FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10 and Rule 13]
“A COUPLING ASSEMBLY FOR A PROPELLER SHAFT”
Name and Address of the Applicant:
TATA MOTORS LIMITED an Indian company having its registered office at Bombay house, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001, Maharashtra, INDIA,
Nationality: India
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
Present disclosure in general relates to a field of transmission unit and drive shaft of vehicles. The transmission unit and the drive shaft transmits torque from an engine to wheels of the vehicle. More particularly, the disclosure relates to a coupling assembly for the propeller shaft to prevent damage during excessive application of torsional and shear loads on a drive train.
BACKGROUND OF THE DISCLOSURE
Transmission system is one of the essential systems in an automobile by means of which power developed by an engine is transmitted to wheels to propel the vehicle. The engine is connected to the transmission system for reducing and regulating power transmitted to the wheels. The transmission system or gear box is connected to a propeller shaft to transmit engine power to a rear drive unit. One end of the propeller shaft is connected to an output shaft of the gear box by a universal joint and other end is connected to the rear drive unit which is also known as a differential. The differential is configured to transmit the power coming from the engine through the drive shaft through the rear wheels to propel the vehicle. The power is transmitted from differential to wheels through individual drive shafts which are connected to the rear wheels.
However, during transmission of the engine power or torque to the rear wheels, the powertrain is subjected to the torsional stress and shear stress, which may cause failure of driveline components in the drive train. Failure of the driveline components mainly occurs due to the low strength and due to prolonged use or may occur if the torsional and shear loads are more than the design limits or factor of safety considered for drive line components. Further, any break down or failure in the drive line components will cut the power flow from engine to the drive wheels. Probable reasons of failures are high torque level which are more than design permissible limits. Due to these high torque level, torque transients are experienced by driveline, which further leads to failure of different components like propeller shafts, drive shaft, differential gears and assemblies. During design of any components factor of safety is considered as critical part. However, on many occasions, the resulting factor for failure such as torque or shear stress is greater than the factor of safety of the components used. Hence, the components tend to fail in such circumstances.

Hence, present disclosure is directed to solve one or more limitations stated above or any other limitations associated with the prior art.
SUMMARY OF THE DISCLOSURE
The one or more shortcomings of the prior art are overcome by a coupling assembly as claimed and additional advantages are provided through the provisions as claimed in the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein.
Present disclosure discloses a coupling assembly for a propeller shaft, the coupling assembly comprises a first flange defined with a first provision to receive a propeller shaft in a driveline. A second flange is positioned in line and opposite to the first flange and is co-axially connectable to the first flange, wherein the second flange is defined with a second provision. Both the first flange and the second flange are connected with each other with the help of a damping member. The first flange, the second flange and the damping member are defined with a fatigue strength lower than the fatigue strength of the drive line components.
In an embodiment, the first flange comprises at least one projection extending radially from a first surface of the first flange.
In an embodiment, the second flange is defined with a recess on a second surface to receive the at least one projection.
In an embodiment, the damping member is defined with a matching surface profile corresponding to the first surface and the second surface to be in flush with the first flange and the second flange.
In an embodiment, the, the first flange, damping member and the second flange are designed with a lower factor of safety than the factor of safety of the drive line components.
In an embodiment, the first flange, the damping member and the second flange are provided around the propeller shaft and the drive line components to transfer torque from an engine of the vehicle

In an embodiment, the first flange, the damping member and the second flange are configured to absorb the torsional and shock loads subjected on the propeller shaft and the drive train components
In an embodiment, the first flange, the damping member, and the second flange are configured to fracture before the fracture of the propeller shaft and the drive line components.
In an embodiment, the driveline components are at least one of a drive axle, a drive shaft, a propeller shaft, a differential or a support beam of a vehicle which is subjected to torsional and shear loads.
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.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features and characteristics of the disclosure are explained herein. The embodiments of 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 drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawing in which:
Fig. 1a illustrates an exploded view of a coupling assembly in accordance with an embodiment of the present disclosure.
Fig. 1b illustrates a perspective view of the coupling assembly in accordance with an embodiment of the present disclosure.
Fig. 2a illustrates a sectional front view of the coupling assembly fixed on a propeller shaft in accordance with an embodiment of the present disclosure.
Fig. 2b illustrates a front view of the coupling assembly fixed on the propeller shaft in accordance with an embodiment of the present disclosure.

Figs. 3a and 3b illustrates a sectional front view and a front view of the coupling assembly in accordance with an embodiment of the present disclosure.
Fig. 4 illustrates a top view of a drive train assembly of an automobile depicting the arrangement of the coupling assembly to the propeller shaft in accordance with an 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
In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure.
The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or process 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 process. 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.

