KR20170107920A - Sealing bellows - Google Patents

Abstract

The present invention relates to a sealing bellows (20) especially for sealing a ball joint (1) having a ball stud (3) mounted to be rotated with relative to a joint housing (2). The sealing bellows (20) comprises: a housing side edge section (23); a stud side edge section (24); and a case (25) connecting the edge sections. A protrusion unit (26) to be engaged with the inside of a groove (7) formed on a ball stud (3) is formed on the stud side edge section (24) to form a sealing area (29) by cooperating with the ball stud (3). One or more additional protrusion units (27, 28) forming one or more additional sealing areas (30, 31) are formed on the stud side edge section (24) by cooperating with the ball stud (3). The present invention has sealing performance which is sustained for a long period.

Description

[0001] SEALING BELLOWS [0002]

The present invention relates to a sealing bellows for sealing a ball joint with a ball stud mounted relatively rotatably relative to the joint housing, in particular according to the preamble of claim 1. The present invention also relates to a ball joint having the sealing bellows.

In the automotive industry, ball joints are used in a variety of ways. Particularly in a chassis, ball joints are used to connect chassis components such as control arm parts, wheel carriers, tie rods, etc., to each other, or to an axle bracket fixed to the vehicle body or the vehicle body. Ball joints typically consist of a joint housing having a housing recess and being open at least on one side and a ball stud mounted relatively rotatably relative to the joint housing within the housing recess, And protrudes from the opening. A bearing bushing is often placed between the joint housing and the joint ball assigned to the ball stud, which sometimes reduces friction and hence wear of the joint despite high operating loads.

In order to ensure the mobility of ball joints with the lowest resistance constantly, it is necessary to take structural measures to enable continuous lubrication with joint grease so that friction between parts capable of relative movement with respect to each other is reduced. In conventional joints, a so-called sealing bellows is used as a reservoir for joint grease. In this case, the sealing bellows is provided with the function of protecting the joint region of the ball joint against external environmental influences such as, for example, contaminants, moisture, mechanical effects and the like. To fulfill this function, the sealing bellows are formed as a tubular hollow body with two open ends from a flexible material, in particular an elastic material, preferably an elastomer. In this case the sealing bellows includes a housing side edge section at the axial end towards the joint housing and a stud side edge section at the opposite end towards the ball stud and includes a case connecting these edge sections do. In this case, the case may in principle be formed in a variety of ways, in order to ensure joint mobility, an outline may be selected, which may be compressed or stretched, for example as a contour with bulging contours and / or pleats. The contour with wrinkles refers to the so-called bellows, and in the case of multiple wrinkles, more specifically refers to multi-bellows.

From the prior art according to DE 100 05 979 A1 there is formed a circumferential protrusion facing inward on the stud side edge section, the circumferential protrusion being in sealing engagement with the ring groove formed in the ball stud (with the ball joint assembled) A bellows is known. By means of a clamping member in the form of a flat-wire clamping ring which surrounds the periphery of the sealing bellows at the axial height of the protrusion, the protrusion is brought into the groove formed in the ball stud under the elastic deformation of the material of the sealing bellows Direction. Accordingly, the protrusion cooperates with the ball stud to form the sealing area, wherein the preload applied by the flat wire clamping ring affects the sealing action.

Based on the geometry of the stud-side edge section, the material of the sealing bellows is seated on the ball stud without interruption over the groove profile (axial profile), so that the sealing bellows, already known from DE 100 05 979 A1, The restoring force exerted by the wire clamping ring is distributed on a relatively large surface, thereby providing a surface seal with a relatively uniformly distributed sealing force.

It is an object of the present invention to provide a sealing bellows with a particularly long lasting sealing action in the region of the stud-side edge section.

