Rotary suspension stop provided with shrink-fit seal and retainer

Abstract

To provide a rotary suspension stop including a seal for sealing between a cover and a lower support and axially retaining them, and usable even for a lower support having imprecise fabrication tolerance and coping with axial molding of the lower support.SOLUTION: A rotary suspension stop 10 for a suspension strut includes: a bearing 18, a lower support 12 forming a bearing surface 14 for an upper turn 16 of a helical spring and an annular shrink-fitting object faces 38, 40 turned radially in a radial reference direction; a cover 20 having annular skirt portions 46, 48 axially extending facing and at a distance from the shrink-fitting object faces 38, 40; and seals 56, 72 having main body portions 58, 74, at least one annular seal lip portions 64, 80 projecting in the radial reference direction toward the annular skirt portions 46, 48 from the main body portions 58, 74, and at least a first set of one or more first shrink-fitting elastic lip portions 60, 76 projecting toward the shrink-fitting object faces 38, 40 from the main body portions 58, 74 and shrink-fitted to the shrink-fitting object faces 38, 40.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a rotary suspension stopper that serves as an interface between the upper winding portion of a coil spring of a vehicle suspension and the vehicle body of the same vehicle.

Background Art

[0002] EP 3 626 486 A1 (Patent Document 1) describes a rotary suspension stopper for a suspension strut. This rotary suspension stopper includes a lower support body that forms a bearing surface for the upper winding portion of a coil spring, a bearing supported by the lower support body, and a cover that cooperates with the lower support body to form a housing portion for the bearing. An annular seal is shrink-fitted to the cover. The annular seal has a sealing lip portion that forms a protective seal for the housing portion provided with the bearing by slidingly contacting the lower support body. The seal further has a heel portion that projects radially into an annular groove formed in the lower support body to ensure the integrity of the cover and the lower support body before the rotary stopper is mounted on the vehicle. This solution is suitable when the lower support body is formed from a molded body in a die that is movable in a radial plane with respect to the rotation axis of the present rotary stopper. When the lower support body is manufactured by an axial casting method, it is necessary to perform machining on the annular groove. This is unacceptable from an economic perspective. Moreover, when the lower support body is made of a metal material, it is necessary to perform a specific finish on the sliding contact surface with the sealing lip portion.

[0003] WO 2021 / 018837 (Patent Document 2) discloses a suspension stopper in which the lower support is made of a metal material formed axially. In the same document, in order to enable the attachment of the rotation stopper cover to the lower support, it is proposed to shrink-fit the lower washer of the roller bearing to the lower support and to position the flange portion of the lower washer in a groove formed in the cover. This solution does not have a sealing function and only has the function of maintaining the integrity of the rotation stopper before it is mounted on the vehicle, but it has the disadvantage that not only are strict tolerances required, but a large stress is generated at the shrink-fit interface between the lower support and the lower washer of the bearing. FR 3101279 A1 (Patent Document 3) recommends achieving a sealing function by overmolding or shrink-fitting a seal having a sealing lip portion that slides against the cover to the lower support. However, overmolding or die-forming such a seal requires a complex shape.

[0004] EP3693625 A1 (Patent Document 4) presents a rotating suspension stopper equipped with a seal and retainer. The seal and retainer has a seal body fixed to the lower support in some unspecified way, and a lip portion that slides against the cylindrical wall of the cover to achieve a sealing function. The end of the cylindrical wall of the cover is provided with a bead portion that overlaps radially with the lip portion to securely hold the cover and the lower support in the axial direction. The seal body is in surface contact with the lower support along a cylindrical interface portion and an annular flat interface portion. One solution for fixing this seal to the lower support is overmolding, as described in FR 2 989 634 A1 (Patent Document 5), for example. Another theoretical solution is shrink fitting. However, in this case, extremely strict manufacturing tolerances are required for the cylindrical wall portion of the lower support that contacts the seal body portion. This is to prevent defects in the cylindricity of the cylindrical wall portion from affecting the sealing lip portion through the seal body, thereby preventing deterioration of the sealing performance and lifespan of the lip portion. Furthermore, in this solution, because the cross-section of the seal is small and the clearance height for shrinkage fitting is low, it is necessary to provide a highly rigid reinforcing portion to the seal in order to reliably control the shrinkage fitting.

