JP2017166497A - Sealing member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing member capable of dissolving an inverted state of an auxiliary lip part even if the auxiliary lip part is inverted upon assembling.SOLUTION: A sealing member 1 includes: a main lip part 11 which is fitted to an annular space A between a shaft 29 and a casing 30 relatively rotated to each other, is brought into contact with an outer circumferential surface of the shaft 29 and, thereby, prevents sealing fluid in the sealing space A from leaking to the outer part side B; and an auxiliary lip part 12 which is provided via a space part 23 on the outer part side B than the main lip part 11, is brought into contact with the outer circumferential surface of the shaft 29 and prevents invasion of foreign matter into the sealing space A from the outer part side B, as the sealing member 1 which encapsulates lubricant into the space part 23 and is fitted to the annular space A. The auxiliary lip part 12 has interference for the shaft 29 and an aventurine rough surface part 28 capable of retaining the lubricant is provided on the outer circumference surface of the auxiliary lip part 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sealing member.

Conventionally, as a sealing member used for the differential side of an automobile, as shown in FIG. 4, a main lip portion 101 that comes into contact with the outer peripheral surface of the shaft 105 and seals the fluid in the sealed space A, A sealing member 100 having an auxiliary lip portion 102 that is provided on the outer side B and prevents foreign matter from entering the inner side is known.
In such a sealing member 100, in order to enhance the effect of preventing the entry of foreign matter by the auxiliary lip portion 102, it is proposed that the auxiliary lip portion 102 is brought into contact with the shaft 105 with a tightening margin (for example, , See Patent Document 1).

JP 2007-225063 A

The above-described assembly of the sealing member 100 to the shaft 105 is usually performed by inserting the shaft 105 from the outer side B (auxiliary lip portion 102 side) of the sealing member 100.
At this time, in the sealing member 100 in which the auxiliary lip portion 102 comes into contact with the shaft 105 with a tightening margin, when the shaft 105 is inserted, the auxiliary lip portion 102 may be inverted to the side of the sealed space A. It was.
When the sealing member 100 is used in a state where the auxiliary lip portion 102 is inverted, abnormal wear occurs in the auxiliary lip portion 102, and this abnormal wear may cause damage to the auxiliary lip portion 102.
This invention is made | formed in view of such a situation, and even if an auxiliary | assistant lip part reverses at the time of an assembly, it aims at providing the sealing member which can eliminate the reverse state.

The sealing member according to the present invention is mounted in an annular space formed between a shaft and a casing that rotate relative to each other, and prevents the sealing fluid in the sealed space from leaking to the outside by contacting the outer peripheral surface of the shaft. A main lip portion that is provided on the outer side of the main lip portion via a space portion, and is in contact with the outer peripheral surface of the shaft to prevent foreign matter from entering the sealed space from the outer side A lip portion, and a sealing member that is attached to the annular space by enclosing a lubricant in the space portion,
The auxiliary lip portion has a tightening margin with respect to the shaft,
The outer peripheral surface of the auxiliary lip portion is provided with a textured rough surface portion capable of holding the lubricant.

The sealing member of the present invention has a main lip portion and an auxiliary lip that come into contact with the outer peripheral surface of the shaft with a tightening margin, and is mounted in the annular space in a state where a lubricant such as grease is sealed in a space portion sandwiched between the two. The sealing member is assembled by inserting a shaft from the auxiliary lip portion side.
At this time, since the auxiliary lip portion has a tightening margin with respect to the shaft, it may be reversed when the shaft is inserted. In addition, since the sealing member is assembled in a state where a lubricant such as grease is sealed in the space portion, the auxiliary lip portion is deformed by the insertion of the shaft, and in some cases, the inversion as described above occurs. As a result, the grease or the like enclosed in the space part also adheres to the outer peripheral surface of the inevitable auxiliary lip part.

