Claims:STATEMENT OF CLAIMS
We claim,
1. A gear and shaft assembly 10 for a power transmission unit 100, said gear and shaft assembly 100 comprising:
a shaft 12 having an outer portion 12A defining a plurality of locking portions 12L provided at corresponding predetermined position, where each locking portion 12L extends along the lengthwise direction of said shaft 12; and
a plurality of gears 14 adapted to be mounted onto the outer portion 12A of said shaft 12 at corresponding predetermined position, where each of said gear 14 having an inner portion 14R defining a plurality of locking portions 14L corresponding to the plurality of locking portions 12L of the outer portion 12A of said shaft 12, and provided at corresponding predetermined position, where each locking portion 14L extends along the inner portion 14R in an axial direction of corresponding said gear 14,
wherein
the plurality of locking portions 14L of the inner portion 14R of each of said gear 14 are adapted to engage corresponding plurality of locking portions 12L of the outer portion 12A of said shaft 12 at corresponding predetermined position therein to restrict a relative movement between said shaft 12 and each of said gear 14 thereby locking each of said gear 14 onto said shaft 12 at corresponding predetermined position therein to enable rotation of said shaft 12 and each of said gear 14 at a same speed during the operation of said power transmission unit 100.
2. The gear and shaft assembly 10 as claimed in claim 1, wherein said shaft 12 is a countershaft.
3. The gear and shaft assembly 10 as claimed in claim 1, wherein said shaft 12 is a driving shaft.
4. The gear and shaft assembly 10 as claimed in claimed in claim 1, wherein each locking portion 12L of the outer portion 12A of said shaft 102 substantially defines a planar surface shape configuration, where each locking portion 12L is parallel to the other.
5. The gear and shaft assembly 10 as claimed in claim 1, wherein each of said gear 14 is a driving gear, where the inner portion 14R of each of said gear 14 is at least a shaft receiving portion adapted to receive corresponding portion of said shaft 12.
6. The gear and shaft assembly 10 as claimed in claim 5, wherein each locking portion 14L of the inner portion 14R of each of said gear 14 substantially defines a planar surface shape configuration, where each locking portion 14L is parallel and opposite to the other.
7. The gear and shaft assembly 10 as claimed in claim 1 is configured to be provided in said power transmission unit 100 of at least one of a vehicle and a machine.
8. A gear and shaft assembly 10 comprising:
a shaft 12 having an outer portion 12A defining a plurality of locking portions 12L provided at corresponding predetermined position, where each locking portion 12L extends along the lengthwise direction of said shaft 12; and
at least one gear 14 adapted to be mounted onto the outer portion 12A of said shaft 12 at corresponding predetermined position, where said gear 14 having an inner portion 14R defining a plurality of locking portions 14L corresponding to the plurality of locking portions 12L of the outer portion 12A of said shaft 12, and provided at corresponding predetermined position, where each locking portion 14L extends along the inner portion 14R in an axial direction of said gear 14,
wherein the plurality of locking portions 14L of the inner portion 14R of said gear 14 are adapted to engage corresponding plurality of locking portions 12L of the outer portion 12A of said shaft 12 at corresponding predetermined position therein to restrict a relative movement between said shaft 12 and said gear 14 thereby locking said gear 14 onto said shaft 12 at corresponding predetermined position therein to enable rotation of said shaft 12 and said gear 14 at a same speed.
9. The gear and shaft assembly 10 as claimed in claimed in claim 8, wherein each locking portion 12L of the outer portion 12A of said shaft 12 substantially defines a planar surface shape configuration, where each locking portion 12L is parallel to the other.
10. The gear and shaft assembly 10 as claimed in claim 8, wherein each locking portion 14L of the inner portion 14R of said gear 14 substantially defines a planar surface shape configuration, wherein each locking portion 14L is parallel and opposite to the other, where the inner portion 14R of said gear 14 is at least a shaft receiving portion adapted to receive corresponding portion of said shaft 12.