[0005] In addition, a rotating suspension stopper is known from WO11103921 A1 (Patent Document 6), which includes a seal that is movably attached to both the lower support and the cover. This seal includes a retaining means that protrudes radially toward the cover and the lower support and holds the cover axially relative to the lower support. However, the quality of the seal obtained is not sufficient. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] European Patent Application Publication No. 3626486 [Patent Document 2] International Publication No. 2021 / 018837 [Patent Document 3] French Patent Application Publication No. 3101279 [Patent Document 4] European Patent Application Publication No. 3693625 [Patent Document 5] French Patent Application Publication No. 2989634 [Patent Document 6] International Publication No. 2011 / 103921 [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention aims to overcome the shortcomings of the prior art and propose a solution for sealing, preferably axially holding, the cover and lower support of a rotating suspension stopper. In particular, it aims to propose a solution that can be used even with lower supports that do not have precise manufacturing tolerances and that can accommodate axial molding of the lower support. Means for solving the invention

[0008] To accomplish this, in a first aspect of the present invention, a rotating suspension stopper for a suspension strut, - The bearings that set the reference axis and upward axis direction of the rotation stopper, - A lower support having a support surface that supports the upper winding portion of the coil spring facing the opposite axial direction of the upward axial direction, and an annular contraction fitting surface facing the reference radial direction, - A cover that, together with the lower support, forms the annular space of the bearing, and has an annular skirt portion that extends axially and is spaced apart from the surface to be contracted and fitted, - A seal attached to the shrink-fitting surface of the lower support, the seal having a main body, at least one annular sealing lip portion projecting from the main body toward the annular skirt portion in the reference radial direction, and at least one of a first set of first shrink-fitting elastic lip portions projecting from the main body toward the shrink-fitting surface and shrink-fitted to the shrink-fitting surface, A rotating suspension stopper equipped with the following is proposed.

[0009] The contact area between the one or more first shrink-fit lip portions and the shrink-fit target surface is relatively small, and is significantly smaller than the surface area of ​​the seal body portion facing the shrink-fit target surface. As a result, a high contact pressure can be obtained without requiring significant effort during assembly. Due to the elasticity of the one or more first shrink-fit lip portions, the shrink-fit pressure can be controlled even when the manufacturing tolerances of the shrink-fit target surface are large. The seal body portion interposed between the one or more first shrink-fit lip portions and the sealing lip portion can suppress the occurrence of cylindricity defects on the shrink-fit target surface due to sliding contact between the sealing lip portion and the skirt portion.

[0010] Preferably, the one or more first shrink-fit lip portions protrude from the joint region with the main body, positioned axially apart from the joint region with the main body of the sealing lip portion, and preferably protrude in the axial direction opposite to the upward axial direction. This axial distance between the joint region of the sealing lip portion and the joint region of the one or more first shrink-fit lip portions increases the elastic deformation capacity of the seal main body, thereby limiting the impact of defects on the shrink-fit target surface on the sealing lip portion and enabling the absorption of such defects.

[0011] Preferably, one or more of the first shrink-fitting lip portions protrude from the main body in a radial direction opposite to the reference radial direction and in the upward axial direction. This orientation of the one or more shrink-fitting lip portions of the first set facilitates assembly by forced insertion of the seal into the lower support in the direction opposite to the upward direction, and also prevents the seal from shrinking in the upward axial direction.

[0012] In one extremely high-performance embodiment, the free ends of one or more first shrink-fit lip portions form vertices having an acute angle greater than 20° in the axial cross-section, preferably greater than 70° and less than 90°, and preferably less than 80°, and the bisector of the axial cross-section of the vertex portion forms an angle with respect to the upward axis direction, preferably greater than 10°, and preferably greater than 30°. These shapes can improve the shrinkage resistance of the seal in the upward axis direction.

[0013] In one highly advantageous embodiment, the cover includes at least one retaining locking portion projecting radially from the annular skirt portion in the opposite direction to the reference radial direction, the sealing lip portion being separated from the retaining locking portion in the upward axial direction and partially overlapping the retaining locking portion radially. This allows the seal to perform a sealing and holding function of the cover before the rotation stopper is mounted on the vehicle.

[0014] In one embodiment, the sealing lip portion has a V-shaped axial cross-section in which the apex of the V-shape faces the upward axial direction. This shape ensures excellent flexibility of the sealing lip portion and provides reliable and good control over the contact pressure with the annular skirt portion, that is, the drag torque resisting the relative rotation of the lower support's rotation stopper with respect to the cover around the reference axis.

