Sealing element with axial air hole

Abstract

A wheel end assembly includes a seal for sealing an annular space between an inner member and an outer member. One of the inner component and the outer component is a static component, and the other one of the inner component and the outer component is a rotatable component. The seal includes an annular box having a cylindrical portion engaged with a stationary component and an annular flange portion extending from the cylindrical portion in a radial direction so as to have a vertical orientation with respect to a horizontal central axis. An annular sealing body is attached to the annular flange portion of the box body, and the annular sealing body is provided with at least one sealing lip engaged with the rotatable component, so that the annular space is divided into a first chamber and a second chamber. In addition, at least one ventilation hole penetrates through the flange part of the box body in the axial direction, so that fluid is connected with the first chamber and the second chamber.

Description

Technical Field

[0001] The present invention relates to seals, and more particularly to seals for vehicle wheel end assemblies. Background Art

[0002] Wheel end assemblies are well known and typically include an inner component such as a shaft or axle and an outer component such as a hub or housing. One of the inner and outer components is connected to the wheel and is rotatable relative to the other component, which is non-rotating or referred to as "stationary". The inner shaft / axle and the outer hub / housing are rotatably coupled by one or more bearings. To retain lubricant within the bearings and prevent contaminants from entering, seals are provided at least near one (typically both) axial ends of the bearings. Such seals generally include a case coupled to either the inner or outer component, and a seal member attached to the case for sealing engagement with the other component. Summary of the Invention

[0003] In one aspect, the present invention is a wheel end assembly including an inner component having a horizontal central axis and an outer component disposed circumferentially around the inner component, an annular space being defined between the inner and outer components. One of the inner and outer components is a rotatable member configured to rotate about the central axis, and the other of the inner and outer components is a stationary member. A seal is provided for sealing the annular space and includes an annular case. The annular case has a cylindrical portion adapted to the stationary member and an annular flange portion extending radially from the cylindrical portion, the flange portion having a vertical orientation relative to the horizontal central axis. An annular seal member is attached to the flange portion of the case, the seal member having at least one seal lip adapted to the rotatable member for dividing the annular space into a first chamber and a second chamber. Further, at least one vent hole (simply referred to as "air hole") axially penetrates the flange portion of the case to fluidly connect the first chamber and the second chamber.

[0004] In a currently preferred application, the outer component is rotatable while the inner component is stationary or fixed relative to the central axis. In this case, the cylindrical portion of the seal case is adapted to the inner component, and the flange portion of the case extends radially outward from the cylindrical portion. At least one seal lip of the seal member is adapted to the outer component. Brief Description of the Drawings

[0005] The present invention will be better understood by reading the above summary in conjunction with the accompanying drawings and the detailed description of the preferred embodiments of the present invention. To illustrate the present invention, the drawings schematically show the presently preferred embodiments of the present invention. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings. In the following drawings:

[0006] Figure 1 is an axial sectional view of the wheel end assembly according to the present invention, showing that it has an outer sealing structure;

[0007] Figure 2 is Figure 1 an enlarged axial sectional view of the upper part;

[0008] Figure 3 is a larger sectional view of the seal of the wheel end assembly of the first structure;

[0009] Figure 4 is Figure 3 a partial enlarged view of;

[0010] Figure 5 is an enlarged alternative view of the seal of the wheel end assembly of the first structure;

[0011] Figure 6 is an enlarged axial sectional view of the wheel end assembly of the first structure, showing that it has an optional protective component ( / protective member / shielding member); and

[0012] Figure 7 An axial sectional view showing the wheel end assembly according to the present invention, showing that it has an inner sealing structure. Detailed Description of the Preferred Embodiments

[0013] In the following description, the use of certain terms is for convenience only and not for purposes of limitation. The terms "upper" and "lower" are used to refer to the reference directions in the drawings, and "inner", "inward" and "outer", "outward" refer to the directions towards and away from the specified center line or geometric center of the component being described, and their specific meanings are apparent from the context of the description. In addition, the terms "connected" and "coupled" as used herein each include both a direct connection between two components (without any other components intervening therebetween) and an indirect connection between two components (with one or more other components intervening therebetween). The terms include the specifically mentioned words above, their derivatives, and words with similar meanings.

