FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
AND
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
“METHOD OF FAILURE PREDICTION OF SYNCHROPACK
ARRANGEMENT”
We, AVTEC Limited, an Indian National of Pithampur Industrial Area, Sector III, Pithampur, Sagore – 454774, Dhar, Madhya Pradesh, India.
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
The present disclosure generally relates to a method of prediction of failure life of a manual transmission system. More particularly, the present disclosure relates to the method employed on a finite element analysis (FEA) simulation tool for prediction of failure life of a synchropack arrangement of the manual transmission system.
BACKGROUND
Transmission systems are commonly known in automobile industry, for transmitting power and concurrently enable incrementing/ reduction of torque/ speed. A manual transmission system employs an output shaft, a number of output gears rotatably mounted on the output shaft, and a number of synchropack arrangements for selectively engaging one of the number of output gears to the output shaft for enabling transfer of power (torque and speed) of the selected output gear to the output shaft. A structure and arrangement of the manual transmission system is commonly known. For ease in reference and understanding, concepts of the disclosure will be discussed in light of a singular output gear (hereinafter referred to as a gear) mounted on the output shaft, and a singular synchropack arrangement (hereinafter referred to as a synchropack arrangement) provided for engagement/ disengagement of the output gear to the output shaft. However, it may be obvious to a person skilled in the art that the concepts of the disclosure may also apply to other output gears and other synchropack arrangement of the manual transmission system. Furthermore, the manual transmission systems may be either of needle bearing supported output gears or an oil lubrication film supported output gears.
In the manual transmission systems with oil lubrication film supported output gear, the output gears are rotatably mounted on the output shaft, separated via the oil lubrication film. The synchropack arrangements are fixedly engaged with the output shaft. It may be noted that generally, one synchropack arrangement is installed between two output gears supported on the output shaft, to be

connected to one of the two output gears. Further, the synchropack arrangement is positioned between two output gears supported on the output shaft, such that a sleeve of the synchropack arrangement can be moved axially, to engage/disengage with one of the two output gears, to facilitate engagement/ disengagement of the output gear to the output shaft.
The synchropack arrangement includes a hub, a synchro cone, three (3) inserts, two (2) synchro rings, and a sleeve. The hub, the synchro cone, the three (3) inserts, the two (2) synchro rings, and the sleeve are arranged with each other, to form the synchropack arrangement. Notably, the hub, the synchro cone, the three (3) inserts, the sleeve, and one synchro ring (positioned on one side of the hub), are used in combination, for engagement/ disengagement of the output shaft to one output gear positioned on one side of the hub. Moreover, the hub the synchro cone, the three (3) inserts, the sleeve, and other synchro ring (positioned on other side of the hub), are used to in combination, for engagement/ disengagement of the output shaft to other output gear positioned on other side of the hub. For ease in reference and understanding, concepts of the present disclosure, hereinafter, will be described as applied to the hub, the three (3) inserts, the sleeve, and one synchro ring, for engagement/ disengagement of the output shaft to the output gear positioned on one side of the hub, similar concepts of the present disclosure may be envisioned as applied to the hub, the three (3) inserts, the sleeve, and other synchro ring, for engagement/ disengagement of the output shaft to the other output gear positioned on other side of the hub.
In the synchropack arrangement, the hub is fixedly attached to the output shaft, while the sleeve moves relative to the output shaft and the hub, to engage/disengage with the output gear. In light of the aforementioned points, the synchropack arrangement plays a vital role in the transmission of power in the manual transmission system. Therefore, the synchropack arrangement is required to be tested for failure. In particular, the synchropack arrangement is

required to be tested, to know a failure strength/ failure life and thus accordingly improve on a design and arrangement of the synchropack arrangement. Such testing of failure life is termed as ‘Failure Analysis’. A number of methods exists to perform ‘failure analysis’ to predict the failure life of the synchropack arrangement.
One method of performing failure analysis to predict the failure life of the synchropack arrangement includes, physical testing of the synchropack arrangement. In the physical testing, the synchropack arrangement is firstly installed on a prototype of the manual transmission system. Thereafter, sensors are coupled to the synchropack arrangement. The manual transmission system is run for a defined life cycle. The sensors then measure the misplacement of the synchropack arrangement. Based on the misplacement, an FEA analysis is performed on the misplacement, for determining the root cause analysis of misplacement, by correlation of physical testing and simulation by FEA analysis. Such method of predicting the failure life of the synchropack arrangement is relatively expensive and incurs substantial effort.
An alternate method of performing failure analysis to predict the failure life of the synchropack arrangement is a finite element analysis (FEA), performed with use of a finite element analysis (FEA) tool. For performing the FEA analysis, a simulation of the manual transmission system similar to that of the working manual transmission system is prepared on the FEA simulation tool. In particular, the FEA simulation tool is formulated, such that the simulated manual transmission system includes a simulated output gear arrangement rotatably supported on the output shaft, and a simulated synchropack arrangement installed adjacent to the simulated output gear arrangement. Furthermore, in such virtually simulated manual transmission system, the output gear arrangement includes a simulated output gear rotatably mounted on the output shaft via the oil lubrication film. For performing the FEA analysis, a torque is virtually applied to the simulated synchropack arrangement, to predict the

