Seal ring for radially engaging the outer surface of a rotating shaft

Abstract

The invention relates to a sealing ring (1) for radially engaging an outer surface of a cylindrical element, in particular a rotating shaft (22), comprising an annular base body (2) having a central rotation axis (8), a first lip (3) and a second lip (4) extending from the annular base body (2) for sealingly engaging the rotating shaft (22), respectively. The sealing tips (13, 14) of the two sealing lips at least partially point in the same axial direction, and the first lip (3) axially overhangs the second lip (4) such that the sealing tip (13) of the first lip (3) is axially spaced apart from the second lip (4).

Description

Technical Field

[0001] The present invention relates to a sealing ring for radially engaging the outer surface of a cylindrical element, particularly the outer surface of a rotating shaft, the sealing ring comprising an annular base having a central axis of rotation, and further comprising a first lip and a second lip extending from the annular base respectively to sealably engage the cylindrical element. Background Technology

[0002] As described above, the sealing ring is known in the prior art, for example, from patent application US 20030102634A1. Sealing rings for radially engaging with a rotating shaft are used in applications to form a seal between, for example, fixed or movable components, particularly between rotating components such as rotating shafts. The sealing ring is used to prevent lubricating fluid from leaking out of the housing supporting the rotating shaft and to prevent dirt particles or other contaminants from entering the housing, particularly the bearings supporting the rotating shaft. In the aforementioned US patent application, the provided sealing ring includes a first lip and a second lip, both extending from an annular base. Both lips extend substantially radially inward from the annular base, thereby giving one lip increased elasticity compared to the other. These lips point in different axial directions, allowing one lip to be optimized to prevent lubricant leakage and the other lip to prevent contaminants from entering the housing.

[0003] Seals, also known as radial shaft seals and / or lip seals, are essential mechanical components used in applications requiring a seal with moving parts such as the rotating shaft of a water pump or gearbox. These seals isolate or prevent contaminants from the surrounding environment from entering the housing or bearing supporting the rotating shaft. Each lip of the seal ensures continuous contact with the rotating shaft by using a defined radial load, or preload. However, this preload can decrease over time due to aging effects and wear. In particular, wear can increase, for example, if the rotating shaft is misaligned or poorly manufactured. Seals can compensate for runout of the rotating shaft to some extent and for a period of time, but generally require a greater spring force to maintain continuous contact between the seal and the rotating shaft around its circumference. This additional force can be generated by a separate spring element. A predetermined radial load or preload is then applied to the rotating shaft at any given time, regardless of its necessity. This constant increase in preload leads to increased wear and, consequently, reduced service life. Summary of the Invention

[0004] The sealing ring of the present invention, having the features of claim 1, is characterized in that the sealing ends of both lips at least partially point in the same axial direction, and wherein the first lip extends beyond the shorter second lip, thereby axially spaced apart from the sealing end of the first lip from the second lip. The sealing lips of the sealing ring according to the invention thus differ from known prior art. Since both lips of the sealing ring extend in the same axial direction, they are also capable of elastic deformation in the same direction. The first lip extends beyond the shorter second lip, thereby allowing the free end of the first lip providing the sealing end to be pressed against the outer circumference of the rotating shaft by the preload of the first sealing lip. Both sealing lips, namely the first lip and the second lip, provide their desired or desired radial preload to the rotating shaft. To extend beyond the shorter second lip, the first lip is longer in its axial extension than the second lip, resulting in the first lip being more deformable than the second lip. This has the advantage that the outer lip, or the first lip, can absorb impacts and deflect water, dust, or debris from the external environment projected onto the sealing ring from multiple directions. Specifically, if a high-energy water jet is directed onto the sealing ring, the first lip deforms without disengaging from the rotating shaft. Conversely, due to the large and long design of the first lip, which extends beyond the shorter second lip, the first lip deforms due to the energy of the water jet, thus amplifying the effect.

[0005] According to a preferred embodiment of the invention, the first lip and the second lip are clamped at an angle of less than 50°, particularly 45° or less, in the relaxed state. Preferably, this angle is between 25° and 45°. Preferably, the first lip is defined such that it clamps at an angle of 40° to 50°, particularly 45°, with respect to the central axis of rotation of the sealing ring.

