Claims:We Claim:
1. A differential assembly (1) for a drive axle of a vehicle, the differential assembly (1) comprising:
a crown wheel (3) structured to receive power from a pinion (2) of the differential assembly (1);
a differential flange assembly (4) comprising a differential flange case (5) and a differential flange cover (6), wherein the differential flange assembly (4) is configured to hold the crown wheel (3);
a spider (7) disposed in the differential flange assembly (4), wherein the spider (7) comprises:
a plurality of legs (7a) each for supporting one of a plurality of differential pinion gears (8);
a pair of protrusions (7b), each extending transverse to the plurality of legs (7a), wherein, each of the pair of protrusions (7b) supports at least one of a pair of side gears (9)and wherein the pair of side gears (9) are in meshing engagement with the plurality of differential pinion gears (8).

2. The differential assembly (1) as claimed in claim 1 wherein the pinion (2) is housed in the driven axle is coupled to an output shaft of the gearbox of the vehicle through a propeller shaft.

3. The differential assembly (1) as claimed in claim 1 wherein the crown wheel (3) comprises an outer surface (3a) having a plurality of gears (3c) and an inner surface (3b) coupled with the differential flange assembly (4).

4. The differential assembly (1) as claimed in claim 1 wherein the differential flange case (5) and the differential flange cover (6) define a plurality of cavities (5d) to secure each of the plurality of legs (7a) of spider, such that the spider (7) is housed in the differential flange assembly (4).

5. The differential assembly (1) as claimed in claim 1 wherein each of the pair of side gears (9) includes proximal end (9a) defined with a gear profile (9c), and a distal end (9b) define with an extended portion (9d) to accommodate a bearing (11).

6. The differential assembly (1) as claimed in claim 1 wherein the proximal end (9a) of each of the pair of side gears (9) is defined with a stepped bore (9e) to accommodate a corresponding protrusion of the pair of protrusions (7b) of the spider (7).

7. The differential assembly (1) as claimed in claim 1 wherein the distal end (9b) of each of the pair of side gears (9) is defined with splined bore (9f) to receive an axle shaft.

8. The differential assembly (1) as claimed in claim 1 wherein the crown wheel (3) is configured to transfer the torque from the pinion (2) to the spider (7) through differential flange assembly (4).

9. The differential assembly (1) as claimed in claim 1, wherein the spider (7) supports the side gears (9) for axial thrust, bending load and is configured to transfer the torque from the differential flange assembly (4) to the plurality of differential pinions (8).

10. The differential assembly (1) as claimed in claim 1 wherein the side gear (9) transmits the torque from the plurality of differential pinions (8) to the axle shaft and acts as a structural member which holds the entire differential assembly (1) in its position.
11. A vehicle comprising a differential assembly (1) as claimed in claim 1 comprising a crown wheel (3) structured to receive power from a pinion (2) of the differential assembly (1);

a differential flange assembly (4) comprising a differential flange case (5) and a differential flange cover (6), wherein the differential flange assembly (4) is configured to hold the crown wheel (3); a spider (7) disposed in the differential flange assembly (4), wherein the spider (7) comprises:
a plurality of legs (7a) each for supporting one of a plurality of differential pinion gears (8);

a pair of protrusions (7b), each extending transverse to the plurality of legs (7a), wherein, each of the pair of protrusions (7b) supports at least one of a pair of side gears (9) and wherein the pair of side gears (9) are in meshing engagement with the plurality of differential pinion gears (8).
, Description:TECHNICAL FIELD:

The present disclosure relates in general to a field of automobiles. Particularly but not exclusively, the disclosure relates to differential assembly of a vehicle. Further, embodiments of the disclosure discloses a lightweight differential assembly in which the weight of the differential is reduced as compared to conventional differential assembly.