On the other hand, the sealing member of the present invention is provided with a textured rough surface portion capable of holding grease or the like on the outer peripheral surface of the auxiliary lip portion. The outer peripheral surface of the auxiliary lip portion having such a rough surface portion can hold the grease or the like attached when the sealing member is assembled as it is.
Therefore, in the sealing member of the present invention, even if the auxiliary lip portion is reversed at the time of assembly, the auxiliary lip portion can be reversed by its own elastic restoring force. This is because when the auxiliary lip portion is inverted during assembly, the outer peripheral surface of the inverted auxiliary lip portion comes into contact with the shaft, but the outer peripheral surface holds the grease or the like by the rough surface portion as described above, This is because the coefficient of friction with the shaft is low.

In the sealing member, the surface roughness of the rough surface portion is preferably an arithmetic average roughness Ra of 2.0 to 10.0 μm.
In the rough surface portion having the arithmetic average roughness Ra in the above range, a lubricant such as grease can be sufficiently retained. Further, when the arithmetic average roughness Ra is increased, foreign matter that has entered from the outside tends to adhere to the rough surface portion. However, by setting the upper limit of the arithmetic average roughness Ra to 10.0 μm, it is possible to retain grease and the like. It is possible to prevent foreign matters that have entered from the outside from being easily attached while securing the property.

  ADVANTAGE OF THE INVENTION According to this invention, even if an auxiliary | assistant lip part reverses at the time of an assembly | attachment, the sealing member which can eliminate the reverse state can be provided.

It is a section explanatory view showing the important section of the sealing member concerning a 1st embodiment. FIG. 2 is a partial side view of the outer side of the sealing member shown in FIG. 1. (A)-(c) is an expanded sectional view for demonstrating the state of the auxiliary | assistant lip part at the time of attaching the sealing member which concerns on 1st Embodiment to a axis | shaft. It is a fragmentary sectional view which shows the principal part of the conventional sealing member.

Hereinafter, a sealing member according to an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional explanatory view showing the main part of the sealing member according to the first embodiment. 2 is a partial side view of the outer side of the sealing member shown in FIG.
The sealing member 1 according to the present embodiment is used for a differential side of an automobile, and is attached to an annular space formed between a shaft 29 and a casing 30 that rotate relative to each other, so that the sealing fluid in the sealed space A is sealed. Is prevented from leaking to the external side B. The sealing member 1 shown in FIG. 1 shows a natural state before deformation, which is before being mounted between the outer peripheral surface 29a of the shaft 29 and the inner peripheral surface 30a of the casing 30.

The sealing member 1 includes an annular core metal 2 having an L-shaped cross section, a seal member 3 fixed to the core metal 2, and an annular spring ring 4.
The core metal 2 is an annular member made of metal (for example, SPCC), and includes a cylindrical portion 6 and an annular plate portion 7 that is bent radially inward from an outer side end portion of the cylindrical portion 6. .

The seal member 3 is made of an elastic material such as synthetic rubber (for example, acrylonitrile-butadiene rubber (NBR), acrylic rubber (ACM)), and is fixed to the core metal 2 by adhesion or baking by vulcanization. The seal member 3 includes a main body portion 10, a main lip portion 11, an auxiliary lip portion 12, and a side lip portion 13.
The main body 10 is provided on the outer side of the cylindrical portion 6 of the core metal 2, and is provided on the outer peripheral side of the annular plate portion 7 with an axial outer peripheral portion 10 a fixed to the inner peripheral surface 30 a side of the casing 30. The outer peripheral part 10b and the radial inner peripheral part 10c provided inside the annular plate part 7 are provided.

The main lip portion 11 extends from the inner peripheral side of the radially inner peripheral portion 10c of the main body portion 10 to the shaft 29 side and the sealed space A side, and a peripheral groove 14 is formed on the outer peripheral surface thereof. . A spring ring 4 called a so-called garter spring is attached to the circumferential groove 14 and fastens the main lip portion 11 inward in the radial direction.
The auxiliary lip portion 12 extends from the inner peripheral side of the radially inner peripheral portion 10 c of the main body portion 10 to the shaft 29 side and to the outer side B.

The side lip portion 13 extends in a skirt shape from the radially outer peripheral portion 10 b of the main body portion 10 to the outer side B in the radially outward direction.
In addition, the front-end | tip part 13a of the side lip part 13 has faced without contacting the deflector (not shown) which is a metal annular member provided in the outer side B from the side lip part 13. FIG. Thereby, it is set as the structure where foreign materials, such as muddy water, cannot approach the sealed space A easily.

