Sealing device

Abstract

The sealing device has a first sealing member and a second sealing member. The first sealing member has a sleeve and a flange mounted to the inner member. The second sealing member has a tubular portion mounted to the outer member, a circular plate portion opposite the flange, a radial lip slidably contacting the sleeve, and a side lip extending from the circular plate portion toward the flange and slidably contacting the flange. The first sealing member has a first annular protrusion protruding from the flange toward the circular plate portion of the second sealing member. The first protrusion is disposed radially outward of the side lip and radially overlaps the side lip. The second sealing member has a second annular protrusion protruding from the circular plate portion toward the flange of the first sealing member. The second protrusion is disposed radially outward of the first protrusion and radially overlaps the first protrusion.

Description

Technical Field

[0001] This invention relates to sealing devices. Background Technology

[0002] A rolling bearing supporting the axle is installed in the wheel hub of a motor vehicle. This rolling bearing is called a wheel hub bearing. A sealing device is installed between the inner and outer rings of the wheel hub bearing. This sealing device seals the lubricant (grease) inside the bearing and prevents foreign objects such as water and dust from entering the bearing from the outside.

[0003] Wheel hub bearings are available in two types: inner ring rotating type and outer ring rotating type (Patent Document 1). The inner ring rotating type has an outer ring fixed to the vehicle body, and the inner ring fixed to the axle rotates with the wheel hub along with the axle. Because the wheel rotates with the axle, this type can be used whether the wheel is a driving wheel or a driven wheel. The outer ring rotating type has an inner ring fixed to a stationary axle, and the outer ring fixed to the wheel rotates with the wheel. Because the axle is stationary, this type can be used when the wheel is a driven wheel.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2015 / 182357 Summary of the Invention

[0007] The sealing device installed in the hub bearing has a sealing member fixed to the outer component, i.e., the outer ring, and another sealing member fixed to the inner component, i.e., the inner ring. These sealing members are slidably in contact with each other.

[0008] In the sealing devices used in outer ring rotating hub bearings, centrifugal force is applied to the sealing members fixed to the outer ring. To maintain contact between the sealing members even under centrifugal force, the contact pressure between them should be increased. Even under such conditions, a long service life for the sealing device is desired.

[0009] Additionally, it is desirable that in environments with high water content (including muddy or salty water), water does not penetrate the interior of the sealed object (e.g., bearing).

[0010] Therefore, the present invention provides a sealing device with high protective performance that has a long service life and is free from the influence of foreign objects.

[0011] One aspect of the sealing device of the present invention is disposed between a fixed inner member and a rotating outer member, and seals the gap between the inner member and the outer member. The sealing device comprises: a first sealing member having a sleeve mounted on the inner member and a flange extending radially outward from the sleeve; and a second sealing member having: a tubular portion disposed radially outward from the flange and mounted on the outer member; a circular plate portion extending radially inward from the tubular portion and opposite the flange; a radial lip disposed radially inward from the circular plate portion and slidably contacting the sleeve; and a side lip extending from the circular plate portion toward the flange and slidably contacting the flange. The first sealing member has an annular first protrusion projecting from the flange toward the circular plate portion of the second sealing member, the first protrusion being disposed radially outside the side lip and overlapping the side lip radially. The second sealing member has an annular second protrusion projecting from the circular plate portion toward the flange of the first sealing member, the second protrusion being disposed radially outside the first protrusion and overlapping the first protrusion radially.

[0012] According to this design, the first protrusion formed on the first sealing member reduces the leakage of grease from the space between the flange of the first sealing member and the circular plate portion of the second sealing member due to centrifugal force. Since the grease within this space reduces wear on the side lip, the life of the side lip is improved by retaining the grease within the space. Furthermore, since the second protrusion formed on the second sealing member is positioned outside the first protrusion, foreign matter is less likely to enter the space between the flange and the circular plate portion from the outside. Because the second sealing member is mounted on the rotating outer member, the second protrusion of the second sealing member can cause foreign matter to splash. Attached Figure Description

[0013] Figure 1 This is a partial cross-sectional view of an example of a rolling bearing used in the sealing device of various embodiments of the present invention.

