Claims:We Claim:

1. An integrated hub (50) for half shaft assembly (25) of a vehicle comprising of a rubber housing (52) and a metal insert (54), wherein
- the rubber housing (52) has the metal insert (54) integrated therein to form an integrated hub (50);
- said metal insert (54) is profiled in the form of circular ring and the section of the ring has L-shaped profile (56);
- said metal insert (54) of the integrated hub (50) has a plurality of pockets (60) on its peripheral side;
- the two ends of the circular metal insert (54) is separated by a gap (70) to have effective compression of the hub (50) over the tulip (12, 14) in response to the clamping force exerted by the clamp (26a);
- said metal insert (54) is integrated inside the rubber housing (52) in such way that the pocket (60) in the metal insert (54) and the rubber pad (80) of the rubber housing (52) are exactly opposite to each other in an integrated hub (50) and the gap (70) between the ends of the metal insert (54) is oriented centrally inside any one of the rubber pads (80).

2. The integrated hub (50) for half shaft assembly (25) as claimed in claim 1, wherein
- the horizontal leg (56a) and vertical leg (56b) of the L-shaped sectional profile (56) of the hub (50) are at 90 degree with each other;
- the horizontal leg (56a) of the L-shaped section is comparatively shorter than the vertical leg (56b) of the L-shaped section (56); and
- the horizontal leg (56a) being in optimized proportion with the vertical leg (56b), the length of horizontal leg (56a) is in between 0.4x to 0.6x with respect to the length ‘x’ of the vertical leg (56b) of the L-shaped section (56) of the metal insert (54).

3. The integrated hub (50) for half shaft assembly (25) as claimed in claim 1, wherein
- the profile of said plurality of pockets (60) is selected from a set of profiles having elliptical, square, circular, triangular, rectangular, and any polygonal profile or combination thereof; and
- the preferred number of pockets (60) is three carved at 120 degree with each other to achieve positive bonding of rubber and metal of the integrated hub (50).

4. The integrated hub (50) for half shaft assembly (25) as claimed in claim 3, wherein
- the most preferred profile of the pockets (60) is elliptical and circular;
- said elliptical pocket (60) has the ratio of d1 and d2 (the diameters in x and y direction) in the range of 0.5 to 0.7; and
- the center of the said pocket (60) is at the distance ranging from 0.38x to 0.56x while the lower edge of the pocket is at the distance of 0.15x from the open end of the vertical leg (56b) of L-section (56).

5. The integrated hub (50) for half shaft assembly (25) as claimed in claim 1, wherein
- the metal insert (54) has the gap (70) between its two ends so as to have effective compression of the hub (50) over the tulip (12, 14) in response to the clamping force exerted by the clamp (26a); and
- the said gap (70) being in optimized proportion with the internal diameter of the metal insert (54), the gap (70) varies between 0.04y to 0.07y with respect to the internal diameter ‘y’ of the metal insert (54).

6. The integrated hub (50) for half shaft assembly (25) as claimed in claims 2 or 4 or 5, wherein
- the thickness of the metal insert (54) is less than the thickness of clamp (26a); and
- the thickness of the said metal insert (54) ranges between 0.20t to 0.45t with respect to the thickness ‘t’ of the clamp (26a).

7. The integrated hub (50) for half shaft assembly (25) as claimed in claim 6, wherein
- said integrated hub (50) has a plurality of rubber pads (80);
- the preferred number of said rubber pads (80) is three carved at 120 degree with each other;
- the profile of the rubber pad (80) is in accordance with the profile of the depressions (82) provided on the outer surface of the tulip (12, 14); and
- said rubber pads (80) integrated hub (50) get locked in the depressions (82) provided on the outer surface of the tulip (12, 14) so as to have positive locking.

8. The integrated hub (50) for half shaft assembly (25) as claimed in claim 7, wherein
- said integrated hub (50) is provided with an annular rib (85) throughout it’s inner circular periphery connecting the rubber pads (80); and
- said rib (85) gets tightly locked inside a groove (87) provided on the outer periphery of the tulip (12, 14).

9. The integrated hub (50) for half shaft assembly (25) as claimed in claim 8, wherein
- the metal insert (54) is made from a material selected from a group of materials of steel, Aluminium (Ferrous & Non-Ferrous) and Magnetic-Nonmagnetic materials; and
- the most preferred material for metal insert (54) is steel so as to effectively compensate with the mechanical properties required for the purpose.