  The main lip portion 11 of the seal member 3 is in contact with the outer peripheral surface 29a of the shaft 29 with an allowance, and prevents the sealed fluid in the sealed space A from leaking to the outer side B. The main lip portion 11 has a tapered shape in which the thickness gradually decreases inward in the radial direction (the axial dimension decreases), and the cross-sectional shape thereof is substantially V-shaped, and the minimum diameter portion is the lip tip portion 19. It is said that. On the inner peripheral surface of the main lip portion 11, the surface on the outer side B from the lip tip 19 is a first inclined surface 20, and the side A in the sealed space from the lip tip 19 is a second inclined surface 21. .

  The auxiliary lip portion 12 of the seal member 3 is provided on the outer side B of the main lip portion 11 via the space portion 23. That is, an annular space 23 is formed between the inner peripheral surface (first inclined surface 24 described later) of the auxiliary lip portion 12 and the inner peripheral surface (first inclined surface 20) of the main lip portion 11. The space 23 is filled with grease.

  The auxiliary lip portion 12 is in contact with the outer peripheral surface 29a of the shaft 29 with a margin to prevent foreign matter from entering the sealed space A from the outer side B. The inner peripheral surface of the auxiliary lip portion 12 has a first inclined surface 24 that is reduced in diameter from the radially inner peripheral portion 10 c of the main body portion 10 of the seal member 3 toward the distal end side, and the outermost surface of the first inclined surface 24. A second inclined surface 25 having a continuously enlarged diameter outwardly from the small diameter portion is formed, and the minimum diameter portion is a lip tip portion 26. That is, on the inner peripheral surface of the auxiliary lip portion 12, the surface on the A side in the sealed space from the lip tip portion 26 is the first inclined surface 24 having a contact surface (sliding contact surface) with the shaft 29, and the lip tip portion A surface on the outer side B with respect to 26 is a second inclined surface 25.

Further, as shown in FIG. 2, the auxiliary lip portion 12 is provided with a textured rough surface portion 28 on the outer peripheral surface 27 and the second inclined surface 25 constituting the inner peripheral surface. The rough surface portion 28 is provided on the entire outer peripheral surface 27 of the auxiliary lip portion 12 and the entire second inclined surface 25. Here, when the sealing member 1 is assembled, the outer peripheral surface 27 and the second inclined surface 25 adhere to the grease sealed in the space portion 23, but the outer peripheral surface 27 and the second inclined surface 25 are attached to the outer peripheral surface 27 and the second inclined surface 25. Since the rough surface portion 28 is provided, the adhered grease can be held as it is.
Although not shown, the rough surface portion 28 is made of a fine protrusion, a fine concave portion, a fine linear groove, or a mixture of these.

  The textured rough surface portion 28 is composed of fine irregularities. The surface roughness of the rough surface portion 28 is preferably set such that the arithmetic average roughness Ra (JIS B 0601: 2013) is in the range of 2.0 to 10.0 μm. If the Ra is less than 2.0 μm, the grease or the like may not be sufficiently retained. On the other hand, when the Ra exceeds 10.0 μm, the grease and the like can be sufficiently retained, but at the same time, foreign matter that has entered from the outside tends to adhere to the rough surface portion.

  The rough surface portion 28 of the auxiliary lip portion 12 may be formed by vulcanizing and molding the auxiliary lip portion 12 to form the overall shape of the contour, and then roughening the corresponding portion. In order to form the rough surface portion 28 of the auxiliary lip portion 12, a fine uneven portion is formed in advance on the inner surface of the vulcanizing mold for the purpose by electric discharge machining or the like, and the fine uneven portion of the mold is transferred to the auxiliary lip portion 12. It is preferable to form. That is, the rough surface portion 28 is preferably formed as a transfer surface transferred by a mold.