[0015] In one embodiment, the main body has two end faces on both axial sides, preferably annular, and preferably two axial end faces that overlap each other radially. This arrangement allows the seals to be stacked on top of each other during manufacturing, transportation, handling, or prior to mounting on a rotation stopper.

[0016] In one embodiment, the entire sealing lip portion is located in the axial direction between the two ends of the main body portion on both sides of the axial direction. Even if the sealing lip portion is significantly deformed, for example during assembly or under extreme operating conditions, it can still contact the seal body portion and ride over it without the risk of damage.

[0017] The present invention is extremely suitable for a suspension stopper in which the lower support is a single product of a light metal material. Specifically speaking, this lower support can be manufactured between two mold parts that are axially formed, that is, by translation parallel to the reference axis of the rotation stopper without requiring a lateral slide valve for an undercut shape. In one embodiment, the shrink-fitting target surface has a cylindrical or substantially cylindrical envelope. Here, "substantially cylindrical" means a surface with a clearance angle of less than 3° within manufacturing tolerances that allows the lower support to be axially removed from the mold without causing deterioration of the shrink-fitting area of the seal.

[0018] In one embodiment, the shrink-fitting target surface is located axially above the bearing surface with reference to the upward axial direction.

[0019] In one embodiment, one or more first shrink-fitting lip portions of the first set are constituted by a first annular shrink-fitting elastic lip portion.

[0020] In an alternative embodiment, one or more first shrink-fitting lip portions of the first set are constituted by a row of N first lip portions having N-fold rotational symmetry about the reference axis, where N is an integer of 2 or more, preferably 3 or more.

[0021] Depending on the configuration, it may be necessary to arrange the shrink-fit lip portions on a plurality of planes orthogonal to the reference axis as the deformation control of the seal body portion during shrink fitting. Therefore, in one embodiment, the seal has at least one second set of one or more second shrink-fit lip portions axially spaced from the one or more first shrink-fit lip portions of the first set. Preferably, the sealing lip portion has an annular region of sliding contact or some contact with the annular skirt portion of the cover, and the annular region is axially between the region of shrink-fit contact of the one or more first shrink-fit lip portions with the shrink-fit target surface and the region of shrink-fit contact of the one or more second shrink-fit lip portions with the shrink-fit target surface. In one embodiment that enables molding of the seal without undercuts, the first set is composed of a plurality of first shrink-fit lip portions distributed over a first common circumference of the seal, the second set is composed of a plurality of second shrink-fit lip portions distributed over a second common circumference of the seal, and the second shrink-fit lip portions do not overlap with the first shrink-fit lip portions.

[0022] In one embodiment, the lower support has an annular transition surface extending in the reference radial direction from the shrink-fit target surface and facing in the upward axial direction. Preferably, the seal is annularly and sealingly supported on the transition surface, and preferably, it is annularly and sealingly supported via a static sealing lip portion or a static sealing heel portion. This annular support constitutes a static seal that protects the annular space of the bearing between the lower support and the cover by making the dynamic seal between the sealing lip portion and the annular skirt portion of the cover complete.

[0023] In one embodiment, the sealing lip portion slides against the annular skirt portion. In a modified example, the seal may be non-contacting to the annular skirt portion. In this case, sealing is achieved by partial closure of the space between the shrink-fitting surface of the lower support and the annular skirt portion of the cover. If a retaining locking portion, preferably an annular retaining locking portion, is provided on the annular skirt portion, the retaining locking portion may, if necessary, constitute a baffle portion that contributes to sealing by a contact-type or non-contacting protruding lip portion relative to the seal.

[0024] In one embodiment, the reference radial direction is radially outward, and preferably, the skirt portion is positioned radially outward of the bearing.

[0025] In one embodiment, the reference radial direction is radially inward, and preferably, the skirt portion is positioned radially inward of the bearing.

[0026] In one embodiment, the bearing includes a fixed-position and annular upper guide passage relative to the cover, a fixed-position and annular lower guide passage relative to the lower support and provided opposite to the upper guide passage, and means interposed between the upper guide passage and the lower guide passage to enable rotation of the rotation stopper of the lower guide passage relative to the upper guide passage about the reference axis. The means may, for example, consist of a lubricating oil film or annular pad that slides against the upper guide passage and the lower guide passage in the case of a sliding bearing, or consist of rolling elements that roll in the upper guide passage and the lower guide passage and are appropriately housed in a cage in the case of a roller bearing. The upper guide passage may be formed integrally with the cover or as a guide washer bearing on the cover. The lower guide passage may be formed integrally with the lower support or as a guide washer bearing on the lower support.