10. The integrated hub (50) for half shaft assembly (25) as claimed in claim 9, wherein the housing (52) of the integrated hub (50) is made from rubber and the said rubber is selected from a group of natural rubber, Neoprene, NBR (Nitrile Butadiene rubber), Styrene butadiene rubber, Ethylene Propylene Diene Monomer (EPDM), Hydrogenated Nitrile (HNBR), and Polyurethane.

Dated this 27th day of March 2021. , Description:FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

TITLE OF THE INVENTION
“INTEGRATED HUB FOR HALF SHAFT ASSEMBLY OF A VEHICLE”

Endurance Technologies Limited
E-92, M.I.D.C. Industrial Area, Waluj,
Aurangabad – 431136, Maharashtra, India

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of Invention

[001] The present invention is related to half shaft assembly of the final drive system of a vehicle. More particularly, the present invention is related to the hub for half shaft assembly wherein said hub is having a uniquely profiled metal insert integrated therein in such way that it improves the load carrying / retention capacity of the hub.

Background of the Invention

[002] A half shaft of a vehicle is essentially a drive axle and it extends from a transaxle or differential to one of the wheels. Its twin on the other side completes the set. The Half shaft assembly is used for transmitting power from differential to wheel in automotive vehicles, particularly in three and four wheelers. When the half shaft assembly of the vehicle is subjected to the articulation angles beyond its acceptable limit and/or sudden jerks due to undulating road conditions, there are likely chances that the shaft assembly along with spiders and rollers mechanism is coming out of the hub leading to complete failure of final drive system.

[003] To address this problem a variety of solutions is provided in the prior art each of the solution differing from the other with varying degree of success. One conventional solution available in public domain is providing hub in thermoplastic having annular groove and fittable on the tulip and press fitting the metallic insert therein in the annular groove. Other prior art document no. 3146/DELNP/2011 discloses an adapter for fastening a bellow to another component wherein it has at least one guiding means which extends beyond the edge and also has an encircling annular groove. But this adapter does not have a metal insert therein. Another prior art document no. US6089574 describes a boot for use with CV joints. The boot is interference fitted with a bush which has projecting lobes and plurality of grooves. The bush is made up of thermoplastic material and has not been provided with a metal insert integrated therein.

[004] The drawback of these solutions is that it impart the clamping force only on the plastic portion of the hub. Therefore, in case of adverse driving condition as mentioned above, the separately fitted metallic insert exerts load on the edges of the hub leading to failure of the half shaft assembly of the final drive system. Hence, there exists a long pending unmet need to provide an integrated hub that addresses the reduction in cycle time of its manufacturing process and assembly method and at the same time provides seamless clamping of the hub over the tulip with improved load carrying / retention capacity.

Objectives of the Invention

[005] The main object of the present invention is to provide an integrated hub for half shaft assembly of the vehicle.
[006] Another object of the present invention is to provide an integrated hub for half shaft assembly of the vehicle wherein the hub has a uniquely profiled metal insert integrated therein.

[007] Yet another object of the present invention is to provide an integrated hub for half shaft assembly of the vehicle wherein the L-shaped metal insert of the hub leads to improvement in load carrying / retention capacity.

[008] Yet the object of the present invention is to provide an integrated hub for half shaft assembly of the vehicle wherein the said hub provides seamless clamping over the tulip thus reducing the chance of any gap between the outer surface of the tulip and the inner surface of the integrated hub.

[009] It is yet another objective of the invention is to provide an integrated hub for half shaft assembly of the vehicle which is very effective and proves to be the most optimized design for the half shaft assembly of the vehicles wherein the torque transmission happens from tulip to tulip and the vehicles are subjected to high articulation angles due to undulating road conditions.

[0010] Further, the objective of the invention is to provide an integrated hub for half shaft assembly of the vehicle that eliminates the chance of any grease leakage and imparts improved overall product performance and durability.

[0011] Still the objective of the invention is to provide an integrated hub for half shaft assembly of the vehicle which is manufactured in a single stroke optimizing the resources and eliminates the lengthy manufacturing process of manufacturing two different components separately and then assembling them.

Brief Description of the Drawings

[0012] This invention is illustrated in the accompanying drawings, throughout which like reference letters / numerals indicate corresponding parts in the various figures. The embodiments herein and advantages thereof will be better understood from the following description when read with reference to the following drawings, wherein

[0013] Figure 1 illustrates a fully assembled half shaft assembly of the vehicle in accordance with the present invention.

[0014] Figure 2 discloses an enlarged cut sectional view of A in Fig.1.