failure life of the actual synchropack arrangement. However, such method of performing the FEA analysis for failure prediction, resulted in deviated results. In particular, the actual synchropack arrangement in the actual manual transmission system, was found to have a relatively lesser failure life than that of as predicted by the FEA analysis on the simulated synchropack arrangement of the simulated manual transmission system. Specifically, the actual hub of the actual synchropack arrangement in the actual manual transmission system failed early than that of predicted by the FEA analysis on the simulated synchropack arrangement of the simulated manual transmission system.
Furthermore, upon performing a root cause analysis for such difference between the predicted failure life through FEA analysis and actual failure life of the synchropack arrangement, it was observed that tilt of the actual output gear occurred in the actual manual transmission system. This tilt was primarily due to the reverse axial force exerted by the mating output gear, and an irregular contact surface (gap) between the output gear and the shaft due to irregular wear of the oil lubrication film upon prolonged usage. As the actual output gear of the actual manual transmission arrangement is supported on the actual output shaft via the oil lubrication film, which is compressible and is irregularly worn out upon prolonged usage. This imparts the tilting effect of the actual output gear relative to the actual output shaft. Such tilt of the actual output gear exerted uneven forces on the actual hub of the actual synchropack arrangement, which further deteriorated the failure life of the actual synchropack arrangement. However, in the FEA analysis for predicting the failure life of the synchropack arrangement, the tilt effect of the simulated output gear and corresponding forces on the simulated synchropack arrangement was not considered. Therefore, such difference between the simulated predicted failure life through FEA analysis and actual failure life of the synchropack arrangement was observed. In addition to aforementioned drawbacks of the conventional methods of

predicting failure life through FEA analysis, there is a well felt need of an improved method of predicting the failure life of the synchropack arrangement, which predicts relatively more accurate simulated failure life closer of the synchropack arrangement.
SUMMARY
One object of the present invention relates to a method of predicting a failure life of the synchropack arrangement by FEA analysis, which is more accurate and relatively more in correlation with the actual failure life of the synchropack arrangement. In particular, the method for predicting the failure life of the synchropack arrangement by FEA analysis, considers the forces applied on the simulated synchropack arrangement due to a tilt of the simulated output gear of the simulated manual transmission system.
Another object of the present invention relates to a method of predicting a failure life of the synchropack arrangement by FEA analysis, which is more accurate and relatively more in correlation with the actual failure life of the actual synchropack arrangement. The method of predicting the failure life of the synchropack arrangement by FEA analysis, includes: forming a simulated manual transmission arrangement comprising of a simulated output gear arrangement and a simulated synchropack arrangement, wherein the simulated output gear arrangement has a simulated output gear rotatably supported on the simulated output shaft separated by a simulated gap; performing the FEA analysis on the synchropack arrangement, such that each of the axial force, the radial force, and the tangential force on the synchropack arrangement is considered therein to calculate a failure life of the synchropack arrangement; and finally retrieving the failure life of the synchropack arrangement calculated based on the FEA analysis. Notably, usage of the simulated gap between the simulated output gear on the simulated output shaft proved to be relatively better for simulation in the simulated manual transmission system, and therefore the failure life determined by the FEA simulation tool on such simulated manual transmission system

