DESC:TECHNICAL FIELD
The present disclosure generally relates to articulated joints. Particularly but not exclusively, embodiments of the disclosure disclose a torque limiting mechanism for a transmission joint in a machine. Further, embodiments of the disclosure disclose a torque limiting mechanism for limiting the torque transferred to a drive shaft connected to transmission joint of a vehicle.

BACKGROUND OF THE DISCLOSURE
Generally, in machines it is common to transfer power from an engine and transmission to an output device via a drive shaft. To transfer torque to the drive shaft at a constant velocity, joints commonly known as constant-velocity joints or CV joints are provisioned. The constant-velocity joints such as tripod joints are configured to transfer constant torque to the output device, irrespective of the angular articulation between the shafts. A tripod joint has three trunion shafts 120 degrees apart, which extends from the main shaft. To each of these trunion shafts, a roller is configured. These rollers facilitate transfer of torque between two shafts, even when there is an angular articulation between the shafts. This trunion assembly is enclosed in a housing to prevent contamination of the joints by way of dirt, dust and the like. The housing is connected to drive shaft and configured with depressions in its profile, so that the three trunion shafts are enclosed on the housing at close tolerances. The depression maintains positive contact with the rollers in the trunion shaft, thereby transfer torque or rotary motion to the drive shaft. At the same time, the constant-velocity joint prevents wobble of the shafts when the torque is transferred to shafts with angular articulation. This prevents undue vibration in the machine during transfer of torque to angular articulated shafts.

These machines, such as vehicles including commercial vehicles, passenger vehicles, people carriers, load carriers etc., tend to be overloaded by the user during transportation of goods and passengers. The overload on the vehicles can be as high as twice the vehicle’s rated load capacity. This will inherently make the vehicle run slowly, when the vehicle is made to operate within permissible limits. However, the user tries to speed up the vehicle by applying excessive torque to the wheels. One way of doing this is by half clutch technique, one of the many driving skills known. The excessive torque increases the burden on the drive shaft especially on the constant velocity joints. This is because torque from the transmission is transferred to the drive shaft via the constant velocity joints. Since, the tripod joints are assembled in housing at very close tolerances and only a filament of lubricating layer such as grease persists between the contact surfaces. Due to the excessive torque, the lubricating layer might fade away leading to wear and tear of the constant-velocity joints. Therefore, at torques above a predetermined limit there exists a high probability that the tripod joint may be damaged

Due to wear and tear, the tripod joint starts to transfer the power from transmission to wheels at different speeds. Hence, the joint will no more be a constant velocity joint, as torque is transferred at different speeds. At later stages, wobbling begins in the constant-velocity joints even for slight angular articulation from the wheels. Ultimately, the entire tripod joint fails and breaks down, and consequently damaging the entire drive shaft. Hence, in case of failure of the tripod joints, the entire driveshaft has to be replaced for proper functioning of the vehicle, which is a costly affair. This also considerably increases the maintenance cost of the vehicle.

In light of foregoing discussion, there is a need to develop a torque limiting mechanism to overcome the limitations stated above.

SUMMARY OF THE DISLCOSURE
The shortcomings of the prior art are overcome and additional advantages are provided through the provision of the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the disclosure.

In one non-limiting embodiment of the present disclosure, a torque limiting mechanism for limiting the torque transferred to a drive shaft is provided. The torque limiting mechanism comprises a housing having a plurality of slots configured on outer circumference of the housing. The housing is connectable to the drive shaft and is configured to accommodate a transmission joint of a transmission unit such that the transmission joint is freely rotatable inside the housing. The torque limiting mechanism also comprises a plurality of rollers adapted to mount onto the plurality of slots, and a first ring mounted coaxially around the housing. The first ring comprises a plurality of protrusions at its inner surface which locks the plurality of rollers from slipping, and a plurality of first provisions provided on its outer surface for receiving a plurality of resilient members. A second ring is mounted coaxially around the first ring and the second ring is configured with plurality of second provisions on its inner surface for securing the plurality of resilient members. A plurality of resilient members is provided in-between the first ring and the second ring such that one end of the plurality of resilient members is mounted in the plurality of first provisions and other end of the plurality of resilient members is mounted onto the plurality of second provisions. The plurality of resilient members apply pressure on the first ring to facilitate positive contact of the plurality of rollers with the transmission joint for transferring torque from the transmission joint to the drive shaft, when the torque is within a predetermined limit.