The mentioned problem is solved by a sealing bellows according to the features of claim 1. A sealing bellows for use in sealing a ball joint having a ball stud pivotally mounted relative to a joint housing, the sealing bellows comprising a housing side edge section, a stud side edge section, , And a case connecting these edge sections. On the stud-side edge section, a protrusion for engaging in the groove formed on the ball stud is formed to form a sealing region in cooperation with the ball stud. According to the present invention, the sealing bellows is characterized in that on the stud-side edge section, one or more additional protrusions are formed which interact with the ball stud to form one or more additional sealing areas.

According to the invention, one or more additional protrusions are formed on the stud-side edge section so that on the stud-side edge section of the sealing bellows there are provided two or more protrusions each forming one independent sealing region through contact with the ball stud do. With this measure, it is ensured that the radially inward facing compression forces are distributed to a plurality of separate sealing areas, in which a particularly high sealing force can be achieved in at least one sealing area of the sealing areas. This is based on a point between two or more protrusions where a region which does not contact the ball stud at all or only contacts with a small pressing force is located. Accordingly, the externally applied compressive force is concentrated onto the sealing areas assigned to the protrusions, which have a smaller contact surface with respect to the ball stud than an unclamped surface seal such as is known from DE 100 05 979 A1. Therefore, the sealing effect of the sealing bellows according to the present invention is enhanced.

According to one preferred refinement of the sealing bellows, the sealing bellows has a minimum inner diameter in the region of the projection assigned to the groove. In this connection, the sealing bellows is regarded as a hollow body with a central axis, which is approximately rotationally symmetric, the inner diameter of which is minimum in the region of the projection assigned to the groove.

In addition, the sealing bellows preferably has an internal contour extending from the projection assigned to the groove to the generally funnel-shaped profile across the profile of the stud-side edge section. Accordingly, the inner surface of the sealing bellows starts to extend from the projection assigned to the groove and expand toward the axial-direction axial end of the sealing bellows.

According to one preferred refinement of the sealing bellows, preferably three protrusions are formed on the stud-side edge section of the sealing bellows.

Particularly preferably, the protrusions formed at the axial ends of the stud-side edge sections form a pre-sealing range in cooperation with the ball studs, and the protrusions engaging in the grooves form a resealing range And a protrusion formed between the pre-seal area and the reseal area with respect to the profile of the inner contour of the stud-side edge section forms a main sealing range. Thereby, different functions are given to the sealing areas formed in cooperation with the ball stud by the three protrusions. In this case, the pre-seal area is responsible for the initial seal, especially to the outer periphery. On the other hand, a maximum sealing force is provided in the main sealing region. The reseal area, nevertheless, ensures that the contaminants that have passed through the pre-seal area and the main seal area can not penetrate into the joint. The reseal region also ensures axial fixation of the stud-side edge section of the sealing bellows based on engagement into the groove on the ball stud.

The protrusions provided on the stud-side edge section are more preferably formed in the peripheral edge. According to one preferred refinement of the invention, the sealing bellows has a third inside diameter in the area of the protrusion assigned to the pre-sealing area, a second inside diameter in the area of the protrusion assigned to the main sealing area, The first inner diameter, the second inner diameter, and the third inner diameter are applied.

For ensuring a continuous sealing action and for axial fixation, the sealing bellows is preferably provided with a ring groove formed on the outer periphery in the region of the stud-side edge section for receiving the clamping member surrounding the sealing bellows, Is preferably a flat wire clamping ring or a circular wire clamping ring.

Preferably, the ring grooves are formed on the sealing bellows in such a manner that the clamping member inserted in the ring groove in a state in which the sealing bellows is assembled on the ball stud, preferentially presses the radially inward facing squeeze onto the main sealing region, ≪ / RTI > For this purpose, the ring groove is preferably positioned in the axial direction such that the ring groove conforms to the projection assigned to the primary sealing area, i. E., Has an axial position corresponding to the projection.

