A double lip dust seal of a wheel-speed sensor unit

Abstract

A double lip dust seal (105) of a wheel-speed sensor unit is disclosed herewith. The double lip dust seal (105) includes an inner lip (110) radially disposed and abutting a wheel hub bore. The double lip dust seal (105) includes an outer lip (115) oriented radially outward of the wheel hub bore. The double lip dust seal (105) includes a sheet metal (120) integrated to the double lip dust seal (105). The double lip dust seal (105) including the inner lip (110), and the outer lip (115) is mounted on a housing of the wheel-speed sensor unit. The double lip dust seal (105) includes a threaded inner profile (125) to mount the double lip dust seal (105) on the housing.

Description

1 202400191“A DOUBLE LIP DUST SEAL OF A WHEEL-SPEED SENSOR UNIT”The following specification particularly describes the nature of this invention and the manner in which it is to be performed.FIELD OF THE INVENTION:

[0001] The present disclosure relates to bearing seals, and in particular, to a seal used in a wheel-speed sensor unit.BACKGROUND TO THE INVENTION:

[0002] A wheel-speed sensor measures the speed of the front wheel and the rear wheel and is typically implemented in vehicles having anti-lock braking system (ABS). By measuring the front wheel speed and the rear wheel speed, the ABS helps to prevent wheel lock and slip of the vehicle. Existing wheel-speed sensor units is mechanically coupled to the front fork unit using fasteners and impulse wheel (Toner wheel) mounted on the alloy wheel. Dust seals are used to protect the wheel bearings. Current dust seal design is a shaft riding seal i.e inner dia of the seal is riding on the wheel shaft. Dust seals are designed to protect the bearings from dust and other contaminants. In existing seal designs, a dust seal that is fitted on to the hub of a front wheel or a rear wheel, includes a lip which is riding on the wheel shaft. Since the lip is riding on the wheel shaft, the whole seal is subject to rotary motion.

[0003] Existing dust seals are usually spring loaded. Since the seal is subject to rotary motion, the spring exerts a force and creates friction between the shaft and the seal lips. This friction increases wear and tear resulting in dust and other contamination entry into the bearing and reduce bearing life. Further, this also necessitates frequent maintenance. The dust seals are radial shaft seals with a lip profile to prevent dust and water ingress. However, existing dust seals used in a wheel is susceptible to dust entry and water ingress.2 202400191

[0004] There is a need for a dust seal design for a wheel that reduces friction and prevents dust entry and water ingress into the wheel bearings.SUMMARY OF THE INVENTION:

[0005] This summary is provided to introduce a selection of concepts in a simple manner that is further described in the detailed description of the disclosure. This summary is not intended to identify key or essential inventive concepts of the subject matter nor is it intended for determining the scope of the disclosure.

[0006] The present disclosure proposes a new concept of optimising sealing performance for the wheel end application with reduced friction and improved sealing performance. The current conventional seal design is a standard radial shaft lip seal with energiser spring leading to high friction, temperature, and wear. This leads to lower life of the system. The present disclosure incorporates dual lip concept having special profile and different interference between the two lips. This ensures lower radial loads and hence reduced friction. The unique feature of the design is the lip profile and orientation which ensures varying degree of radial load during non-contamination condition and high contamination condition. In presence of contamination, due to axial force on the lip the radial load increases to ensure optimum and efficient sealing. In absence of contamination (no axial force) the radial load on the lip is reduced ensuring reduced friction.

[0007] An objective of the present disclosure is to provide a double lip dust seal for a wheel.

[0008] Another objective of the present disclosure is to provide a double lip dust seal to prevent dust entry and water ingress into the bearings.

[0009] Another objective of the present disclosure is to provide an integrated modular wheel-speed sensor with dust seal mounted on plastic housing of a wheelspeed sensor body.3 202400191

[0010] Another objective of the present disclosure is to provide an integrated seal alignment / stopper lug on wheel-speed sensor body to avoid misalignment of the dust seal.

[0011] Accordingly, a double lip dust seal of a wheel-speed sensor unit is disclosed. The double lip dust seal includes an inner lip radially disposed and abutting a wheel hub bore, and an outer lip oriented radially outward of the wheel hub bore. The double lip dust seal includes a sheet metal integrated to the double lip dust seal. The double lip dust seal including the inner lip, and the outer lip is mounted on a housing of the wheel-speed sensor unit. The double lip dust seal includes a threaded inner profile to mount the double lip dust seal on the housing.