[0027] Preferably, the seal and retainer is made of a synthetic material, preferably plastic, particularly polyketone (PK) or polyoxymethylene (POM), and preferably made of the same material without any reinforcing parts.

[0028] Other features and advantages of the present invention will become apparent upon consideration of the following disclosures with reference to the accompanying drawings. [Brief explanation of the drawing]

[0029] [Figure 1] This is a half-axial cross-sectional view of a rotating suspension stopper according to a first embodiment of the present invention. [Figure 2] Figure 1 is a detailed perspective view of the outer seal and retainer of the stopper. [Figure 3] This is a detailed perspective view of the inner seal of the stopper shown in Figure 1. [Figure 4] This is a half-sectional view of the axial direction of a rotating suspension stopper according to a second embodiment of the present invention. [Figure 5] Figure 4 is a detailed perspective view of the seal / retainer, which is part of the stopper. [Figure 6] This is a detailed axial cross-sectional view of a rotating suspension stopper according to a third embodiment of the present invention. [Figure 7] Figure 6 is a detailed perspective view of the seal / retainer, which is part of the stopper. [Figure 8] Figure 7 is a detailed perspective view of a modified seal and retainer. [Modes for carrying out the invention]

[0030] For clarity, the same reference numerals refer to the same or similar components in all figures.

[0031] Figure 1 shows a rotation stopper 10 for a vehicle suspension strut. The rotation stopper 10 comprises a lower support 12 that forms a support surface 14 for the upper winding portion 16 of a coil spring, a bearing 18 supported by the lower support 12, and a cover 20 that, together with the lower support 12, forms a housing space 300 for the bearing 18.

[0032] In this example, the bearing 18 is described as a roller bearing including an upper washer 22 supported below the cover 20, a lower washer 24 supported on the lower support 12, and rolling elements 26 held in a rolling cage 28 so as to roll in an upper guide passage 30 formed in the upper washer 22 and a lower guide passage 32 formed in the lower washer 24, but the present invention is not limited thereto. The bearing 18 enables relative rotational motion between the upper guide passage 30 and the lower guide passage 32, that is, between the cover 20 and the lower support 12, around the rotation axis 100 which constitutes the reference axis of the rotation stopper 10. The bearing 18 further has an upward direction 200 parallel to the reference axis 100, and the bearing 18 is located below the cover 20, with the support surface 14 of the lower support 12 located below the bearing 18. After being installed on the vehicle, the reference axis 100 of the rotation stopper 10 may be in a vertical or inclined state.

[0033] The lower washer 24 is supported on the bearing surface 34 of the lower support 12, which faces in the upward axial direction. In this embodiment, the bearing surface 34 is provided so as to radially overlap the coil spring 16 support surface 14 formed on the lower support 12. The support surface 14 of the lower support 12 faces in the opposite direction from the upward axial direction 200, and has a centering skirt portion 36 that protrudes downward in the axial direction. The lower support 12 further has an outer, annular contraction fitting target surface 38 that faces radially outward and is located radially outside the bearing surface 34, and an inner, annular contraction fitting target surface 40 that faces radially inward and is located radially inside the bearing surface 34. These two shrink-fit surfaces 38 and 40 are cylindrical or tapered with a certain clearance angle (converging upward in the case of the outer shrink-fit surface 38 and downward in the case of the inner shrink-fit surface 40), preferably tapered with a clearance angle of less than 5°. The outer shrink-fit surface 38 has an outer, annular transition surface 42 extending radially outward from the outer shrink-fit surface 38 and facing the upward axis direction 200. Similarly, the inner shrink-fit surface 40 has an inner, annular transition surface 44 extending radially inward from the inner shrink-fit surface 40 and facing the upward axis direction 200.