proved to be more in correlation with the actual failure life of the synchropack arrangement.
BRIEF DESCRIPTION OF DRAWINGS
The present invention, both as to its organization and manner of operation,
together with further objects and advantages, may best be understood by
reference to the following description, taken in connection with the
accompanying drawings. These and other details of the present invention will be
described in connection with the accompanying drawings, which are furnished
only by way of illustration and not in limitation of the invention, and in which
drawings:
Figure 1 illustrates an exploded view of a manual transmission system,
illustrating an output gear arrangement and a synchropack arrangement, in
accordance with the concepts of the present disclosure.
Figure 2 illustrates a perspective view of the output gear arrangement, in
accordance with the concepts of the present disclosure.
Figure 3 illustrates a sectional view of a portion of the manual transmission
system of Figure 1, in accordance with the concepts of the present disclosure.
Figure 4a shows a perspective view of a simulated manual transmission system,
illustrating an arrangement between a simulated output shaft, a simulated
output gear arrangement, and a simulated synchropack arrangement, in
accordance with the concepts of the present disclosure.
Figure 4b illustrates an orthographic side view of a portion of the simulated
manual transmission system of Figure 1, illustrating a tilt of the output gear
arrangement relative to the simulated output shaft, in accordance with the
concepts of the present disclosure.
Figure 4c shows an arrangement between a simulated output gear [105’] of the
simulated output gear arrangement [104’] and the simulated output shaft [102’],
illustrating the tilt therebetween, in accordance with the concepts of the present
disclosure.

Figure 5 illustrates a flowchart of a method of predicting failure life of the
synchropack arrangement, in accordance with the concepts of the present
disclosure.
Figure 6a illustrates a deformation plot of simulation results of the simulated
synchropack arrangement, in accordance with the concepts of the present
disclosure.
Figure 6b illustrates a deformation plot of simulation results of the simulated hub
of the simulated synchropack arrangement, in accordance with the concepts of
the present disclosure.
Figure 6c illustrates a deformation plot of simulation results of the simulated
sleeve of the simulated synchropack arrangement, in accordance with the
concepts of the present disclosure.
Figure 7a shows a stress plot of simulation results of the simulated sleeve of the
simulated synchropack arrangement, in accordance with the concepts of the
present disclosure.
Figure 7b shows a stress plot of simulation results of the simulated hub of the
simulated synchropack arrangement, in accordance with the concepts of the
present disclosure.
DETAILED DESCRIPTION OF DRAWINGS
In the following description, for the purposes of explanation, various specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent, however, that embodiments of the present invention may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address any of the problems discussed above or might address only one of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein. Example embodiments of the present invention are described below, as illustrated in

various drawings in which like reference numerals refer to the same parts throughout the different drawings.
Fig. 1 shows a schematic of a portion of manual transmission system [100], illustrating components of a singular output gear arrangement [104] and a singular synchropack arrangement [106], in accordance with the concepts of the present disclosure. Figure 2 shows a perspective view of the singular output gear arrangement [104] of the manual transmission system [100]. Figure 3 shows a cut-sectional view of the portion of manual transmission system [100] of Figure 1. For ease in reference and understanding, a number of other components of the manual transmission system [100] are not shown in Figure 1 and Figure 3, and should be referred as conventionally known in the art. In particular, for ease in reference and understanding and better clarity purposes, only the singular output gear arrangement [104] and the singular synchropack arrangement [106] are shown in Figure 1 and Figure 3, however, conventionally known other components of the manual transmission system [100] may also be envisioned. Figure 1, Figure 2, and Figure 3, should be referred to in conjunction, in order to clearly understand a structure and arrangement of the manual transmission system [100]. As is conventionally known, the manual transmission system [100] includes an input shaft fixedly carrying an input gear arrangement; a layshaft fixedly carrying a number of lay gear arrangements; and an output shaft [102] rotatably carrying a number of output gear arrangements [104], and a number of synchropack arrangements [106] provided between the output gear arrangements [104]. The synchropack arrangements [106] are provided to perform engagement/ disengagement of one of the output gear arrangements [104] with the output shaft [102], to transmit a motion (torque and rotational speed) of the engaged output gear arrangement [104] to the output shaft [102]. For ease in reference and understanding and clarity purposes, a structure and arrangement of a singular output gear arrangement [104] (hereinafter referred to as an output gear arrangement [104]) and a singular synchropack

