BRAKE ROTOR AND TONE RING ASSEMBLY

Abstract

A wheel assembly includes a wheel hub and brake rotor that rotate about an axis. The brake rotor includes a first mount interface for attachment to the wheel hub and a second mount interface for attachment to a tone ring. The first and second mount interfaces are independent of each other. The first mount interface comprises a first plurality of apertures that receive a first set of fasteners to secure the brake rotor to the wheel hub. The second mount interface comprises a second plurality of apertures that receive a second set of fasteners to secure the tone ring to the brake rotor.

Description

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 11/145,407, which was filed Jun. 3, 2005.

TECHNICAL FIELD

The subject invention relates to a brake rotor that provides independent wheel hub and tone ring attachment interfaces such that a tone ring is independently removable from the brake rotor without requiring removal of the brake rotor from the wheel hub, and such that the brake rotor is removable from the wheel hub without have to remove the tone ring from the brake rotor.

BACKGROUND OF THE INVENTION

A wheel assembly includes a brake rotor that is attached to a wheel hub for rotation about an axis. When utilized with an anti-lock brake system, a tone ring is often attached to a rotating wheel component, such as the brake rotor for example, to form part of a wheel speed sensor. Due to packaging constraints, it is often difficult to leave the tone ring attached to the brake rotor while still providing access to attachment bolts that are used to attach the brake rotor to the wheel hub.

In one known configuration, a single set of fasteners is used to attach the tone ring, brake rotor, and wheel hub together. In order to remove the brake rotor from the wheel hub for service, the tone ring must be removed from the brake rotor. Further, in order to remove the tone ring from the brake rotor for service, the brake rotor must be removed from the wheel hub. In either situation, labor costs and downtime are increased as a result of additional wheel components having to be removed from the wheel assembly.

One known attempted solution has been to provide a brake rotor with an integrally formed tone ring. This solution has several disadvantages. One disadvantage with this solution is that both the brake rotor and tone ring are formed from a common material. In order to reduce material costs and component weight, it is often desirable to form the tone ring and brake rotor from different materials. Another disadvantage is that if one component is damaged, i.e. if a portion of the brake rotor or a portion of the tone ring is damaged, then both components have to be replaced. This significantly increases service costs.

Thus, there is a need for a brake rotor, tone ring, and wheel hub configuration that allows for independent removal of the various components without requiring removal of all of the components.

SUMMARY OF THE INVENTION

A wheel assembly includes a tone ring and brake rotor, which are mounted to a wheel hub for rotation about an axis. The brake rotor is mounted to the wheel hub at a first mount interface and the tone ring is mounted to the brake rotor at a second mount interface that is independent from the first mount interface. The subject invention provides that the brake rotor is removable from the wheel hub while the tone ring remains attached to the brake rotor, and provides that the tone ring is removable from the brake rotor while the brake rotor remains attached to the wheel hub.

In one disclosed embodiment, first mount interface of the brake rotor comprises a first plurality of openings for receiving a first set of fasteners to attach the brake rotor to the wheel hub. The second mount interface comprises a second plurality of apertures for receiving a second set of fasteners to independently attach the tone ring to the brake rotor.

This wheel assembly provides several advantages including providing separate pieces for the tone ring and brake rotor, which allows the tone ring to be fabricated from a different material than the brake rotor. Also, as described above, access is provided to the first plurality of apertures to remove the brake rotor from the wheel hub without having to remove the tone ring from the brake rotor. In addition, removal of the tone ring is possible without having to remove the brake rotor from the wheel hub. This significantly facilitates maintenance, inspection, and cleaning operations for the various components. These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a wheel hub, brake rotor, and tone ring assembly incorporating the subject invention.

FIG. 2 is a front view of the brake rotor shown in FIG. 1.

FIG. 3 is a cross-sectional view of the brake rotor of FIG. 2 as indicated by line 3-3 in FIG. 2.

FIG. 4 is a front view of the tone ring shown in FIG. 1.

FIG. 5 is a cross-sectional view of the tone ring of FIG. 4 as indicated by line 5-5 in FIG. 4.

FIG. 6 is a side view of an assembly of the brake rotor and the tone ring.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A hub and rotor assembly for a vehicle wheel is shown generally at 10 in FIG. 1. The hub and rotor assembly 10 includes a wheel hub 12, a brake rotor 14, and a tone ring 16. The tone ring 16 forms part of a wheel speed sensor for an anti-lock braking system. The hub and rotor assembly 10 can be used with any type of anti-lock braking system. The operation of an anti-lock brake system and wheel speed sensors are well known and will not be discussed in further detail.

The wheel hub 12, brake rotor 14, and tone ring 16 are mounted together for rotation about an axis 18. The wheel hub 12 is mounted to another wheel component (not shown), such as a wheel rim, with a plurality of fasteners 20. The wheel hub 12 includes a central bore 22 that surrounds a non-rotating axle component (not shown), such as a spindle for example. The wheel hub 12 is rotatably supported by a pair of bearings 24 that are positioned between the wheel hub 12 and the spindle.