According to one preferred refinement, the projection of the sealing bellows, which is assigned to the main sealing area, is characterized in that, in the state in which the sealing bellows is assembled on the ball stud, the projection is inclined with respect to the central axis of the ball stud, As shown in Fig. With this measure, an adjusting function is realized which is preferably guided by sliding the stud-side edge section clamped from the outside by the clamping member, with respect to the inclined, especially conical, surface of the ball stud.

Preferably, the projections assigned to the pre-seal area are arranged and formed such that the projections engage over a camber formed on the ball stud with the seal bellows assembled on the ball stud, A high sealing effect is achieved. The grip realized in this way serves to reduce the gaps that exist to allow contaminants or moisture to flow between the sealing bellows and the ball studs and / or to make access of the contaminants or moisture more difficult. In addition, the shape of the projections thus formed and assigned to the pre-seal area allows the sealing force to remain high in the pre-seal area even when the stud-side edge section slides in the direction of the joint housing due to actuation.

The present invention also relates to a ball joint according to claim 11, wherein the ball joint comprises a ball stud mounted rotatably relative to the joint housing and the sealing bellows described above.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described in more detail with reference to the embodiments described in the following figures. Additional advantageous effects of the present invention are also presented from the illustrated embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a ball joint with a sealing bellows already known from the prior art.
2 is a half sectional view of a sealed bellows according to a single embodiment of the present invention assembled in a partially shown ball joint;
3 is a cross-sectional view of an unassembled state of a sealing bellows according to a single embodiment of the present invention.

1 shows a cross section of a ball joint with a sealing bellows, known from the prior art according to DE 100 05 979 A1. The ball joint 1 shown in the figure includes a joint housing 2 having one side opened as a main member, a ball stud 3 rotatably mounted relative to the joint housing 2, a conventional sealing bellows 10, . The ball stud 3 has a joint ball 4 at the end facing the joint housing 2, and the joint ball is received by the joint housing 2. An end of the ball stud 3 facing the opposite side of the joint housing 2 protrudes from the joint housing 2 along the central axis 6. The ball stud 3, including the joint ball 4, is formed as a rotationally symmetrical part with respect to the central axis 6. Between the joint housing 2 and the joint ball 4 of the ball stud 3 is disposed a ball socket 5 made of plastic and surrounding the joint ball 4 inside the joint housing 2. Based on the predetermined elasticity of the ball socket 5 and the surface characteristics thereof, the ball stud 3 can be rotated and rotated with relatively little friction over a long operating period even under the action of a relatively high force on the joint housing 2 . The opening of the joint housing 2 is closed by a peripheral closing ring 8 having an inner diameter smaller than the outer diameter of the joint ball 4 so that the ball stud 3 is closed by the closing ring 8, (2). In the case of the ball joint 1 shown, the closing ring 8 was inserted into the area of the housing opening and then fixed through flanging of the material of the joint housing 2.

Subsequently, the ball joint 1 shown in Fig. 1 and known from the prior art comprises a sealing bellows 10 which seals the ball joint 1 against the outer periphery. In this case, the sealing bellows 10 is used in particular to prevent penetration of contaminants or moisture into the inner region of the ball joint 1, in particular into the contact area between the joint ball 4 and the ball socket 5. The sealing bellows 10 is made in the form of a hollow body of a flexible elastic material, particularly an elastomer. The sealing bellows 10 includes a housing side edge section 13, a stud side edge section 14 and a case 15 connecting the edge sections, wherein the housing side edge section 13 and the stud side edge section 14, (14) are located at opposite axial ends of the hollow body.

On the stud side edge section 14 of the sealing bellows 10 there is formed an inwardly facing peripheral protrusion 16 which is circumferentially engaged in a groove 7 formed in the circumferential direction on the ball stud 3, All. At the axial height of the groove 7, a peripheral groove is formed at the outer periphery of the sealing bellows 10, which receives the peripheral clamping ring 12 in the form of a flat wire clamping ring. The clamping ring 12 applies a preloading radially outwardly on the stud side edge section 14 and thereby urges the ball stud 3 in the axial direction of the stud side edge section 14 of the sealing bellows 10 Lt; / RTI > This axial fixation allows the stud side edge section 14 of the sealing bellows 10 to be moved in the region of the groove 7 in the region of the groove 7 even during the relative pivoting and rotational movement of the ball stud 3 relative to the joint housing 2. [ It is ensured that it is seated on the stud 3.