arrangement [106] (hereinafter referred to as a synchropack arrangement [106]) will be described hereinafter. Similar structure and arrangement of other output gear arrangements [104] and other synchropack arrangements [106], may be contemplated. For ease in reference and understanding, an arrangement between the singular output gear arrangement [104] and the singular synchropack arrangement [106] is shown and described, however other conventionally known components and arrangements thereof of the manual transmission system [100’] may also be envisioned.
In the manual transmission system [100], the output gear arrangement [104] includes an output gear [105] and a dog crown [107]. The dog crown [107] is fixedly mounted on a mating face of the output gear [105], and defines a cone attachment portion thereon. The cone attachment portion is mated with a conical mating portion of a synchro ring [116] of the synchropack arrangement [106], to form a conical coupling when required. Moreover, the output gear [105] and the dog crown [107] are rotatably supported on the output shaft [102], with a simulated snap ring [120] there between. Additionally, the output gear [105] is separated from the output shaft [102], via an oil lubrication film. Further, in the manual transmission [100], the synchropack arrangement [106] includes a synchro hub [110], an insert assembly [114], the synchro ring [116], and a sleeve [118]. Each of the synchro hub [110], the insert assembly [114], the synchro ring [116], and the sleeve [118] are arranged with each other and relative to the output gear arrangement [104], such that the synchropack arrangement [106] facilitates engagement/ disengagement of the output gear [105] with the output shaft [102], upon manipulation. In particular, the synchro hub [110] is fixedly attached to output shaft [102]. The sleeve [118] is coaxial to and surrounds a periphery of the synchro hub [110], and is laterally slidebaly positioned relative to the synchro hub [110]. The insert assembly [114] is positioned within an outer periphery slot in the synchro hub [110], and normally pushing against an inner periphery slot of the sleeve [118] that surrounds the

synchro hub [110]. The synchro ring [116] is further rotatably positioned adjacent the sleeve [118]. The synchro ring [116] defines a recess to laterally receive the insert assembly [114], and also defines a conical mating portion capable of mating with the cone attachment portion of the dog crown [107] of the output gear arrangement [104] to form a simulated conical coupling. With such arrangement of the output gear arrangement [104] and the synchropack arrangement [106], the synchropack arrangement [106] is capable of facilitating smooth engagement/ disengagement of the output gear [105] with the output shaft [102], upon manipulation. Thereby, the synchropack arrangement [106] facilitates engagement of the output gear [105] with the output shaft [102], broadly in five (5) phases.
In the first phase, i.e. Asynchronizing phase, the sleeve [118] is in the middle position, and the synchropack arrangement [106] is kept disengaged from the output gear arrangement [104]. In such conditions, the output gear [105] is rotating, while the synchropack arrangement [106] is at rest. Thereafter, to initiate engagement, a gearshift force is applied on the sleeve [118]. With such gearshift force, the sleeve [118] pushes the synchro ring [116] against the dog crown [107] of the gear arrangement [104]. This causes mating of the cone attachment portion of the dog crown [107] of the output gear arrangement [104] with the conical mating portion of the synchro ring [116] of the synchropack arrangement [106], forming a conical coupling. This further causes a rotation of the synchro ring [116].
In second phase, i.e. synchronizing phase, the sleeve [118] is pushed further, which brings the internal teeth of the sleeve [118] in contact with the teeth of the synchro ring [116]. Moreover, the friction torque starts to counteract the inertia torque and the speed difference starts to decrease.
In the third phase, the gearshift force is further kept applied on the synchro ring [116] through the sliding sleeve [118]. When speed synchronization has been achieved, the friction forces are increased to maximum and the relative speed of

the dog crown [107] and the synchro ring [116] become zero.
In the fourth phase, the sleeve [118] passes through the teeth of the synchro ring [116] and comes into contact with the locking tooth of the dog crown [107] of the output gear arrangement [104].
In the fifth phase, the sleeve [118] is completely moved into the locking tooth of the dog crown [107] of the output gear arrangement [104]. Back tapers at the teeth of the sleeve [118] and the dog crown [107] locking tooth avoid decoupling under load. Therefore, at the fifth phase, the sleeve [118] of the synchropack arrangement [106] is engaged with the dog crown [107] of the output gear arrangement [104]. As the dog crown [107] is fixedly attached to the output gear [105], and the sleeve [118] is coupled to the synchro hub [110] that is further fixedly attached to the output shaft [102]. Such engagement of the sleeve [118] of the synchropack arrangement [106] with the dog crown [107] of the output gear arrangement [104], corresponds to engagement of the output gear [105] of the output gear arrangement [104] with the output shaft [102].
It may be noted that various component of the manual transmission system [100] including the output gear arrangement [104], the synchropack arrangement [106], the output gear [105], the dog crown [107], the synchro hub [110], the insert assembly [114], the synchro ring [116], and the sleeve [118], as described herein in the aforementioned disclosure in Figs. 1, Fig. 2, and Fig. 3, relates to actual working components of the manual transmission system [100]. Therefore, the manual transmission system [100], the output gear arrangement [104], the synchropack arrangement [106], the output gear [105], the dog crown [107], the synchro hub [110], the insert assembly [114], the synchro ring [116], and the sleeve [118], may be interchangeably referred to as the actual manual transmission system [100], the actual output gear arrangement [104], the actual synchropack arrangement [106], the actual output gear [105], the actual dog crown [107], the actual synchro hub [110], the actual insert assembly [114], the actual synchro ring [116], and the actual sleeve [118], respectively.