[0014] Now referring to the drawings in detail, where like numerals are used throughout to refer to like components. Figures 1 to 7Figure 0 shows a seal 10 for a wheel end assembly 1, which includes an internal component 2 such as a shaft or axle, and an external component 3 such as a hub or housing. The internal component 2 has a central axis A C , and the external component 3 is arranged to surround the internal component 2 in the circumferential direction, defining an annular space AS between the inner and outer components 2 and 3( Figure 1 ). Specifically, the external component 3 has an inner hole 4, and the internal component 2 is arranged at the center of the inner hole 4. One of the components 2 and 3 is a rotatable part CR, which is arranged to be able to rotate around the central axis A C ; the other of the components 2 and 3 is a stationary part CS, which is fixed relative to the central axis A C , as shown in Figure 1 and 7 .

[0015] The seal 10 is arranged to close the annular space AS, and generally includes an annular case 12 that engages (fits) with the stationary part CS and an annular seal member 14 attached to the case 12. The annular seal member 14 sealingly engages (fits) with the rotatable part CR, so that the annular space AS is divided into a first chamber C1 containing lubricant and a second chamber C2 that opens to (leads to) the external environment, that is, the seal member 14 is fluidly connected to the outside of the wheel end assembly 1. As will be described in detail later, the case 12 has at least one axial vent hole 16 that fluidly connects the first chamber C1 and the second chamber C2, so as to reduce the air pressure in the first chamber C1, and the vent hole 16 is positioned so as to prevent any potential flow of lubricant between the first chamber C1 and the second chamber C2 (through the vent hole 16). In addition, the seal 10 preferably further includes an annular sleeve 18 that is installed around or within the rotatable part CR, so that the seal member 14 directly engages with the sleeve 18, as will be described below.

[0016] The annular case 12 includes a cylindrical part 20 and an annular flange portion 22 that extends radially from the cylindrical part 20. Specifically, the cylindrical part 20 has inner and outer circumferential surfaces 21A and 21B and first and second axial ends 20a and 20b that are opposite to each other. When the internal component 2 is used as the stationary part CS, the inner circumferential surface 21A of the cylindrical part 20 frictionally engages (frictionally fits) with the outer circumferential surface 2a of the internal component 2, as shown in Figure 2 . In another case, when the external component 3 is used as the stationary part CS, the outer circumferential surface 21B of the cylindrical part 20 frictionally engages with the inner circumferential surface 3a of the external component 3, as shown inFigure 7 as shown

[0017] In either case, the flange portion 22 has a first radial end 22a formed integrally with the second axial end 20b of the cylindrical portion 20, a second radial (free) end 22b, and first and second axial ends 22c and 22d that are opposite to each other. The first axial end 22c partially encloses ( / bounds) the first chamber C1, and the second axial end 22d partially encloses the second chamber C2. The flange portion 22 may be entirely or substantially made of a metallic material such as mild steel or aluminum, but preferably includes both a metal portion 24 and an elastomeric portion 26 attached to the metal portion 24, as Figure 3 and 4 shown. The elastomeric portion 26 of the flange portion 22 may be formed integrally with the seal body 14, as Figure 5 shown, or may be made of a separate seal body 26 and is provided between the cylindrical portion 20 of the casing 12 and the stationary member CS to function as a seal, as Figures 1 to 4 and Figure 6 shown.

[0018] As Figures 1 to 3 , Figure 6 and Figure 7 shown, the flange portion 22 is preferably formed by two radially extending portions 23A and 23B that are axially offset from each other and are connected by an axial portion 23C, as Figure 2 and 3 shown. As an alternative, the flange portion 22 may also be formed to be substantially "linear", i.e., extending entirely in the radial direction, as Figure 5 shown, or may extend obliquely in both the radial and axial directions (not shown). In addition, the flange portion 22 may also be formed as three or more radially extending portions connected by (multiple) axial portions, one or more curved portions, or formed in any other desired form. Regardless of the flange structure, when the annular case 12 engages ( / fits) with the stationary member CS, the flange portion 22 is oriented vertically with respect to the horizontal central axis CS, such that the flange portion 22 has an uppermost point P U in the vertical direction and a lowermost point P L in the vertical direction, as Figure 1 and 7 shown.

