refers to the direction from the outside of the bearing, separated by the bearing shield plate, toward the inside of the bearing, which contains the rolling elements.

[0016] According to the first bearing with sealing device of the present invention, an additional member for preventing foreign matter from entering the gap between the extension part and the outer diameter surface of the bearing inner ring is provided, thereby improving reliability in preventing foreign matter from entering the inside of the bearing. Moreover, only one shield plate is required for one sealing device, so the cost of the molding die does not increase.

[0017] The additional member is a ring fitted onto the outer diameter surface of the inner ring of the bearing, and the ring may be interposed between the extension and the outer diameter surface of the inner ring of the bearing, or the raised end face of the ring may face closely to the axially inner end of the extension. Whether the additional member is interposed between the extension and the outer diameter surface of the inner ring of the bearing, or the raised end face of the ring faces closely to the inner diameter end of the extension, it can be configured to stably prevent foreign matter from entering the inside of the bearing.

[0018] The second bearing with a sealing device of the present invention is a bearing with a sealing device comprising a bearing inner ring, a bearing outer ring, rolling elements interposed between a raceway surface formed on the outer diameter surface of the inner ring and a raceway surface formed on the inner diameter surface of the outer ring, a cage that holds the rolling elements between the outer diameter surface of the inner ring and the inner diameter surface of the outer ring, and a sealing device that seals the axial opening between the inner ring and the outer ring, and is provided with a metal shield plate attached to the axial opening end between the inner ring and the outer ring, the shield plate comprising a cylindrical mounting portion that is fitted into the outer diameter surface of the inner ring, a main body portion that extends radially from the axial outer end edge of the mounting portion and covers the axial opening end, and an extension portion that extends axially inward from the radial end edge of the main body portion, and an additional member for preventing foreign matter from entering the gap between the extension portion and the inner diameter surface of the outer ring is arranged on the inner diameter surface of the outer ring facing the extension portion. In this case, the definitions of "axial direction," "radial direction," "circumferential direction," and "axially inward" are the same as those described above.

[0019] According to the second bearing with sealing device of the present invention, an additional member for preventing foreign matter from entering the gap between the extension part and the inner diameter surface of the bearing outer ring is provided, thereby improving reliability in preventing foreign matter from entering the bearing. Moreover, only one shield plate is required for one sealing device, which does not increase the cost of the molding die.

[0020] The additional member may be a ring fitted to the inner diameter surface of the bearing outer ring, and the ring may be interposed between the extension and the inner diameter surface of the bearing outer ring, or the raised end face of the ring may be closely opposed to the inner diameter end of the extension. In either case, a stable configuration can be achieved that prevents foreign matter from entering the bearing.

[0021] The additional member is preferably made of an elastic material. The elastic material may be made of resin or rubber. The material can be selected depending on the environment in which it will be used.

[0022] In this way, the bearings with sealing devices according to the present invention (the first bearing with sealing device and the second bearing with sealing device) can effectively prevent foreign matter from entering from the outside, and can also prevent leakage of internal grease in addition to preventing the intrusion of foreign matter from the outside. This results in bearings with excellent sealing properties, suppressing increases in bearing temperature, and excellent durability. [Effects of the Invention]

[0023] The present invention can provide a high-quality sealing device that can effectively prevent foreign matter from entering the bearing and the internal grease from leaking out, without increasing production costs. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a simplified cross-sectional view of a bearing assembly using a pair of bearings with sealing devices according to the present invention. [Figure 2] FIG. 2 is a simplified enlarged cross-sectional view of one bearing provided with a first sealing device. [Figure 3] FIG. 4 is a simplified enlarged cross-sectional view of one of the bearings equipped with a second sealing device. [Figure 4] FIG. 10 is a simplified enlarged cross-sectional view showing one of the bearings equipped with a second sealing device during assembly. [Figure 5] 10 is a simplified view of the main part of the sealing device of the other bearing equipped with the first sealing device. FIG. [Figure 6] 10 is a simplified view of the main part of the sealing device of the other bearing equipped with the second sealing device. FIG. [Figure 7] FIG. 10 is a simplified enlarged cross-sectional view of one of the bearings equipped with a third sealing device. [Figure 8] FIG. 10 is a simplified enlarged cross-sectional view of one of the bearings equipped with a fourth sealing device. [Figure 9] 10 is a simplified view of the main parts of the other bearing equipped with a third sealing device. [Figure 10] 10 is a simplified view of the main part of the sealing device of the other bearing equipped with the fourth sealing device. FIG. [Figure 11] FIG. 1 is a simplified cross-sectional view of a bearing device that uses a sealing device that is designed to reduce costs. [Figure 12]FIG. 1 is a cross-sectional view of a conventional bearing with a sealing device. DETAILED DESCRIPTION OF THE INVENTION