The brake rotor 14 includes a first set of mounting bosses 26 and a second set of mounting bosses 28 that are both circumferentially spaced about the axis 18 (FIG. 2). The first 26 and second 28 sets of mounting bosses are positioned in a non-overlapping relationship to each other. Thus, the first set of mounting bosses 26 is circumferentially spaced about the axis 18 in a first pattern and the second set of mounting bosses 28 is circumferentially spaced about the axis 18 in a second pattern that is different than the first pattern.

The tone ring 16 is mounted to the brake rotor 14 via the first set of mounting bosses 26 and the brake rotor 14 is independently mounted to the wheel hub 12 via the second set of mounting bosses 28. Thus, the first set of mounting bosses 26 provides a first mount interface between the tone ring 16 and the brake rotor 14 and the second set of mounting bosses 28 provides a second mount interface between the brake rotor 14 and the wheel hub 12. The first mount interface is independent from the second mount interface such that the brake rotor 14 is removable from the wheel hub 12 without having to remove the tone ring 16 from the brake rotor 14, and such that the tone ring 16 is removable from the brake rotor 14 without having to remove the brake rotor 14 from the wheel hub 12.

The brake rotor 14 is shown in greater detail in FIGS. 2 and 3. The brake rotor 14 includes an outer circumferential portion 30 that includes opposing braking surfaces 32 for engagement with frictional material supported by a pair of brake pads (not shown). The brake rotor 14 also includes an inner circumferential portion 34 that includes an opening 36 that surrounds the wheel hub 12 (FIG. 1).

The inner circumferential portion 34 includes a generally flat disc-shaped portion 38 that includes the second set of mounting bosses 28. A wall portion 40 extends from the inner circumferential portion 34 to the outer circumferential portion 30. The wall portion 40 extends generally parallel to the axis 18. The wall portion 40 includes a plurality of extensions 42 that form the first set of mounting bosses 26. Each extension 42 extends radially inwardly from an inner surface 44 of the wall portion 40 toward the axis 18.

The extensions 42 of the first set of mounting bosses 26 each include an aperture 46 that is defined by a first center point. The first center points from all of the apertures 46 are spaced from the axis by a first radial distance R1. The second set of mounting bosses 28 includes a plurality of apertures 50 that are formed within the disc-shaped portion 38. Each aperture 50 is defined by a second center point. The second center points from all of the apertures 50 are spaced from the axis by a second radial distance R2. In the example shown, the first R1 and second R2 radial distances are different from each other to facilitate independent mounting for the tone ring 16 to the brake rotor 14, and for the brake rotor 14 to the wheel hub 12. In the example shown in FIG. 2, the first radial distance R1 is greater than the second radial distance R2, however, an opposite configuration, with the second radial distance R2 being greater than the first radial distance R1, could also be used. Further, the patterns of the apertures could be positioned such that the first R1 and second R2 radial distances are approximately equal.

As shown in FIG. 1, the apertures 46 for the first set of mounting bosses 26 receive a first set of fasteners 52 (only one is shown) to attach the tone ring 16 to the brake rotor 14. The apertures 50 for the second set of mounting bosses 28 receive a second set of fasteners 54 (only one is shown) to attach the brake rotor 14 to the wheel hub 12. Because the apertures 46 for the first set of mounting bosses 26 do not overlap the apertures 50 for the second set of mounting bosses 28 installation of the first 52 and second 54 sets of fasteners do not interfere with each other.

The tone ring 16 is shown in greater detail in FIGS. 4 and 5. The tone ring 16 includes an outer circumferential portion 60 that includes a plurality of slots 62 that are circumferentially spaced about the axis 18. The slots 62 cooperate with other wheel speed sensor components (not shown) to measure and monitor wheel speed as known. The outer circumferential portion 60 includes a ring-shaped body 64 that includes a center opening 66. When mounted to the wheel hub 12 the center opening 66 surrounds the spindle.

The tone ring 16 also includes a plurality of tabs 68 that extend radially inwardly from the outer circumferential portion 60. Each tab 68 includes a support portion 70 that extends transversely relative to the ring-shaped body 64. The support portions 70 axially extend in a direction along the axis 18. From an outer end of each support portion 70 extends a mount portion 72. The mount portions 72 each include an aperture 74 that is aligned with a corresponding aperture 46 on the extensions 42 of the first set of mounting bosses 26.

The apertures 74, 46 receive the first set of fasteners 52 to attach the tone ring 16 to the brake rotor 14 as shown in FIG. 6. The brake rotor 14 includes recessed area 76 into which the ring-shaped body 64 extends.