Furthermore, a finite element analysis (FEA) tool and a method [200] implemented thereon is provided to predict a failure life of the synchropack arrangement [106’]. Figure 4a shows a perspective view of a simulated manual transmission system [100’], illustrating an arrangement between a simulated output shaft [102’], a simulated output gear arrangement [104’], and a simulated synchropack arrangement [106’], in accordance with the concepts of the present disclosure. Figure 4b illustrates another perspective view of the simulated manual transmission system [100’], illustrating the arrangement between the simulated output shaft [102’], the simulated output gear arrangement [104’], and the simulated synchropack arrangement [106’], in accordance with the concepts of the present disclosure. Figure 4c illustrates an arrangement between a simulated output gear [105’] of the simulated output gear arrangement [104’] and the simulated output shaft [102’], in accordance with the concepts of the present disclosure. Figure 5 illustrates a flowchart of the method [200] of predicting failure life of the synchropack arrangement [106]. Figures 3, 4a, 4b, 4c, and 5, should be referred to in conjunction with each other, to clearly understand concept of the disclosure hereinafter in details.
The FEA simulation tool is a computing device, comprising of an input/output (I/O) unit, a processing unit, and a storage unit. The storage unit stores the method of predicting the failure life of the synchropack arrangement [106]. In nutshell, the FEA simulation tool is equipped: to form a simulated manual transmission system [100’] thereon; to perform an FEA analysis on the simulated manual transmission system [100’] for calculating the failure life of the synchropack arrangement [106]; and further to output the failure life of the synchropack arrangement [106] to a user. In an embodiment, the FEA simulation tool is the computer device equipped with an user controlled FEA software such as but not limited to an ANSYS software, which works in combination with the input/output (I/O) unit, the processing unit, and the storage unit, to assist in performing the method of predicting the failure life of the synchropack

arrangement [106]. In such embodiment of the FEA simulation tool with the user controlled FEA software (for example ANSYS software) implemented on the computing device, a user can controllably perform the steps of the method of predicting the failure life of the synchropack arrangement [106], including: forming the simulated manual transmission system [100’]; performing the FEA analysis on the simulated manual transmission system [100’] for calculating the failure life of the synchropack arrangement [106]; and further retrieving the failure life of the synchropack arrangement [106] to the user. The steps of the method of predicting the failure life of the synchropack arrangement [106], will be explained hereinafter.
The method [200] of predicting the failure life of the synchropack arrangement [106], includes: Step 1: forming the simulated manual transmission system [100’], with use of the I/O unit of the FEA simulation tool; Step 2: performing the FEA analysis on the simulated manual transmission system [100’] for calculating the failure life of the synchropack arrangement [106], with use of the processing unit of the FEA simulation tool; and Step 3: further outputting the failure life of the synchropack arrangement [106] to the user, with use of the I/O unit of the FEA simulation tool.
The step 1 of forming the simulated manual transmission system [100’] is performed in the FEA software with use of the I/O unit of the FEA simulation tool. Fig. 3 shows the simulated manual transmission system [100’] formed by the I/O unit of the FEA simulation tool. It may be noted that the simulated manual transmission system [100’] will be similar to the actual manual transmission system [100]. The simulated manual transmission system [100’] herein refers to a virtual manual transmission system formed in the FEA software of the FEA simulation tool to predict the failure life of the synchropack arrangement [106]. A structure and arrangement of the simulated manual transmission system [100’] as prepared by a user on the FEA simulation tool is described hereinafter.