In an embodiment of the present disclosure, the plurality of rollers move radially upwards from the plurality of slots by overcoming the pressure of the plurality of resilient members, thereby the positive contact between the plurality of rollers and the transmission joint slips to cut-off torque transmission to the drive shaft, when torque from the transmission unit exceeds the predetermined limit.

In an embodiment of the present disclosure, the transmission joint is a tripod joint which facilitates angular movement to the drive shaft, and is coupled to the transmission unit by an input shaft.

In an embodiment of the present disclosure, at least one pin is provisioned in the plurality of slots to prevent misalignment of the plurality of rollers.

In an embodiment of the present disclosure, a method of assembling a torque limiting mechanism to limit torque transferred to a driveshaft is disclosed. The method comprises acts of firstly a transmission joint of a transmission unit mounted in a housing comprising a plurality of slots configured on its outer circumference, such that the transmission joint is freely rotatable inside the housing.. Secondly, a plurality of rollers is mounted onto the plurality of slots, and thirdly a first ring is mounted coaxially around the housing. The first ring comprises a plurality of first protrusions at inner surface of the first ring and a plurality of first provisions at outer surface. The plurality of first protrusions locks the plurality of rollers from slipping. Subsequently, a second ring is coaxially mounted around the first ring. . In-between the first ring and the second ring that the plurality of resilient members are positioned such that, one end of the plurality of resilient members is mounted on the plurality of the first provisions and the other end of the plurality of resilient members is mounted to the plurality of second provisions. The plurality of resilient members apply pressure on the first ring to facilitate positive contact of the plurality of rollers with the transmission joint for transferring torque from the transmission joint to the drive shaft, when the torque is within a predetermined limit.

In an embodiment of the present disclosure, the method comprises act of engaging at least one of roller of the plurality of rollers with subsequent protrusion of the plurality of protrusion, when the plurality of rollers slip from the plurality of protrusions to limit the torque transferred to the drive shaft.

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

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The novel features and characteristic of the disclosure are set forth in the appended description. 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 the 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 drawings.

Figure 1 illustrates exploded view of the torque limiting mechanism, according to one embodiment of the present disclosure.

Figure 2 illustrates side view of the assembly of torque limiting mechanism of figure 1, according to one embodiment of the present disclosure.

Figure 3 illustrates front view of the assembly of torque limiting mechanism of figure 1 during working when torque is within predetermined limit, according to some embodiment of the present disclosure.

Figure 4 illustrates front view of the assembly of torque limiting mechanism of figure 1 during working when torque exceeds predetermined limit, according to some 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 assembly illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE DISCLOSURE
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

Referral numerals
Referral Numerals Description
100 Torque limiting mechanism
101 Housing of transmission joint
1 Transmission joint
2 Slot
3 Roller
4 First ring
4a Protrusions on first ring
4b First provision
5 Resilient member
6 Second ring
6a Second provision
7 Output shaft
8 Input shaft

