WO2012050791A1

WO2012050791A1 - Low load offset seal

Info

Publication number: WO2012050791A1
Application number: PCT/US2011/052908
Authority: WO
Inventors: John B. Wagner
Original assignee: Freudenberg-Nok General Partnership
Priority date: 2010-09-29
Filing date: 2011-09-23
Publication date: 2012-04-19
Also published as: BR112013004899A2; EP2622252A1; EP2622252A4; CN103080624A; BR112013004899B1

Abstract

A seal is provided for insertion in a bore in an outer member and engaging an inner member received in the bore. The seal includes an outer annular insert having a first diameter and an inner annular insert having a second diameter smaller than the first diameter. An elastomeric body includes an outer portion over-molded on the outer annular insert and an inner seal over-molded on the inner annular insert and including an intermediate web extending between the outer portion and the inner portion. The web extends both axially and radially relative to a center axis of the outer annular insert. The inner seal includes an inboard sealing surface and the outer portion including an outboard sealing surface.

Description

LOW LOAD OFFSET SEAL

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a Continuation-in-Part of U.S. Patent Application No. 12/861 ,892, filed August 24, 2010, which claims the benefit of U.S. Provisional Application No. 61 /236,640, filed August 25, 2009; and also claims the benefit of U.S. Provisional Application No. 61 /387,638, filed on September 29, 2010. The entire disclosures of the above applications are incorporated herein by reference.

FIELD

[0002] The present disclosure relates to seals and more particularly, a low load dual insert offset seal. BACKGROUND AND SUMMARY

[0003] This section provides background information related to the present disclosure which is not necessarily prior art.

[0004] Seals are commonly used for sealing a gap disposed around an outer surface of an inner member received within a bore of an outer member, such as a fuel injector, a spark plug tube, or a shaft. Conventional seals incorporate a rubber outer dimension (OD) for engaging a bore and may have various inner dimension (ID) seal configurations for engaging a shaft or other inner member.

[0005] A seal is provided for insertion in a bore in an outer member and engaging an inner member received in the bore. The seal includes an outer annular insert having a first diameter and an inner annular insert having a second diameter smaller than the first diameter. An elastomeric body includes an outer portion over-molded on the outer annular insert and an inner seal over- molded on the inner annular insert and including an intermediate web extending between the outer portion and the inner portion. The web extends both axially and radially relative to a center axis of the outer annular insert. The inner seal includes an inboard sealing surface and the outer portion including an outboard sealing surface. The seal provides for reduced installation and removal force requirements and improved sealing during cycle tests and thermal cycles.

DRAWINGS

[0006] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0007] Figure 1 is a cross-sectional view of a low load dual insert offset seal according to the principles of the present disclosure;

[0008] Figure 2 is a cross-sectional view of a second embodiment low load dual insert offset seal according to the principles of the present disclosure;

[0009] Figure 3 is a perspective view of a support ring according to the principles of the present disclosure;

[0010] Figure 4 is a cross-sectional view of a third embodiment of the low load offset seal according to the principles of the present disclosure;

[0011] Figures 5A and 5B illustrate the low load offset seal of Figure 1 with the depiction of Figure 5B showing the seal in an offset position;

[0012] Figures 6A and 6B each disclose cross-sectional views of the low load offset seal shown in Figure 4 with the Figure 6B illustration of the seal being in an offset position;

[0013] Figure 7 is a cross-sectional view of a fourth embodiment of a low load dual insert offset seal according to the principles of the present disclosure;

[0014] Figure 8 is a cross-sectional view of a fifth embodiment of a low load dual insert offset seal according to the principles of the present disclosure;

[0015] Figure 9 is a cross-sectional view of a sixth embodiment of a low load dual insert offset seal according to the principles of the present disclosure, illustrated in an offset position;

[0016] Figure 10 is a cross-sectional view of the low load dual insert offset seal of Figure 8, illustrated in an offset position; [0017] Figure 1 1 is a cross-sectional view of a seventh embodiment of a low load dual insert offset seal according to the principles of the present disclosure illustrated in an offset position; and

[0018] Figure 12 is a cross-sectional view of an eighth embodiment of a low load dual insert offset seal according to the principles of the present disclosure illustrated in an offset position.