In addition to axial fixation, the clamping ring 12 applies a sealing force through the material of the sealing bellows 10 which is seated in the region of the groove 7 of the ball stud 3. The material of the sealing bellows 10 is seated on the ball stud 3 in the region of the stud side edge section 14 without interruption so that the ball stud 3 and the stud side edge section 14 of the sealing bellows 10, A single continuous sealing area is formed in the contact area between the sealing surfaces in the face seal.

In the housing side edge section 13 of the sealing bellows 10 the sealing bellows 10 abuts the joint housing 2 and the clamping ring 11 in the form of a flat wire clamping ring arranged in the peripheral groove formed in the outer periphery And is fixed axially with respect to the joint housing 2.

2 and 3, a sealing bellows 20 according to a single embodiment of the present invention is described. In Figure 2, the sealing bellows 20 is shown in an enlarged half-sectional view assembled in a ball joint (the rest of which is shown as in Figure 1), while in Figure 3 the sealing bellows 20 is shown as an unassembled , And thus not deformed. The configuration and shape of the sealing bellows 20 will be described first with reference to Fig.

3, a sealing bellows 20 suitable for sealing the ball joint is shown. In particular, the sealing bellows 20 is suitable for sealing the ball joint 1 as shown in Fig. 1, at this time preferably replacing the conventional sealing bellows 10. The sealing bellows 20 is made in the form of a multi-bellows as a hollow body which is formed of a flexible elastic material, in particular an elastomeric material, and which is rotationally symmetric with respect to the central axis 6. The sealing bellows 20 has one opening at each of the end portions opposed to each other in the axial direction. The sealing bellows 20 includes a housing side edge section 23, a stud side edge section 24, and a case 25 connecting these edge sections. A peripheral groove (not separately shown) is formed on the outer periphery of the housing side edge section 23, and this groove is used for accommodating the clamping ring 21 in the form of a flat wire clamping ring or a circular wire clamping ring, for example.

The stud side edge section 24 is formed with a protrusion 26 for engaging in the groove 7 formed in the ball stud 3. The projecting portion 26 is a peripheral contraction portion of the sealing bellows 20 having an inner diameter d1.

The sealing bellows 20 is characterized in that the stud side edge section 24 is provided with a further protrusion 27 and an additional protrusion 28 in addition to the protrusion 26. These protrusions 27 and 28 are also protrusions formed in the circumferential direction respectively and the sealing bellows 20 has an inner diameter d2 in the region of the protrusion 27 and an inner diameter d3 in the region of the protrusion 28. [ The sealing bellows 20 has a minimum inner diameter d1 in the region of the protrusion 26. [ In other words, the closest point of the sealing bellows relative to the axial extension of the sealing bellows 20 is located in the region of the projection 26.

3, the sealing bellows 20 has an internal contour extending from the protrusion 26 and extending generally in the form of a funnel across the profile of the stud-side edge section 24. Three projections 26, 27 and 28 are formed which are spaced apart from each other not only in the axial direction but also in the radial direction, over an inner region extending in the form of a rough funnel of the stud side edge section 24 in this way.

The projection 28 formed at the axial end of the stud-side edge section 24, in cooperation with the ball stud 3, with the sealing bellows 20 assembled on the ball joint (as shown in Figure 2) The protruding portion 26 forming the sealing region 31 and engaging in the groove 7 forms the resealable region 29 and forms the resilient sealing region 29 in relation to the profile of the inner contour of the stud- The protruding portion 27 formed between the resealed regions forms the main sealing region 30. In this case, due to the inner contour extending in the form of funnel of the stud-side edge section 24, the relationship of d1 < d2 < d3 is applied.