To overcome the limitations stated in the background, the present disclosure provides for a torque limiting mechanism. The torque limiting mechanism limits torque transfer from a transmission unit to the drive shaft of a machine. In an exemplary embodiment, the machine is a ‘vehicle’ or an automobile which includes passenger vehicles, commercial vehicles, etc. The torque limiting mechanism comprises a housing connected to the drive shaft and configured to accommodate a transmission joint of a transmission unit. The transmission joint is configured to rotate freely in the housing. The transmission joint is connected to the transmission unit by an input shaft for receiving torque that is to be transferred to the drive shaft. In an embodiment, the transmission joint is connected to the input shaft of the transmission unit by means such as but not limited to splines. A provision for positive contact is provided in the housing for transfer of torque to the drive shaft from the transmission unit. The housing is further configured with a plurality of slots on its outer circumference to accommodate a plurality of rollers onto the plurality of slots in order to obtain positive contact between the housing and the transmission joint. At least one pin is provided in the plurality of slots for mounting the rollers into the plurality of slots which prevents misalignment of the plurality of rollers in the plurality of slots. The pin holds the rollers extreme ends axially when the rollers seats onto the plurality of slots.

The torque limiting device is further provided with a first ring which is coaxially mounted to the housing. The first ring comprises a plurality of protrusions at inner surface and a plurality of first provisions on its outer surface. The first ring is mounted onto the housing in such a way that the plurality of protrusions of the first ring contacts and presses the plurality of rollers intact with housing to maintain positive contact between the transmission joint and the housing for transferring of the torque. The torque limiting device is further configured with a second ring having diameter greater that the first ring. The second ring is provided around the first ring. The second ring is configured with a plurality of second provisions on its inner surface. A plurality of resilient members are strategically placed in between the first ring and the second ring such that, one end of the plurality of resilient members is provisioned or seated or located in the plurality of first provisions of the first ring and the other end of the plurality of resilient members is provisioned or seated or located in the plurality of second provisions of the second ring. Thus, the resilient members placed in between the first ring and the second ring exerts pressure on to the first ring which in turn exerts pressure onto the rollers for maintaining positive contact between the housing and the transmission joint. That is, the plurality of resilient members exerts force or pressure on the first ring to facilitate positive contact of the plurality of rollers with the transmission joint for transferring torque from the transmission joint to the drive shaft via the housing, when the torque is within a predetermined limit. In an embodiment, the predetermined limit of torque is defined as a rated torque of the drive shaft.

If the torque transferred from transmission unit is within the predetermined limit, there always exists a positive contact between the transmission joint and the plurality of rollers, thereby transferring the torque to the drive shaft via the housing. However, if the torque exceeds the predetermined limit, the plurality of rollers move upwards from the plurality of slots, by overcoming the pressure of the plurality of resilient members. Due to this upward movement of the plurality of rollers, positive contact between the transmission joint and the plurality of rollers, and in turn the contact between the housing and the transmission joint is discontinued. This makes the transmission joint to slip in the housing and thereby, cut-off transfer of torque to the drive shaft, when the torque exceeds the predetermined limit. The excess torque is dissipated as slip energy of the transmission joint. At the same time, due to the upward movement of the plurality of rollers, the first ring elastically deforms. Thus allows the plurality of rollers to slip from the plurality of protrusions and engage the subsequent protrusion. The additional slip in the plurality of slots adds on for dissipation of excess torque transfer. This sequence of slip in transmission joint and plurality of rollers repeats until the excess torque is dissipated. In one embodiment of the present disclosure, the plurality of protrusions and the plurality of rollers are placed such that, one roller of the plurality of rollers will be in contact with at least one of the plurality of protrusions. This facilitates positive contact between the transmission joint and the plurality of rollers, even when there is angular articulation of the drive shaft. Once excess torque is dissipated as slip energy, the plurality of rollers moves back to their initial position due to decrease in speed of rotation of the transmission joint. Hence, the entire mechanism move back to their initial position to transfer torque to the drive shaft.

Reference will now be made to figures which are exemplary embodiments of the present disclosure, as illustrated in the accompanying drawings. Wherever possible, referral numerals are used to refer to the same or like parts.