[0019] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0020] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0021] Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0022] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having," are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0023] When an element or layer is referred to as being "on," "engaged to," "connected to," or "coupled to" another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

[0024] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0025] Spatially relative terms, such as "inner," "outer," "beneath," "below," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0026] With initial reference to Figures 1 , 5A, and 5B, an arrangement for sealing an annular space is shown. The arrangement generally includes a seal 12 disposed in an annular space defined between an inner member 16 and an outer member 18. During operation, the seal 12 engages respective sealing surfaces 22 and 24 on the inner and outer members 1 6 and 18, respectively, in an assembled position. For purposes of discussion, the inner member 16 will be referred to herein as a shaft, while the outer member 18 will be referred to herein as a bore. It is appreciated that while the specific examples provided herein relate to a shaft and bore arrangement, the teachings may be similarly applicable to other sealing arrangements and are not limited to a shaft and bore arrangement, as described herein.

[0027] With specific reference now to Figure 1 , the seal 12 will be described in greater detail. In general, the seal 12 includes a outer portion 30, an inner seal 32, and an intermediate web 34 extending between the outer portion 30 and the inner seal 32. The outer portion 30 is radially offset outwardly relative to the inner seal 32. The outer portion 30 defines an outboard sealing surface 36 for engaging the sealing surface 24 of the bore 18 in an installed position. Similarly, the inner seal 32 defines an inboard sealing surface 38 for engaging the sealing surface 22 of the shaft or other member 16 in an installed position. The outboard and inboard sealing surfaces 36 and 38 of the seal 12 may be made of an elastomeric material such as rubber, although other materials may be used. The outboard sealing surface 36 of the seal 12 generally defines a cylindrical face. The sealing surface 36 can include sealing beads 40 thereon in order to enhance its retention and sealing properties. The inboard sealing surface 38 of the seal 12 can be disposed on a flap 42 which will be described in greater detail herein. The web portion 34 is adapted to flex to accommodate the inner seal being radially offset relative to the outer portion 30 so that the inner seal 32 can maintain contact with the inner member 16 upon movement of the inner member 16 relative to the outer member 18. [0028] The outer portion 30 of the seal 12 includes an outer annular insert ring 44 disposed therein. The inner seal 32 of the seal 12 includes an inner annular insert ring 46 disposed therein. The annular insert rings 44 and 46 may be of a rigid material such as metal, although other rigid materials may be used. Annular insert rings 44 and 46 provide rigidity to the respective outer portion 30 and inner seal 32 and to the seal 12 as a whole.

[0029] The flap 42 of the inner seal 32, in an uninstalled condition, can extend at an angle relative to the overmolded insert ring 46 and in an assembled position, is disposed within a gap 48 between a spring portion 49 defined by the overmolded insert ring 46 and the shaft 16. The insert ring 46 partially loads the spring portion 49 and flap 42 in the assembled position, generally illustrated in Figure 5A. The angle and thickness of the flap 42 can vary depending on the required sealing force as well as the required loading forces for installation on the shaft 16. The geometry of the flap 42 can allow for ease of fill during the molding process and for mold removal. Furthermore, the flap 42 can include multiple seal beads 50 which can vary in shape and size. The gap 48 disposed between the spring portion 49 and the shaft 16 provides limited space for compression of the flap 42 therebetween. The flap 42 allows for reduction in the rubber stress as compared to a solid rubber bead and allows the inner seal 32 to follow the shaft 16 under a thermal cycle from hot to cold and vice versa and due to other movement such as vibration and part to part shift. This provides improved shaft follow-ability as compared to prior designs. The flap 42 lowers the elastomer strain limit of the material by creating two separate spring elements (i.e., two elastomer elements), as compared to current designs with one spring element.