[0034] The cover 20 has an outer, annular skirt portion 46 spaced apart from the outer shrink-fit surface 38, and an inner, annular skirt portion 48 spaced apart from the inner shrink-fit surface 40. This creates an outer, annular passage 50 for accessing the bearing 18 housing space 300 between the outer shrink-fit surface 38 and the outer skirt portion 46, and an inner, annular passage 52 for accessing the bearing 18 housing space 300 between the inner shrink-fit surface 40 and the inner skirt portion 48. One of the two skirt portions 46, 48 of the cover 20 (in this example, the outer skirt portion 46) may be provided with at least one retaining locking portion projecting radially from the skirt portion toward the lower support (in this example, it is formed in the form of a bead portion 54 at the end of the outer skirt portion 46).

[0035] An outer, annular passage 50 is engaged with a seal and retainer 56 (hereinafter referred to as the outer seal), which is intended to protect the bearing 18 from external contamination and to maintain the integrity of the cover 20 and the lower support 12 before the rotation stopper 10 is attached to the vehicle. In this embodiment, the outer seal 56, as shown in detail in Figure 2, consists of a single piece of synthetic material without an insert and has an annular body portion 58, a shrink-fit elastic lip portion 60 that protrudes from the joint area 62 with the body portion 58 toward the shrink-fit target surface 38 on the outside of the lower support 12, a sealing lip portion 64 that protrudes from the joint area 66 with the body portion 58 toward the outer skirt portion 46 of the cover 20 and slides against the outer skirt portion 46 of the cover 20, and a heel portion 68 that elastically contacts the outer, annular transition surface 42.

[0036] In this example, the shrinkable elastic lip portion 60 is an annular, substantially frustoconical shape, and its dimensions interfere with those of the shrinkable surface 38. As a result, prior to the attachment of the cover 20 during the assembly of the rotation stopper 10, the shrinkable elastic lip portion 60 is forcibly moved downward relative to the shrinkable surface 38, thereby shrinking and fitting it onto the shrinkable surface 38. To facilitate this attachment movement while also preventing the outer seal 56 from coming loose, the shrinkable lip portion 60 protrudes radially and upward in the axial direction 200 from the main body portion 56 of the outer seal toward the outer shrinkable surface 38.

[0037] The sliding sealing lip portion 64 has a V-shaped axial cross-section with the V-shaped apex facing upward in the axial direction 200. At the same time, the free end of the sealing lip portion 64 that contacts the outer skirt portion 46 of the cover is oriented downward in the axial direction toward the locking portion formed by the bead portion 54 at the end of the outer skirt portion 46. This shape allows the cover 20 to be easily assembled by snap-fixing to the assembly consisting of the lower support 12, the bearing 18, and the outer seal 56. Furthermore, it enables elastic mounting that prevents the cover 20 from coming off after assembly or before installation on the vehicle.

[0038] The joint region 66 between the main body 58 of the seal and the sealing retaining lip portion 64 is axially spaced apart from the joint region 62 between the main body 58 of the seal and the shrink-fitting lip portion 60. As a result, even if stress is generated in the seal material 56 due to the deformation of the shrink-fitting lip portion 60 when it is shrink-fitted onto the shrink-fitting target surface 38, this stress is distributed to the main body 58 of the seal, preventing significant deformation of the sealing retaining lip portion 64. In this embodiment, which is the first embodiment, the joint region 66 between the main body 58 of the seal and the sealing lip portion 64 is located below the joint region 62 between the main body 58 of the seal and the shrink-fitting lip portion 60, with respect to the upward direction 200.

[0039] In this embodiment, the heel portion 68 is provided at the lower end of the main body portion 58 of the seal, and constitutes a static seal to the lower support 12. The upper end portion 70 of the seal protrudes axially more than the shrink-fit lip portion 60 and the sealing lip portion 64. Therefore, the entirety of each of the two lip portions 60 and 64 is located axially between the two ends 68 and 70 on both sides of the main body portion 58. This ensures that even if large radial stress is generated in one lip portion or the other lip portion during assembly or use, the lip portions 60 and 64 can be reliably controlled to ride up onto the main body portion 58 of the seal. Furthermore, the upper end portion 70 of the seal overlaps radially with the heel portion 68. This makes it possible to stack multiple seals 56 before assembly without them becoming nested or the lip portions 60 and 64 of adjacent seals coming into contact with each other.