Figure 1 illustrates an exploded view of a torque limiting mechanism (100) according to an exemplary embodiment of the present disclosure. The torque limiting mechanism (100) is configured to limit torque transferred to a drive shaft (7) of a machine [not shown in figures]. The torque limiting mechanism (100) comprises a housing (101) configured to connect with the drive shaft (7) [shown in figure 2] of the machine and accommodate a transmission joint (1) [shown in figure 3]. The transmission joint (1) is configured to freely rotate in the housing (101). The transmission joint (1) is coupled to an input shaft (8) of a transmission unit, to receive torque to be transferred to the drive shaft (7). In an exemplary embodiment of the present disclosure, the transmission joint (1) is coupled to the input shaft (8) by way such as but not limiting to splines. In one embodiment of the present disclosure, the transmission joint (1) is a constant velocity joint such as a tripod joint [as shown in figure 3], which is used to transfer torque from the transmission unit to the drive shaft (7).

In an embodiment of the present disclosure, the transmission joint (1) is located at the transaxle end of the vehicle in case of front wheel drive configured vehicle. In another embodiment of the present disclosure, the transmission joint (1) is located in the propeller shaft in case of a rear wheel drive configured vehicle. For an all-wheel drive vehicle, the transmission joint (1) is located at both transaxle as well as propeller shaft of the vehicle.

The torque limiting mechanism (100) is further provided with a plurality of slots (2), provisioned on an outer circumference of the housing (101). In one embodiment of the present disclosure, slot refers to an aperture or slit provisioned on housing of the tripod joint, for inserting a roller. The plurality of slots (2) accommodates a plurality of rollers (3), which makes positive contact with the transmission joint (1). In one embodiment of the present disclosure, the shape of the plurality of slots (2) is selected from group comprising rectangular, square and circular, which serves the purpose of accommodating plurality of rollers (3). The number of plurality of slots (3) corresponds to the number of trunion shafts [not shown] provided to the transmission joint (1). In an exemplary embodiment of the present disclosure, the number of plurality of slots (2) provisioned for a tripod joint is three. The plurality of slots (2) is apart based on the angular position of trunion shafts on the transmission joint (1). As an example, for a tripod joint if the trunion shafts are spaced apart by 120 degrees, the plurality of slots (2) is also spaced apart by 120 degrees. This is to maintain positive contact between the plurality of rollers (3) and all the trunion shafts of the transmission joint (1). If the plurality of slots (2) is spaced apart by varying angles, not all the trunion shafts be in positive contact with the plurality of rollers (3), which is undesirable. To the plurality of slots (2), at least one pin (2a) is provisioned to prevent misalignment of plurality of rollers (3). The at least one pin (2a) extends from the sides of the plurality of slots (2) and holds axial ends of the plurality of rollers (3) when the rollers seats onto the plurality of slots. The axial contact maintains orientation of the plurality of rollers (3) in the plurality of slots (2), even if there is radially outward movement of the plurality of rollers (3).

To the housing (101), a first ring (4) is adapted to be mounted coaxially. The first ring (4) is configured with a plurality of protrusions (4a) on the inner surface. In one embodiment of the present disclosure, protrusion refers to a bump provided on surface of the first ring. The first ring (4) is mounted in such a way that the plurality of protrusion (4a) contacts and presses the plurality of rollers (3) intact with the housing (101). Thus, the plurality of protrusions (4a) locks the plurality of rollers (3) from slipping. In one embodiment of the present disclosure, the number of plurality of protrusions (4a) corresponds to the number of plurality of rollers (3). The plurality of protrusions (4a) also enables dissipation of the rotational energy of the plurality of rollers (3), when torque exceeds predetermined limit. The plurality of protrusions (4a) are provided on the plurality of slots (3) such that, when the plurality of slots (3) slip from one of the protrusion and engage subsequent protrusion of the plurality of protrusions (4a), the rotational energy in the plurality of rollers (3) is lost as slip energy. The plurality of protrusions (4a) is spaced apart by angle equal to the plurality of rollers (3), so that the plurality of rollers (3) are in contact with the plurality of protrusions (4a), even when there is an angular articulation between the input shaft (8) and the drive shaft (6). Thus enable positive contact between the transmission joint (1) and the housing (101) via the plurality of rollers (3), for transfer of torque to the drive shaft (7). To the outer circumference of the first ring (4), a plurality of first provisions (4b) is provisioned. The plurality of first provisions (4b) acts as a seat for receiving a resilient member. In one embodiment of the present disclosure, first provision refers to recess provided to surface of first ring to accommodate a spring member.