11. A method 200 for locking a plurality of gears 14 onto a shaft 12 in a power transmission unit 100, said method 200 comprising:
providing said shaft 12 with an outer portion 12A defining a plurality of locking portions 12L provided at corresponding predetermined position, where each locking portion 12L extends along the lengthwise direction of said shaft 12;
providing each of said gear 14 with an inner portion 14R defining a plurality of locking portions 14L corresponding to the plurality of locking portions 12L of the outer portion 12A of said shaft 12, and provided at corresponding predetermined position, where each locking portion 14L extends along the inner portion 14R in an axial direction of corresponding said gear 14; and
engaging the plurality of locking portions 14L of the inner portion 14R of each of said gear 14 with corresponding plurality of locking portions 12L of the outer portion 12A of said shaft 12 at corresponding predetermined position therein to restrict a relative movement between said shaft 12 and each of said gear 14 thereby locking each of said gear 14 onto said shaft 12 at corresponding predetermined position therein to enable rotation of said shaft 12 and each of said gear 14 at a same speed during the operation of said power transmission unit 100.
12. The method 200 as claimed in claim 11, wherein said shaft 12 is a countershaft.
13. The method 200 as claimed in claim 11, wherein said shaft 12 is a driving shaft.
14. The method 200 as claimed in claim 11, wherein each locking portion 12L of the outer portion 12A of said shaft 102 substantially defines a planar surface shape configuration, where each locking portion 12L is parallel to the other.
15. The method 200 as claimed in claim 11, wherein each of said gear 14 is a driving gear.
16. The method 200 as claimed in claim 15, wherein each locking portion 14L of the inner portion 14R of each of said gear 14 substantially defines a planar surface shape configuration, where each locking portion 14L is parallel and opposite to the other.
17. The method 200 as claimed in claim 11, wherein said power transmission unit 100 is configured to be provided in at least one of a vehicle and a machine.

Dated: 27th July 2017 Signature:
Somashekar Ramakrishna
, Description:TECHNICAL FIELD
[001] The embodiments herein generally relate to power transmission members such as shaft and gears, and more particularly, to a gear and shaft assembly, and a method for locking gears (can be considered as driving gears) onto a shaft (can be considered as a counter shaft and/or a driving shaft) in a power transmission unit of at least one of a vehicle, a machine (industrial machine) and the like, which restricts a relative movement between the gears and the shaft thereby locking the gears onto the shaft at corresponding predetermined position therein to enable rotation of the shaft and the gears mounted on the shaft at a same speed during the operation of power transmission unit.
BACKGROUND
[002] Power transmission members such as shaft and gears are used to transmit power from one component to another component. Gears and shaft are commonly used in power transmission unit of vehicles, industrial machines and the like. The primary requirement of a gear and shaft assembly is that the gears should be securely locked onto the shaft therein to enable rotation of the shaft and the gears mounted on the shaft at a same speed during the operation of power transmission unit. Conventional power transmission unit have driving gears press fitted to a driving shaft (can be considered as counter shaft) at corresponding predetermined position thereby facilitating secure mounting (locking) of the gears onto the shaft. However, if any one of the driving gear fails due to wear and tear, then the individual driving gear which is worn out cannot be easily serviced or replaced thereby requiring the complete gear and shaft assembly to be replaced which in turn incurs high cost for replacement. Some power transmission units have driving gears spline fitted to the driving shaft, where the driving gears have a plurality of internal splines, and the driving shaft have a plurality of external splines corresponding to the plurality of internal splines of the driving gear. In the aforementioned power transmission unit, the individual driving gear which is worn out can be serviced or replaced. However, the process of machining (producing) internal splines and external splines to the driving gears and driving shaft respectively incurs high manufacturing costs. Other power transmission units have driving gears integrated with the driving shaft (counter shaft) at corresponding predetermined position. However, the individual gear which is worn out cannot be serviced or replaced thereby requiring the complete shaft with integrated gears to be replaced which in turn incurs high cost for replacement. Another power transmission unit have driving gears key fitted to the driving shaft thereby allowing replacement of individual driving gear which fails due to wear and tear. However, the process of machining keyways and key seats to the driving gear and the driving shaft respectively incurs high manufacturing costs.
[003] Therefore, there exists a need for a gear and shaft assembly, and a method for locking a plurality of gears (driving gears) onto a shaft (countershaft/driving shaft) in a power transmission unit of at least one of a vehicle, a machine and the like, which obviates the aforementioned drawbacks. Further, there exists a need for a gear and shaft assembly, which obviates the aforementioned drawbacks.