[0015] Figure 3 shows a magnified view of the rubber housing of the integrated hub in accordance with the present invention.

[0016] Figure 4 shows the magnified view of the metal insert of the integrated hub in accordance with the present invention.
[0017] Figure 5 presents an integrated hub as per the invention with cut views disclosing the novel and inventive features.

[0018] Figure 6 illustrates an integrated hub as per the invention and its sectional views disclosing the novel and inventive features.

[0019] Figure 7 shows the assembly view of the integrated hub over the tulip as per the objectives of the present invention.

Detailed Description of the Present Invention

[0020] The invention will now be described in detail with reference to the accompanying drawings which must not be viewed as restricting the scope and ambit of the invention.

[0021] Referring to Fig. 1, half shaft assembly (25) of the vehicle comprises of shaft (10), in-board joint (12), out-board joint (14), bellow (20), clamps (26a and 26b) and hub (50). The in-board joint (12) and out-board joint (14) is also called as tulip and portion of the tulip shown by numerals 16 and 18 has the cavity to accommodate the spider and roller assembly (24) connected on either ends of the shaft (10). The spider and roller assemblies (24) are rotatably and freely hold inside the tulip (12 and 14). The hub (22) is fitted over the tulip (12 and 14) so as to restrict the movement of spider and roller assembly (24) outside the tulip (12 and 14) when the half shaft assembly (25) of the vehicle is subjected to high articulation angle (beyond the acceptable limit) and sudden jerks due to uneven road condition. The joinery of the tulip (12 and 14) with the shaft (10) which is through the hub (50) is covered by the bellow (20) so as to avoid the entry of dirt, dust, mud, water and like foreign material into the cavity (16 and 18) of the tulip (12 and 14). One end of the flexible bellow (20) is fitted over the hub (50) with the help of clamp (26a) and the other end is fitted on the shaft (10) with the help of clamp (26b).

[0022] Referring to Figs. 3 – 5, the hub (50) of the invention comprises of the rubber housing (52) and the metal insert (54) wherein the said housing (52) has a metal insert (54) integrated therein to form an integrated hub (50) for the half shaft assembly (25) of the vehicle. The metal insert (54) is profiled in the form of circular ring as shown in Fig. 4 and the section of the ring has L-shaped profile (56). The metal insert (54) is made from a group of materials selected from steel, Aluminium (Ferrous & Non-Ferrous), Magnetic-Nonmagnetic materials, etc. The most preferred material for metal insert (54) is steel so as to effectively compensate with the mechanical properties required for the purpose. The housing (52) of the integrated hub (50) is made from rubber as against to the thermoplastic in conventional design of the hub. The rubber of the hub is selected from a group of natural rubber, Neoprene, NBR (Nitrile Butadiene rubber), Styrene butadiene rubber, Ethylene Propylene Diene Monomer (EPDM), Hydrogenated Nitrile (HNBR), Polyurethane, etc. as against to that of thermoplastic conventionally used for the hub. Further, the metal insert (54) of the integrated hub (50) has a plurality of pockets (60) on its peripheral side to have effective bonding between the rubber and metal of the integrated hub (50). The metal insert (54) is also provided with the gap (70) between its two ends so as to have effective compression of the hub (50) over the tulip (12, 14) in response to the clamping force exerted by the clamp (26a).

[0023] Referring to Fig. 5, the horizontal leg (56a) and vertical leg (56b) are at 90 degree with each other and the horizontal leg (56a) of the L-shaped section is comparatively shorter as compared to the vertical leg (56b) of the L-shaped section (56). Assuming the length of vertical leg (56b) as ‘x’, the horizontal leg (56a) being in optimized proportion with the vertical leg (56b), the length of horizontal leg (56a) mandatorily varies between 0.4x to 0.6x with respect to the length ‘x’ of the vertical leg (56b) of the L section (56) of the metal insert (54).

[0024] Referring to the Fig. 4, the metal insert (54) of the integrated hub (50) has a plurality of pockets (60) on its peripheral side to have effective bonding between the rubber and metal of the integrated hub (50). The profile of said plurality of pockets (60) is selected from a set of profiles having elliptical, square, circular, triangular, rectangular, and any polygonal profile or combination thereof. The most preferred profile of the pockets is elliptical and circular being easy to manufacture and having effective heat dissipation properties as the corners are being avoided in these profiles. The most preferred number of pockets (60) is three carved at 120 degree with each other to achieve positive bonding of rubber and metal of the integrated hub (50). If the number of pockets (60) are given less than three, there are likely chances that the rubber is getting slip over the metal while assembling over tulip (12, 14) leading to poor fitting of the integrated hub (50) over the tulip (12, 14). If the number of pockets are more than three, the mechanical properties and strength of the metal insert (54) and thereby the integrated hub (50) is affected badly leading to defeat the functional objective of the integrated hub (50) of the invention. In case of elliptical pocket (60), the ratio of d1 and d2 (the diameters in x and y direction) is in the range of 0.5 to 0.7 and center of the said pocket (60) is at the distance ranging from 0.38x to 0.56x while the lower edge of the pocket is at the distance of 0.15x from the open end of the vertical leg (56b) of L-section (56).