[0006] The angle ensures a hollow space between the sealing lip and the rotating shaft, allowing the first lip to deflect into this space if it is impacted by a high-energy water jet from the outside. The first and second lips are positioned such that the axial extension of the second lip is equivalent to 20% to 30% of the total axial extension of the sealing ring, particularly the total axial extension of the annular base, and the total axial extension of the first lip. In other words, the axial distance between the sealing ends of the first and second lips is equivalent to 60% to 80%, particularly 70%, of the total height or total axial extension of the annular base and the first lip or sealing ring.

[0007] Preferably, the first lip includes a radially outer surface and a radially inner surface, the outer surface extending along the bend, such that the cross-section of the first lip decreases towards the first sealing end. Therefore, the first lip includes a wedge-shaped design in its cross-section, which allows for high stability and effective elasticity. Due to the bend on the outer side or outer surface of the first lip, water jets or other particles or contaminants projected onto the outer surface of the sealing ring, particularly the outer surface of the first lip, are advantageously deflected from the first lip without compromising the seal.

[0008] Preferably, the first lip is radially inwardly curved between the first sealing end and the annular base. The cross-section of the first lip allows it to bend in a concave manner to maintain sealed contact with the rotating shaft in the event of an external impact.

[0009] Further preferably, the inner surface of the first lip can contact the shaft in a tactile manner between the first sealing end and the annular base. Therefore, the axial distance between the first end and the second end must be at least far enough that the first lip can bend radially inward to contact the rotating shaft between the annular base on the first end and the second end.

[0010] Furthermore, the annular base preferably includes radially inwardly projecting support protrusions, wherein the second lip is disposed between the first lip and the support protrusions. While the first and second lips also serve as support structures for the sealing ring, the function of the support protrusions is not sealing but rather aligning and attaching the sealing ring to the rotating shaft. Therefore, the support protrusions, along with the second and first lips, extend over the entire circumference of the sealing ring. The elasticity of the support protrusions is substantially less than that of the first and second lips to ensure that the sealing ring is securely fitted onto or fitted onto the rotating shaft, particularly ensuring that the sealing ring is properly aligned with or fitted onto the rotating shaft. Thus, during use, the second and first lips are uniformly pressurized, particularly with respect to radial preload. The support protrusions preferably include a convex cross-section that allows the sealing ring to be securely and reliably aligned onto the rotating shaft.

[0011] Preferably, a radial recess is provided in the sealing ring, particularly in the support base, between the support protrusion and the second lip, to accommodate grease or lubricating material. This recess allows for the storage of lubricating material during use, and particularly before the sealing ring is assembled onto the rotating shaft. When the sealing ring is axially pushed onto the rotating shaft, the lubricating material or grease previously applied to the recess is dragged along with the sealing ring to a position on the rotating shaft where the sealing ring is positioned during use.

[0012] Preferably, each sealing end has a rounded edge in its cross-section, thereby ensuring maximum contact between the sealing lip and the rotating shaft even if the corresponding sealing lip is deformed.

[0013] Particularly preferably, the first end and the second lip are arranged at least substantially on the front side of the annular base, while the support element is provided on the radially inner surface of the annular base, i.e., on the back side of the annular base opposite to the front side. This connecting element is used to connect the sealing ring to a housing or bearing, preferably a support shaft, so that, for example, the sealing ring can be pre-assembled onto a pre-existing housing. The total height of the sealing ring is preferably measured from the back side of the annular base to the first sealing end in the axial extension of the sealing ring. The connecting element is preferably constructed as an insert element, which is inserted into a corresponding recess in the housing or bearing, particularly in a form-fit and / or force-fit manner. According to a preferred embodiment, the connecting element is designed as a connecting ring extending over the entire circumference of the sealing ring. According to another embodiment, the connecting element is annular in structure but has particularly equidistant openings or sections, allowing adjacent connecting element portions to move or deform independently of each other. Furthermore, the openings can serve as a rotation lock, provided that the housing or bearing has corresponding protrusions that can be inserted into the openings, thereby locking the sealing ring circumferentially to the housing in a form-fit manner during use.