[0019] Now refer to Figures 1 to 3 and Figures 5 to 7, the annular seal 14 is preferably made of an elastomeric material such as natural or synthetic rubber, polyurethane, etc., and is attached to the flange portion 22 of the cartridge 12. Specifically, the seal 14 is attached to at least the second radial end 22b of the flange portion 22. The seal 14 has at least one sealing lip 28 that engages (fits) with the rotatable member CR, preferably having at least one, and preferably two, radial sealing lips 28, namely a main sealing lip 27 and a dust-proof lip 29. The radial sealing lip 28 either engages (fits) with the circumferential surface of the rotatable member CR or with the circumferential surface of a member disposed (or inside) on the rotatable member CR. The member is preferably an annular sleeve 18, as shown in Figures 1 to 3 , Figure 6 and 7 . However, the seal 14 may also comprise any combination of radial and axial sealing lips, or even only have one or more axial sealing lips (none of the above candidates are shown).

[0020] Moreover, the at least one vent hole 16 extends axially through the flange portion 22 of the cartridge 12, such that the first chamber C1 is in fluid communication with the second chamber C2. Specifically, the at least one vent hole 16 has an air inlet 17A located at the first axial end 22c of the flange portion 22 and an air outlet 17B located at the second axial end 22d of the flange portion 22. Thus, the seal 10 is arranged to prevent the lubricant from flowing between the first chamber C1 and the second chamber C2, while the vent hole 16 is arranged to fluidly connect the first chamber C1 and the second chamber C2, such that the air pressure in the first chamber C1 is reduced, especially when the pressure in the first chamber is greater than the ambient or external air pressure.

[0021] To prevent a single vent hole 16 from becoming clogged or obstructed, thereby causing a gas isolation between the first chamber C1 and the second chamber C2, the at least one vent hole 16 preferably comprises a plurality of vent holes 16. The plurality of vent holes 16 are preferably spaced apart in the circumferential direction, and the position of each vent hole is above the central axis A in the vertical direction C , as will be further elaborated in detail later. The plurality of vent holes 16 may also be located on the same diameter (common diameter), or be diametrically staggered, or even be located on the same radius, such that they are radially aligned and thus do not form a circumferential spacing.

[0022] For any number and relative positions of the vent holes 16, each vent hole 16 preferably has a first axial portion 16a passing through the metallic portion 24 of the flange portion 22 and a second axial portion 16b passing through the elastomeric portion 26 of the flange portion 22. Herein, the second axial portion 16b is aligned with the first axial portion 16a, as Figure 4 shown. However, the vent hole 16 may also only include a single axial portion passing through the flange metallic portion 24 (this structure is not shown).

[0023] In addition, to further reduce the potential for lubricant to pass through the vent holes 16, the position of one or more of the vent holes 16 in the vertical direction is preferably higher than the central axis A C , and preferably close to (i.e., radially and angularly) the highest point P of the flange U , and each vent hole has a minimized diameter d H , to reduce the likelihood of lubricant passing through it. More specifically, each vent hole 16 is preferably formed in the upper half of the annular flange portion 22 of the housing (i.e., the portion of the flange portion 22 above the central axis A C when the housing 12 is engaged ( / mated) with the stationary component CS), and most preferably is located within a thirty degree angular sector (not labeled) centered on the highest point P U of the flange portion 22.

[0024] When the wheel end assembly 1 is in a stationary state, i.e., when the rotatable component RS is not rotating, the lubricant therein tends to collect in a "pool" below the central axis A C . In this case, the position of the vent holes 16 above the central axis A C minimizes the likelihood that the lubricant will even reach, let alone pass through, the vent holes 16. However, although not optimal, the vent holes 16 may also be formed in the "lower half region" of the flange portion 22 below the central axis A C when the height of the lubricant "pool" relative to the diameter of the seal 10 is at a minimum, at least at positions on the flange portion 22 that are closer to the central axis A C than to the lowest point P L .