[0014] Figure 2 This is a partial cross-sectional view of the sealing device according to the first embodiment of the present invention.

[0015] Figure 3 This is a partial cross-sectional view of the second sealing member of the sealing device according to the first embodiment.

[0016] Figure 4 This is a partial cross-sectional view of the sealing device according to the second embodiment of the present invention.

[0017] Figure 5 This is a partial cross-sectional view of the second sealing member of the sealing device according to the second embodiment.

[0018] Figure 6This is a partial cross-sectional view of the sealing device according to the third embodiment of the present invention.

[0019] Figure 7 This is a partial cross-sectional view of the second sealing member of the sealing device according to the third embodiment.

[0020] Figure 8 This is a partial cross-sectional view of the second sealing member of the sealing device in a modified example of the third embodiment.

[0021] Figure 9 This is a partial cross-sectional view of the sealing device of a modified example of the first embodiment. Detailed Implementation

[0022] The following is a reference to the attached document. Figure 1 Various embodiments of the present invention will be described below. The scale of the accompanying drawings may not be accurate, and sometimes some features may be enlarged or omitted.

[0023] Figure 1 An example of a rolling bearing used in the sealing device of various embodiments of the present invention is shown, namely a wheel hub bearing for motor vehicles. However, the application of the present invention is not limited to wheel hub bearings; the present invention can also be applied to other rolling bearings. Furthermore, although the wheel hub bearing described below is a ball bearing, the application of the present invention is not limited to ball bearings; the present invention can also be applied to other rolling bearings such as roller bearings and needle roller bearings having other types of rolling elements. In addition, the present invention can also be applied to rolling bearings used in machinery other than motor vehicles.

[0024] The wheel hub bearing 1 is an outer ring rotating type, with an inner ring fixed to a stationary axle and an outer ring fixed to the wheel that rotates together with the wheel. The wheel hub bearing 1 has: an inner ring (inner member) 6 with a hole 2 for axle insertion, an outer ring (outer member) 8 disposed outside the inner ring 6, a plurality of balls 10 arranged in a row between the inner ring 6 and the outer ring 8, a plurality of balls 12 arranged in a row between the inner ring 6 and the outer ring 8, and a plurality of retainers 14, 15 for holding these balls in predetermined positions.

[0025] The inner ring 6 is fixed to the stationary axle. The outer ring 8 serves to be fixed to the wheel hub. Therefore, a hub flange 18 is formed on the outer ring 8, and the wheel can be mounted on the hub flange 18 by means of hub bolts 19. In this way, the outer ring 8 is fixed to the wheel and rotates together with the wheel. However, the outer ring 8 and the hub flange 18 can also be formed as separate components and fixed together.

[0026] The common central axis Ax of the axle and wheel hub bearing 1 along Figure 1 It extends vertically. Figure 1In the diagram, only the left portion is shown relative to the central axis Ax. Although not illustrated in detail, Figure 1 The lower side is the outer side (external side) where the wheels of the motor vehicle are located, and the upper side is the inner side (internal side) where differential gears and the like are located. Figure 1 The outer and inner sides shown refer to the outer and inner sides of their respective radial directions.

[0027] A sealing device 20 is disposed near the cylindrical end 8A on the inner side of the outer ring 8 to close the gap between the outer ring 8 and the inner ring 6. The sealing device 20 prevents the outflow of grease, i.e., lubricant, from the internal space of the hub bearing 1, and prevents foreign matter (including water (including muddy water or salt water) and dust) from flowing into the interior of the hub bearing 1 from the outside. Figure 1 In the image, arrow F illustrates an example of the direction of flow from external foreign matter.