[0025] An embodiment of the present invention will now be described with reference to Figs. 1 to 10. Fig. 1 is a simplified cross-sectional view of a bearing assembly using a pair of bearings with sealing devices according to this embodiment. The bearing assembly in this case has a pair of bearings 48 (48A, 48B). Each bearing 48 (48A, 48B) includes a bearing inner ring 50 having a raceway surface 50a formed on its outer diameter surface 49, a bearing outer ring 52 having a raceway surface 52a formed on its inner diameter surface 51, rolling elements 53 interposed between the raceway surface 50a of the bearing inner ring 50 and the raceway surface 52a of the bearing outer ring 52, a cage 54 that holds the rolling elements 53 between the outer diameter surface 49 of the bearing inner ring 50 and the inner diameter surface 51 of the bearing outer ring 52, and a sealing device S that seals an axial opening between the bearing inner ring 50 and the bearing outer ring 52.

[0026] The axial direction of the central axes of the inner ring 50 and the outer ring 52 is defined as the "axial direction." The direction perpendicular to the "axial direction" is defined as the "radial direction." The "circumferential direction" refers to the direction along the circumference around the central axis of the central axes of the inner ring 50 and the outer ring 52. The definitions of these directions are the same in the following explanation. Furthermore, the "axial inward" refers to the direction from the outside of the bearing, separated by a shield plate 80 (described later), toward the inside of the bearing, which includes the rolling elements 53.

[0027] A flange 49a is provided at one axial end of the outer diameter surface 49 of the inner ring 50 of one bearing 48A, while the inner ring 50 of the other bearing is provided with a flange ring 55 without being provided with a flange portion 49a. That is, the inner ring 50 of the other bearing has an inner ring main body 56 having a raceway surface 50a, and a flange ring 55 provided alongside the inner ring main body 56. Furthermore, flanges 51a, 51b are provided at both axial ends of the inner diameter surface 51 of each outer ring 52.

[0028] 2, the sealing device S includes a metal shield plate 80 that is a pressed product, and an additional member 81 that enhances sealing performance. In this case, the shield plate 80 includes a cylindrical mounting portion 80a that is fitted and fixed to the axially outer flange portion 51a of the outer ring 52, a ring-shaped main body portion 80b that extends radially inward from the axially outer end portion of the mounting portion 80a and covers the axial opening between the inner ring 50 and the outer ring 22, and an extension portion 80c that extends axially inward from the radially inner end portion of the main body portion 80b.

[0029] In this embodiment, an O-ring 82 is used as the additional member 81. In this case, a pair of circumferential grooves 83 are provided on the outer diameter surface 49a1 of the flange 49a of the inner ring 50 of one of the bearings 48A, and O-rings 82 are fitted into the respective circumferential grooves 83. As a result, portions of the O-rings 82 enter the gap formed between the extension portion 80c and the outer diameter end face of the flange 49a of the inner ring 50, thereby narrowing a portion of the passage connecting the inside and outside of the bearing. In other words, the additional member 81 is a ring body (O-ring 82) fitted onto the outer diameter surface 49 of the inner ring 50 of the bearing. The ring body (O-ring 82) is interposed between the extension portion 80c and the outer diameter surface of the inner ring of the bearing (in this case, the outer diameter surface 49a1 of the flange 49a), and can function to prevent foreign matter from entering the gap between the extension portion 80c and the outer diameter surface of the inner ring of the bearing. It is preferable that the O-rings 82, 82 and the extension portion 80c are not in contact with each other.