The torque limiting mechanism (100) also includes a second ring (6) having diameter greater than the first ring (3). The second ring (6) comprises a plurality of second provisions (6b) and is adapted to be coaxially mounted on the first ring (4). In one embodiment of the present disclosure, second provision refers to pin provided to inner surface of second ring to accommodate a spring member. The second ring (6) acts a support for the entire torque limiting mechanism (100) and at the same time make the system integral to the housing (101).

The mechanism (100) also comprises a plurality of resilient members (5) strategically provisioned or seated or located in between the first ring (4) and the second ring (6). In one embodiment of the present disclosure, the plurality of resilient members (5) is selected from group such as but not limiting to spring member. The plurality of resilient members (5) apply pressure on the first ring (4), so as to maintain positive contact between the transmission joint (1) and the plurality of rollers (3). The plurality of resilient members (5) are selected such that there is no deflection of the plurality of resilient members (5) until the torque input from the transmission unit exceeds predetermined limit. In one embodiment of the present disclosure, the predetermined amount of torque is rated torque or design torque of the drive shaft (7) of a machine.

Figure 2 illustrates side view of the assembly torque limiting mechanism (100) according to exemplary embodiment of the present disclosure. Firstly, the transmission joint (1) coupled to input shaft (8) of the transmission unit of the vehicle is provisioned in the housing (101). Secondly, the housing (101) is connected to the drive shaft (7) to transfer torque. Subsequently, the plurality of rollers (3) are provisioned in the plurality of slots (2), such that the plurality of rollers (3) are in-between the at least one pin (2a). On the housing (101), the first ring (4) is mounted coaxially such that the plurality of protrusions (4a) of the first ring (4) contacts and locks the plurality of rollers (3) from slipping. Finally, a second ring (6) is mounted coaxially on the first ring (4). In-between the first ring (4) and the second ring (6), the plurality of resilient members (5) is positioned such that one end of the plurality of resilient members (5) is provisioned or seated or located in the plurality of first provisions (4b) and the other end is provisioned or seated or located in the plurality of second provisions (6a).

Figure 3 illustrates front view of the assembly torque limiting mechanism (100) during working when the torque transfer is within predetermined limit, according to an exemplary embodiment of the present disclosure. If the torque to be transferred is within the rated value of the drive shaft (7), positive contact between the transmission joint (1) and the plurality of rollers (3) persists. Thereby, the plurality of rollers (3) rotates along with the transmission joint (1). Due to the rotation of plurality of rollers (3), the housing (101) also rotates, thereby transferring torque to the drive shaft (7). Due to this arrangement of the torque limiting mechanism (100) the entire assembly rotates along with the housing (101).

Figure 4 illustrates side view of the assembly torque limiting mechanism (100) during working when the torque exceeds the predetermined limit, according to an exemplary embodiment of the present disclosure. Once torque exceed the rated value, due to the speed of rotation of the transmission joint (1), the plurality of rollers (3) move radially upwards by overcoming pressure exerted by the plurality of resilient members (5) [clearly shown in figure 1]. Due to this radially upward movement of the plurality of rollers (3), the positive contact between the transmission joint (1) and the plurality of rollers (3) is discontinued. Thus the transmission joint (1) slips or rolls in the housing (101). As, there is no positive contact between the transmission joint (1) and the plurality of rollers (3) due to the slip, there is no torque transfer to the housing (101). In one embodiment of the present disclosure, excess torque applied on the input shaft (8) [clearly shown in figure 1] is as high as twice the rated value of the drive shaft (7) [clearly shown in figure 2]. At the same time the excess torque is dissipated in the housing (101) as slip energy. This prevents damage of the transmission joint (1) and the drive shaft (7), due to excess torque transfer. As the plurality of rollers (3) have moved radially upwards, the first ring (4) elastically deforms. This enables the plurality of rollers (3) to slip from the plurality of protrusions (4a) in the first ring (4) and engage the subsequent protrusion of the plurality of protrusion (4a), which further contribute for excess torque dissipation. Once all the excess torque is dissipated in the form of slip energy, the speed of the rotation transmission joint (1) decreases, thereby the plurality of rollers (3), the first ring (4) and the plurality of resilient members (5) return to their initial positions, to transfer input torque to drive shaft (7).