[0028] First Implementation Method

[0029] like Figure 2 As shown, the sealing device 20 is disposed within the gap between the inner end 8A of the outer ring 8 of the hub bearing 1 and the inner ring 6 of the hub bearing 1. The sealing device 20 is annular, but... Figure 2 Only the left side is shown. From Figure 2 It is obvious that the sealing device 20 has a composite structure including a first sealing member 30 and a second sealing member 40.

[0030] The first sealing member 30 is a fixed sealing member that is fixed to the stationary inner ring 6 and does not rotate. The first sealing member 30 is a composite structure having a rigid ring 31 and an elastic ring 32. The rigid ring 31 is formed of a rigid material, such as a metal. The elastic ring 32 is formed of an elastic material, such as an elastomer.

[0031] The rigid ring 31 has a generally L-shaped cross-section. Specifically, the rigid ring 31 includes a cylindrical sleeve 31A and an annular flange 31B extending radially outward from the sleeve 31A. The sleeve 31A is mounted on an inner ring 6. Specifically, the end of the inner ring 6 is inserted into the sleeve 31A with an interference fit. The flange 31B is a flat plate and lies in a plane perpendicular to the axis of the sleeve 31A. The flange 31B is disposed on the inner side of the sleeve 31A.

[0032] The elastic ring 32 is in close contact with the flange 31B of the rigid ring 31. Specifically, the elastic ring 32 covers the entire inner surface of the flange 31B, the outer edge of the flange 31B, and a portion of the outer side of the outer surface. Therefore, the elastic ring 32 and the flange 31B can be considered to form a flange 33.

[0033] The second sealing member 40 is a rotary sealing member fixed to and rotating on the outer ring 8. The second sealing member 40 is also a composite structure having an elastic ring 41 and a rigid ring 42. The elastic ring 41 is formed of an elastic material, such as an elastomer. The rigid ring 42 is formed of a rigid material, such as a metal, and reinforces the elastic ring 41. The rigid ring 42 has a generally L-shaped cross-section. A portion of the rigid ring 42 is embedded in and in close contact with the elastic ring 41.

[0034] The second sealing member 40 has: a tubular portion 44, a circular plate portion 45, a grease lip (radial lip) 46, a sealing lip (radial lip) 47, and a side lip 48.

[0035] The tubular portion 44 is mounted on the outer ring 8. Specifically, the tubular portion 44 is inserted into the end 8A of the outer ring 8 by an interference fit. The tubular portion 44 is composed of an elastic ring 41 and a rigid ring 42.

[0036] The circular plate portion 45 extends radially inward from the tubular portion 44 and is opposite to the flange 31B of the rigid ring 31 of the first sealing member 30. The circular plate portion 45 is disposed on the outer side of the tubular portion 44. The circular plate portion 45 is also composed of an elastic ring 41 and a rigid ring 42.

[0037] The grease lip 46 and the sealing lip 47 are disposed radially inside the circular plate portion 45 and can slidably contact the sleeve 31A. The grease lip 46 and the sealing lip 47 are formed by an elastic ring 41.

[0038] Grease is disposed in the space on the outer side of the circular plate portion 45 (the internal space of the hub bearing 1) between the outer ring 8 and the inner ring 6. This grease reduces the mutual friction between the balls 10, balls 12, outer ring 8, and inner ring 6.

[0039] The grease lip 46 is a thin plate in the shape of a truncated cone that extends radially inward and outward from the elastic portion of the radially inner end of the circular plate portion 45. The front end of the grease lip 46 contacts the outer peripheral surface of the sleeve 31A. The grease lip 46 prevents grease from flowing outward from the internal space of the hub bearing 1.

[0040] The sealing lip 47 is a bulge formed on the annular portion 49 extending radially inward from the elastic portion at the inner end of the circular plate portion 45. The annular portion 49 is also composed of an elastic ring 41. Figure 3 As shown, in the initial state where the first sealing member 30 and the second sealing member 40 are not combined, the bulge has a triangular cross-section. The sealing lip 47 contacts the outer peripheral surface of the sleeve 31A, supporting the grease lip 46. That is, it prevents grease passing through the grease lip 46 from flowing out from the outside to the inside.