OBJECTS
[004] The principal object of an embodiment of this invention is to provide a gear and shaft assembly for a power transmission unit of at least one of a vehicle, a machine (industrial machine) and the like, which restricts a relative movement between the gears (driving gears) and the shaft (countershaft/driving shaft) thereby locking the gears onto the shaft at corresponding predetermined position therein to enable rotation of the shaft and the gears mounted on the shaft at a same speed during the operation of power transmission unit.
[005] Another object of an embodiment of this invention is to provide a method for locking gears (driving gears) onto a shaft (countershaft/driving shaft) in a power transmission unit of at least one of a vehicle, a machine and the like, which restricts a relative movement between the gears and the shaft thereby locking the gears onto the shaft at corresponding predetermined position therein to enable rotation of the shaft and the gears mounted on the shaft at a same speed during the operation of power transmission unit.
[006] Another object of an embodiment of this invention is to provide a gear and shaft assembly for a power transmission unit of at least one of a vehicle, a machine and the like, where the gears (driving gears) are transition fitted to the shaft (counter shaft/ driving shaft) at corresponding predetermined position.
[007] Yet, another object of an embodiment of this invention is to provide a gear and shaft assembly for a power transmission unit of at least one of a vehicle, a machine and the like, which facilitates easy assembly of gears (driving gears) onto the shaft (counter shaft/ driving shaft) and dis-assembly of gears from the shaft.
[008] Still, another object of an embodiment of this invention is to provide a gear and shaft assembly for a power transmission unit of at least one of a vehicle, a machine and the like, which facilitates easier servicing and also enables easy replacement of individual gear (driving gear) that is worn out.
[009] A further object of an embodiment of this invention is to provide a gear and shaft assembly for a power transmission unit of at least one of a vehicle, an industrial machine and the like, which reduces the manufacturing cost and assembly cost, and also eliminates the tool cost.
[0010] 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
[0011] 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:
[0012] FIG. 1 depicts an exploded view of a gear and shaft assembly for a power transmission unit, according to an embodiment of the invention as disclosed herein;
[0013] FIG. 2 depicts a perspective view of the gear and shaft assembly, according to an embodiment of the invention as disclosed herein;
[0014] FIG. 3 depicts a cross sectional view of the gear and shaft assembly, according to an embodiment of the invention as disclosed herein;
[0015] FIG. 4 depicts a cross sectional view of the power transmission unit, according to an embodiment of the invention as disclosed herein;
[0016] FIG. 5 depicts a perspective view of a shaft of the gear and shaft assembly, according to an embodiment of the invention as disclosed herein;
[0017] FIG. 6 depicts a side view of a gear of the gear and shaft assembly, according to an embodiment of the invention as disclosed herein; and
[0018] FIG. 7 depicts a flowchart showing the steps of a method for locking gears onto a shaft in a power transmission unit, according to an embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
[0019] 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.
[0020] The embodiments herein achieve a gear and shaft assembly, and a method for locking gears (driving gears) onto a shaft (countershaft/driving shaft) in a power transmission unit of at least one of a vehicle, a machine and the like, which restricts a relative movement between the gears and the shaft thereby locking the gears onto the shaft at corresponding predetermined position therein to enable rotation of the shaft and the gears mounted on the shaft at a same speed during the operation of power transmission unit. Referring now to the drawings and more particularly to FIGS. 1 through 7, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0021] FIG. 1 depicts an exploded view of a gear and shaft assembly 10 for a power transmission unit 100, according to an embodiment of the invention as disclosed herein. In an embodiment, the power transmission unit 100 includes a gear and shaft assembly 10 (as shown in fig. 1 to fig. 4) and may include other standard components as present in a standard power transmission unit. In an embodiment, the gear and shaft assembly 10 includes a shaft 12 (as shown in fig. 1, fig. 2, fig. 3 and fig. 5) and a plurality of gears 14 (as shown in fig. 1, fig. 2, fig. 3 and fig. 6). For the purpose of this description and ease of understanding, the gear and shaft assembly 10 is explained herein below with reference to be provided in a power transmission unit 100 of a vehicle. However, it is also within the scope of the invention to provide the gear and shaft assembly 10 in any other systems/machines using power transmission unit or wind turbines or generators or turbines or any other machines/systems using rotary shafts and gears.