As an example, considering that rated torque of a drive shaft (7) is 100 Nm, the plurality of resilient members (5) is designed to withstand pressure of 100 Nm to exert pressure onto the plurality of rollers (3). If the input torque from the transmission unit is within the rated torque, then positive contact between the transmission joint (1) and the plurality of rollers (3) persists. Thus, the housing (101) rotates along with the transmission joint (1), thereby transfer torque to the drive shaft (7). In this scenario, the predetermined torque can be defined as a torque which is less than 100 Nm.

If the input torque from the transmission unit is exceeding the rated torque say 300Nm, the pressure exerted by the plurality of resilient members (5) onto the plurality of rollers (3) is overcome and plurality of rollers (3) are displaced upwards from the plurality of slots (3). Thus the positive contact between the transmission joint (1) and the housing (101) is discontinued, thereby the transmission joint (1) slips or rolls inside the housing (101) without transferring torque to the drive shaft (7). Thus the excess torque in the transmission joint (1) is disspated as slip energy. As the plurality of rollers (3) are displaced upwards, the first ring (4) elastically deforms. Thus enable the plurality of rollers (3) to slip from the plurality of protrusions (4a) and engage subsequent protrusion, which further contributes to dissipation of torque. Once all the excess torque that is 200Nm is dissipated in the form of slip energy, the speed of the rotation transmission joint (1) decreases, thereby the plurality of rollers (3), the first ring (4) and the plurality of resilient members (5) return to their initial positions, to transfer input torque to drive shaft (7).

INDUSTRIAL APPLICABILITY
The torque limiting mechanism is used in vehicles with configurations such as rear wheel drive, front wheel drive and all-wheel drive vehicles. In front wheel drive vehicles, the mechanism is located to the transaxle, in rear wheel drive vehicles, the mechanism is located to the propeller shaft of the vehicle and in all-wheel drive vehicles, the mechanism is located at the transaxle end as well as at the propeller shaft end.

The torque limiting mechanism is used in chain drives of the vehicles, by locating the mechanism in line with the power train of the vehicle.

The torque limiting mechanism is used in transfer cases to limit excess torque flow in the system.

The torque limiting mechanism can be used in power driven machines as fuse to avoid failure due to shock and excessive torque.

Advantages
In one embodiment of the present disclosure, a unique and robust design for limiting the torque transferred to the drive shaft is disclosed.

In one embodiment of the present disclosure, the torque limiting mechanism limits vehicle overloading relating failures in powertrain.

In one embodiment of the present disclosure, the torque limiting mechanism is simple in design and retrofittable.

In one embodiment of the present disclosure, the torque limiting mechanism is cost effective and highly effective solution for commercial vehicles.

The present disclosure provides a torque slip mechanism for a transaxle assembly which can avoid failures of the transaxle due to overloads in the powertrain.

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.”