[0030] With continued reference to Figures 1 , 5A and 5B, the web portion 34 of the seal 12 extends both axially and radially relative to a center axis A1 of the outer portion 30 to accommodate lateral and angular movement of the shaft 16 relative to an axis of the bore 18 while maintaining a seal at an interface between the inboard sealing surface 38 of the seal 12 and the sealing surface 22 of the shaft 16. In Figure 5B, the shaft 16 is shown moved from a center axis A1 laterally rightward to an offset axis A2. The inner seal 32 of the seal 12 moves complementary to movement of the shaft 16. To maintain an interface between the seal 12 and the shaft 16, the intermediate web 34 stretches on a first portion and buckles on an opposite portion. It is appreciated that the intermediate web 34 may comprise a thin web between the outer portion 30 and the inner seal 32 to accommodate further deflection and/or rotation of the shaft 16. While the seal 12 is shown deflected laterally it is appreciated that the seal 12 may experience one of lateral deflection or possibly rotation in the installed position or, alternatively, not experience any movement. The design of the present application allows greater movement or misalignment between the shaft and the bore as compared to present designs while still maintaining low installation forces. The seal 12 can be compactly designed with the inner seal 32 being disposed entirely axially between opposite ends of the outer annular insert 44.

[0031] With reference now to Figure 2, an arrangement for sealing an annular space according to additional features is shown. The arrangement generally includes a seal 1 12 disposed in an annular space defined between an inner member 16 and an outer member 18. During operation, the seal 1 12 engages respective sealing surfaces 22 and 24 on the inner and outer members 16 and 18, respectively, in an assembled position.

[0032] With specific reference now to Figure 2, the seal 1 12 will be described in greater detail. In general, the seal 1 12 includes an outer portion 130, an inner seal 132, and an intermediate web portion 134 extending between the outer portion 130 and the inner seal 132. The outer portion 130 is radially offset outwardly relative to the inner seal 132. The outer portion 130 defines an outboard sealing surface 136 for engaging the sealing surface 24 of the bore 18 in an installed position. Similarly, the inner seal 132 defines an inboard sealing surface 138 for engaging the sealing surface 22 of the shaft 16 in an installed position. The intermediate web 134 generally defines a web portion extending between the outer portion 130 and inner seal 132. The outboard and inboard sealing surfaces 136 and 138 of the seal 1 12 may be made of an elastomeric material such as rubber, although other materials may be used. The outboard sealing surface 136 of the seal 1 12 generally defines a cylindrical face. The sealing surface 136 can include sealing beads 140 thereon. The inboard sealing surface 138 of the seal 1 12 is disposed on a flap 142 which will be described in greater detail herein. The intermediate web 134 and inner seal 132 is adapted to deflect with the inner member 16 and maintain contact with the inner member 16 upon movement of the inner member 16 relative to the outer member 18.

[0033] The outer portion 130 of the seal 1 12 includes an outer annular insert ring 144 disposed therein. The inner seal 132 of the seal 1 12 includes a second annular insert ring 146 disposed therein. The annular rings 144 and 146 may be made of a rigid material such as metal. Annular rings 144 and 146 provide rigidity to the respective outer portion 130 and the inner seal 132 and to the seal 1 12 as a whole. The inner annular insert ring 146 can include an axially extending cylindrical leg 146a and a radially inwardly extending leg 146b which extends toward the shaft 16 and having an inner diameter that prevents excessive inner seal movement at extreme offset. The radially inwardly extending leg 146b can include a series of spaced tabs 156. The radially inwardly extending leg 146b can be axially spaced from the flap 142 and restricts movement of the inner seal 132 relative to the shaft 16 to prevent excessive load on the flap 142.