The sealing bellows 20 shown in Fig. 3 then includes a clamping member 22 in the form of a flat wire clamping ring or a circular wire clamping ring, which surrounds the sealing bellows 20 in the region of the stud side edge section 24, (See Fig. 2) for accommodating the ring grooves 32. The ring grooves 32 are formed on the outer periphery of the ring grooves 32 (see Fig. The use of a flat wire clamping ring has the advantage of reducing the sensitivity to overstretching due to assembly compared to a circular wire clamping ring.

The additional shape and manner of operation of the sealing bellows 20 are now described in a schematic half sectional view with the sealing bellows 20 shown in Figure 3 assembled to the joint housing 2 or the ball stud 3 of the ball joint Will be described in more detail with reference to FIG. 2 which is shown. With respect to the rest of the configuration, the ball joint may already be the ball joint described in connection with FIG. 1, and reference is made to the above in relation to the configuration of the ball joint. The following describes in particular the effects of the sealing bellows 20 according to the invention, which is achieved on the basis of the shape of the stud-side edge section 24 according to the invention.

2 it is confirmed that the stud side edge section 24 of the sealing bellows 20 has a shape different from the shape of the edge section 14 of the sealing bellows 10 known from the prior art according to Fig. . In short, based on the geometry described above with reference to Fig. 3 relative to the stud side edge section 24, by the plurality of protrusions 26, 27 and 28 formed in the stud side edge section 24, the sealing bellows 20 Is brought into contact with the ball stud 3 under the formation of the three sealing areas 29, 30 and 31 in the region of the stud-side edge section 24. In this case, the projections 28 formed at the axial ends of the stud-side edge sections 24 are arranged such that the projections engage over the circumferential camber 33 formed on the ball stud 3 to cause an elastic deformation of the sealing bellows 20 material So as to match the sealing bellows. Due to the shape that is surrounded and gripped in this manner, a pre-seal area 31 is formed which effectively prevents the initial penetration of contaminants or moisture into the more inwardly located joint seal areas 30, 29. Thus, through the pre-seal area, a desired seal is achieved with respect to the outer periphery.

The ring groove 32 is positioned in conformity with the projection 27 assigned to the main sealing area 30 in the axial direction on the sealing bellows 20. This arrangement allows the clamping member 22 disposed in the ring groove 32 to preferentially apply its own radial inward pressing to the primary sealing region 30. [ Thereby, the maximum sealing force inside the stud-side edge section 24 is formed between the elastically deformed projection 27 and the ball stud 3 under the action of the radially inward facing compression force according to the drawing of Fig.

2, the projections 27 assigned to the main sealing area 30 are arranged such that the projections are in contact with the ball stud 3, which is particularly conical, inclined with respect to the central axis 6 of the ball stud 3. [ As shown in Fig. As a result, the projecting portion 27 is in close contact with the inclined surface, not the vertical surface. As a result, an axial sealing action as well as a radial sealing action is preferably achieved. Also, automatic re-adjustment (sliding in the groove 7 direction) is also preferable. It is ensured that the sliding due to abrasion which occurs over the life span can be preferably maintained so that the desired sealing force can be maintained while the shrinkage of the sealing bellows 20 is accompanied by the condition that the preload of the clamping ring 22 is maintained as a whole .

The projections 26 engaging in the grooves 7 of the ball stud 3 form together with the ball stud 3 a resealable region 29. In addition, the protrusion 26 achieves axial fixation of the stud-side edge section 24 of the sealing bellows 20 relative to the ball stud 3.

In sum, it is ensured that the stud-side edge section 24 is divided into the plurality of sealing areas 29, 30, 31, so that a relatively high sealing force is applied to the main sealing area 30 in particular, A very high sealing action can be achieved as a whole in the area of the section 24.