[0014] Preferably, the sealing ring having a first lip, a second lip, a support protrusion, and a connecting element is designed as a single piece. This allows for easy assembly of the sealing ring and its low-cost manufacture. Attached Figure Description

[0015] The sealing ring is described in more detail below with reference to the accompanying drawings. Wherein:

[0016] Figure 1 A perspective view of the preferred sealing ring is shown;

[0017] Figure 2 A cross-sectional view of the sealing ring is shown;

[0018] Figure 3 A detailed cross-sectional view of the sealing ring is shown;

[0019] Figures 3A to 3C This illustrates various scenarios during the use of the sealing ring;

[0020] Figures 4A to 4D The steps of assembling the sealing ring onto the rotating shaft are shown; and

[0021] Figure 5 An exemplary use with a sealing ring is shown. Detailed Implementation

[0022] Figure 1 A preferred embodiment of the sealing ring 1 is shown in perspective, arranged coaxially with a cylindrical element such as a rotating shaft, like a gearbox, pump assembly, or similar device. The sealing ring 1 is made of an elastically deformable material, such as rubber or plastic. The sealing ring includes an annular base 2, designed as a closed ring with a given inner and outer diameter. A first sealing lip 3, a second sealing lip 4, and a connecting element 5 are provided on the base 2. The sealing ring 1 is integrally constructed such that the lips 3 and 4, the base 2, and the connecting element 5 are all made of the same material and are integrally constructed.

[0023] Figure 2 It shows the relationship with Figure 1 The same sealing ring 1 shown is along Figure 1 The image shows a cross-sectional view of line AA. While the first lip 3 and the second lip 4 extend along the entire circumference of the annular base 2, the connecting element 5 of this embodiment is provided with uniformly distributed openings 6 extending axially from the base 2 to the end of the connecting element 5, thus dividing the connecting element 5 into a plurality of equally sized connecting element portions 7 by the openings 6. The connecting element 5 and the connecting element portions 7 are inserted into corresponding recesses in the housing supporting the rotating shaft. For this purpose, the connecting element 5 extends axially or parallel to the axis of rotation 8 of the sealing ring 1. Since the connecting element portions 7 are separated from each other, adjacent connecting element portions 7 can elastically deform independently of each other. Furthermore, the openings 6 allow protrusions of the housing to insert between adjacent connecting element portions 7, which provides rotational locking between the housing and the sealing ring 1. According to an alternative embodiment, the sealing ring 1 may have fewer openings 6 or no openings in the connecting element 5. The sealing ring 1 may also be without a connecting element 5.

[0024] Figure 3 According to Figure 2 A more detailed view of the sealing ring 1, which is drawn as a dashed circle B. Figure 3 An exemplary housing 9 with a recess 10 is also shown, into which the connecting element 5 is inserted. The recess 10 includes a plurality of axial protrusions 11 corresponding to the number and arrangement of the openings 6 of the connecting element 5, thereby connecting the sealing ring 5 to the housing by providing rotational locking for the sealing ring 1, as previously described.

[0025] The first lip 3 and the second lip 4 both extend at least partially in the same axial direction, particularly pointing away from the connecting element 5. The longer first lip 3 extends beyond the shorter second lip 4, thereby axially spaced the first sealing end 13 located at the free end of the first lip 3 from the second sealing end 14 located at the free end of the second lip 4. Preferably, the distance between the first sealing end 13 and the second sealing end 14 corresponds to 60% to 80%, particularly 70%, of the total height or axial extension of the sealing ring 1.

[0026] The angle α formed by the first lip 3 and the second lip 4 is preferably between 25° and 45°. Preferably, according to this exemplary embodiment, the first lip 3 forms an angle of approximately 45° with the axis of rotation 8.

[0027] Due to the design of lips 3 and 4, a free space is provided between lips 3 and 4. If the sealing ring is installed on the rotating shaft, this free space specifically allows the first lip 3 to deform or bend radially inward toward the outer circumference of the rotating shaft.

[0028] The first lip 3 includes an outer surface 15 having a bend 16 extending from the lip 3 to the annular base 2. This bend follows a given radius and increases the sealing ring's ability to seal the rotating shaft, even under harsh conditions, as will be explained in more detail below. The first lip 3 itself includes a wedge-shaped cross-section, such that the thickness or width of the first lip 3 decreases towards the first sealing end 13. The free end providing the sealing end 13, or the sealing end 13 itself, has a rounded edge 17 that provides a secure seal with the rotating shaft independently of deformation of the first lip 3.