[0030] In the sealing device S for the other bearing, as shown in FIG. 5, an O-ring 82 constituting an additional member 81 is attached to the flange 55. That is, circumferential grooves 83 are formed in the outer diameter surface 55a of the flange 55, and O-rings 82 are fitted into these circumferential grooves 83. Therefore, in the sealing device for the other bearing, the ring bodies (O-rings 82) are also interposed between the extension portion 80c and the outer diameter surface of the bearing inner ring 50 (in this case, the outer diameter surface 55a of the flange 55), and can function to prevent foreign matter from entering the gap between the extension portion 80c and the outer diameter surface of the bearing inner ring 50 (in this case, the outer diameter surface 49a1 of the flange 49a). In this case, it is preferable that the O-rings 82 and the extension portion 80c do not come into contact with each other.

[0031] In the present invention, additional member 81 is provided to prevent foreign matter from entering the gap between extension portion 80c and the outer diameter surface of bearing inner ring 50 (outer diameter surface 49a1 of flange portion 49a), thereby improving reliability in preventing foreign matter from entering the inside of the bearing. Moreover, one metal shield plate 80 is sufficient for one sealing device, so the cost of the molding die does not increase.

[0032] Therefore, the bearing with a sealing device of the present invention can effectively prevent the intrusion of foreign matter from the outside, and can also prevent the leakage of internal grease in addition to the intrusion of foreign matter from the outside. This results in a bearing with excellent sealing properties, suppresses the rise in bearing temperature, and is excellent in durability. In other words, the present invention can effectively prevent the intrusion of foreign matter into the bearing and the leakage of internal grease to the outside, providing a high-quality sealing device. Moreover, this does not result in a rise in production costs.

[0033] 3, the additional member 81 uses a ring body (square ring) 84 with a rectangular cross section, and a circumferential groove 85 with a rectangular cross section is formed in the outer diameter surface 49a1 of the flange portion 49a of the inner ring 50 of one bearing 48A, and the ring body 84 is fitted into this circumferential groove 85. The rising end face 84a of the ring body 84 and the inner diameter end 80c1 of the extension portion 80c are closely opposed to each other. It is preferable that the rising end face 84a of the ring body 84 and the inner diameter end 80c1 of the extension portion 80c do not contact each other.

[0034] As a result, a so-called labyrinth portion is formed between the rising end surface 84a of the ring body 84 and the inner diameter end 80c1 of the extension portion 80c, which can function to prevent foreign matter from entering the gap between the extension portion 80c and the outer diameter surface (outer diameter surface 49a1 of the flange portion 49a) of the bearing inner ring 50. Therefore, even with the configuration shown in Figure 4, it is possible to provide a high-quality sealing device that can effectively prevent foreign matter from entering the inside of the bearing and the internal grease from leaking out. Moreover, this does not result in a rise in production costs.

[0035] 6, a ring body (square ring) 84 having a rectangular cross section is attached to the flange ring 55. That is, a circumferential groove 85 having a rectangular cross section is formed in the outer diameter surface 55a of the flange ring 55, and the ring body 84 is fitted into the circumferential groove 85. The rising end surface 84a of the ring body 84 and the inner diameter end 80c1 of the extension portion 80c are closely opposed to each other. Therefore, even in this case, a so-called labyrinth portion is formed between the rising end surface 84a of the ring body 84 and the inner diameter end 80c1 of the extension portion 80c, which can function to prevent foreign matter from entering the gap between the extension portion 80c and the outer diameter surface 49 of the bearing inner ring 50.

[0036] Whether the ring body is an O-ring or a square ring, it is preferable to use an elastic material for ease of installation. The elastic material may be made of resin or rubber. In this case, a material suitable for the environment in which it will be used can be used.

[0037] By making the additional member 81 elastic, it becomes easier to assemble a separable bearing such as a cylindrical roller bearing. For example, in a cylindrical roller bearing for a railway vehicle axle, the inner ring, outer ring assembly, and flange ring are assembled to the axle in this order. In this case, in a bearing in which the rising end face 84a of the ring body 84 and the inner diameter end 80c1 of the extension portion 80c are closely opposed to each other as shown in Fig. 3, the outer diameter of the additional member 81 protrudes from the inner diameter of the shield plate during assembly as shown in Fig. 4, but by using a resin material, elastic deformation becomes possible, making it possible to assemble as shown in Fig. 3.