1: ball joint
2: Joint housing
3: Ball Stud
4: joint ball
5: ball socket
6: center axis
7: Groove
8: Closed ring
10: Sealing bellows (according to the prior art)
11: Clamping ring
12: Clamping ring
13: housing side edge section
14: Stud side edge section
15: Case
16:
20: Sealing bellows
21: Clamping ring
22: Clamping ring
23: housing side edge section
24: Stud side edge section
25: Case
26:
27:
28:
29: Re-sealing area
30: main sealing area
31: preliminary sealing area
32: Ring groove
33: Camber
d1: inner diameter
d2: inner diameter
d3: inner diameter

Claims (11)

In particular, a sealing bellows 20 for sealing a ball joint 1 having a ball stud 3 rotatably mounted relative to a joint housing 2, the sealing bellows 20 having a housing- Side edge section 24 and a case 25 connecting these edge sections and on the stud-side edge section 24 in cooperation with the ball stud 3 to form a sealing region Wherein a protrusion (26) is formed for engaging in a groove (7) formed on the ball stud (3) to form a sealing bell (29)
Characterized in that on the stud-side edge section (24), one or more additional protrusions (27, 28) are formed in cooperation with the ball stud (3) to form one or more additional sealing areas (30, 31) The bellows 20. 2. Sealing bellows according to claim 1, characterized in that the sealing bellows has a minimum internal diameter (d1) in the region of the projection (26) assigned to the groove (7). A sealing bellows according to any one of the preceding claims, characterized in that the sealing bellows has an inner contour starting from a projection (26) assigned to the groove (7) and extending substantially in the form of a funnel over the profile of the stud- Features, sealing bellows. A sealing bellows according to any one of claims 1 to 3, characterized in that three projections (26, 27, 28) are formed on the stud-side edge section (24) of the sealing bellows (20). The stud according to any one of claims 1 to 4, characterized in that the protrusion (28) formed at the axial end of the stud-side edge section (24) forms a pre-seal area (31) in cooperation with the ball stud (3) The projections 26 engaging in the grooves 7 form a resealable region 29 and protrusions formed between the pre-seal region and the resealable region in relation to the profile of the inner contour of the stud- 27 form a main sealing region (30). The sealing bellows according to claim 5, wherein the sealing bellows has an inner diameter (d3) in the region of the protruding portion (28) assigned to the pre-sealing region (31) (d2) in the region of the protrusion (26) assigned to the resealed area (29), and d1 <d2 <d3. 7. A clamping device according to any one of claims 1 to 6, characterized in that the clamping member (22) surrounding the sealing bellows (20), in particular the side of the stud side edge section (24) for receiving a flat wire clamping ring or a circular wire clamping ring Characterized by a ring groove (32) formed in the outer circumferential surface in the region. The clamping device according to claim 7, wherein the ring groove (32) is formed by a clamping member (22) inserted in the ring groove (32) in a state in which the sealing bellows (20) is assembled on the ball stud To be positioned so as to correspond to the projections 27 assigned to the sealing bellows 20 in the axial direction and preferably to the primary sealing area 30 in such a manner that the pressing of the primary sealing area 30 is first applied to the primary sealing area 30. [ Features, sealing bellows. 9. A method according to any one of claims 1 to 8, wherein the projections (27) assigned to the primary sealing area (30) are such that, in a state in which the sealing bellows (20) is assembled on the ball stud (3) Is in contact with the surface of the ball stud (3) which is inclined with respect to the central axis (6) of the stud (3), in particular a conical shape. 10. A method according to any one of claims 1 to 9, wherein the protruding portion (28) assigned to the pre-sealing region (31) is such that, in a state in which the sealing bellows (20) is assembled on the ball stud (3) Is arranged and formed to engage over a camber (33) formed on the stud (3). A ball joint (1) comprising a ball stud (3) mounted rotatably relative to a joint housing (2) and a sealing bellows (20) according to one of the claims 1 to 10.

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