[0040] Figure 3 is a detailed view of the second seal 72 (hereinafter referred to as the inner seal) located in the inner, annular passage 52 formed by the inner skirt portion 48 of the cover 20 and the inner shrink-fit target surface 40 of the lower support 12. The inner seal 72 has the same structure as the outer seal 56 described above, and includes a main body portion 74, a shrink-fit elastic lip portion 76 that protrudes from the joint region 78 with the main body portion 74 toward the inner shrink-fit target surface 40 of the lower support 12 and shrink-fits onto the shrink-fit target surface 40, a sealing lip portion 80 that protrudes from the joint region 82 with the main body portion 78 toward the inner skirt portion 48 of the cover 20 and slides against the inner skirt portion 48, and a heel portion 84 that elastically contacts the inner, annular transition surface 44 and forms a static seal on the inner, annular transition surface 44. The joining regions 78, 82 of the two lip portions 76, 80 with the main body portion 74 are spaced apart from each other, and the entirety of these two lip portions 76, 80 is located axially between the axial ends 84, 86 of the main body portion 74. In this embodiment, the inner seal 72 is not provided with a retaining function. However, those skilled in the art will see that, as one modification, a bead portion projecting radially toward the inner shrink-fit surface 40 may be provided at the lower end of the inner skirt portion 48. This allows the cover 20 to be elastically attached to the temporary assembly composed of the lower support 12 and the inner seal 72. In other words, depending on the conditions, it is possible to provide a retaining function to only one of the two seals (the outer seal 56 or the inner seal 72), or to both seals.

[0041] The embodiments shown in Figures 4 and 5 differ from those described above in that there is no inner seal, and furthermore, the structure of the outer seal 56 is such that the joining region 66 between the main body 58 and the sealing lip portion 64 is located above and spaced apart from the joining region 62 between the main body 56 and the shrink-fitting lip portion 60, with respect to the upward direction 200. The bead portion 54, which functions as a locking portion, is also positioned to maintain a desired clearance with the sealing retaining lip portion 64.

[0042] The embodiments shown in Figures 6 and 7 differ from those described above in the structure of the outer seal 56. The shape of the sealing lip portion 64 has changed to a substantially frustoconical shape, and the static sealing heel portion has been replaced by an elastic lip portion 168 resting on an annular transition surface 42. Furthermore, the shrink-fit of the outer seal 56 to the outer shrink-fit target surface 38 is performed by two annular shrink-fit lip portions 60 and 160 that are spaced apart from each other in the axial direction.

[0043] As shown in detail in Figure 6, the free ends of each of the two shrinkable lip portions 60,160 form a vertex with an acute angle 400 greater than 20° in the axial cross-section before shrinkable fitting to the shrinkable surface, preferably greater than 70° but less than 90°, and preferably less than 80°. The bisector of the axial cross-section of this vertex forms an angle 500 with respect to the upward axial direction 200, preferably greater than 10°, and preferably greater than 30°.

[0044] The first shrinkable lip portion 60 of the two shrinkable lip portions has a bonding region 62 with the main body portion 58 of the seal located lower and spaced apart from the bonding region 66 of the sealing lip portion 64 with the main body portion 58 of the seal. The free end of the sealing lip portion 64 that slides against or in some way contacts the annular skirt portion 46 of the cover is located in the axial direction between the shrinkable contact region between the first shrinkable lip portion 60 and the shrinkable surface 38 and the shrinkable contact region between the second shrinkable lip portion 160 and the shrinkable surface 38.

[0045] The seal obtained in this manner has excellent properties in terms of the mechanical strength of the shrink fit. However, the presence of an undercut shape hinders the molding of the seal in a mold that has a mold section that can move parallel to the rotation axis of the seal.

[0046] The modified example in Figure 8 provides a solution to the above problem by providing not two annular shrink-fitting lip portions, but two sets of multiple shrink-fitting lip portions, namely a first set comprising a first row of N first lip portions 60 having N-th order rotational symmetry around the reference axis, and a second set comprising a second row of N second lip portions 160 also having N-th order rotational symmetry around the reference axis, and offsetting the second lip portions 160 relative to the first lip portions 60 so that there is no overlap between the first lip portions and the second lip portions over an angle of, for example, 360° / (2N) (wherein N is an integer of 2 or more, preferably 3 or more).