[0025] The metal insert (54) is also provided with the gap (70) between its two ends so as to have effective compression of the hub (50) over the tulip (12, 14) in response to the clamping force exerted by the clamp (26a). Assuming internal diameter of the metal insert (54) as ‘y’, the said gap (70) being in optimized proportion with the internal diameter of the metal insert (54), the gap (70) mandatorily varies between 0.04y to 0.07y with respect to the internal diameter ‘y’ of the metal insert (54).

[0026] The thickness of metal insert (54) should be less than the thickness of clamp (26a) so that the mechanical properties of the insert (54) are overpowered by the mechanical properties of the clamp (26a) so as to impart tight clamping of the hub over the tulip (12, 14). Assuming the thickness of the clamp (26a) as ‘t’, the thickness of the metal insert (54) should range in between 0.20t to 0.45t.

[0027] The integrated hub (50) of the present invention is provided with a plurality of rubber pads (80) as shown in Fig. 5. The most preferred number of rubber pads (80) is three carved at 120 degree with each other to achieve positive bonding with the outer profile of the tulip (12, 14). Generally the spider and roller assembly (24) has three legs and that’s why the outer profile of the tulip is provided with three depressions (82) as shown in Fig. 7. To get locked in these three depressions (82), the integrated hub (50) is provided with three rubber pads (80). The profile of the rubber pad (80) is in accordance with the profile of the depressions (82) provided on the outer surface of the tulip (12, 14) so as to have positive locking.

[0028] While integrating the metal insert (54) in the rubber housing (52) during injection moulding process to form an integrated hub (50) of the invention, the metal insert (54) is placed in such way that pocket (60) in the metal insert (54) and the rubber pad (80) of the rubber housing (52) is exactly opposite to each other in an integrated hub (50) and at the same time, the gap (70) between the ends of the metal insert (54) is oriented centrally inside any one of the rubber pads (80). This unique integration imparts effective bonding of rubber and metal at minimum rubber thickness of the integrated hub and also provides positive locking over the tulip (12, 14). Orienting the gap (70) centrally in the rubber pad (80), facilitates the effective compression of the metal insert (54) in the rubber pad without tearing off the rubber or damaging the rubber housing (52) of the integrated hub (50). Further the integrated hub (50) is provided with an annular rib (85) throughout it’s circular periphery (as shown in Fig.5) connecting the rubber pads (80) so as to get tightly locked inside the grooves (87) provided on the outer periphery of the tulip (12, 14).

[0029] Thus, the novelty of the integrated hub (50) resides in the seamless integration of metal insert (54) inside the rubber housing (52) wherein the said metal insert (54), having L-shaped section (56) and a plurality of pockets (60), moulded inside the rubber in such way that the each of the pocket (60) of the metal insert (54) is exactly opposite to the rubber pad (80) of the hub and the gap (70) between the ends of metal insert (54) is centrally accommodated within the rubber pad (80). These novel features of the integrated hub contribute to the technology domain of the hub and also impart technical advantages as discussed above. Additionally the technical advantages derived from the invention are as under. Thus, the invention qualifies the test of inventive step also.
- Lengthy manufacturing process of manufacturing two different components separately and then assembling them is eliminated totally. In a single stroke, an integrated hub is getting manufactured optimizing the resources i.e. time, manpower, etc.
- Increased strength of hub due to L-shaped metal insert leading to improvement in load carrying / retention capacity.
- The change of housing material from thermoplastic to rubber leads to seamless clamping of the hub over the tulip thus reducing the chance of any gap between the outer surface of the tulip and the inner surface of the integrated hub.
- It eliminates the chance of any grease leakage and imparts improved overall product performance and durability.
- The integrated hub of the invention is very effective and proves to be the most optimized design for the half shaft assembly of the vehicles wherein the torque transmission happens from tulip to tulip and the vehicles which are subjected to high articulation angles

[0030] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.