DESC:CROSS-REFERENCE TO RELATED APPLICATIONS
[001] This application is based on and derives the benefit of Indian Provisional Application 201741011881, the contents of which are incorporated herein by reference.
TECHNICAL FIELD
[002] The embodiments herein relate to a tool and a method for aligning a sun gear shaft to assemble a planetary gear assembly and a rear axle carrier assembly with a rear power transmission assembly of a vehicle.

BACKGROUND
[003] To assemble a planetary gear assembly and a rear axle carrier assembly with a rear power transmission assembly of a tractor, a plurality of planet gears of the planetary gear assembly must be in an exact location in order to properly engage with a sun gear and a ring gear.
[004] The assembly of rear axle carrier assembly with the rear power transmission assembly is difficult and takes a lot of time, as one end of a sun gear shaft is slightly bend which in turn leads to mis-alignment of the planet gears with respect to the sun gear and the ring gear, and also the fastening of the ring gear and a rear axle carrier with a transmission rear housing is problematic. During the assembly, the sun gear shaft gets displaced and a last brake liner comes out of splines and hence develop bend, thus resulting in loss of primary function.
[005] The conventional process of assembling the planetary gear assembly and the rear axle carrier assembly to the rear power transmission assembly is difficult and is one of the challenges posed to original equipment manufacturers (OEM). Further, the conventional processes for assembling the planetary gear assembly and the rear axle carrier assembly to the rear power transmission assembly are tedious, difficult, and time consuming.
[006] Therefore, there exists a need for a tool and a method for aligning a sun gear shaft to assemble a planetary gear assembly and a rear axle carrier assembly with a rear power transmission assembly of a vehicle. Further, there exists a need for a tool, which obviates the aforementioned drawbacks.

OBJECTS

[007] The principal object of an embodiment of this invention is to provide a tool for aligning a sun gear shaft to assemble a planetary gear assembly and a rear axle carrier assembly with a rear power transmission assembly of a vehicle.
[008] Another object of an embodiment of this invention is to provide a method for aligning a sun gear shaft to assemble a planetary gear assembly and a rear axle carrier assembly with a rear power transmission assembly of a vehicle.
[009] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF DRAWINGS
[0010] The embodiments of the invention are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0011] FIG. 1 depicts a perspective view of a tool for aligning a sun gear shaft to assemble a planetary gear assembly and a rear axle carrier assembly with a rear power transmission assembly of a vehicle, according to an embodiment of the invention as disclosed herein;
[0012] FIG. 2 depicts another perspective view of the tool, according to an embodiment of the invention as disclosed herein;
[0013] FIG. 3 depicts a photographic view of a first member of the tool being engaged with a transmission rear housing to align the sun gear shaft, according to an embodiment of the invention as disclosed herein;
[0014] FIG. 4 depicts a photographic view of the tool, the transmission rear housing and a linkage element, where one end of the linkage element is engaged with a brake lever of a brake unit and another end of the linkage element is locked with the transmission rear housing, according to an embodiment of the invention as disclosed herein;
[0015] FIG. 5 depicts a cross-sectional view of the planetary gear assembly, the rear axle carrier assembly and the rear power transmission assembly in assembled condition, according to an embodiment of the invention as disclosed herein; and
[0016] FIG. 6 depicts a flowchart showing the steps of a method for aligning a sun gear shaft to assemble a rear axle carrier assembly and a planetary gear assembly with a rear power transmission assembly of a vehicle.