[0022] FIG. 5 depicts a perspective view of a shaft 12 of the gear and shaft assembly 10, according to an embodiment of the invention as disclosed herein. In an embodiment, the shaft 12 includes an outer portion 12A (as shown in fig. 1 and fig. 5), a portion 12G (as shown in fig. 1 and fig. 5) and an intermediate gear 12I (as shown in fig. 5). The outer portion 12A defines one portion of the shaft 12 and the portion 12G defines another portion of the shaft 12. The intermediate gear 12I is integrated with the shaft 12 between the outer portion 12A and the portion 12G of the shaft 12. In an embodiment, the outer portion 12A of the shaft 12 defines a plurality of locking portions 12L (as shown in fig. 1 and fig. 5) provided at corresponding predetermined position, where each locking portion 12L extends along the lengthwise direction of the shaft 12. In an embodiment, each locking portion 12L of the outer portion 12A of the shaft 102 substantially defines a planar surface shape configuration, where each locking portion 12L is parallel to the other. In an embodiment, the shaft 12 is a counter shaft. In another embodiment the shaft 12 is a driving shaft 12. It is also within the scope of the invention to provide any other type of shaft (input shaft or output shaft or any shaft) with the plurality of locking portions 12L as mentioned above.
[0023] FIG. 6 depicts a side view of a gear 14 of the gear and shaft assembly 10, according to an embodiment of the invention as disclosed herein. In an embodiment, each gear 14 includes an inner portion 14R (as shown in fig. 1) defining a plurality of locking portions 14L (as shown in fig. 1 and fig. 6) corresponding to the plurality of locking portions 12L of the outer portion 12A of the shaft 12, and provided at corresponding predetermined position, where each locking portion 14L extends along the inner portion 14R in an axial direction of corresponding gear 14. In an embodiment, each locking portion 14L of the inner portion 14R of each gear 14 substantially defines a planar surface shape configuration, where each locking portion 14L is parallel and opposite to the other. In an embodiment, each gear 14 is a driving gear. It is also within the scope of the invention to provide any other type of gear (range gear or driven gear or any gear) with the plurality of locking portions 14L as mentioned above. In an embodiment, the plurality of locking portions 14L of the inner portion 14R of each gear 14 are adapted to engage corresponding plurality of locking portions 12L of the outer portion 12A of the shaft 12 at corresponding predetermined position therein to restrict a relative movement between the shaft 12 and each gear 14 thereby locking each gear 14 onto the shaft 12 at corresponding predetermined position therein to enable rotation of shaft 12 and each gear 14 at a same speed during the operation of power transmission unit 100.
[0024] FIG. 7 depicts a flowchart showing the steps of a method 200 for locking gears 14 onto a shaft 12 in a power transmission unit 100 of a vehicle, according to an embodiment of the invention as disclosed herein. In an embodiment, the method 200 for locking gears 14 onto the shaft 12 in the power transmission unit 100 is as follows, the method 200 comprising, providing the shaft 12 with an outer portion 12A defining a plurality of locking portions 12L provided at corresponding predetermined position, where each locking portion 12L extends along the lengthwise direction of the shaft 12 (step 202); providing each gear 14 with an inner portion 14R defining a plurality of locking portions 14L corresponding to the plurality of locking portions 12L of the outer portion 12A of the shaft 12, and provided at corresponding predetermined position, where each locking portion 14L extends along the inner portion 14R in an axial direction of corresponding gear 14 (step 204); and engaging the plurality of locking portions 14L of the inner portion 14R of each gear 14 with corresponding plurality of locking portions 12L of the outer portion 12A of the shaft 12 at corresponding predetermined position therein to restrict a relative movement between the shaft 12 and each gear 14 thereby locking each gear 14 onto the shaft 12 at corresponding predetermined position therein to enable rotation of the shaft 12 and each gear 14 at a same speed during the operation of power transmission unit 100 (step 206).
[0025] 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.