[0041] A clamping spring 50 is wound around the outer periphery of the annular portion 49. The clamping spring 50 applies a radially inward compressive force to the sealing lip 47, thereby increasing the clamping force of the sealing lip 47 relative to the sleeve 31A.

[0042] The side lip 48 is a thin plate extending from the elastic portion of the circular plate portion 45 toward the flange 31B. The side lip 48 is formed by an elastic ring 41. The side lip 48 has a base 51 adjacent to the circular plate portion 45, and a front end portion 52 extending radially outward from the base 51 toward the flange 31B and having a truncated conical shape. The front end portion 52 of the side lip 48 can slidably contact the flange 31B.

[0043] The tubular portion 44 is disposed radially outside the flange 33 of the first sealing member 30, that is, further outside the elastic portion that is in close contact with the outer end edge of the flange 31B of the rigid ring 31. An annular gap 54 is provided between the tubular portion 44 and the flange 33. Foreign matter can enter the space 55 between the flange 33 of the first sealing member 30 and the circular plate portion 45 of the second sealing member 40 from the outside of the hub bearing 1 through the gap 54. Conversely, foreign matter can also be discharged from the space 55 to the outside through the gap 54.

[0044] The side lip 48 contacts the flange 31B and serves to prevent foreign objects that have entered the space 55 from further intruding toward the sealing lip 47. The side lip 48 has a very large length compared to the distance between the protruding circular portion 45 of the side lip 48 and the flange 33. This is because centrifugal force is applied to the side lip 48 as the second sealing member 40 rotates together with the outer ring 8. Since the side lip 48 should maintain contact with the flange 31B even with centrifugal force, it is designed to have a large length to increase the contact pressure between the side lip 48 and the flange 31B. Even with the high contact pressure between the side lip 48 and the flange 31B, grease is applied to the side lip 48 to reduce the torque exerted by the flange 31B on the second sealing member 40. This grease is typically a different type from the grease used to lubricate the balls 10, balls 12, outer ring 8, and inner ring 6.

[0045] However, due to the centrifugal force applied to the side lip 48, grease splashes around the side lip 48. Therefore, an annular first protrusion 60 is provided in the first sealing member 30 to block grease splashing onto the side lip 48. The first protrusion 60 protrudes from the elastic portion of the flange 33 toward the circular plate portion 45 of the second sealing member 40. Therefore, in this embodiment, the first protrusion 60 is formed by an elastic ring 32. The first protrusion 60 is disposed radially outward of the side lip 48 and overlaps with the side lip 48 radially. The first protrusion 60 reduces the leakage of grease from the space 55 between the flange 33 and the circular plate portion 45 due to centrifugal force. Since the grease in this space 55 reduces wear on the side lip 48, the life of the side lip 48 is improved by keeping the grease in the space 55.

[0046] On the other hand, the second sealing member 40 has an annular second protrusion 62 that protrudes from the elastic portion of the circular plate portion 45 toward the flange 33 of the first sealing member 30. In this embodiment, the second protrusion 62 is formed by an elastic ring 41. The second protrusion 62 is disposed radially outward of the first protrusion 60 and overlaps with the first protrusion 60 radially. A peripheral groove 63 is formed on the radially outward side of the second protrusion 62, which is recessed relative to the second protrusion 62.

[0047] Because the second protrusion 62 formed on the second sealing member 40 is disposed outside the first protrusion 60, it is difficult for foreign objects to invade the space 55 between the flange 33 and the circular plate portion 45 from the outside. Even if foreign objects invade the peripheral groove 63, the second protrusion 62 of the second sealing member 40 can cause the foreign objects to splash because the second sealing member 40 is mounted on the rotating outer ring 8.