[0034] The flap 142 of the inner seal 132 can extend at an angle relative to the cylindrical leg 146a of the overmolded insert ring 146 and in an assembled position, is disposed within a gap 148 between a spring portion 149 defined by the overmolded cylindrical leg 146a and the shaft 16. The axially extending leg 146a partially loads the spring portion 149 and flap 142 in the assembled position. The angle of the flap 142 (illustrated in the un-assembled position in Figure 2) can vary depending on the required sealing force as well as the required loading forces for installation on the shaft 16. The geometry of the flap 142 can allow for ease of fill during the molding process and for mold removal. Furthermore, the flap 142 can include multiple seal beads 150 which can vary in shape and size. The gap 148 disposed between the spring portion 149 and the shaft 16 provides limited space for compression of the flap 142 therebetween. The flap 142 allows for reduction in the rubber stress as compared to a solid rubber bead and allows the inner seal 132 to follow the shaft 16 under a thermal cycle from hot to cold and vice versa and due to other movements such as vibration and part to part shift. This design provides the same benefits as the design of Figure 1 while limiting the amount of compression of the spring elements.

[0035] With continued reference to Figure 2, the seal 1 12 accommodates lateral and angular movement of the shaft 16 relative to an axis of the bore 18 while maintaining a seal at an interface between the inboard sealing surface 138 of the seal 1 12 and the sealing surface 22 of the shaft 16. In the same manner as illustrated in Figure 5B, the inner seal 132 of the seal 1 12 moves complementary to movement of the shaft 16. To maintain an interface between the seal 1 12 and the shaft 16, the intermediate web 134 stretches on a first portion and buckles on an opposite portion. It is appreciated that the intermediate web 134 may comprise a thin web between the outer portion 130 and the inner seal 132 to accommodate further deflection and/or possibly rotation of the shaft 16.

[0036] With reference now to Figure 4, an arrangement for sealing an annular space according to additional features is shown. The arrangement generally includes a seal 212 disposed in an annular space defined between an inner member 16 and an outer member 18. During operation, the seal 212 engages respective sealing surfaces 22 and 24 on the inner and outer members 16 and 18, respectively, in an assembled position.

[0037] With specific reference now to Figure 4, the seal 212 will be described in greater detail. In general, the seal 212 includes an outer portion 230, an inner seal 232, and an intermediate web 234 extending between the outer portion 230 and the inner seal 232. The outer portion 230 is radially offset outwardly relative to the inner seal 232. The outer portion 230 defines an outboard sealing surface 236 for engaging the sealing surface 24 of the bore 18 in an installed position. Similarly, the inner seal 232 defines an inboard sealing surface 238 for engaging the sealing surface 22 of the shaft 16 in an installed position. The intermediate portion 234 generally defines a web extending between the outer portion 230 and inner seal 232.

[0038] The outboard and inboard sealing surfaces 236 and 238 of the seal 212 may be made of an elastomeric material such as rubber, although other materials may be used. The outboard sealing surface 236 of the seal 212 generally defines a cylindrical face. The sealing surface 236 can include sealing beads 240 thereon. The inboard sealing surface 238 of the seal 212 includes an angularly disposed seal lip 242a and a seal bead 242b. The intermediate web 234 and the inner seal 232 are adapted to deflect with the inner member 16 and maintain contact with the inner member 16 upon movement of the inner member 16 relative to the outer member 18.

[0039] The outer portion 230 of the seal 212 includes an outer annular insert ring 244 disposed therein. The inner seal 232 of the seal 212 includes an inner annular insert ring 246 disposed therein. The annular insert rings 244 and 246 may be of a rigid material such as metal, although other rigid materials can be utilized. Annular rings 244 and 246 provide rigidity to the respective outer portion 230 and inner seal 232 and to the seal 212 as a whole. The inner annular insert ring 246 can include an axially extending cylindrical leg 246a and a radially inwardly extending leg 246b which extends toward the shaft 16 and having an inner diameter that prevents inner seal movement at extreme offset. The radially inwardly extending leg 246b can include a series of spaced tabs in the same manner as illustrated in Figure 3. The radially inwardly extending leg 246b restricts movement of the inner seal 232 relative to the shaft 16 to prevent excessive load on the angularly disposed seal lip 242a and the seal bead 242b. The radially inwardly extending leg 246b can be disposed axially between the angularly disposed seal lip 242a and the seal bead 242b.