[0012] To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended figures. It is to be appreciated that these figures depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying figures.BRIEF DESCRIPTION OF THE FIGURES:

[0013] The invention will be described and explained with additional specificity and detail with the accompanying figures in which:

[0014] Figure 1A illustrates a sectional view of a double lip dust seal, in accordance with an embodiment of the present disclosure;

[0015] Figure IB illustrates a perspective view of the double lip dust seal, in accordance with an embodiment of the present disclosure;

[0016] Figure 1C illustrates a sectional view of an integrated modular wheelspeed sensor with dust seal mounted on plastic housing of a wheel-speed sensor body, in accordance with an embodiment of the present disclosure;4 202400191

[0017] Figure ID illustrates a sectional view of a bore riding double lip dust seal with an integrated lug on the wheel-speed sensor body, in accordance with an embodiment of the present disclosure;

[0018] Figures 2A and 2B illustrate a sectional view of a double lip dust seal implemented on a rear wheel of a vehicle, in accordance with an embodiment of the present disclosure; and

[0019] Figure 3 illustrates a sectional view of the integrated modular wheelspeed sensor with dust seal mounted on plastic housing of the wheel-speed sensor body, in accordance with an embodiment of the present disclosure.

[0020] Further, skilled artisans will appreciate that elements in the figures are illustrated for simplicity and may not have been necessarily drawn to scale. Furthermore, in terms of the construction of the system, one or more components of the system may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the figures with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.DESCRIPTION OF THE INVENTION:

[0021] For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.5 202400191

[0022] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.

[0023] In the present disclosure, relational terms such as first and second, and the like, may be used to distinguish one entity from the other, without necessarily implying any actual relationship or order between such entities.

[0024] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by "comprises... a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components. Appearances of the phrase “in an embodiment,” “in another embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

[0026] Embodiments of the present disclosure includes a double lip dust seal integrated to a wheel-speed sensor body of a wheel-speed sensor unit.

[0027] Figure 1 A illustrates a sectional view of a double lip dust seal (105), in accordance with an embodiment of the present disclosure.

[0028] The double lip dust seal (105) includes two lips. One lip is an inner lip (110) that is radially disposed and abutting a wheel hub bore (170). The other lip is6 202400191an outer lip (115) oriented radially outward of the wheel hub bore (170). The outer lip (115) prevents ingress of water into the wheel hub bore (170). The double lip profile and orientation of the inner lip (110) and the outer lip (115) ensures varying degree of radial load during non-contamination condition and high contamination condition. In presence of contamination, due to axial force on the outer lip (115), the radial load on the outer lip (115) increases to ensure optimum and efficient sealing. The axial force, for example, is the force due to the ingress of water. Further, in absence of contamination, i.e., there is no axial force on the outer lip (115), then the radial load on the outer lip (115) is reduced. The unique design of the double lip dust seal (105) reduces friction. Firstly, since the radial load on the outer lip (115) is reduced when there is no axial force due to ingress of water, it reduces the friction. Further, it is to be noted that the inner lip (110) and the outer lip (115) is without spring. Since, there is no spring loading, the double lip dust seal (105) reduces friction. Furthermore, since the double lip dust seal (105) is fixed on a housing (135) of the sensor body of a wheel speed sensor unit (130), it reduces friction.

[0029] The double lip dust seal (105) includes a sheet metal (120) integrated to the double lip dust seal (105). The double lip dust seal (105) is made of rubber and the sheet metal (120), and the double lip dust seal (105) are vulcanized to achieve the desired form factor. The sheet metal (120) provides shape and stiffness to the double lip dust seal (105). Further, the sheet metal (120) creates tolerance for interference fit to assemble the double lip dust seal (105) into the housing (135) of the sensor body of the wheel-speed sensor unit (130). It is to be noted that the double lip dust seal (105) consisting of the inner lip (110) and the outer lip (115) is mounted and fixed on the housing (135) of the wheel-speed sensor unit (130). The housing (135) is a plastic housing and forms part of the sensor body of the wheel-speed sensor unit (130). Another feature of the double lip dust seal (105) is that it includes a threaded inner profile (125). The threaded inner profile (125) helps in mounting the double lip dust seal (105) on to the housing (135) easily. The threaded inner profile (125) is illustrated in Figure IB.7 202400191

[0030] Figure 1C illustrates a sectional view of an integrated modular wheelspeed sensor with dust seal mounted on plastic housing (135) of a wheel-speed sensor body, in accordance with an embodiment of the present disclosure. The double lip dust seal (105) is fixed and integrated on the wheel-speed sensor unit (130). The wheel-speed sensor unit (130) includes the housing (135), a spacer shaft (140), an impulse ring (145), a printed circuit board (PCB) (155), a sensor cable (160) and a sensor connector (165).

[0031] The housing (135), the spacer shaft (140), and the PCB (155) together forms the wheel-speed sensor body. The spacer shaft (140) has a knurling on the outer diameter, this helps to fix the housing position accurately by overmolding process. The impulse ring (145) is a sheet metal part having multiple slots. The PCB (155) includes one or more sensors for sensing the wheel speed. Typically, the sensor is a hall effect sensor. When the outer ring of the bearing (150) rotates, the impulse ring (145) rotates post that the sensor designed to respond to the magnetic field variation generated by each change in polarity. The sensor then supplies a signal whose frequency is a function of the number of polarity changes per second. It is thus possible to measure the rotational movement of one ring relative to the other. Typically, the impulse ring (145) is a sheet metal which is mounted on the outer ring of the bearing (150).