[0029] The second lip 4 is also preferably provided with a rounded edge 18 at its free end, the rounded edge providing a sealing end 14.

[0030] The annular base 2 also includes a support protrusion 19 extending radially inward from the annular base 2. The support protrusion 19 causes the second lip 4 to be disposed between the first lip 3 and the support protrusion 19. Compared to the first lip 3 or the second lip 4, the support protrusion 19 extends less in the radial direction. However, the support protrusion 19 is less elastic than the elasticity of the lip 3 and the lip 4, thus making the support protrusion 19 less prone to deformation during use. The support protrusion 19 is configured to ensure that the sealing ring 1 is securely and permanently aligned on the rotating shaft. Furthermore, the support protrusion ensures that the sealing ring 1 is securely disposed on the rotating shaft during assembly of the sealing ring 1 onto the rotating shaft.

[0031] Due to the advantageous design of the sealing ring 1 as described above, this sealing ring is well-suited for plastic injection processes that utilize a given elastomer for partial injection or overmolding injection.

[0032] A recess 20 is provided between the radial protrusion 19 and the second lip 4, which is smaller than the recess or free space between the first lip 3 and the second lip 4. The recess 20 is designed as a receiving portion for a lubricating medium or grease medium, which will be explained in more detail below.

[0033] The outer shape of the main lip or first lip 3 absorbs and deflects water, dust, or debris projected directly onto the sealing ring 2 from multiple directions. The combination of the robust core provided by the annular base element 2 and the notched contour of the outer lip or first lip 3 allows the sealing ring to deflect and dissipate water directed at high pressure onto the sealing ring 1, thereby dissipating energy in multiple directions. Furthermore, the greater the pressure applied to the first lip 3, the greater the contact force provided by the lip to the rotating shaft.

[0034] Figures 3A to 3C This effect is shown in different situations. Figure 3A In this process, the water jet 23 is radially guided onto the outer surface of the sealing ring 2, thereby pressing the first and second lips against the outer surface 21 of the rotating shaft 22, on which the sealing ring 2 is mounted. The water jet 23, with its pressure and direction of action... Figures 3A to 3C The arrows indicate the pressure. The higher the pressure, the larger the arrow. If the water jet 23 is directed to the end of the first lip 3 near the annular base 2, the first lip 3 and the second lip 4 will deflect or deform more.

[0035] exist Figure 3B In the illustrated case, the water jet 23 is oriented substantially axially, thereby causing the water jet 23 to impact the first lip 3 substantially axially. Due to the length of the first lip 3, the first lip is still deformed, thereby increasing the radial pressure applied to the outer surface 21 of the rotating shaft 22 and thus ensuring a tight seal. The water jet 23 is deflected by the bend of the first lip 3 and the overall design, thereby reducing the pressure along the path and causing the water jet to be deflected radially outward.

[0036] Figure 3C The direction of water jet 23 is shown. Figure 3A The first direction shown and Figure 3B The situation is shown somewhere between the second directions. Even in this case, the force of the water jet 23 is advantageously distributed in the sealing ring 1, thereby allowing the first lip 3 and the second lip 4 to be securely pressed against the rotating shaft 22. The inner lip or the second lip 4 particularly facilitates different functions, such as a second line of defense. Even if the main lip or the first lip 3 breaks or fails, the second lip can still provide a seal.

[0037] Furthermore, the radial protrusion 19, which serves as a primary alignment feature, provides optimal coaxial alignment during assembly, such as... Figure 4A and Figure 4D As shown, the vibrations absorbed from and to the contacted components, in this embodiment referring to vibrations from and to the rotating shaft 22. The radial protrusion 19 provides a higher contact pressure to the rotating shaft 22. This higher contact pressure is achieved, for example, through the contour of the radial protrusion 19 itself and / or through the difference between the outer diameter of the rotating shaft 22 in the contact area and the inner diameter of the radial protrusion 19 in a relaxed state. The recess 20 facilitates fitting onto the shaft and improves protection against friction and wear. In particular, the recess allows the use of grease or grease-like materials, which facilitates fitting and improves protection against friction and wear.