BACKGROUND OF THE DISCLOSURE

In automobiles and other wheeled vehicles, the differential allows the outer drive wheel to rotate faster than the inner drive wheel while taking a turn. This is necessary when the vehicle turns, making the wheel that is traveling around the outside of the turning curve roll farther and faster than the other. The average of the rotational speed of the two driving wheels equals the input rotational speed of the drive shaft. An increase in the speed of one wheel is balanced by a decrease in the speed of the other, Differential is a key component used in the drive axle. The wheels on the driving axle must be interconnected in order to receive their energy from the pinion to the driving shaft and at the same time it must be free to revolve at different speeds when necessary. The differential has three main function i.e., to transmit the engine power to the wheels, to make the final gear reduction in the vehicle and reducing the rotational speed of the transmission before it goes the wheels and to allow the wheels to rotate at different speeds.

At present, trends for emission limitations and fuel saving impose a more efficient energy exploitation in many sectors of mechanical engineering and weight reduction is one of the strategies that may be adopted to reach this goal. Besides the environmental requirements, weight reduction is a key aspect in all the applications where the weight is a crucial aspect for the overall performance of the system, such as automotive industries. Geared power transmissions, which are key components in many mechanical systems, cannot be excluded from such a light weighting trend and competition. Traditionally, the differentials are designed with heavy differential case and cover in order to achieve a high load carrying capacity. Conventional differential is one of the components in axle which contributes to almost 35-40% of differential carrier weight. Modifying conventional differential will help in achieving the weight and fuel performance targets.

Figure 1 illustrates conventional differential assembly (100) showing the flow of torque from crown wheel to the axle shaft . As illustrated in the figure, plurality of pinions (104) and side gear (105) are packaged inside a differential case assembly (102) of the conventional differential assembly(100) due to which size of the differential case assembly (102) becomes large which thereby makes the differential case assembly (102) quite heavy. Further, the differential case assembly (102) is then supported by two taper roller bearings (106) which is also mounted on the differential case assembly (102). The drawback of the conventional differential assembly (100) is that the differential case assembly (102) which is considered as one of the major component contributes to most of the weight and makes the whole assembly bulky. As seen in figure 1, the torque flow path of the conventional differential assembly (100) is from crown wheel (101) to side gears (105) through differential case assembly (102), spider(103) and pinions (104). Since all the components such as spider (103), pinion (104) and side gears (105) are disposed inside the differential case assembly (102) and they are subjected to torque and axial thrust from the input shaft of engine . Thus, the conventional differential case assembly is required to be made up of large size and to withstand the torque and axial force which leads to the increase in the weight of conventional differential assembly (100).

The present disclosure is directed to overcome one or more problems stated above, or any other limitations associated with the prior arts.

SUMMARY OF THE DISCLOSURE

The one or more shortcomings of the prior art are overcome by an assembly as claimed and additional advantages are provided through the provision of assembly as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In a non-limiting embodiment of the disclosure, a differential assembly for a drive axle of a vehicle is disclosed. The differential assembly for a drive axle of a vehicle, comprising a crown wheel structured to receive power from pinion, which receives input power from propeller shaft. A differential flange assembly comprising a differential flange case and a flange cover, wherein the differential flange assembly is configured to hold the crown wheel. A spider is disposed in the differential flange assembly, wherein the spider comprises plurality of legs each for supporting one of a plurality of differential pinion gears and a pair of protrusions, each extending transverse to the plurality of legs. Each of the pair of protrusions supports at least one of pair of side gears and wherein the pair of side gears are in meshing engagement with the plurality of differential pinion gears.

In an embodiment, the pinion is housed in the driven axle which is coupled to an output shaft of the gearbox of the vehicle through a propeller shaft.

In an embodiment, the crown wheel comprises an outer surface having a plurality of gears and an inner surface coupled with the differential flange assembly.

In an embodiment, the differential flange case and the differential flange cover define a plurality of cavities to secure each of the plurality of legs of spider, such that the spider is housed in the differential flange assembly.

In an embodiment, each of the pair of side gears includes proximal end defined with a gear profile, and a distal end define with an extended portion to accommodate a bearing. The proximal end of each of the pair of side gears is defined with a stepped bore to accommodate a corresponding protrusion of the pair of protrusions of the spider. Further, the distal end of the pair of side gears is defined with splined bore to receive an axle shaft.