The present disclosure relates to a coupling assembly for a propeller shaft. Generally, engine power is transmitted to wheels of an automobile/vehicle though a driveline assembly. The driveline includes the propeller shaft connected to the differential which further transmits the engine power or torque to the wheels through axles. During this torque transmission, the propeller shafts are subjected to the torsional stress and shear stress, which on some occasions exceeds a predefined limit and thus causes failure of driveline components. Such shearing/failures of the driveline components will cut the power flow from engine to the drive wheels which will render the vehicle immobile which is not desirable. In view of this, the present disclosure discloses a coupling assembly mounted on the propeller shaft to resist the torsional and shear stress subjected on the driveline.
The following paragraphs describe the present disclosure with reference to Figures. 1a to 3. In the figures, the same element or elements which have similar functions are indicated by the same reference signs.
Referring to Fig. 1 which illustrates an exploded view of a coupling assembly (100). The coupling assembly (100) comprises a first flange (2), a second flange (6) and a damping member (8) disposed in between the first flange (2) and the second flange (6) to couple both the first and second flanges (2, 6). The first flange (2) is defined with a first provision (3) to receive a propeller shaft (4). The first flange (2) is defined in a circular shape, but this may not be considered as a limitation and the first flange (2) may be configured in a rectangular, squared, polygonal shape or any other geometrical shape that serves purpose. The first provision (3) may be defined centrally on the first flange (2) and is structured corresponding to a shape of the propeller shaft (4). In an embodiment, the first flange (2) may be defined in a split configuration having at least one hole (14) to receive a fastener (16) or in an alternative configuration, the fastening holes may be provided on one of the flange surfaces. The first flange (2) is configured to rigidly couple to the propeller shaft (4) by introducing the fastener (16) through the at least one hole (14). In an embodiment, a diameter of the first provision (3) may be adjusted by adjusting the fastener (16) within the at least one hole (14) based on the requirement such that the first flange (2) may be coupled to the of the propeller shafts (4) of different diameters. In another embodiment, the second flange (6) may be structured identical to the first flange (2) in a circular configuration, and this cannot be considered as a

limitation and the second flange (6) may be defined in any suitable shape. The second flange (6) is defined with a second provision (5) to receive the propeller shaft (4). The second flange (6) may include the least one hole to receive the fastener (16) such that the second flange (6) is rigidly coupled to the propeller shaft (4). The first flange (2) is defined with at least one projection (10) which extends radially from a first surface (11) of the first flange (2). The second flange (6) is defined with a recess (12) to receive the at least one projection (10) of the first flange (2). In an embodiment, the at least one projection (10) and the at least one recess (12) may be interchangeably defined on the second flange (6) and the first flange (2) respectively.
A damping member (8) may also be defined with at least one recess (12) on one side and with at least one projection (10) on its other side. In an embodiment, the damping member (8) is designed with a matching profile to that of the first surface (11) and the second surface (15), such that the first flange (2), the second flange (6) and the damping member (8) are in flush with each other to form the coupling assembly (100) as shown in figs. 2a & 2b. In an embodiment, the first flange (2) and the second flange (6) may be manufactured of a stainless steel and its alloys. However, this cannot be considered as a limitation and the first and second flanges (2, 6) may be manufactured of high strength materials such as cast iron, brass etc. In an embodiment, a plurality of through holes may be defined on a circumferential surface of the first and second flanges (2, 6) running through the damping member (8) along an axis A-A to receive the fasteners (16). The coupling assembly (100) is coupled to the drive shaft (4) by passing the fasteners (16) through the plurality of through holes. The first flange (2), the damping member (8) and the second flange (6) of the coupling assembly (100) may be defined with a fatigue strength lower than the fatigue strength which is generally considered for driveline components. In an embodiment the driveline components may be any one of a drive axle, a drive shaft, the propeller shaft, a differential or a support beam of a vehicle which is subjected to torsional and shear loads.
Now referring to Fig. 3, a drive train arrangement (200) is disclosed depicting the mounting of the coupling assembly (100) to the propeller shafts (4). The coupling assembly (100) is mounted on the propeller shaft (4) attached to the engine as well to the axles [rear axles] which are driven by a rear drive vehicle. The propeller shaft (4) is coupled to an engine to transmit power and torque from the engine to the wheels of the vehicle. The rear drive may be a differential (35) which distributes the torque equally to the rear wheels through two separate drive shafts (4). The rear