[0040] The angularly disposed seal lip 242a of the inner seal 232 can extend at an angle relative to the cylindrical leg 246a of the overmolded insert ring 246. The angle of the seal lip 242a can vary depending on the required sealing force as well as the required loading forces for installation on the shaft 16. The seal bead 242b can be disposed radially inward of the axially extending leg 246a of the insert ring 246 and can have a geometry to allow for ease of fill during the molding process and for mold removal. The seal bead 242b is partially loaded by the axially extending leg 246a being located radially outwardly therefrom. [0041] With continued reference to Figures 4, 6A and 6B, the seal 212 accommodates lateral and angular movement of the shaft 16 relative to an axis of the bore 18 while maintaining a seal at an interface between the inboard sealing surface 238 of the seal 212 and the sealing surface 22 of the shaft 16. As illustrated in Figure 6B, the inner seal 232 of the seal 212 moves complementary to movement of the shaft 16. To maintain an interface between the seal 212 and the shaft 16, the intermediate web 234 stretches on a first portion and buckles on an opposite portion. It is appreciated that the intermediate web 234 may comprise a thin web between the outer portion 230 and the inner seal 232 to accommodate further deflection and/or rotation of the shaft 16. While the seal 212 is shown deflected laterally it is appreciated that the seal 212 may experience one of lateral deflection or possibly rotation in the installed position or, alternatively, not experience any movement.

[0042] Figure 7 is a cross-sectional view of a low load dual insert offset seal 312 according to the principles of the present disclosure. The seal 312 includes an inboard and an outboard seal 330, 332 connected by a web portion 334. The inboard and outboard seals each include an annular insert ring 336, 338. The inboard seal includes a flap 342 having a smooth inner surface (although a textured or annular ribbed surface can be used) that engages the outer surface 22 of the inner member 16 to be sealed. The inner annular insert ring 336 can be provided with a radially inwardly extending flange 340 located adjacent to a hinge point of the flap 342. The outer surface 344 of the flap 342 can be provided with one or more raised beads 352 that provide a spring effect for biasing the flap 342 against the inner member 16 being sealed. The web 334 can accommodate radial offset between the inner and outer members 16, 18.

[0043] Figure 8 is a cross-sectional view of a second embodiment low load dual insert offset seal 412 (in an unassembled state) according to the principles of the present disclosure. The seal 412 includes an inboard and an outboard seal 430, 432 connected by a web portion 434. The inboard and outboard seals 430, 432 each include an annular insert ring 436, 438. The inboard seal 430 includes a flap 442 having a smooth inner surface (although a textured or annular ribbed surface can be used) that engages the outer surface 22 of an inner member 16 to be sealed. The inner annular insert ring 436 can be provided with a radially inwardly extending flange 440 located distal to a hinge point of the flap 442. The outer surface of the flap 442 can be provided with one or more raised beads 452 that provide a spring effect for biasing the flap against the inner member being sealed. Figure 10 shows the seal of Figure 8 in an assembled condition accommodating an offset between and inner and an outer member being sealed. Figure 9 shows a seal similar to the seal of Figs 8 and 10 with a single bead 452 on the outer surface of the flap 442. The web 434 can accommodate radial offset between the inner and outer members 16, 18.

[0044] Figure 1 1 is a cross-sectional view of a third embodiment of the low load offset seal 512(in an assembled state) according to the principles of the present disclosure. The seal 512 includes an inboard and an outboard seal 530, 532 connected by a web portion 534. The web portion 534 extends diagonally between opposite ends of the inboard and outboard seals 530, 532. The inboard and outboard seals 530, 532 each include an annular insert ring 536, 538. The inboard seal 530 includes a flap 542 having a smooth inner surface (although a textured or annular ribbed surface 548 can be used, as shown in Fig. 12) that engages the outer surface 22 of an inner member 16 to be sealed. The inner annular insert ring 536 can optionally be provided with a radially inwardly extending flange 550 (fig. 6) located either distal to or adjacent to the hinge point of the flap 542. Omission of the flange 550, as shown in Fig. 5 can reduce the assembly force required on the inner member 16. The outer surface of the flap 542 can be provided with one (Fig. 5) or more (Fig. 6) raised beads 552 that provide a spring effect for biasing the flap 542 against the inner member 16 being sealed. The web 534 can accommodate radial offset between the inner and outer members 16, 18.

