FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION Hub bearing assembly
APPLICANT
TATA MOTORS LIMITED, an Indian company
Having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Munibai 400 001 Maharashtra, India
INVENTOR
Mr. Mahesh Joshi
Indian National
of TATA MOTORS LIMITED,
An Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner
in which it is to be performed.

FIELD OF INVENTION
The present invention relates to a bearing assembly for vehicles and more particularly to a hub bearing unit for vehicles to assemble and match the centerline of the hub bearing unit with that of the centre line of the tire to increase the life of the hub bearings.
BACKGROUND OF THE INVENTION
Wheel ends and bearing assemblies for motor vehicles are known and are widely used in the automobile industries. A typical vehicle wheel end may include a bearing assembly which is disposed about a shaft and hub and is mounted to a steering knuckle by means of fasteners or interference fittings. The bearing assembly is preloaded by a locking nut which secures the bearing assembly with the hub and the shaft. The life of the bearing unit in a conventional 4x2 front wheel automobile is very less. This is due to the usage of two taper roller bearings assembled with spacer in between the two bearings. The use of single taper roller bearing has a limited field life, and whereas this needs to be enhanced further. In conventional assembly the bearing is assembled from outside of the hub and then the tire is assembled over the brake disc. Due to this in conventional design tire load line will be at an offset to the bearing centre line. This leads to early failure of the bearing and hence low life of the bearing. Hence there is a need for a novel arrangement of the wheel end with the hub bearing to increase the life of the hub bearing unit.
OBJECTIVE OF THE INVENTION
The primary object of the present invention is to obviate the above mentioned drawbacks.
Another object of the invention is to enhance the life of the bearing unit in a vehicle by suitable new wheel end bearing arrangement.

Yet another object of the present invention is to assemble and match the centerline of the hub bearing unit to that of the centre line of the tire.
SUMMARY OF THE INVENTION
The embodiments herein provide a hub bearing assembly to match tire load centre line with the centre line of a bearing unit to increase the life of the bearings. The assembly comprising a bearing unit pressed in the hub and bolted to the brake disc and then the whole assembly is inserted over an extended stub axle. To achieve matching of tire load centre line with bearing centre line the brake disc assembly is reversed as compared to the conventional design. According to present invention, the brake disc is assembled from inner side of the hub to provide space and to make the wheel end compact. The load line of the tire will be exactly matched with the centre line of the bearing. The benefit of the present arrangement is that both the rows of needle rollers are equally loaded and intern the bearing will have optimum life during its working.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows a sectional view of the conventional wheel end arrangement with two taper roller bearings assembled with the spacer ring in-between.
FIG. 2 shows a sectional view of an alternative proposal of conventional wheel end arrangement.
FIG. 3 shows a sectional view an yet another alternative proposal of conventional wheel end arrangement and
FIG. 4 shows a sectional view a wheel end arrangement, according to embodiment of the present invention,

DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting the same,
FIG. 4 shows a sectional view of the hub bearing assembly according to present invention. The hub bearing assembly comprising a pair of bearing unit 2 pressed in the hub 1 and bolted with brake disc 4. An extended stub axle 3 is provided for inserting said baring unit 2 with hub 1 and brake disc 4. The extended stub axle 3 is provided to match the tire load centre line with the centre line of a bearing unit. The brake disc 4 is assembled from inner side of said hub 1 to offer space and to make the wheel end compact. According to present invention the needle roller bearing rows are equally loaded to enhance the life of the bearings.
FIG. 1 to FIG 3 shows a conventional wheel end arrangement with bearings. The conventional wheel end arrangements with two taper roller bearings 2 are assembled with the spacer ring in-between as shown in the FIG. 1. The disadvantages of this arrangement are the assembly time in more, less bearing life, difficult to service and high IPTV (Incidents per Thousand Vehicles). If IPTV for particular aggregate is zero it indicates that its reliability is very good. More over the tire load centre line is not matching with the centre line of the hub bearing unit, hence there will be more load on the bearing unit and over a period of time the bearing unit may get damaged. The above mentioned drawbacks are eliminated by changing wheel end arrangement with the hub bearing unit 2, according to present invention (FIG. 4). The wheel end unit arrangement according to present invention is provided to reduce the assembly time, includes less number of parts, less parts for service, easy servicing and enhanced bearing life.
However the arrangements as shown in the FIG. 2 is lacking with the disadvantages such as high weight of the assembly, very high offset between the load line and

bearing unit 2 centerline and difficult to access the nut. Similarly, the arrangement shown in FIG, 3 is also lacking following disadvantages of more weight of the assembly, but again offset between the load line and bearing 2 centerline is not meeting with expected zero clearance.
The assembly according to present invention is as shown in FIG. 4. It has following advantages such as optimum weight of the assembly, optimum zero offset between the load line and bearing 2 centerline thereby making preset arrangement with optimum bearing 2 life, easy servicing of the assembly and easy servicing of the brake disc 4. The hub bearing assembly according to present invention gives optimum bearing life because in this arrangement the tire centre line is matched with the bearing centre line. This is the new arrangement of wheel end developed with the new hub bearing unit by using the different shape of brake disc, hub and stub axle.
ADVANTAGE:
• wheel end unit arrangement according to present invention is provided to reduce the assembly time, includes less number of parts, less parts for service, easy servicing and enhanced bearing life.
• The tire load centre line is exactly matching with the centre line of the bearing to increase the bearing life.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

We claim
1. A hub bearing assembly, comprising;
a pair of bearing unit (2) pressed in the hub (1) and bolted with brake disc (4);
an extended stub axle (3) for inserting said baring unit (2) with hub (1) and brake
disc (4).
2. The hub bearing assembly according to claim 1, wherein said extended stub axle is provided to match the tire load centre line with the centre line of a bearing unit.
3. The hub bearing assembly according to claim 1, wherein said brake disc is assembled from inner side of said hub to provide space and to make the wheel end compact.
4. The hub bearing assembly according to claim 1, wherein said needle roller bearings rows are equally loaded to enhance the life of the bearings.
5. The hub bearing assembly as herein described with reference to accompanying drawings.