axle may include two drive shafts to transmit the torque to the rear wheels. The propeller shaft (4) may be subjected to torsional, and shear loads during the power transmission. The coupling assembly (100) is mounted on the propeller shaft (4) to reduce the torsional and shear loads on the propeller shaft (4) and prevents failure of the driveline components. In an embodiment, the coupling assembly (100) is designed with lesser factor of safety as that considered for driveline components, such that the coupling assembly (100) will fail first before any driveline components. In other words, the first flange (2), the damping member (8) and the second flange (6) will be subjected to failure before the driveline components. In an embodiment, the first flange (2) may be subjected to failure if the power transmission takes place in a forward direction i.e., to say when the vehicle is in moving forward. Whereas the second flange (6) is subjected to failure during the power transmission which takes place when the vehicle is moving in reverse direction.
In an embodiment, the coupling assembly (100) is defined with a predetermined mass which may be varied based on the requirement and magnitude of the torsional and shear stress induced on the propeller shaft (4).
In an embodiment, the coupling assembly (100) may be manufactured using low strength steel, aluminium alloy and the like.
In an embodiment, the coupling assembly (100) may be easily replaced by dissembling the coupling assembly in an event of the torsional and shear loads which may be generated near to the design limits of the first and second flanges (2, 6) as well as the propeller shafts (4). Advantageously, this enables easy maintenance of the coupling assembly (100).
During transient events the coupling assembly (100) fails before any driveline components and avoid the torsional and shear loads subjected on propeller shaft (4) and prevents failure of drive line components advantageously, this reduces cost of maintenance of repair and replacement of the entire coupling assembly (100) by mitigating the failure of the propeller shaft (4) and driveline aggregates.
It is to be understood that a person of ordinary skill in the art may develop a structure of similar configuration without deviating from the scope of the present disclosure. Such modifications and variations may be made without departing from the scope of the present invention. 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. Further, various embodiments of the present disclosure can be combined or used in combination with each other without departing from the scope of the disclosure to provide damper assembly (100) with improved functionality.
Equivalents:
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations.
In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction

is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
REFERENCE NUMERALS:

Coupling Assembly 100
Drive train arrangement 200
First flange 2
First provision 3
Propeller shaft 4
Second Provision 5
Second flange 6
Damping member 8
At least one projection 10
First surface 11

At least one recess 12
At least one hole 14
Second surface 15
Fastener 16
Differential 35 5

We claim:
1. A coupling assembly (100) for a propeller shaft, the coupling assembly (100) comprises:
a first flange (2) defined with a first provision (3) to receive the propeller shaft (4) in a driveline;
a second flange (6) positioned in line and opposite to the first flange (2) and co-axially connectable to the first flange (2), wherein the second flange (6) is defined with a second provision (5);
wherein the first flange (2) and the second flange (6) are connectable with each other by a damping member (8), the damping member (8) is disposed between the first flange (1) and the second flange (6); and
wherein the first flange, the second flange and the damping member (8) are
defined with a fatigue strength lower than the fatigue strength of the fatigue strength
of the driveline components.
2. The coupling assembly (100) as claimed in claim 1, wherein the first flange (2) comprises at least one projection (10) extending radially from a first surface (11) of the first flange (2).
3. The coupling assembly (100) as claimed in claim 1, wherein the second flange (6) is defined with a recess (12) on a second surface (15) to receive the at least one projection (10).

4. The coupling assembly (100) as claimed in claim 1, wherein the damping member (8) is defined with a matching surface profile corresponding to the first surface (11) and the second surface (15) to be in flush with the first flange (2) and second flange (6).
5. The coupling assembly (100) as claimed in claim 1, wherein the first flange (2), the damping member and the second flange (6) are designed with a lower factor of safety than the factor of safety of the driveline components (200).

6. The coupling assembly (100) as claimed in claim 1, wherein the first flange (2), the
damping member and the second flange (6) are provided around the propeller shaft and the
drive line components to transfer torque from an engine of the vehicle.
7. The coupling assembly (100) as claimed in claim 1, wherein the first flange (2), the damping member (8) and the second flange (6) are configured to absorb the torsional and shock loads subjected on the propeller shaft (4) and the driveline components.
8. The coupling assembly (100) as claimed in claim 1, wherein the first flange (2), the damping member (8) and the second flange (6) are configured to fracture before fracture of the propeller shaft (4) and the drive line components.
9. The coupling assembly (100) as claimed in claim 1, wherein the driveline components are at least one of a drive axle, a drive shaft, differential, a propeller shaft or a support beam of a vehicle which is subjected to torsional and shear loads.