In an embodiment, the crown wheel is configured to transfer the torque from the pinion to the spider through differential flange assembly.

In an embodiment, the spider supports the side gears for axial thrust and bending load. It is configured to transfer the torque from the differential flange assembly to the plurality of pinions.

In an embodiment the side gear transmits the torque from the plurality of pinions to the axle shaft and acts as a structural member which holds the entire differential assembly in its position.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES

The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

Figure. 1 illustrates the flow of torque in the conventional differential assembly.

Figure. 2 and 3 illustrates the perspective views of the differential assembly in accordance with the embodiment of the present disclosure.

Figure 4 illustrates the exploded view of differential assembly in accordance with the embodiment of the present disclosure.

Figures 5 and 6 illustrates perspective views of crown wheel in accordance with the embodiment of the present disclosure.

Figure 7 illustrates perspective view of differential flange case in accordance with the embodiment of the present disclosure.

Figure 8 illustrates perspective view of differential flange cover in accordance with the embodiment of the present disclosure.

Figures 9 and 10 illustrates perspective views of differential flange assembly in accordance with the embodiment of the present disclosure.

Figure 11 illustrates perspective views of spider in accordance with the embodiment of the present disclosure.

Figure 12 illustrates perspective views of pinion in accordance with the embodiment of the present disclosure.

Figure 13 illustrates perspective views of side gear in accordance with the embodiment of the present disclosure.

Figure 14 the flow of torque in accordance with the embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other mechanism for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

Accordingly, the present disclosure discloses a differential assembly for a drive axle of a vehicle. The differential assembly comprising a crown wheel structured to receive power from pinion, which received power from propeller shaft. A differential flange assembly including a differential flange case and a differential flange cover is provided, wherein the differential flange assembly is configured to hold the crown wheel. A spider is disposed in the flange assembly, wherein the spider includes a plurality of legs, each for supporting one of a plurality of differential pinion gears and a pair of protrusions, each extending transverse to the plurality of legs, Each of the pair of protrusions supports at least one of pair of side gears and wherein the pair of side gears are in meshing engagement with the plurality of pinion gears. The pinion is housed in the driven axle is coupled to an output shaft of the gearbox of the vehicle through a propeller shaft. The crown wheel comprises an outer surface having a plurality of gears and an inner surface coupled with the differential flange assembly. The differential flange case and the differential flange cover define a plurality of cavities to secure each of the plurality of legs of spider, such that the spider is housed in the differential flange assembly and each of the pair of side gears includes proximal end defined with a gear profile, and a distal end define with an extended portion to accommodate a bearing. The proximal end of each of the pair of side gears is defined with a stepped bore to accommodate a corresponding protrusion of the pair of protrusions of the spider. The distal end of the pair of side gears is defined with splined bore to receive an axle shaft. The crown wheel is configured to transfer the torque from the pinion to the spider through differential flange assembly. The spider supports the side gears for axial thrust, bending load and is configured to transfer the torque from the differential flange assembly to the plurality of differential pinions. The side gear transmits the torque from the plurality of differential pinions to the axle shaft and acts as a structural member which holds the entire differential assembly in its position.

A differential assembly for a drive axle of a vehicle according to embodiments of the present disclosure may be employed in any vehicles such as passenger vehicles and commercial vehicles including heavy and light commercial vehicles, rickshaws, and the like.

The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that an assembly, device, or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.

In the following description, the words such as upper, lower, front, and rear are referred with respect to particular orientation of the assembly as illustrated in drawings of the present disclosure. The words are used to explain the aspects of the present disclosure and for better understanding. However, one should not construe such terms as limitation to the present disclosure, since the terms may interchange based on the orientation of the assembly.

Henceforth, the present disclosure is explained with the help of figures of differential assembly However, such exemplary embodiments should not be construed as limitations of the present disclosure. A person skilled in the art can envisage various such embodiments without deviating from scope of the present disclosure. In the figures, the differential assembly is shown for a commercial vehicle and the same is included for the purpose of simplicity. Such illustration should not be considered as a limitation to the present disclosure.