In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

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.
,CLAIMS:We claim:

1. A torque limiting mechanism (100), comprising:
housing (101) comprising a plurality of slots (2) configured on outer circumference of the housing (101), and configured to accommodate a transmission joint (1) of a transmission unit such that the transmission joint (1) is freely rotatable inside the housing (101), wherein the housing (101) is connectable to a drive shaft (7);
a plurality of rollers (3) adapted to mount onto the plurality of slots (2);
a first ring (4) mounted coaxially around the housing (101), comprising a plurality of first protrusions (4a) at inner surface of the first ring (4), wherein said first protrusions (4a) locks the plurality of rollers (3) from slipping, and a plurality of first provisions (4b) provided on outer surface of the first ring (4);
a second ring (6) mounted coaxially around the first ring (4), wherein the second ring (6) is configured with plurality of second provisions (6a) on its inner surface;
a plurality of resilient members (5) provided in-between the first ring (4) and the second ring (5) such that, one end of the plurality of resilient members (5) is mounted in the plurality of first provisions (4b) and other end of the plurality of resilient members (5) is mounted to the plurality of second provisions (6a),
wherein the plurality of resilient members (5) apply pressure on the first ring (4) to facilitate positive contact of the plurality of rollers (3) with the transmission joint (1) for transferring torque from the transmission joint (1) to the drive shaft (7), when the torque is within a predetermined limit.

2. The torque limiting mechanism (100) as claimed in claim 1, wherein, the plurality of rollers (3) move radially upwards from the plurality of slots (2) by overcoming the pressure of the plurality of resilient members (5), thereby the positive contact between the plurality of rollers (3) and the transmission joint (1) slips to cut-off torque transmission to the drive shaft (7), when torque from the transmission unit exceeds the predetermined limit.

3. The torque limiting mechanism (100) as claimed in claim 1, wherein the transmission joint (1) is a tripod joint which facilitates angular movement to the drive shaft (7).

4. The torque limiting mechanism (100) as claimed in claim 1, wherein the transmission joint (1) is coupled to the transmission unit by an input shaft (8).

5. The torque limiting mechanism (100) as claimed in claim 1, wherein at least one pin (2a) is provisioned in the plurality of slots (2) to prevent misalignment of the plurality of rollers (3).

6. The torque limiting mechanism (100) as claimed in claim 1, wherein the predetermined limit of torque is rated torque of the drive shaft (7).

7. The torque limiting mechanism (100) as claimed in claim 1, wherein the plurality of resilient members (5) is a spring member.

8. A method of assembling a torque limiting mechanism (100) to limit torque transmission to a driveshaft (7) , said method comprises acts of:
mounting a transmission joint (1) of a transmission unit in a housing (101) comprising a plurality of slots (2) configured on outer circumference of the housing (101), such that the transmission joint (1) is freely rotatable inside the housing (101), wherein the housing (101) is connectable to the drive shaft (7);
mounting a plurality of rollers (3) onto the plurality of slots (2);
mounting a first ring (4) coaxially around the housing (101), comprising a plurality of first protrusions (4a) at inner surface of the first ring (4), wherein said first protrusions (4a) locks the plurality of rollers (3) from slipping, and a plurality of first provisions (4b) at outer surface of the first ring (4);
mounting a second ring (6) coaxially around the first ring (4);
positioning a plurality of resilient members (5) in-between the first ring (4) and the second ring (5) such that, one end of the plurality of resilient members (5) is mounted in the plurality of the first provision (4b) and the other end of the plurality of resilient members (5) is mounted to the plurality of second provisions (6a),
wherein the plurality of resilient members (5) apply pressure on the first ring (4) to facilitate positive contact of the plurality of rollers (3) with the transmission joint (1) for transferring torque from the transmission joint (1) to the drive shaft (7), when the torque is within a predetermined limit;

9. The method as claimed in claim 8 comprises act of engaging at least one of roller of the plurality of rollers (3) with subsequent protrusion of the plurality of protrusions (4a), when the plurality of rollers (3) slip from the plurality of protrusions (4a) to limit the torque transferred to the drive shaft (7).

10. A machine comprising the mechanism (100) as claimed in claim 1.

11. The machine as claimed in claim 10, wherein the machine is a vehicle.

Dated this 26th Day of March, 2015
P.H.D RANGAPPA
OF K&S PARTNERS
IN/PA 1538
AGENT FOR THE APPLICANT