The wheel hub 12 includes a plurality of apertures (not shown) that are aligned with the apertures 50 formed in the disc-shaped portion 38. The apertures 50 in the disc-shaped portion 38 and the apertures in the wheel hub 12 receive the second set of fasteners 54 to attach the brake rotor 14 to the wheel hub 12. To facilitate assembly, the tone ring 16 can first be attached to the brake rotor 14 to form a brake rotor and tone ring sub-assembly. The brake rotor and tone ring subassembly can then be attached to the wheel hub 12 as a unit.

This unique configuration provides separate pieces for the tone ring 16 and brake rotor 14, which allows the tone ring 16 to be fabricated from a different material than the brake rotor 14. This provides weight saving, material, and manufacturing benefits. Also, as described above, access is provided to the second set of mounting bosses 28 to remove the brake rotor 14 from the wheel hub 12 without having to remove the tone ring 16 from the brake rotor 14, in addition to allowing removal of the tone ring 16 without having to remove the brake rotor 14 from the wheel hub 12. This significantly facilitates maintenance, inspection, and cleaning operations for the various components.

Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.

Claims

1. A wheel assembly comprising:

a wheel hub defining an axis of rotation;

a brake rotor having a first mount interface comprising a first plurality of apertures to receive a first set of fasteners to secure said brake rotor to said wheel hub, and wherein said brake rotor includes a second mount interface comprising a second plurality of apertures to receive a second set of fasteners, said second mount interface being independent of said first mount interface; and

a tone ring mounted to said brake rotor via said second mount interface.

2. The wheel assembly according to claim 1 wherein said first and said second plurality of apertures have a non-overlapping relationship with each other.

3. The wheel assembly according to claim 1 wherein said first and said second plurality of apertures are non-coaxial.

4. The wheel assembly according to claim 1 wherein said brake rotor and said tone ring remain attached to each other via said second mount interface as said brake rotor is removed from said wheel hub at said first mount interface.

5. The wheel assembly according to claim 1 wherein said tone ring is separably removable from said brake rotor via said second mount interface while said brake rotor remains attached to said wheel hub at said first mount interface.

6. The wheel assembly according to claim 1 wherein said brake rotor and said tone ring remain attached to each other via said second mount interface as said brake rotor is removed from said wheel hub at said first mount interface and wherein said tone ring is separably removable from said brake rotor via said second mount interface while said brake rotor remains attached to said wheel hub at said first mount interface.

7. The wheel assembly according to claim 1 including a third plurality of apertures formed within said tone ring, said third plurality of apertures being aligned with said second plurality of apertures when said tone ring is attached to said brake rotor at said second mount interface.

8. The wheel assembly according to claim 1 wherein said brake rotor includes an inner circumferential portion with an opening surrounding an outer surface of said wheel hub, an outer circumferential portion defining a braking surface, and a wall portion interconnecting said inner circumferential portion with said outer circumferential portion, and wherein said first plurality of apertures are formed within said inner circumferential portion and said second plurality of apertures are formed within said wall portion.

9. The wheel assembly according to claim 8 wherein said inner circumferential portion comprises a generally flat disc-shaped portion with said first plurality of apertures extending through said generally flat disc-shaped portion, each of said first plurality of apertures being spaced apart from each other about said axis of rotation.

10. The wheel assembly according to claim 8 wherein said wall portion extends in a direction generally parallel to said axis of rotation with said second plurality of apertures being formed within a plurality of discretely spaced extensions extending radially inwardly from said wall portion toward said axis of rotation, each of said plurality of discretely spaced extensions including one of said second plurality of apertures.

11. A method for assembling a wheel comprising the steps of:

(b) mounting a brake rotor to a wheel hub at a first mount interface by inserting a first set of fasteners through a first set of apertures formed within the brake rotor; and

(b) mounting a tone ring to the brake rotor at a second mount interface that is independent from the first mount interface by inserting a second set of fasteners through a second set of apertures formed within the brake rotor.

12. The method according to claim 11 wherein the first and the second plurality of apertures are non-coaxial.

13. The method according to claim 11 including unfastening the first set of fasteners to remove the brake rotor from the wheel hub while the tone ring remains fastened to the brake rotor via the second mount interface.

14. The method according to claim 11 including unfastening the second set of fasteners to remove the tone ring from the brake rotor while the brake rotor remains fastened to the wheel hub via the first mount interface.

15. The method according to claim 11 including unfastening the first set of fasteners at the first mount interface to remove the brake rotor from the wheel hub while the tone ring remains fastened to the brake rotor during removal of the brake rotor via the second mount interface, and in an independently operable step, unfastening the second set of fasteners at the second mount interface to remove the tone ring from the brake rotor while the brake rotor remains fastened to the wheel hub during removal of the tone ring via the first mount interface.

16. The method according to claim 11 wherein the wheel hub, the brake rotor, and the tone ring rotate about an axis of rotation and including circumferentially spacing the first plurality of apertures about the axis of rotation and circumferentially spacing the second plurality of apertures about the axis of rotation such that the first and the second plurality of apertures have a non-overlapping relationship.