[0048] The inner circumferential surface 62a of the annular second protrusion 62 is inclined, and its diameter increases towards the flange 33 of the first sealing member 30. Therefore, even if foreign matter intrudes into the space 55, it can be easily discharged along the inner circumferential surface 62a of the second protrusion 62. The outer circumferential surface 60a of the first protrusion 60, which is opposite to the inner circumferential surface 62a of the second protrusion 62, is also inclined, and its diameter increases towards the flange 33 of the first sealing member 30. Therefore, the outer circumferential surface 60a does not impede the flow of foreign matter along the inner circumferential surface 62a.

[0049] Second Implementation Method

[0050] Figure 4 as well as Figure 5 This relates to a second embodiment of the invention. In Figure 4 In the following figures, the same reference numerals will be used to indicate the structural elements that have already been described, and these structural elements will not be described in detail again.

[0051] In the second sealing member 40A of the sealing device 20 in the second embodiment, the front end portion 52 of the side lip 48 has a first portion 52a located on the side of the base 51 and a second portion 52b located on the side opposite to the base 51.

[0052] like Figure 5 As shown, in the initial state where the first sealing member 30 and the second sealing member 40A are not combined (no force is applied to the side lip 48), the inclination angle β of the second portion 52b relative to the axial direction of the sealing device 20 is smaller than the inclination angle α of the first portion 52a relative to the axial direction of the sealing device 20. That is, the front end 52 of the side lip 48 has two truncated conical portions 52a and 52b, with the second portion 52b, being the foremost part, being more cylindrical than the first portion 52a. Figure 4 As shown, due to the shape of the first portion 52a and the second portion 52b of the front end portion 52 of the side lip 48 in the initial state, when the first sealing member 30 and the second sealing member 40A are combined so that the side lip 48 of the second sealing member 40A contacts the flange 33 of the first sealing member 30, only the narrow region CA of the front end portion 52 of the side lip 48 contacts the flange 33.

[0053] In this regard, such as Figure 3 As shown, in the first embodiment, in the initial state, the front end portion 52 of the side lip 48 is composed of a single truncated cone-shaped portion. Figure 2 As shown, when the first sealing member 30 and the second sealing member 40 are combined such that the side lip 48 of the second sealing member 40 contacts the flange 33 of the first sealing member 30, a very wide area CA of the front end portion 52 of the side lip 48 contacts the flange 33.

[0054] Therefore, compared to the first embodiment, the second embodiment is more capable of reducing the torque exerted by the flange 33 on the second sealing member 40. This effect is further enhanced when the outer ring 8 and thus the second sealing member 40 rotate at low speeds. This is because when the second sealing member 40 rotates at high speeds, the centrifugal force exerted on the side lip 48 is increased, and the contact area CA between the side lip 48 and the flange 33 is also smaller in the first embodiment.

[0055] Third Implementation Method

[0056] Figure 6 as well as Figure 7 This relates to a third embodiment of the invention. In the second sealing member 40B of the sealing device 20 of the third embodiment, the side lip 48, in addition to the base 51 and the front end portion 52, also has an annular protrusion 70. The protrusion 70 is formed as a continuous ring on the surface of the front end portion 52 facing the flange 33. Figure 7As shown, in the initial state where the first sealing member 30 and the second sealing member 40B are not combined (no force is applied to the side lip 48), the raised portion 70 has a triangular cross section.

[0057] like Figure 6 As shown, when the first sealing member 30 and the second sealing member 40B are combined, such that the side lip 48 of the second sealing member 40B contacts the flange 33 of the first sealing member 30, the annular protrusion 70 formed at the front end portion 52 of the side lip 48 contacts the flange 33. Figure 6 In the middle, the foremost end of the front end 52 of the side lip 48 also contacts the flange 33, but due to the position of the raised portion 70 and the centrifugal force applied to the side lip 48, the foremost end of the front end 52 may not contact the flange 33.

