JP4045705B2 - Sealed thrust ball bearing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealed thrust ball bearing such as a double lip seal inner ring integrated strut mount bearing.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is a sealed thrust ball bearing as shown in FIG. The sealed thrust ball bearing includes a first race 21, a second race 22, a plurality of balls 23 arranged between the first race 21 and the second race 22, and a first race. And an elastic sealing material 24 that seals between the inner peripheral portions and the outer peripheral portions of the first race 21 and the second race 22.
[0003]
3, the elastic sealing material 24 covers the surface excluding the raceway surface 21a of the first race 21 as shown in FIG. An inner seal portion 25 and an outer seal portion 26 are provided for sealing between the outer peripheral portions. The inner seal portion 25 is formed with first and second lips 25a and 25b that are in sliding contact with the inner surface 22a of the second race 22 on the first race 21 side, and the outer seal portion 26 has a second race. The first and second lips 26a and 26b are formed in sliding contact with the inner peripheral surface 22b of 22. A sealed space between the first race 21 and the second race 22 by the first and second lips 25a and 25b of the inner seal portion 25 and the first and second lips 26a and 26b of the outer seal portion 26. This prevents muddy water from entering.
[0004]
[Problems to be solved by the invention]
Incidentally, in the sealed thrust ball bearing, when a radial load in the direction of arrow R shown in FIG. 2 is applied, the second race 22 is about 0.3 mm / ton to the right in the radial direction with respect to the first race 21. Displace. At this time, the first and second lips 26a and 26b of the outer seal portion 26 which are in contact with the inner peripheral surface of the second race 22 shown in FIG. 3 are fastened because the outer seal portion 26 moves to the right side in FIG. The margin is reduced. As a result, when the interference between the first and second lips 26a and 26b is reduced, muddy water or the like easily enters the inside due to a decrease in the sealing performance of the outer seal portion 26, and there is a problem that water resistance is lowered.
[0005]
Therefore, an object of the present invention is to provide a sealed thrust ball bearing having excellent water resistance.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a sealed thrust ball bearing according to the invention of claim 1 comprises:
An inner circumference of the first race, the second race, a plurality of balls disposed between the first race and the second race, and the first race and the second race; In a sealed thrust ball bearing provided with an elastic sealant that seals between parts and between outer peripheral parts,
A bent portion that is bent toward the second race side is formed on the outer periphery of the first race,
A cylindrical portion extending toward the first race is formed on the outer periphery of the second race,
The elastic sealing material that seals between the outer peripheral portions is directly attached to the base of the bent portion, and has a lip that extends from the base of the bent portion toward the end surface in the axial direction of the cylindrical portion and contacts the end surface. Yes, and
The cylindrical portion of the outer peripheral portion of the second race is located radially outside the bent portion of the outer peripheral portion of the first race .
[0007]
According to the sealed thrust ball bearing of the first aspect of the present invention, even if the second race is displaced in the radial direction relative to the first race by a radial load, the clearance between the outer peripheral portions is increased. Since the lip of the elastic sealing material to be sealed is in contact with the axial end surface of the second race, the interference of the lip of the elastic sealing material is not reduced. Therefore, the sealing property of the elastic sealing material is not lowered, and muddy water or the like is less likely to enter inside, thereby improving water resistance.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The sealed thrust ball bearing of the present invention will be described in detail below with reference to the illustrated embodiments.
[0009]
FIG. 1 is a cross-sectional view of a main part of a sealed thrust ball bearing according to an embodiment of the present invention. As shown in FIG. 1, this sealed thrust ball bearing has a plurality of bores arranged between a first race 1, a second race 2, and a first race 1 and a second race 2. And an elastic seal material 4 that seals between the inner peripheral portions and between the outer peripheral portions of the first race 1 and the second race 2.
[0010]