[0032] Figure 3 illustrates another sectional view of the integrated modular wheel-speed sensor with dust seal mounted on plastic housing of the wheel-speed sensor body. The housing (135) includes a stopper lug (175). The stopper lug (175), also known as seal alignment lug is provided on the housing (135) for accurate mounting of the double lip dust seal (105) and to avoid any misalignment. The double lip dust seal (105) is a bore riding seal, i.e., the inner lip (110) is in contact and abuts with the bore (170) of the wheel hub. Figure ID illustrates a sectional view of the bore riding double lip dust seal (105) with the integrated stopper lug (175) on the housing (135) of the wheel-speed sensor body.8 202400191

[0033] The double lip dust seal (105) is a dust seal for preventing ingress of water and other contaminants into the wheel hub, and into the shaft and the bearings in the wheel hub. The double lip dust seal (105) reduces friction as it is fixed on the sensor body (135) of the wheel-speed sensor unit (130) and does not rotate with a wheel shaft.

[0034] It is to be noted that the double lip dust seal (105) can be mounted on the wheel-speed sensor unit (130) of a front wheel and a rear wheel of a two wheeler vehicle. The two wheeler vehicle may be an internal combustion engine (ICE) motorbike, an ICE scooter, an electric scooter, or an electric motorbike. Figures 2A and 2B illustrate a sectional view of a double lip dust seal implemented on a rear wheel of a vehicle, in accordance with an embodiment of the present disclosure.

[0035] The present disclosure proposes a new concept of optimising sealing performance for the wheel end application with reduced friction and improved sealing performance. The current conventional seal design is a standard radial shaft lip seal with energiser spring leading to high friction, temperature, and wear. This leads to lower life of the system. The present disclosure incorporates dual lip concept having special profile and different interference between the two lips. This ensures lower radial loads and hence reduced friction. The unique feature of the design is the lip profile and orientation which ensures varying degree of radial load during non-contamination condition and high contamination condition. In presence of contamination, due to axial force on the lip the radial load increases to ensure optimum and efficient sealing. In absence of contamination (no axial force) the radial load on the lip is reduced ensuring reduced friction.

[0036] There are various advantages of the double lip dust seal design disclosed in the present disclosure. The double lip dust seal is mounted on the wheel sensor body and is stationary unlike the existing dust seals which rotate along with the bearing. Since the dust seal is stationary, it does not give rise to friction, thereby reducing wear and tear of the bearing. Further, it reduces frequent maintenance of the bearing and the wheel hub. The double lip dust seal increases the bearing life.9 202400191

[0037] Further, because of the double lip design of the dust seal, it prevents dust or water entering the shaft or bearing, and into the wheel hub. Furthermore, the double lip dust seal along with the integrated lug prevents any seal misalignment and reduces assembly operations. Another advantage is that the double lip dust seal is a lightweight dust seal.

[0038] While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.

[0039] The figures and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts necessarily need to be performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.

Claims

10 202400191WE CLAIM:

1. A double lip dust seal (105) of a wheel-speed sensor unit (130), the double lip dust seal (105) comprising:an inner lip (110) radially disposed and abutting a wheel hub bore (170);an outer lip (115) oriented radially outward of the wheel hub bore (170); anda sheet metal (120) integrated to the double lip dust seal (105); wherein the double lip dust seal (105) comprising the inner lip (110), and the outer lip (115) is mounted on a housing (135) of the wheelspeed sensor unit (130),wherein the double lip dust seal (105) comprises a threaded inner profile (125) to mount the double lip dust seal (105) on the housing (135).

2. The double lip dust seal (105) as claimed in claim 1, whererin the double lip dust seal (105) is fixed and integrated on the wheel-speed sensor unit (130).

3. The double lip dust seal (105) as claimed in claim 1, whererin the wheelspeed sensor unit (130) comprises:the housing (135);a spacer shaft (140);an impulse ring (145);a printed circuit board (155);a sensor cable (160);a sensor connector (165); anda bearing (150).

4. The double lip dust seal (105) as claimed in claim 1, wherein the sheet metal (120) provides shape and stiffness to the double lip dust seal (105) and11 202400191creates tolerance for interference fit to assemble the double lip dust seal (105) into the housing (135).

5. The double lip dust seal (105) as claimed in claim 1, wherein the housing (135)comprises a stopper lug (175).

6. The double lip dust seal (105) as claimed in claim 5, wherein the stopper lug (175) is provided on the housing (135) for accurate mounting of the double lip dust seal (105) and to avoid any misalignment.

7. The double lip dust seal (105) as claimed in claim 1, wherein the outer lip (H5)prevents ingress of water into the wheel hub bore (170).

8. The double lip dust seal (105) as claimed in claim 1, whererin the double lip dust seal (105) reduces friction as it is fixed on the wheel-speed sensor unit (130) anddoes not rotate with a wheel.

9. The double lip dust seal (105) as claimed in claim 1, wherein the double lip dust seal (105) is mounted on the wheel-speed sensor unit (130) of a front wheel and a rear wheel of a two wheeler vehicle.

10. The double lip dust seal (105) as claimed in claim 1, wherein the inner lip (110) and the outer lip (115) is without spring.

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