[0025] In addition, each vent hole 16 preferably has a diameter d not exceeding 50‰ (i.e., 0.050) millimeters H , and the diameter d H is further preferably not exceeding 25‰ (i.e., 0.025) millimeters. Such a vent hole diameter d HMinimization reduces the likelihood of any relatively viscous lubricant passing through the air holes 16. To further reduce the likelihood of lubricant migration, each hole 16 preferably tapers inwardly from the air inlet 17A to the air outlet 17B. Specifically, the air inlet 17A has a first diameter d H1 , and the air outlet 17B has a second diameter d H2 , and the value of the second diameter d H2 is less than the first diameter d H1 , as Figure 4 most clearly shows.

[0026] See especially Figure 6 . To further ensure that no lubricant can reach one or more of the air holes 16, the cartridge 12 preferably further includes a shield member 30 attached to the cylindrical portion 20 of the cartridge. The shield member 30 is axially spaced from the flange portion 22 such that when extending radially, it overlaps with at least one (preferably multiple) air hole 16. In a preferred case, the shield member 30 includes a cylindrical portion 32 and a flange portion 34. Among them, the cylindrical portion 32 is attached to the circumferential surface of the cylindrical portion 20 of the cartridge, and the flange portion 34 extends radially from the cylindrical portion 32 and is inclined axially towards the radial flange portion 22 of the cartridge such that it overlaps with the air holes 16 radially. The shield member 30 can be in an arc shape, extending only over the angular range required to cover all the air holes 16 in the circumferential direction, or it can be annular, extending in the entire circumferential direction around the central axis. However, the shield member 30 can have any other suitable structure, or the seal 10 can be provided without any type of shield member.

[0027] The representative non - restrictive embodiments of the present invention have been described in detail above with reference to the accompanying drawings. Such detailed description is only to teach those skilled in the art further details of the preferred aspects of implementing the present invention, and is not to limit the scope of the present invention.

[0028] Moreover, the combinations of features and steps disclosed in the above - detailed description may not be necessary for implementing the present invention in the broadest sense, but are specifically described for the purpose of teaching the representative embodiments of the present invention. In addition, the various features of the above - mentioned representative embodiments and the various independent claims and dependent claims attached thereto can also be combined in a way that is not specifically and explicitly enumerated to provide additional useful embodiments of the present invention.

[0029] All features disclosed in the description and / or the claims are separately and independently disclosed for the purpose of the original written disclosure and for the purpose of delimiting the claimed subject matter, and are not related to the combination of features in the embodiments and / or the claims. In addition, for the purpose of the original written disclosure and for delimiting the claimed subject matter, all numerical ranges or characterizations of entity groups are intended to disclose every possible intermediate value or intermediate entity. The present invention is not limited to the above embodiments and may be varied within the scope of the appended claims.

Claims

1. A wheel end assembly, comprising: An internal component having a horizontal central axis; An external member is provided to surround the internal member in the circumferential direction, such that an annular space is defined between the internal member and the external member. One of the internal member and the external member is a rotatable member, which is provided to be rotatable about the central axis, and the other of the internal member and the external member is a stationary member; And A seal for sealing the annular space, comprising: An annular housing having a cylindrical portion and an annular flange portion, the cylindrical portion being joined to a stationary component, the flange portion extending radially from the cylindrical portion such that it has a vertical orientation relative to the horizontal central axis; An annular seal body attached to the flange portion of the housing and having at least one sealing lip for engaging a rotatable component, such that the annular space is divided into a first chamber and a second chamber; and At least one vent hole axially passing through the flange portion of the housing to fluidly connect the first chamber and the second chamber.

2. The wheel end assembly according to claim 1, characterized in that: The seal is arranged to prevent lubricant from flowing between the first chamber and the second chamber, and the at least one vent hole is arranged to fluidly connect the first chamber and the second chamber so as to reduce the air pressure in the first chamber.

3. The wheel end assembly according to claim 1, characterized in that: The housing is positioned relative to the stationary component such that the at least one vent hole is vertically above the central axis.

4. The wheel end assembly according to claim 3, characterized in that: The flange portion has a highest point relative to the central axis, and the at least one vent hole is located near the highest point of the flange portion.

5. The wheel end assembly according to claim 1, characterized in that: The vent hole has a diameter not exceeding 50‰ mm.