A cylindrical portion 7 extending toward the second race 2 side is formed on the inner peripheral portion of the first race 1, while the outer periphery of the first race 1 is bent toward the second race 2 side. A bent portion 8 is formed. Further, a cylindrical portion 9 extending toward the first race 1 is formed on the outer peripheral portion of the second race 2. The inner diameter of the cylindrical portion 9 of the second race 2 is larger than the outer diameter of the bent portion 8 of the first race 1.
[0011]
The elastic sealing material 4 covers the surface of the first race 1 excluding the raceway surface 1a, and seals between the inner periphery and the outer periphery of the first race 1 and the second race 2. An inner seal portion 5 and an outer seal portion 6 are provided. The inner seal portion 5 has first and second lips 5 a and 5 b that are in sliding contact with the inner surface 2 a of the second race 2 facing the cylindrical portion 7, while the outer seal portion 6 is formed of the second race 2. It has a first lip 6 a that is in sliding contact with the inner peripheral surface 9 a of the cylindrical portion 9, and a second lip 6 b that is in sliding contact with the axial end surface 9 b of the cylindrical portion 9. The first lip 6 a extends from the tip of the bent portion 8, and the second lip 6 b extends from the root of the bent portion 8.
[0012]
The sealed thrust ball bearing configured as described above is, for example, an outer seal that is in sliding contact with the inner peripheral surface 9a of the cylindrical portion 9 when the second race 2 moves to the right in FIG. The first lip 6a of the portion 6 has the outer seal portion 6 moved to the right side in FIG. 1 so that the interference in the radial direction is reduced. However, the first lip 6a of the outer seal portion 6 is in sliding contact with the axial end surface 9b of the cylindrical portion 9. Since the two lips 6b are sealed with a margin in the axial direction with respect to the axial end surface 9b of the second race 2, even if the outer seal portion 6 moves to the right side (radial direction) in FIG. Directional interference does not decrease. Accordingly, the second lip portion 6b of the outer seal portion 6 that seals between the outer peripheral portions is not deteriorated in sealing property, so that muddy water or the like is less likely to enter inside, and water resistance can be improved.
[0013]
In the above embodiment, the inner seal portion 5 and the outer seal portion 6 are integrally formed. However, the inner seal portion 5 and the outer seal portion 6 may be formed separately.
[0014]
The second race refers to a race that comes into contact with the lip of the elastic seal material on the end face in the axial direction of the two races, and the race to which the elastic seal material is attached is referred to as a first race.
[0015]
【The invention's effect】
As apparent from the above, according to the sealed thrust ball bearing of the invention of claim 1, even if the second race is displaced in the radial direction relative to the first race due to the radial load, the first Since the lip of the elastic sealing material that seals between the outer peripheries of the lace and the second race is in contact with the axial end surface of the second lace, the interference of the lip of the elastic sealing material does not decrease. , It becomes difficult for muddy water or the like to enter inside, and water resistance can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of a sealed thrust ball bearing according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a conventional sealed thrust ball bearing.
FIG. 3 is an enlarged cross-sectional view of a main part of the conventional sealed thrust ball bearing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st race 2 2nd race 3 Ball 4 Elastic seal material 5 Inner seal part 5a First lip of inner seal part 5b Second lip of inner seal part 6 Outer seal part 6a First lip of outer seal part 6b Outer seal part Second lip 9 Second race cylindrical portion 9a Inner peripheral surface 9b End surface

Claims (1)

An inner circumference of the first race, the second race, a plurality of balls disposed between the first race and the second race, and the first race and the second race; In a sealed thrust ball bearing provided with an elastic sealant that seals between parts and between outer peripheral parts,
A bent portion that is bent toward the second race side is formed on the outer periphery of the first race,
A cylindrical portion extending toward the first race is formed on the outer periphery of the second race,
The elastic sealing material that seals between the outer peripheral portions is directly attached to the base of the bent portion, and has a lip that extends from the base of the bent portion toward the end surface in the axial direction of the cylindrical portion and contacts the end surface. Yes, and
The sealed thrust ball bearing, wherein the cylindrical portion of the outer peripheral portion of the second race is located radially outside the bent portion of the outer peripheral portion of the first race .

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