The present disclosure relates to a lightweight differential assembly. In the present disclosure, the weight of the differential assembly is reduced by modifying the differential case assembly to differential flange assembly. The spider being a key component of the lightweight differential is modified to hold the plurality of pinions along with the side gears. In the present disclosure, the side gears are also modified to carry the axial loads and supports the bearings. Overall, the differential assembly is light in weight, and also consumes less space in the vehicle.

Figures 2 and 3 are exemplary embodiments of the present disclosure, which illustrates perspective view of a differential assembly (1) for a vehicle. The differential assembly (1) is housed in the driven axle and is coupled to an output shaft of the gearbox of the vehicle . The differential assembly (1) housed in the driven axle is coupled to a propeller shaft (not shown in figure) which is driven by a power source (not shown in figure) such as engine or electric motor and additional powertrain components such as a transmission, gearbox, clutch, or any other known powertrain components may be positioned between the power source and the shaft. In a vehicle, the drive axle may comprise a forward axle and a rear axle. The forward axle may include a forward differential assembly that is coupled to forward axle shafts that drive a pair of laterally opposed forward wheel ends . The rear axle may include a rear differential assembly that is coupled to rear axle shafts that drive a pair of laterally opposed rear wheel ends.

As illustrated in figure 4 the differential assembly (1) may include a pinion (2), a crown wheel (3), a differential flange case (5), a differential flange cover (6), a spider (7), plurality of differential pinions (8), side gears (9). The pinion (2) of differential assembly (1) is housed in the driven axle coupled to the output shaft of the gearbox and transmits power to the differential assembly (1). The pinion (2) having a first end (2a) coupled with the output shaft of the gear box [not shown] and a second end (2b) having hypoid gears around its circumference and meshed with the crown wheel (3). The crown wheel (3) and pinion (2) is having a bevel gearing arrangement wherein the crown wheel (3) is structured to receive power from the pinion (2).

As illustrated in figures 4, 5 and 6 the crown wheel (3) includes a plurality of gear teeth (3c) formed about its outer surface (3a) and is meshed with the hypoid gears of pinion (2). An inner surface (3b) of crown wheel (3) is coupled to a differential flange assembly (4). The inner surface (3b) of crown wheel may comprise plurality of openings (3d) which connects the crown wheel (3) to the differential flange assembly (4) by means of fasteners (10). Referring to figures 4 and 7-10, the differential flange assembly (4) may include the differential flange case (5) and differential flange cover (6) and is configured to hold the crown wheel (3). The differential flange case (5) may comprise an outer surface (5a) and an inner surface (5b), wherein the inner surface (5b) extends axially from the outer surface (5a).

The outer surface (5a) of differential flange case may comprise plurality of openings (5c) around its circumference and is coupled with the inner surface (3b) of the crown wheel (3) by means of the fasteners (10). The inner surface (5b) of differential flange case may comprise plurality of cavities (5d) around its circumference to secure each of the plurality of legs (7a) of the spider (7), such that the spider (7) is housed in the differential flange assembly (4). The differential flange cover (6) is disposed on the inner surface (5b) of differential flange case to secure the spider (7) inside the differential flange assembly (4). In an embodiment, the differential flange cover (6) may also defined with matching cavities (5d).