6. The wheel end assembly according to claim 5, characterized in that: The value of the diameter does not exceed 25‰ mm.

7. The wheel end assembly according to claim 1, wherein: The flange portion of the housing has a first axial end partially surrounding the first chamber and a second axial end partially surrounding the second chamber; and The at least one vent hole has an air inlet opening at the first axial end of the flange portion and an air outlet opening at the second axial end of the flange portion.

8. The wheel end assembly according to claim 7, characterized in that: The air inlet has a first diameter, the air outlet has a second diameter, the second diameter is numerically smaller than the first diameter, and the at least one vent hole tapers inward from the air inlet to the air outlet.

9. The wheel end assembly according to claim 1, wherein: The flange portion of the housing has a metal portion and an elastomeric portion attached to the metal portion; and The at least one vent hole has a first axial portion extending through the metal portion and a second axial portion extending through the elastomeric portion and aligned with the first axial portion.

10. The wheel end assembly according to claim 9, characterized in that: The elastomeric portion of the flange portion of the housing is integrally formed with the seal body.

11. The wheel end assembly according to claim 1, characterized in that: The at least one vent hole includes a plurality of vent holes spaced apart circumferentially, and each of the vent holes is vertically above the central axis.

12. The wheel end assembly according to claim 1, characterized in that: The housing further includes a protective component attached to the cylindrical portion and axially spaced from the flange portion such that its radial extension overlaps with the at least one vent hole.

13. The wheel end assembly according to claim 1, characterized in that: At least one sealing lip of the seal body is a radial sealing lip that engages the circumferential surface of the rotatable component or the circumferential surface of a component provided on / inside the rotatable component.

14. The wheel end assembly according to claim 1, characterized in that, One of the following: The internal component is a stationary component, the flange portion of the housing extends radially outward from the cylindrical portion of the housing, and the sealing lip of the seal body engages the inner circumferential surface of the external component; And The external component is a stationary component, the flange portion of the housing extends radially inward from the cylindrical portion of the housing, and the sealing lip of the seal body engages the outer circumferential surface of the internal component.

15. A wheel end assembly, comprising: An internal component having a horizontal central axis; An outer member is provided to surround the inner member in the circumferential direction such that an annular space is defined between the inner member and the outer member, and the outer member is a rotatable member configured to rotate about the central axis; and A seal for sealing the annular space, comprising: An annular housing having a cylindrical portion and an annular flange portion, the cylindrical portion being joined to the internal component, the flange portion extending radially outward from the cylindrical portion such that it has a vertical orientation relative to the horizontal central axis; An annular seal body attached to the flange portion of the housing and having at least one sealing lip for engaging with the external component, such that the annular space is divided into a first chamber and a second chamber, the sealing lip being configured to prevent the flow of lubricant between the first chamber and the second chamber; and At least one vent hole extending axially through the flange portion of the housing to fluidly connect the first chamber and the second chamber in order to reduce the air pressure in the first chamber.

16. The wheel end assembly according to claim 15, wherein: The housing is positioned relative to the stationary component at a location where the vent hole is vertically above the central axis.

17. The wheel end assembly according to claim 16, characterized in that: The flange portion has a highest point relative to the central axis, and the at least one vent hole is located near the highest point of the flange portion.

18. The wheel end assembly according to claim 15, characterized in that: The vent hole has a diameter not exceeding 50‰ mm.

19. The wheel end assembly according to claim 1, wherein: The flange portion of the housing has a first axial end partially surrounding the first chamber and a second axial end partially surrounding the second chamber; and The at least one vent hole has an air inlet opening at the first axial end of the flange portion and an air outlet opening at the second axial end of the flange portion.

20. The wheel end assembly according to claim 19, characterized in that, At least one of the following: The air inlet has a first diameter, the air outlet has a second diameter, the second diameter is numerically smaller than the first diameter, and the at least one vent hole tapers inward from the air inlet to the air outlet; The flange portion of the housing has a metal portion and an elastomeric portion attached to the metal portion, the at least one vent hole has a first axial portion extending through the metal portion and a second axial portion extending through the elastomeric portion and aligned with the first axial portion; and The at least one vent hole includes multiple vent holes spaced apart in the circumferential direction, and the position of each vent hole in the vertical direction is higher than the central axis.

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