In one embodiment, the simulated manual transmission system [100’] is similar in structure and arrangement to the actual manual transmission system [100]. In particular, the simulated manual transmission system [100’] also includes a simulated input shaft fixedly carrying a simulated input gear; a simulated layshaft fixedly carrying a number of simulated lay gears; and a simulated output shaft [102’] rotatably carrying a number of simulated output gear arrangements [104’], and a number of simulated synchropack arrangements [106’] provided between the simulated output gear arrangements [104’]. The simulated synchropack arrangements [106’] are provided to perform engagement/ disengagement of one of the simulated output gear arrangements [104’] with the simulated output shaft [102’], to transmit a motion (torque and rotational speed) of the engaged simulated output gear arrangement [104’] to the simulated output shaft [102’]. For ease in reference and understanding, a structure and arrangement of a singular simulated output gear arrangement [104’] (hereinafter referred to as the simulated output gear arrangement [104’]) and a singular synchropack arrangement [106’] (hereinafter referred to as the simulated synchropack arrangement [106’]), relative to the simulated output shaft [102’] will be described hereinafter. Similar structure and arrangement of other simulated output gear arrangements [104’] and other simulated synchropack arrangements [106’], relative to the simulated output shaft [102’], may be contemplated.
In a preferred embodiment, as disclosed herein in the present disclosure, the simulated manual transmission system [100’] formed at step 1, as disclosed herein, is similar in structure and arrangement to a portion of the actual manual transmission system [100]. Specifically, in the preferred embodiment, as disclosed herein, the simulated manual transmission system [100’] includes a portion of simulated output shaft [102’], one (1) simulated output gear arrangement [104’], and one (1) simulated synchropack arrangement. In other words, the a simulation of only the portion of simulated output shaft [102’], the

simulated output gear arrangement [104’], and the simulated synchropack arrangement [106’], is described in the present disclosure, and is in conjunction referred to as the simulated manual transmission system [100’]. Such simulated manual transmission system [100’] is shown in Figures 4a and 4b.
In the simulated manual transmission system [100’], the simulated output gear arrangement [104’] includes a simulated output gear [105’] and a simulated dog crown [107’]. The dog crown [107’] is fixedly mounted on a mating face of the simulated output gear [105’], and defines a cone attachment portion thereon. The cone attachment portion is mated with a conical mating portion of a synchro ring of the simulated synchropack arrangement [106], to form a conical coupling when required. Moreover, the simulated output gear [105’] and the dog crown [107’] are rotatably supported on the simulated output shaft [102’] separated by a simulated gap [108’].
Further, in the simulated manual transmission [100’], the simulated synchropack arrangement [106’] includes a simulated synchro hub [110’], a simulated synchro ring [116’], and a simulated sleeve [118’]. Each of the synchro hub [110’], the simulated synchro ring [116’], and the simulated sleeve [118’] are arranged with each other and relative to the simulated output gear arrangement [104’], such that the synchropack arrangement [106’] facilitates engagement/ disengagement of the simulated output gear [105’] with the simulated output shaft [102’], upon manipulation. In particular, the simulated synchro hub [110’] is fixedly attached to the simulated output shaft [102’]. The simulated sleeve [118’] is coaxial to and surrounds a periphery of the synchro hub [110’], and is laterally slidebaly positioned relative to the simulated synchro hub [110’]. Notably, in the preferred embodiment, as disclosed herein, the simulated synchropack arrangement [106’] does not include the simulated insert assembly. However, in an alternate embodiment, the simulated synchropack arrangement [106’] may include the simulated insert assembly positioned within an outer periphery slot in the simulated synchro hub [110’], and normally pushing against an inner periphery

slot of the simulated sleeve [118’] that surrounds the simulated synchro hub [110’]. The simulated synchro ring [116’] is further rotatably positioned adjacent the simulated sleeve [118’]. The simulated synchro ring [116’] defines a conical mating portion capable of mating with the cone attachment portion of the dog crown [107] of the output gear arrangement [104] to form a simulated conical coupling. Although, the present disclosure describes step 1 of formation of the manual transmission arrangement [100’] defines formation of the simulated synchropack arrangement [106’] including each of the simulated synchro hub [110’], the simulated synchro ring [116’], and the simulated sleeve [118’], however it may be obvious to a person ordinarily skilled in the art that the step 1 of formation of the manual transmission arrangement [100’] may also be defined by formation of the simulated synchropack arrangement [106’] including each of the simulated synchro hub [110’], the simulated synchro ring [116’], and the simulated sleeve [118’] as well. Upon forming of such simulated manual transmission system [100’], the step 1 of the method of predicting the failure life of the synchropack arrangement [106] is completed. In particular, in the step 1, the simulated manual transmission system [100’] is formed, such that the simulated output gear [104’] rotatably supported on the simulated output shaft [102’], separated by the simulated gap [108’]. Notably, the simulated output gear [105’] is rotatably supported on the simulated output shaft [102’]. Thereafter, the method proceeds to perform step 2.
At step 2, the FEA analysis is performed, with use of the processing unit of the FEA simulation tool, to calculate the failure life of the synchropack arrangement [106]. Such step of performing the FEA analysis further includes: sub-step 2a: applying, with use of the FEA simulation tool, a simulated force on one or more meshing tooth of a simulated sleeve [118’] of the simulated synchropack arrangement [106’]; and sub-step 2b: calculating, with use of the FEA simulation tool, the failure life of the synchropack arrangement [106] based on a predefined calculation. Each of the sub-steps 2a and 2b are performed by predefined