DETAILED DESCRIPTION
[0017] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following 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.
[0018] The embodiments herein achieve a tool and a method for aligning a sun gear shaft to assemble a rear axle carrier assembly and a planetary gear assembly with a rear power transmission assembly of a vehicle. Referring now to the drawings, and more particularly to FIGS. 1 through 6, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0019] FIG. 1 depicts a perspective view of a tool 100 for aligning a sun gear shaft 20S to assemble a planetary gear assembly 40 and a rear axle carrier assembly 30 with a rear power transmission assembly 20 of a vehicle, according to an embodiment of the invention as disclosed herein. FIG. 2 depicts another perspective view of the tool 100, according to an embodiment of the invention as disclosed herein. In general, the vehicle includes a rear power transmission assembly 20 (as shown in fig. 5), arear axle carrier assembly 30, a planetary gear assembly 40 (as shown in fig. 5), a brake unit BR (as shown in fig. 5) and may include other standard components, mechanism s and systems as present in a standard vehicle. The rear power transmission assembly 20 includes a transmission rear housing 20H (a shown in fig. 3 to fig. 5), a sun gear shaft 20S (as shown in fig. 5), a differential gear assembly (not shown) and may include other standard components as present in a standard rear power transmission assembly. One end of the sun gear shaft 20S is connected to the differential gear assembly and the other end of the sun gear shaft 20S is rotatably connected to the planetary gear assembly 40. A sun gear 20G is provided on the sun gear shaft 20S. In one embodiment, the sun gear 20G is integrated with the sun gear shaft 20S. In another embodiment, the sun gear 20G is a separate part provided on the sun gear shaft 20S. The rear axle carrier assembly 30 includes a rear axle carrier 30C (as shown in fig.5), a rear drive axle 30A (as shown in fig. 5) and may include other standard components as present in a standard rear axle carrier assembly. The planetary gear assembly 40 includes a plurality of planet gear 40P (only one of which is shown in fig. 5), a planet gear carrier 40C and may include other standard components as present in a standard planetary gear assembly. The ring gear RG is disposed between the transmission rear housing 20H of the rear power transmission assembly 20 and the rear axle carrier 30C of the rear axle carrier assembly 30. The ring gear RG is rotatably connected to the plurality of planet gears 40P of the planetary gear assembly 40. The planetary gear assembly 40 is preassembled with the rear axle carrier assembly 30. The brake unit BR (as shown in fig. 5) is connected to the sun gear shaft 20S of the rear power transmission assembly 20. In an embodiment, the tool 100 includes a first member 102, a second member 104 and a handle 106. For the purpose of this description and ease of understanding, the tool 100 is explained herein below with reference for aligning the sun gear shaft 20S of the rear power transmission assembly 20 to assemble the rear axle carrier assembly 30 and the planetary gear assembly 40 with the rear power transmission assembly 20 of an agricultural vehicle such as tractor. However, it is also within the scope of the invention to implement/practice the tool 100 for aligning the sun gear shaft for assembling the rear axle carrier assembly and the planetary gear assembly with the rear power transmission assembly of at least one of an off-road vehicle, an agricultural harvester, a constructional vehicle, tractor mounted combine harvester, any other type of vehicle and any other power transmission systems without otherwise deterring the intended function of the tool 100 as can be deduced from the description and corresponding drawings.
[0020] The first member 102 of the tool 100 is engaged with the transmission rear housing 20ZH in which an outer portion of the first member 102 is engaged with a spigot inner diametrical portion of the transmission rear housing 20H to align the sun gear shaft 20. The first member 102 is at least a ring member.
[0021] The second member 104 is connected to the first member 102. In one embodiment, the second member 104 defines a sun shaft receiving portion 104s (as shown in fig. 2) adapted to receive corresponding portion of the sun gear shaft 20S to align the sun gear shaft 20. In another embodiment, the second member 104 defines a protrusion provided thereon to engage corresponding cavity of the sun gear shaft 20S to align the sun gear shaft 20S, where the protrusion defined by the second member 104 is a conical protrusion. It is also within the scope of the invention to provide the second member 104 with protrusion in any other shape. In one embodiment, the protrusion provided on the second member 104 is an integral portion of the second member 104. In another embodiment, the protrusion provided on the second member 104 is a separate part. The second member 102 is at least a vertical member.
[0022] The handle 106 is transversely connected to the second member 104. The handle 106 is engaged by an operator to engage the tool 100 with the transmission rear housing 20H and the sun gear shaft 20S.
[0023] The first member 102 and the second member 104 are adapted to be engaged with the transmission rear housing 20H and the sun gear shaft 20S respectively to align the sun gear shaft 20S in which a center axis of the sun gear shaft 20S is aligned with respect to a center axis of the transmission rear housing 20H. Maintaining the sun gear shaft 20S at a fixed position by actuating the brake unit BR connected to the sun gear shaft 20S. The brake unit BR is actuated by pulling a brake lever BRL (as shown in fig. 4) of the brake unit BR through a linkage element L (as shown in fig. 4), wherein the brake unit BR is maintained in an actuated position by securing the linkage element L with the transmission rear housing 20H.
[0024] The first member 102 and the second member 104 are dis-engaged from the transmission rear housing 20H and the sun gear shaft 20S respectively to facilitate assembly of the rear axle carrier assembly 30 and the planetary gear assembly 40 with the rear power transmission assembly 20 by engaging the plurality of planet gears 40P with the ring gear RG and the sun gear 20G, and securing the ring gear RG and the rear axle carrier 30C to the transmission rear housing 20H.
[0025] FIG. 6 depicts a flowchart showing the steps of a method 200 for aligning a sun gear shaft 20S to assemble a rear axle carrier assembly 30 and a planetary gear assembly 40 with a rear power transmission assembly 20 of a vehicle. In an embodiment, method 200 for aligning the sun gear shaft 20S to assemble the rear axle carrier assembly 30 and the planetary gear assembly 40 with the rear power transmission assembly 20 is as follows. The method 200 comprising, aligning the sun gear shaft 20S, in which a center axis of the sun gear shaft 20S is aligned with respect to a center axis of a transmission rear housing 20H by engaging a tool 100 with the transmission rear housing 20H and the sun gear shaft 20S (step 202); maintaining the sun gear shaft 20S at a fixed position by actuating a brake unit BR connected to the sun gear shaft 20S (step 204); dis-engaging the tool 100 from the transmission rear housing 20H and the sun gear shaft 20S (step 206); assembling the rear axle carrier assembly 30 and the planetary gear assembly 40 with the rear power transmission assembly 20 by engaging a plurality of planet gears 40P with a ring gear RG and a sun gear 20G, and securing the ring gear RG and a rear axle carrier 30C to the transmission rear housing 20H (step 208). The method 200 includes, engaging the ring gear RG with the transmission rear housing 20H (step 207) prior to the method step (208) of said assembling the rear axle carrier assembly 30 and the planetary gear assembly 40 with the rear power transmission assembly 20. The method 200 includes pulling a brake lever BRL of the brake unit BR through a linkage element L for actuation of the brake unit BR and maintaining the brake unit BR in an actuated position by securing the linkage element L with the transmission rear housing 20H. The method step (202) of said aligning the sun gear shaft 20S by engaging the tool 100 with the transmission rear housing 20H and the sun gear shaft 20S occurs by engaging a first member 102 of the tool 100 with the transmission rear housing 20H, and a second member 104 of the tool 100 with the sun gear shaft 20S.
[0026] Therefore, a tool 100 and a method 200 for aligning a sun gear shaft 20S to assemble a rear axle carrier assembly 30 and a planetary gear assembly 40 with a rear power transmission assembly 20 of a vehicle is provided.
[0027] 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 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. ,CLAIMS:STATEMENT OF CLAIMS
We claim,
1. A tool 100 for aligning a sun gear shaft 20S to assemble a rear axle carrier assembly 30 and a planetary gear assembly 40 with a rear power transmission assembly 20 of a vehicle, said tool 100 comprising:
a first member 102; and
a second member 104 adapted to be connected to said first member 102,
wherein
said first member 102 and said second member 104 are adapted to be engaged with a transmission rear housing 20H and the sun gear shaft 20S respectively to align the sun gear shaft 20S in which a center axis of the sun gear shaft 20S is aligned with respect to a center axis of the transmission rear housing 20H;
maintaining the sun gear shaft 20S at a fixed position by actuating a brake unit BR connected to the sun gear shaft 20S; and
said first member 102 and said second member 104 are dis-engaged from the transmission rear housing 20H and the sun gear shaft 20S respectively to facilitate assembly of the rear axle carrier assembly 30 and the planetary gear assembly 40 with the rear power transmission assembly 20 by engaging a plurality of planet gears 40P with a ring gear RG and a sun gear 20G, and securing the ring gear RG and a rear axle carrier 30C to the transmission rear housing 20H.
2. The tool 100 as claimed in claim 1 comprises a handle 106 adapted to be connected to said second member 104.