[0045] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.

Claims

CLAIMS What is claimed is:

1 . A seal for insertion in a bore in an outer member and engaging an inner member received in the bore, comprising:

an outer annular insert having a first diameter;

an inner annular insert having a second diameter smaller than said first diameter; and

an elastomeric body including an outer portion over-molded on said outer annular insert and an inner seal over-molded on said inner annular insert and including an intermediate web extending between said outer portion and said inner portion, said web extending both axially and radially relative to a center axis of said outer annular insert, said inner seal including an inboard sealing surface and said outer portion including an outboard sealing surface, said inner seal includes an annular flap that in an installed position, is adapted to be compressed between said inner annular insert and the inner member, said annular flap including at least one raised bead on an outer surface thereof.

2. The seal according to claim 1 , wherein said outer portion of said elastomeric body includes at least one sealing bead extending radially outwardly therefrom.

3. The seal according to claim 1 , wherein said annular flap includes at least one sealing bead on an inner surface thereof.

4. The seal according to claim 3, wherein said annular flap includes a hinge portion connected at a junction between said over-molded inner annular insert and said intermediate web.

5. The seal according to claim 1 , wherein said inner annular insert includes an axially extending leg and a radially inwardly extending leg extending from an end of said axially extending leg.

6. The seal according to claim 5, wherein said radially inwardly extending leg of said inner annular insert is disposed adjacent to a distal end of said annular flap.

7. A seal for insertion in a bore in an outer member and engaging an inner member received in the bore, comprising:

an outer annular insert having a first diameter;

an elastomeric body including an outer portion over-molded on said outer annular insert and an inner seal over-molded on said inner annular insert and including an intermediate web extending between said outer portion and said inner portion, said web extending both axially and radially relative to a center axis of said outer annular insert, said inner seal including an inboard sealing surface and said outer portion including an outboard sealing surface, said inner seal includes an annular flap that in an installed position, is adapted to be compressed between said inner annular insert and the inner member, said inner annular insert includes an axially extending leg and a radially inwardly extending leg extending from an end of said axially extending leg, said radially inwardly extending leg of said inner annular insert is disposed adjacent to a distal end of said annular flap.

8. The seal according to claim 7, wherein said outer portion of said elastomeric body includes at least one sealing bead extending radially outwardly therefrom.

9. The seal according to claim 7, wherein said annular flap includes at least one bead on an inner surface thereof.

10. The seal according to claim 9, wherein said annular flap includes a hinge portion connected at a junction between said overmolded inner annular insert and said intermediate web.

1 1 . A seal for insertion in a bore in an outer member and engaging an inner member received in the bore, comprising:

an outer annular insert having a first diameter;

an elastomeric body including an outer portion over-molded on said outer annular insert and an inner seal over-molded on said inner annular insert and including an intermediate web extending between said outer portion and said inner portion, said web extending both axially and radially relative to a center axis of said outer annular insert, said inner seal including an inboard sealing surface and said outer portion including an outboard sealing surface, said inner seal includes an annular flap that in an installed position, is adapted to be compressed between said inner annular insert and the inner member, said intermediate web extending diagonally between opposite ends of the outer and inner seals.

12. The seal according to claim 1 1 , wherein said outer portion of said elastomeric body includes at least one sealing bead extending radially outwardly therefrom.

13. The seal according to claim 1 1 , wherein said annular flap includes at least one sealing bead on an inner surface thereof.

14. The seal according to claim 1 1 , wherein said annular flap includes at least one raised bead on an outer surface thereof.

15. The seal according to claim 1 1 , wherein said annular flap includes a hinge portion connected at a junction between said over-molded inner annular insert and said intermediate web.

16. The seal according to claim 1 1 , wherein said inner annular insert includes an axially extending leg and a radially inwardly extending leg extending from an end of said axially extending leg.

17. The seal according to claim 16, wherein said radially inwardly extending leg of said inner annular insert is disposed adjacent to a proximal end of said annular flap.