features defined in the FEA software of the FEA simulation tool. Notably, the simulated force as applied in the sub-step 2a on the simulated sleeve [118’] of the simulated synchropack arrangement [106’] includes consideration of all 3 forces i.e. the axial force, the radial force, and the tangential force. In particular, as the simulated output gear [105’] is supported on the simulated output shaft [102’] separated by the simulated gap [108’] in the simulated manual transmission arrangement [100’], a tilt action of the output gear [105’] is observed. Fig. 4b and 4c shows a tilt action between the simulated output gear [105’] and the simulated output shaft [102’]. The tilt action of the simulated output gear [105’] is observed due to the simulated gap [108’] between the simulated output gear [105’] and the simulated output shaft [102’], which is similar to the tilt action of the actual output gear [105] and the simulated output shaft. Such tilt action of the simulated output gear [105’] exerts axial force on one or more meshing tooth of the simulated sleeve [118’] of the synchropack arrangement [106’]. In addition to the axial force, the radial force and the tangential force acts on the meshing tooth of the simulated synchropack arrangement [106’]. Therefore, the simulated synchro hub [110’] is observed to be impacted by the tilt action as well. Thereafter, as per sub-step 2b, the failure life of the synchropack arrangement [106] is calculated based on the predefined calculation on the reverse exerted forces, including all three (3) forces, i.e. radial, tangential, and axial force, on meshing teeth of the simulated synchropack arrangement [106’]. In particular, the failure life of each of the simulated sleeve [118’] and the simulated hub [110’] is calculated, which corresponds to the failure life of the simulated synchropack arrangement [106’]. The failure life of the simulated synchropack arrangement [106’] corresponds to the failure life of the synchropack arrangement [106]. Moreover, the failure life of the simulated synchropack arrangement [106’], the simulated sleeve [118’], and the simulated hub [110’] is dependent on a deformation and/or stress on each of the simulated synchropack arrangement [106’], the simulated sleeve [118’], and the simulated

hub [110’]. Figures 6a, 6b, and 6c, shows a deformation plot of the simulated manual transmission system [100’], the simulated hub [110’], and the simulate sleeve [118’], respectively. Figure 7a and 7b shows a stress plot of the simulate sleeve [118’] and the simulated hub [110’], respectively. Although, at step 2, the method considers application of simulated forces on the simulated sleeve [118’] of the synchropack arrangement [106’] for prediction of the failure life of synchropack arrangement [106], it may be obvious to a person ordinarily skilled in the art that the method may also consider application of simulated torque on the simulated synchro hub [110’] of the synchropack arrangement [106’] for prediction of the failure life of synchropack arrangement [106], or application of a combination of the simulated torque on the simulated synchro hub [110’] and the simulated forces on the simulated sleeve [118’] of the synchropack arrangement [106’], for prediction of the synchropack arrangement [106]. At this stage, step 2 is completed. The method then proceeds to perform step 3. At step 3, the failure life is retrieved from the FEA simulation tool, to the user. In particular, the failure life of the simulated synchropack arrangement [106’] is outputted to the user. As each of the three forces, i.e. axial, radial, and tangential forces are considered step 2 for calculation of the failure life of the simulated synchropack arrangement [106’], the predicted failure life is in more correlation with the actual failure life of the actual synchropack arrangement [106] employed in the actual manual transmission system [100]. Such correlation is established due to: the simulated gap [108’] between the simulated output shaft [102’] and the simulated output gear [105’] in simulated manual transmission system [100’]; consideration of all three (3) reverse exerted forces in place of only the reverse axial force on the simulated synchropack arrangement [106’]; and consideration of frictional contact between the simulated output gear [105’] and the simulated output shaft [102’]. Therefore, with such improved method of predicting the failure life, a design of the synchropack arrangement [106] may be improved at reduced costs.