[0038] In the sealing device shown in FIG. 1 and elsewhere, the shield plate 80 is attached to the bearing outer ring side. However, as shown in FIGS. 7 and 8, the shield plate 80 may be attached to the bearing inner ring 52. That is, the attachment portion 80a of the shield plate 80 is fitted and fixed to the flange 49a of the inner ring 52, and the extension portion 80c faces the flange 51a at the axially outer end of the outer ring 52. O-rings 82 are attached to the flange 51a at the axially outer end of the outer ring 52. That is, circumferential grooves 83 are formed in the outer diameter surface 51a1 of the flange 51a at the axially outer end of the outer ring 52, and the O-rings 82 are fitted into the recessed circumferential grooves 83. In this case, it is also preferable that the O-rings 82 and the extension portion 80c do not come into contact with each other.

[0039] The additional member 81 is a ring body (O-ring 81) fitted onto the inner diameter surface of the bearing outer ring 52, and the ring body (O-ring 81) is interposed between the extension portion 80c and the inner diameter surface of the bearing outer ring 52 (inner diameter surface 51a1 of the flange portion 51a), and can function to prevent foreign matter from entering the gap between the extension portion 80c and the inner diameter surface of the bearing outer ring 52 (inner diameter surface 51a1 of the flange portion 51a).

[0040] In the sealing device for the other bearing, as shown in FIG. 9 , a shield plate 80 is attached to the bearing inner ring (i.e., the outer diameter surface 55a of the flange ring 55), and an O-ring 82, which is an additional member 81, is attached to the flange portion 49a on the axially outer side of the outer ring 52. That is, circumferential grooves 83, 83 are formed in the inner diameter surface 49a1 of the flange portion 49a on the axially outer side of the outer ring 52, and O-rings 82, 82 are fitted into the grooves. This also serves to prevent foreign matter from entering the gap between the extension portion 80c and the inner diameter surface of the bearing outer ring 52 (the inner diameter surface 51a1 of the flange portion 51a). In this case, it is also preferable that the O-rings 82, 82 and the extension portion 80c do not come into contact with each other. In this case, it is also preferable that the O-rings 82, 82 and the extension portion 80c do not come into contact with each other.

[0041] Next, in the sealing device shown in FIG. 8, a circumferential groove 85 having a rectangular cross section is formed on the inner diameter surface 51a1 of the flange 51a of the outer ring 52, and each ring (ring body) 84 is fitted into the circumferential groove 85. The rising end surface 84a of the ring body 84 and the inner diameter end 80c1 of the extension portion 80c are closely opposed to each other. Therefore, even in this case, a so-called labyrinth portion is formed between the rising end surface 84a of the ring body 84 and the inner diameter end 80c1 of the extension portion 80c, which can function to prevent foreign matter from entering the gap between the extension portion 80c and the inner diameter surface of the bearing outer ring (the inner diameter surface 51a1 of the flange 51a). In this case, it is also preferable that the rising end surface 84a of the ring body 84 and the extension portion 80c are not in contact with each other.

[0042] 10, in the sealing device of the other bearing, a circumferential groove 85 with a rectangular cross section is provided in the inner diameter surface 51a1 of the flange 51a on the axially outer side of the outer ring 52, and each ring (ring body) 84 is fitted into the circumferential groove 85. Then, the extension portion 80c of the shield plate 80, whose mounting portion 80a is attached to the flange 55 on the inner ring 52 side, faces opposite to the inner diameter surface of the flange 51a on the axially outer side of the outer ring 52, and the rising end face 84a of the ring body 84 and the inner diameter end 80c1 of the extension portion 80c face closely opposite to each other. This forms a so-called labyrinth portion between the rising end surface 84a of the ring body 84 and the inner diameter end 80c1 of the extension portion 80c, and can function to prevent foreign matter from entering the gap between the extension portion 80 and the inner diameter surface (inner diameter surface 51a1 of the flange portion 51a) of the bearing outer ring 52. In this case as well, it is preferable that the rising end surface 84a of the ring body 84 and the inner diameter end 80c1 of the extension portion 80c are not in contact with each other.