[0038] like Figures 4A to 4D As shown, the installation or assembly process of the sealing ring 1 on the rotating shaft 22 is illustrated in four steps. The recess 20 helps to deliver grease or other lubricating media from the first contact point between the sealing ring 1 and the rotating shaft 22 to the... Figure 4D The second lip 4 assists in conveying the medium 24 along the outer surface of the shaft to its final assembly position. The radial support protrusion 19 has the further advantage of providing a secure fit and alignment of the seal ring 1 as a whole, allowing greater flexibility in designing the primary and secondary contact areas provided by the first lip 3 and the second lip 4. This allows the first lip 3 and the second lip 4 to be designed so that they are optimally adapted to the runout or potential runout of the rotating shaft 22. This ensures continuous contact between the first lip 3 and / or the second lip 4 without the use of external or auxiliary spring elements, even in the presence of runout.

[0039] Since the contact between the first lip 3 and the rotating shaft 22 increases with the pressure applied to the first lip 3, such as by the water jet 23 as described above, the preload of the first lip 3 can be designed to be lower than before, thereby avoiding excessive wear of the sealing ring 1 due to high friction in normal application or use.

[0040] Figure 5 The device, comprising a housing 9 and two sealing rings 1, is shown in an exploded view. In this case, the housing 9 is the housing of a steering wheel angle sensor or the like. The housing includes a through opening 25 through which the steering shaft can be pushed. One of the sealing rings 1 is attached to the housing from both ends, thereby preventing unwanted media such as water or debris from entering the sensor operating area between the sealing ring 1 and the housing 9. Figure 5As shown, the housing includes a plurality of protrusions 11 that provide rotational locking with corresponding sealing rings 1, as previously described. Optionally, a rotatable tubular gear is disposed in an opening 25. The steering shaft is then placed through the opening 25 and locked onto the tubular gear, wherein the sealing rings 1 are placed on the housing 9, specifically as cylindrical elements abutting upward against the tubular gear.

Claims

1. A sealing ring (1) for radially engaging the outer surface of a cylindrical element, the sealing ring (1) comprising an annular base (2) having a central axis of rotation (8), the sealing ring further comprising a first lip (3) and a second lip (4) extending from the annular base (2) respectively to sealably engage the cylindrical element, wherein, The sealing ends (13, 14) of the two sealing lips (3, 4) point at least partially in the same axial direction, and the first lip (3) extends beyond the second lip (4) in the axial direction, such that the first sealing end (13) of the first lip (3) is axially spaced from the second lip (4), wherein the first lip (3) includes a radially outer surface (15) and a radially inner surface, the radially outer surface (15) extending along a bend (16) following a given radius, such that the cross-section of the first lip (3) faces the first sealing end (14). 13) Reduction, characterized in that the annular base (2) includes a radially inwardly projecting support protrusion (19), and the support protrusion aligns and attaches the sealing ring (1) to the cylindrical element, wherein the second lip (4) is disposed between the first lip (3) and the support protrusion (19), and wherein the support protrusion (19) extends less in the radial direction than the first lip (3) or the second lip (4), such that the elasticity of the support protrusion is substantially less than that of the first lip (3) and the second lip (4).

2. The sealing ring (1) according to claim 1, characterized in that, The first lip (3) and the second lip (4) are sandwiched at an angle of less than 90°.

3. The sealing ring (1) according to claim 1 or 2, characterized in that, The first lip (3) is capable of bending radially inward between the first sealing end (13) and the annular base (2) or the second sealing end (14).

4. The sealing ring (1) according to claim 1 or 2, characterized in that, Each of the sealing ends (13, 14) has a rounded edge (17, 18) in its cross-section.

5. The sealing ring (1) according to claim 1 or 2, characterized in that, In the annular base (2), a radial recess is provided between the support protrusion (19) and the second lip (4).

6. The sealing ring (1) according to claim 1 or 2, characterized in that, The first lip (3) and the second lip (4) are arranged at least substantially on the front side of the annular base, while the support protrusion is provided on the radial inner surface of the annular base, and a connecting element (5) is provided on the back side of the annular base opposite to the front side, the connecting element (5) connecting the sealing ring (1) to the housing or bearing.

7. The sealing ring (1) according to claim 6, characterized in that, The first lip (3), the second lip (4), the support protrusion (19) and the connecting element (5) are integrally constructed with the annular base (2).

8. The sealing ring (1) according to claim 1 or 2, characterized in that, The cylindrical element is a rotating shaft (22).

Images