[0047] The illustrated and described examples are for illustrative purposes only. Other embodiments, specifically embodiments combining the configurations of the described embodiments, are also conceivable. Specifically, the annular shrink-fit lip portions 60, 76 in the embodiments of Figures 1 to 5 may be replaced with a set of shrink-fit lip portions forming a row as shown in Figure 8. In any embodiment, the external shape of the shrink-fit lip portions 60, 160 shown in Figure 6 can be adopted. The description of the seal and retainer may be adapted to a seal that has only a sealing function. Depending on the magnitude and direction of the force applied to the rotation suspension stopper, the seals 56, 72 may be in permanent sliding contact with the corresponding annular skirt portions 46, 48, or they may be in intermittent sliding contact. Furthermore, it is conceivable that the seals 56, 72 do not slide against the corresponding annular skirt portions 46, 48 under normal operating conditions, and in this case, sealing is ensured by a labyrinth formed between the skirt ring portions 46, 48 and the region of the seal 56, 72 that directly faces the skirt ring portions 46, 48. The description of the outer seal may be replaced with that of the inner seal, and vice versa. Also, the bearing 18 may be of any type, such as a rolling bearing or a sliding bearing, and the guide passages 30, 32 may be formed in the attached washers 22, 24, or may be formed directly in the cover 20 and the lower support 12. The annular bead portion 54 may be replaced with one or more locking portions distributed around the circumference of the relevant skirt portions 46, 48 and projecting radially toward the shrink-fit surface. To enhance the mechanical non-connection between one or more shrink-fit lip portions 60, 160 and the sealing lip portions 64, 80, it is also possible to provide annular, high-rigidity reinforcing portions made of a material with higher rigidity than the lip portions on the seals 56, 72.

Claims

1. A pivoting suspension stopper (10) for a suspension strut, comprising: a bearing (18) defining the reference axis (100) and the upward axial direction (200) of said pivoting suspension stop (10); a lower support (12) forming a bearing surface (14) oriented axially opposite to the upward axial direction (200) for supporting the upper winding (16) of the coil spring, and annular shrink-fit mating surfaces (38, 40) oriented in a reference radial direction; a cover (20) which defines, together with the lower support (12), an annular space (300) for the bearing (18), the cover (20) having annular skirt portions (46, 48) extending axially and spaced apart from and facing the shrink-fit mating surfaces (38, 40); a seal (56, 72) attached to the shrink-fit mating surface (38, 40) of the lower support (12), the seal (56, 72) having a body (58, 74) and at least one annular sealing lip (64, 80) projecting from the body (58, 74) in the radial direction towards the annular skirt (46, 48); wherein the seal (56, 72) has at least a first set of one or more first shrink-fit lip portions (60, 76) that protrude from the body portion (58, 74) toward the shrink-fit mating surface (38, 40) and are shrink-fitted to the shrink-fit mating surface (38, 40).

2. 2. The pivotal suspension stopper (10) of claim 1, wherein the one or more first shrink-fit lip portions (60, 76) protrude from a joining region (62, 78) with the body portion (58, 74) that is axially spaced from a joining region (66, 82) of the sealing lip portion (64, 80) with the body portion.

3. A rotating suspension stopper (10) as described in claim 1 or 2, characterized in that the one or more first shrink-fitting lip portions (60, 76) protrude from the joining area (66, 82) of the sealing lip portion (64, 80) with the main body portion in an axial direction opposite to the upward axial direction (200).

4. 3. The pivotal suspension stopper (10) of claim 1 or 2, wherein the one or more first shrink-fit lip portions (60, 76) protrude from the main body portion (58, 74) in a radial direction opposite to the reference radial direction and in the upward axial direction (200).

5. 3. The pivoting suspension stopper (10) of claim 1 or 2, wherein the free end of the one or more first shrink-fit lip portions (60, 76) forms, in an axial cross section, a vertex portion (400) having an acute angle of more than 20°, and a bisector of the axial cross section of the vertex portion forms an angle (500) with the upward axial direction (200).

6. A rotating suspension stopper (10) as described in claim 5, characterized in that the free end of the one or more first shrink fitting lip portions (60, 76) forms a vertex portion (400) having an acute angle of more than 70° and less than 90° in axial cross section.

7. A rotating suspension stopper (10) as described in claim 5, characterized in that the free end of the one or more first shrink fitting lip portions (60, 76) forms a vertex portion (400) having an acute angle of less than 80° in axial cross section.

8. A rotating suspension stopper (10) as described in claim 5, characterized in that the angle (500) is an angle (500) greater than 10°.