3. The tool 100 as claimed in claim 2, wherein the brake unit BR is actuated by pulling a brake lever BRL of the brake unit BR through a linkage element L,
wherein
the brake unit BR is maintained in an actuated position by securing the linkage element L with the transmission rear housing 20H.

4. The tool 100 as claimed in claim 3, wherein said second member 104 defines a sun shaft receiving portion 104s adapted to receive corresponding portion of the sun gear shaft 20S to align the sun gear shaft 20.

5. The tool 100 as claimed in claim 3, wherein said second member 104 defines a protrusion adapted to engage corresponding cavity of the sun gear shaft 20S to align the sun gear shaft 20S.

6. The tool 100 as claimed in claim 5, wherein said first member 102 is at least a ring member.

7. The tool 100 as claimed in claim 6, wherein said second member 102 is at least a vertical member.

8. A method 200 for aligning a sun gear shaft 20S to assemble a rear axle carrier assembly 30 and a planetary gear assembly 40 with a rear power transmission assembly 20 of a vehicle, said method 200 comprising:
aligning the sun gear shaft 20S, in which a center axis of the sun gear shaft 20S is aligned with respect to a center axis of a transmission rear housing 20H by engaging a tool 100 with the transmission rear housing 20H and the sun gear shaft 20S;
maintaining the sun gear shaft 20S at a fixed position by actuating a brake unit BR connected to the sun gear shaft 20S;
dis-engaging the tool 100 from the transmission rear housing 20H and the sun gear shaft 20S; and
assembling the rear axle carrier assembly 30 and the planetary gear assembly 40 with the rear power transmission assembly 20 by engaging a plurality of planet gears 40P with a ring gear RG and a sun gear 20G, and securing the ring gear RG and a rear axle carrier 30C to the transmission rear housing 20H.

9. The method 200 as claimed in claim 8 comprises, engaging the ring gear RG with the transmission rear housing 20H prior to the method step of said assembling the rear axle carrier assembly 30 and the planetary gear assembly 40 with the rear power transmission assembly 20.

10. The method 200 as claimed in claim 9 comprises, pulling a brake lever BRL of the brake unit BR through a linkage element L for actuation of the brake unit BR and maintaining the brake unit BR in an actuated position by securing the linkage element L with the transmission rear housing 20H.

11. The method 200 as claimed in claim 8, wherein said aligning the sun gear shaft 20S by engaging the tool 100 with the transmission rear housing 20H and the sun gear shaft 20S occurs by engaging a first member 102 of the tool 100 with the transmission rear housing 20H, and a second member 104 of the tool 100 with the sun gear shaft 20S.