[0058] In this regard, such as Figure 2 As shown, in the first embodiment, when the first sealing member 30 and the second sealing member 40 are combined such that the side lip 48 of the second sealing member 40 contacts the flange 33 of the first sealing member 30, a very wide region CA of the front end portion 52 of the side lip 48 contacts the flange 33.

[0059] Therefore, in the third embodiment, the area where the front end 52 of the side lip 48 contacts the flange 33 is reduced compared to the first embodiment, thereby reducing the torque exerted by the flange 33 on the second sealing member 40B. This effect is further amplified when the outer ring 8 and thus the second sealing member 40 rotate at low speeds. This is because when the second sealing member 40 rotates at high speeds, the centrifugal force exerted on the side lip 48 is increased, and the contact area CA between the side lip 48 and the flange 33 is also smaller in the first embodiment.

[0060] Figure 8 The second sealing member 40C of the sealing device is shown as a modified example of the third embodiment. In the second sealing member 40C, the side lip 48 has a raised portion 71 instead of a raised portion 70 having a triangular cross section, and the raised portion 71 has a semi-circular cross section. Thus, the cross-sectional shape of the raised portion formed on the side lip 48 in its initial state is not limited.

[0061] Other variations

[0062] The present invention has been illustrated above with reference to preferred embodiments, but it is to be understood that those skilled in the art can make formal and detailed changes without departing from the scope of the invention as set forth in the claims. Such changes, alterations, and modifications should be included within the scope of the present invention.

[0063] For example, in the above embodiment, the first protrusion 60 of the first sealing member 30 is formed on the elastic ring 32. However, as... Figure 9As shown in the modified example, a first protrusion 61 may also be formed on the rigid ring 31, protruding from the outer edge of the flange 31B toward the circular plate portion 45 of the second sealing member 40. The first protrusion 61 is disposed radially outward of the side lip 48 and overlaps with the side lip 48 radially. The first protrusion 61 reduces the leakage of grease from the space 55 between the flange 33 and the circular plate portion 45 due to centrifugal force. The outer peripheral surface 61a of the first protrusion 61 is inclined and has a diameter that increases towards the flange 33 of the first sealing member 30. Figure 9 The variation is a variation of the first embodiment, but in other embodiments, a first protrusion 61 formed of a rigid material may also be provided.

[0064] The features of the present invention are also described in the following numbered entries.

[0065] Item 1. A sealing device disposed between a fixed inner member and a rotating outer member, and for sealing the gap between the inner member and the outer member, characterized in that it has:

[0066] A first sealing member has a sleeve mounted on the inner member and a flange extending radially outward from the sleeve; and

[0067] The second sealing member has: a tubular portion disposed radially outside the flange and mounted on the outer member; a circular plate portion extending radially inward from the tubular portion and opposite the flange; a radial lip disposed radially inward from the circular plate portion and slidably contacting the sleeve; and a side lip extending from the circular plate portion toward the flange and slidably contacting the flange.

[0068] The first sealing member has an annular first protrusion projecting from the flange toward the circular plate portion of the second sealing member. The first protrusion is disposed radially outside the side lip and overlaps the side lip radially.

[0069] The second sealing member has an annular second protrusion projecting from the circular plate portion toward the flange of the first sealing member, the second protrusion being disposed radially outside the first protrusion and overlapping the first protrusion radially.

[0070] Item 2. The sealing device according to Item 1, characterized in that,

[0071] The second protrusion has an inner circumferential surface with a diameter that increases toward the flange of the first sealing member.

[0072] According to this entry, even if a foreign object enters the space between the flange of the first sealing member and the circular plate portion of the second sealing member, the foreign object can be easily discharged along the inner circumferential surface of the second protrusion.

[0073] Item 3. The sealing device according to item 1 or 2, characterized in that,

[0074] The side lip has a base adjacent to the circular plate portion, and a front end portion that extends radially outward from the base and obliquely toward the flange and has a truncated conical shape.