While the preferred embodiments of the present invention have been described hereinabove, it should be understood that various changes, adaptations, and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims. It will be obvious to a person skilled in the art that the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.
List of Components:
100 - Manual Transmission System 102 – Output Shaft
104 – Output Gear Arrangement of 100
105 – Output Gear of 104
106 – Synchropack arrangement of 100
107 – Dog Crown of 104 110 - Hub of 106
114 – Insert Assemblies of 106
116 - Synchro Ring of 106
118 - Sleeve of 106
120 - Simulated snap Ring of 104
100’ - Simulated Manual Transmission System
102’ – Simulated Output Shaft of 100’
104’ – Simulated Output Gear Arrangement of 100’
105’ – Output Gear of 100’
106’ – Simulated Synchropack arrangement of 100’
107’ – Simulated Dog Crown of 104’
108’ – Simulated Gap of 100’
110’ – Simulated Synchro Hub of 106’
118’ – Simulated Sleeve of 106’

We Claim:
1. A method of predicting a failure life of a synchropack arrangement [106] of
a manual transmission system [100], the method comprising:
- forming, with use of a finite element analysis (FEA) simulation tool, a simulated manual transmission arrangement [100’] comprising of a simulated output gear arrangement [104’] and a simulated synchropack arrangement [106’], wherein the simulated output gear arrangement [104’] has a simulated output gear [105’] rotatably supported on the simulated output shaft [102’] separated by a simulated gap [108’];
- performing, with use of the FEA simulation tool, an FEA analysis on the simulated synchropack arrangement [106’] to calculate a failure life of the simulated synchropack arrangement [106’]; and
- retrieving, with use of the FEA simulation tool, the failure life of the simulated synchropack arrangement [106’] calculated based on the FEA analysis.
2. The method as claimed in claim 1, wherein the step of performing the
FEA analysis on the simulated synchropack arrangement [106’] includes:
- applying, with use of the FEA simulation tool, a simulated force on one or more meshing tooth of a simulated sleeve [118’] of the simulated synchropack arrangement [106’]; and
- calculating, with use of the FEA simulation tool, the failure life of simulated the synchropack arrangement [106’] based on a predefined calculation.
3. The method as claimed in claim 2, wherein the simulated force includes a
simulated axial force, a simulated radial force, and a simulated tangential
force.

4. The method as claimed in claim 1, wherein the simulated output gear arrangement [104’] includes the simulated output gear [105’] rotatably supported on the simulated output shaft [102’] separated by the simulated gap [108’], and a dog crown [107’] defining a cone attachment portion.
5. The method as claimed in claim 4, wherein the simulated gap imparts a tilt effect on the simulated output gear [105’] relative to the simulated output shaft [102’].
6. The method as claimed in claims 1-5, wherein the simulated synchropack arrangement [106’] includes:

- a simulated synchro hub [110’] fixedly attached to the simulated output shaft [102’];
- the simulated sleeve [118’] surrounding a periphery of the simulated synchro hub [110’], and arranged axially slide able relative to the simulated synchro hub [110’]; and
- a simulated synchro ring [116’] positioned adjacent the simulated sleeve [118’], and defining a conical mating portion capable of mating with the cone attachment portion of the dog crown [107’] of the simulated output gear [105’] to form a simulated conical coupling therewith.
7. The method as claimed in claims 6, wherein the simulated synchropack
arrangement [106’] includes:
- a simulated insert assembly positioned within an outer periphery slot
of the simulated synchro hub [110’], and normally pushing against an
inner periphery slot of the simulated sleeve [118’], the simulated insert
assembly being capable of being received in a recess of the simulated

synchro ring [116’].
8. The method as claimed in claim 2, wherein the failure life of the simulated synchropack arrangement [106’] as calculated by the FEA simulation tool includes a combination of a failure life of the simulated synchro hub [110’] and a failure life of the simulated sleeve [118’].
9. The method as claimed in claim 2, wherein the failure life of the synchropack arrangement [106’] is calculated based on a predefined calculation defined in the FEA simulation tool, on the simulated force as applied on one or more meshing tooth of the simulated sleeve [118’].
10. The method as claimed in claims 1-9, wherein the FEA simulation tool is a computing device, comprising of an input/output unit, a processing unit, and a storage unit.