9. A rotating suspension stopper (10) as described in claim 5, characterized in that the angle (500) is an angle (500) greater than 30°.

10. 3. The pivotal suspension stopper (10) according to claim 1 or 2, characterized in that the cover (20) includes at least one retaining engagement portion (54) protruding from the annular skirt portion (46) in a radial direction opposite to the reference radial direction, and the sealing lip portion (64, 80) is spaced from the retaining engagement portion (54) in the upward axial direction and partially overlaps the retaining engagement portion (54) in the radial direction.

11. 3. The pivotal suspension stopper (10) according to claim 1 or 2, wherein the sealing lip portion (64, 80) has a V-shaped axial cross section with the apex of the V facing in the upward axial direction (200).

12. 3. The rotary suspension stopper (10) according to claim 1 or 2, wherein the main body portion (58, 74) has two end faces (68, 70, 84, 86) on both axial sides.

13. A rotating suspension stopper (10) as described in claim 12, characterized in that the two end faces (68, 70, 84, 86) on both axial sides are annular.

14. A rotating suspension stopper (10) as described in claim 13, characterized in that the two end faces (68, 70, 84, 86) on both axial sides overlap each other radially.

15. 13. The pivotal suspension stopper (10) of claim 12, wherein the entire sealing lip portion (64, 80) of the first set of one or more first shrink-fit lip portions (60, 76) is located axially between the two axially opposite ends (68, 70, 84, 86) of the body portion (58, 74).

16. 3. A pivoting suspension stopper (10) according to claim 1 or 2, characterized in that the lower support (12) is a single piece of light metal material.

17. 3. A pivoting suspension stopper (10) according to claim 1 or 2, characterized in that the shrink-fitting mating surfaces (38, 40) have a cylindrical or nearly cylindrical envelope.

18. 3. The pivoting suspension stopper (10) of claim 1 or 2, wherein the first set of one or more first shrink-fit lip portions (60, 76) comprises a first annular shrink-fit lip portion (60, 76) or a row of N first lip portions (60, 76) having N-th order rotational symmetry about the reference axis, where N is an integer greater than or equal to 2.

19. A rotating suspension stopper (10) as described in claim 18, characterized in that N is an integer greater than or equal to 3.

20. 3. The pivotal suspension stopper (10) of claim 1 or 2, wherein the seal (56, 72) has at least one second set of one or more second shrink-fit lip portions (160) axially spaced from the one or more first shrink-fit lip portions (60) of the first set.

21. 21. The pivotal suspension stopper (10) of claim 20, wherein the sealing lip portion (64) has an annular area of ​​sliding contact or some other contact with the annular skirt portion of the cover, the annular area being located axially between an area of ​​shrink-fit contact between the one or more first shrink-fit lip portions (60) and the shrink-fit mating surface (38) and an area of ​​shrink-fit contact between the one or more second shrink-fit lip portions (160) and the shrink-fit mating surface (38).

22. 21. The pivotal suspension stopper (10) of claim 20, wherein the first set of one or more first shrink-fit lip portions (60, 76) is comprised of a plurality of first shrink-fit lip portions (60) distributed about a first common circumference of the seal (56), and the second set of one or more second shrink-fit lip portions (160) is comprised of a plurality of second shrink-fit lip portions (160) distributed about a second common circumference of the seal (56), and the second shrink-fit lip portions (160) do not overlap the first shrink-fit lip portions (60).

23. 3. The rotary suspension stopper (10) according to claim 1 or 2, wherein the lower support (12) has an annular transition surface (42, 44) extending from the shrink-fitted object surface (38, 40) in the reference radial direction and facing the upward axial direction (200), and the seal (56, 72) is annularly sealingly supported on the transition surface (42, 44) and annularly sealingly supported via a static sealing lip portion (68) or a static sealing heel portion (68, 84).

24. 3. The pivotal suspension stopper (10) according to claim 1 or 2, wherein the sealing lip portion (64, 80) is in sliding contact with the annular skirt portion (46, 48).

25. 3. A rotating suspension stopper (10) according to claim 1 or 2, characterized in that the reference radial direction is directed radially outward, and the skirt portion (46) is arranged radially outward of the bearing (18).

26. 3. A rotating suspension stopper (10) according to claim 1 or 2, characterized in that the reference radial direction is a radially inward direction, and the skirt portion (48) is arranged radially inward of the bearing (18).

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