3A to 3C are enlarged sectional views for explaining the state of the auxiliary lip portion when the sealing member according to the present embodiment is assembled to the shaft.
As shown in FIG. 3A, the sealing member 1 is assembled to the shaft 29 by inserting the shaft 29 from the outer side B.
At this time, as shown in FIG. 3B, the auxiliary lip portion 12 is deformed when contacting the chamfered portion 29b provided on the outer peripheral surface on the end surface 29c side of the shaft 29, and is reversed to the main lip portion side. Sometimes. In this case, in the auxiliary lip portion 12, the outer peripheral surface 27 provided with the rough surface portion 28 and the second inclined surface 25 come into contact with the chamfered portion 29 b of the shaft 29. At this time, the grease sealed in the space 23 before assembly is adhered to the outer peripheral surface 27 and the second inclined surface 25, and the adhered grease is held by the rough surface portion 28. Therefore, the outer peripheral surface 27 and the second inclined surface 25 of the auxiliary lip portion 12 have a low coefficient of friction with the shaft 29, and the auxiliary lip portion 12 cancels the inverted state by its own elastic restoring force. As shown in FIG. 3C, the outer peripheral surface 29a of the shaft 29 can be brought into contact with a tightening margin in a normal assembled state.

Moreover, even if the sealing member 1 is once assembled at a predetermined position on the outer peripheral surface 29a of the shaft 29 with the auxiliary lip portion 12 being inverted, as described above, the outer peripheral surface 27 and the auxiliary lip portion 12 The second inclined surface 25 has a low coefficient of friction with the shaft 29 due to the grease held by the rough surface portion 28. Therefore, after the sealing member 1 is assembled, the auxiliary lip portion 12 can be easily reversed by rotating the shaft 29 or swinging the shaft 29 in the axial direction. It can be in a normal state as shown in c).
Thus, according to the sealing member of the present embodiment, even if the auxiliary lip portion 12 is reversed at the time of assembly, the reversed state is eliminated by its own elastic restoring force and the action of the grease held by the rough surface portion 28. Can do.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and can be appropriately changed within the scope described in the claims.
In the first embodiment, the rough surface portion is provided on the outer peripheral surface and the second inclined surface of the auxiliary lip portion. In the sealing member according to the embodiment of the present invention, the rough surface portion is at least the outer periphery of the auxiliary lip portion. As long as it is provided on the surface, it is not necessarily provided on the second inclined surface.

In the first embodiment, the rough surface portion is provided on the entire outer peripheral surface of the auxiliary lip portion. However, the rough surface portion does not necessarily have to be provided on the entire outer peripheral surface of the auxiliary lip portion, for example, the second inclined surface. It may be provided only in a half region on the side.
In the first embodiment, the rough surface portion is provided in the entire circumferential direction on the outer peripheral surface and the second inclined surface of the auxiliary lip portion. However, the rough surface portion is not necessarily formed in the entire circumferential direction. As long as sufficient grease can be retained to eliminate the inverted state of the auxiliary lip portion, it may be provided intermittently in the circumferential direction.

  The sealing member which concerns on embodiment of this invention is not limited to what seals the differential side of a motor vehicle, It can use suitably as a sealing member for sealing various apparatuses including another rolling bearing.

  1: sealing member, 2: cored bar, 3: sealing member, 11: main lip portion, 12: auxiliary lip portion, 13: side lip portion, 23: space portion, 25: second inclined surface, 27: outer peripheral surface, 28: Rough surface part, 29: Shaft, 30: Casing

Claims (2)

A main lip portion that is mounted in an annular space formed between a shaft and a casing that rotate relative to each other, and that contacts the outer peripheral surface of the shaft to prevent the sealing fluid in the sealed space from leaking to the outside; and An auxiliary lip portion that is provided on the outer side of the main lip portion via a space portion, and that contacts the outer peripheral surface of the shaft to prevent entry of foreign matter from the outer side into the sealed space; A sealing member that encloses a lubricant in the space and is mounted in the annular space;
The auxiliary lip portion has a tightening margin with respect to the shaft,
A sealing member, characterized in that a satin-like rough surface portion capable of holding the lubricant is provided on an outer peripheral surface of the auxiliary lip portion.   2. The sealing member according to claim 1, wherein the surface roughness of the rough surface portion is an arithmetic average roughness Ra of 2.0 to 10.0 μm.

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