[0075] The front end has a first portion located on the base side and a second portion located on the opposite side of the base. In the initial state where no force is applied to the side lip, the tilt angle of the second portion relative to the axial direction of the sealing device is smaller than the tilt angle of the first portion relative to the axial direction of the sealing device.

[0076] According to this entry, due to the shapes of the first and second portions of the front end of the side lip in the initial state, when the first and second sealing members are combined, and the side lip of the second sealing member contacts the flange of the first sealing member, only a narrow region of the front end of the side lip contacts the flange. Therefore, the torque applied to the second sealing member by the flange is reduced.

[0077] Item 4. The sealing device according to Item 1 or 2, characterized in that,

[0078] The side lip has: a base adjacent to the circular plate portion; a front end portion extending radially outward from the base and obliquely toward the flange and having a truncated conical shape; and an annular ridge formed in the front end portion on a surface facing the flange.

[0079] According to this entry, when the first sealing member and the second sealing member are combined such that the side lip of the second sealing member contacts the flange of the first sealing member, the annular ridge formed at the front end of the side lip contacts the flange. Therefore, the area where the front end of the side lip contacts the flange is reduced, and the torque applied by the flange to the second sealing member is reduced.

[0080] Explanation of reference numerals in the attached figures

[0081] 1. Wheel hub bearing

[0082] 2 holes

[0083] 6. Inner ring (inner component)

[0084] 8. Outer ring (outer component)

[0085] 20 Sealing device

[0086] 30 First sealing component

[0087] 31 Rigid Ring

[0088] 31A Sleeve

[0089] 31B flange

[0090] 32 Elastic Ring

[0091] 33 Flange

[0092] 40, 40A, 40B, 40C Second sealing components

[0093] 44 Tubular portion

[0094] 45. Circular plate section

[0095] 46. ​​Lubricated Lip (Radial Lip)

[0096] 47 Sealing lip (radial lip)

[0097] 48 Side lips

[0098] 51 Base

[0099] 52 Front end

[0100] 52a Part 1

[0101] 52b Part 2

[0102] 55 Space

[0103] 60, 61 First protrusion

[0104] 62 Second protrusion

[0105] 62a Inner circumferential surface

[0106] 70, 71 raised sections

Claims

1. A seal device configured between a fixed inner member and a rotating outer member and closing a gap between the inner member and the outer member, the seal device characterized by comprising: a first seal member having a sleeve fitted to the inner member and a flange extending radially outward from the sleeve; and a second seal member having a tubular portion fitted to the outer member radially outward of the flange, a circular plate portion extending radially inward from the tubular portion and opposing the flange, a radial lip configured radially inward of the circular plate portion and slidably contacting the sleeve, and a side lip extending from the circular plate portion toward the flange and slidably contacting the flange, the first seal member having a first annular protrusion protruding from the flange toward the circular plate portion of the second seal member, the first protrusion being configured radially outward of the side lip and radially overlapping the side lip, the second seal member having a second annular protrusion protruding from the circular plate portion toward the flange of the first seal member, the second protrusion being configured radially outward of the first protrusion and radially overlapping the first protrusion, the second protrusion having an inner circumferential surface that is larger in diameter toward the flange of the first seal member.

2. The seal device according to claim 1, wherein the side lip has a base portion adjacent to the circular plate portion, and a front end portion extending obliquely toward a radial outer side and toward the flange from the base portion and having a truncated conical shape, the front end portion having a first portion on the base portion side and a second portion on a side opposite to the base portion, the second portion having a smaller inclination angle with respect to an axial direction of the seal device than the first portion in an initial state in which no force is applied to the side lip.

3. The seal device according to claim 1, wherein the side lip has a base portion adjacent to the circular plate portion, a front end portion extending obliquely toward a radial outer side and toward the flange from the base portion and having a truncated conical shape, and an annular protrusion formed in a surface of the front end portion facing the flange. ​ ​ ​ ​ ​ ​ ​ ​

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