In an embodiment and as shown in figures 4 and 11-13, the spider (7) is disposed in the differential flange assembly (4). The spider (7) may include a plurality of legs (7a) each for supporting one of a plurality of differential pinions (8). Preferably, in the present disclosure four legs (7a) extend outwardly to form a cross shaped or cruciform member and one differential pinion (8) is supported on each leg (7a). The differential pinion (8) may have an opening (8a) at its central portion and plurality of gears (8b) disposed around its circumference. The opening (8a) of the differential pinion secures each leg (7a) of spider thereby mounting the plurality of differential pinions (8) on the spider (7). The spider (7) may also include a pair of protrusions (7b) each extending transverse to the plurality of legs (7a). Each protrusion (7b) of the spider may have a cylindrical cross section and each of the pair of protrusions (7b) supports at least one of pair of side gears (9). The spider (7) in accordance with embodiment of present disclosure supports four differential pinions (8) and two side gears (9) in such a manner that the pair of side gears (9) are in meshing engagement with the plurality of differential pinion gears (8). The pair of side gears (9) may include a proximal end (9a) defined with a gear profile (9c), and a distal end (9b) defined with an extended portion (9d) to accommodate a bearing (11).
The proximal end (9a) of each of the pair of side gears (9) is defined with a stepped bore (9e) to accommodate a corresponding protrusion (7b) of the pair of protrusions of the spider (7) and the distal end (9b) of the pair of side gears (9) is defined with splined bore (9f) to receive an axle shaft (not shown in figure).

Referring to figure 14, which illustrates the differential assembly (1) in fully assembled view and flow of torque inside the differential assembly (1). The crown wheel (3) is configured to transfer the torque from the pinion (2) to the spider (8) through differential flange assembly (4). The differential flange assembly (4) retains the crown wheel (3) as well as spider (7) in their respective place and transfers the torque coming from the crown wheel (3) to the spider (7). The differential flange assembly (4) comprise the differential flange cover and differential flange case bolted together to hold the spider (7). As disclosed above, the spider (7) is designed to hold the plurality of differential pinions (8) and supports side gears (9) for axial thrust. The spider (7) transfers the torque coming from the differential flange assembly (4) to the plurality of differential pinions (8). The spider (7) is also subjected to the forces coming from the crown wheel (3), plurality of differential pinion (8) and side gear (9). The plurality of differential pinions (8) are used to transfer the power coming from spider (7) to side gears (9). All four differential pinions (8) are in mesh with the pair of side gears (9) simultaneously. The side gear (9) transmits the torque coming from the differential pinion (8) to the axle shaft. In the present arrangement, the side gears (9) also acts as a structural member which holds the entire differential assembly (1) at its position. The side gears (9) are subjected to the torque coming from the differential pinions (8). Further, they are also subjected to the radial and axial load coming from the crown wheel (3). Due to this additional torques, side gears (9) are designed to have more rigidity.

Thus, the present disclosure discloses a lightweight differential assembly where the differential case assembly is replaced to differential flange assembly and the spider is modified to hold the plurality of pinions along with the side gears. The differential assembly is compact having light weight with more rigidity.

It is to be understood that the configuration of the differential assembly illustrated in figures and configuration of mechanism are exemplary configurations. One skilled in the art may use a different mechanism and such variations may be made without departing from the scope of the present disclosure. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents. However, one should not consider such application as limitation to the present disclosure.

LIST OF REFERENCE NUMERALS

100 Conventional differential assembly
101 Crown wheel of conventional differential assembly
102 Differential case assembly of conventional differential assembly
103 Spider of conventional differential assembly
104 Pinions of conventional differential assembly
105 Side gears of conventional differential assembly
106 Roller bearings of conventional differential assembly
1 Differential assembly in accordance with present disclosure
2 Pinion
2a First end of Pinion
2b Second end of Pinion
3 Crown wheel
3a Outer surface of crown wheel
3b Inner surface (3b) of crown wheel
3c Plurality of gear teeth
3d Plurality of openings
4 Differential Flange assembly
5 Differential Flange Case
5a Outer surface of Differential flange case
5b Inner surface of Differential flange case
5c Plurality of openings
6 Differential flange cover
7 Spider
7a Plurality of legs
7b Pair of protrusions
8 Plurality of Differential Pinions
8a Opening of Differential Pinion
8b Plurality of Gears
9 Side Gears
9a Proximal end of side Gear
9b Distal end of side gear
9c Gear profile of side gear
9d Extended portion of side gear
9e Stepped Bore
9f Splined Bore
10 Fasteners
11 Bearing

Equivalents:
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

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.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.