[0043] Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments and various modifications are possible. For example, while the embodiments have shown a bearing device with a double-row bearing, a single-row bearing may also be used. Furthermore, the rolling elements are not limited to cylindrical rollers, but may also be tapered rollers or balls. In the case of a double-row bearing, one of the sealing devices may use an O-ring 82 as shown in FIG. 2, and the other sealing device may use a square ring 84 as shown in FIG. 3. That is, the two types of sealing devices may be the same type or different types. Furthermore, in the embodiments, when O-rings 82 are used as the additional member 81, two O-rings 82 are used. However, the number of O-rings 82 may be one, or even three or more. [Explanation of symbols]

[0044] 49 Outer diameter surface 50 bearing inner ring 50a Raceway surface 51 Inner diameter surface 52 Bearing outer ring 52a Raceway surface 53 Rolling elements 54 Cage 55 Tsuba ring 80 Shield plate 80a attachment part 80b Main body 80c extension part 80c11 Inner diameter end 81 Additional parts S sealing device

Claims

1. A bearing with a sealing device comprising: a bearing inner ring, a bearing outer ring, rolling elements interposed between a raceway surface formed on the outer diameter surface of the bearing inner ring and a raceway surface formed on the inner diameter surface of the bearing outer ring, a cage that holds the rolling elements between the outer diameter surface of the bearing inner ring and the inner diameter surface of the bearing outer ring, and a sealing device that seals an axial opening between the bearing inner ring and the bearing outer ring, a metal shield plate attached to an axially open end between the inner ring and the outer ring of the bearing; The shield plate comprises a cylindrical mounting portion that is fitted into the inner diameter surface of the bearing outer ring, a main body portion that extends radially from the axial outer end edge of the mounting portion and covers the axial open end, and an extension portion that extends axially inward from the radial end edge of the main body portion, and the bearing with a sealing device is characterized in that an additional member for preventing foreign matter from entering the gap between the extension portion and the outer diameter surface of the bearing inner ring is arranged on the outer diameter surface of the bearing inner ring facing the extension portion.

2. 2. The bearing with a sealing device according to claim 1, wherein the additional member is a ring body fitted to the outer diameter surface of the inner ring of the bearing, and the ring body is interposed between the extension portion and the outer diameter surface of the inner ring of the bearing.

3. 2. The bearing with a sealing device according to claim 1, wherein the additional member is a ring body fitted onto the outer diameter surface of the bearing inner ring, and the rising end face of the ring body and the axial inner end of the extension portion are closely opposed to each other.

4. A bearing with a sealing device comprising: a bearing inner ring, a bearing outer ring, rolling elements interposed between a raceway surface formed on the outer diameter surface of the bearing inner ring and a raceway surface formed on the inner diameter surface of the bearing outer ring, a cage that holds the rolling elements between the outer diameter surface of the bearing inner ring and the inner diameter surface of the bearing outer ring, and a sealing device that seals an axial opening between the bearing inner ring and the bearing outer ring, 1. A bearing with a sealing device, comprising: a metal shield plate attached to the axially open end between an inner ring and an outer ring of the bearing, wherein the shield plate comprises a cylindrical attachment portion that is fitted into the outer diameter surface of the inner ring of the bearing; a main body portion that extends radially from the axially outer end edge of the attachment portion and covers the axially open end; and an extension portion that extends axially inward from the radial end edge of the main body portion, and wherein an additional member for preventing foreign matter from entering a gap between the extension portion and the inner diameter surface of the outer ring of the bearing is disposed on the inner diameter surface of the outer ring of the bearing facing the extension portion.

5. 5. A bearing with a sealing device according to claim 4, characterized in that the additional member is a ring body fitted to the inner diameter surface of the bearing outer ring, and the ring body is interposed between the extension portion and the inner diameter surface of the bearing outer ring.

6. 5. A bearing with a sealing device according to claim 4, characterized in that the additional member is a ring body fitted onto the inner diameter surface of the bearing outer ring, and the rising end face of the ring body and the axial inner end of the extension portion are closely opposed to each other.

7. 5. The bearing with a sealing device according to claim 1, wherein the additional member is an elastic member.

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