TECHNICAL FIELD

[0001] The present subject matter relates to a motor vehicle and particularly but not exclusively, the present subject matter relates to the motor vehicle provided with a rear disc brake.

BACKGROUND

[0002] Typically, motor vehicles are provided with a braking system that is used for slowing down the motor vehicle or to bring the motor vehicle to a halt. Generally, the motor vehicles are provided with either drum brakes or disc brakes or a combination of both. For example, in low-performance motor vehicles, the disc brake may be provided on both the front wheel(s) and the rear wheel(s) or a front wheel(s) may be provided with a disc brake. Whereas, in high-performance motor vehicles or in motor vehicles that require effective braking, the rear wheel(s) is also provided with disc brakes. Typically, similar trend is followed in small capacity vehicles like two-wheeled or three-wheeled motor vehicles, which are catering to commuter applications.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The detailed description is described with reference to an embodiment of a two-wheeled saddle-ride type motor vehicle along with the accompanying figures. Similar numbers are used throughout the drawings to reference like features and components.

[0004] Fig. 1 illustrates a right-side view of an exemplary motor vehicle, in accordance with an embodiment of the present subject matter.

[0005] Fig. 2 (a) illustrates a right-side view of a rear structure of the motor vehicle, in accordance with an embodiment of the present subject matter.

[0006] Fig. 2 (b) a left-side view of a rear structure of the motor vehicle, in accordance with an embodiment of the present subject matter.

[0007] Fig. 2 (c) illustrates a sectional (top) view of a rear structure, the section being taken along axis A-A’ as shown in Fig. 2 (a), in accordance with an embodiment of the present subject matter. [0008] Fig. 2 (d) illustrates a sectional (rear) view of a rear structure, the section being taken along axis B-B’ as shown in Fig. 2 (a), in accordance with an embodiment of the present subject matter.

[0009] Fig. 2 (e) illustrates an enlarged view of a portion of the rear structure, in accordance with an embodiment of the present subject matter. Fig. 2 (e)

[00010] Fig. 2 (f) illustrates an exploded view of the rear structure, in accordance with an embodiment of the present subject.

[00011] Fig. 2 (g) illustrates a perspective view of a portion of the rear structure, in accordance with an embodiment of the present subject matter.

[00012] Fig. 2 (h) illustrates an enlarged view of a portion of the rear structure, in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION

[00013] Generally, in motor vehicle that require effective braking, the rear wheel is equipped with a disc brake. Such a braking system is predominantly seen in motorcycles. In the motorcycles, a rear wheel axle is a dead axle and the rear wheel is rotatably disposed on the rear wheel axle . A disc plate of the disc brake is fastened to the rear wheel, which is freely rotatable about the dead axle. A disc caliper is supported on the dead axle or on a swing arm. Typically, removal of the wheel, say for servicing or for similar purposes, requires the disc caliper to be removed, which is a cumbersome process. During the servicing the disc plate may receive any undesired forces or impact, which may alter its profde or damage the part. Moreover, when the disc plate is removed, the disc caliper is left hanging on the adjacent parts, which may also damage the caliper or may exert tension on a brake hose, which may damage or elongate the brake hose.

[00014] Further, in certain other type of motor vehicles, which have a crankcase that supports the rear wheel, it is a challenge to provide a disc brake in the rear. Typically, certain attempts were made in the art to provide a disc brake in the rear. In those designs, in addition to the crankcase, which is a swinging type member, an additional swing arm is used for mounting the disc caliper and to support the rear wheel. This requires provision of extra swing arm for mounting the disc caliper. The disc plate is, typically, fastened to the wheel. Hence, there is need for providing bolts or nuts, which have threads for fastening, on the wheel. Correspondingly, nuts or bolts are used to fasten the disc plate to the wheel. When excessive force is used for fastening, the disc plate may get deformed. Deformation of the disc plate may affect braking performance and may cause uneven wear out of the disc plate or early wear out of the frictional parts on the disc caliper. In certain other cases, the threading may get damaged due to excessive force or due to improper fastening. In case of alloy wheels, the wheel may get damaged due to application of excessive force.

[00015] With the addition of the disc brake with disc plate & disc calipers, and the swing arm, the weight of the motor vehicle increases significantly. Increase in weight of the motor vehicle affects the performance and efficiency of the motor vehicle, which is undesired. In case of a motor vehicle with an internal combustion, the space for mounting of a muffler or similar components in the vicinity of the rear wheel becomes narrow. Further, during removal of the wheel, various components have to be disconnected. For example, removal of the rear wheels requires disengaging the wheel from the crankcase and the swing arm. Further, since the wheel is connected with the disc plate, the disc caliper has to be disengaged from the wheel (disc plate) eventually increasing the service difficulty as well as time required.

[00016] Moreover, is some of the motor vehicles, the wheel size is kept smaller for better manoeuvrability. Such a practice is seen in certain motor vehicle with the swinging type power unit. Removal of disc caliper is a challenge in such vehicles. Due to the smaller diameter of the wheel, a wheel rim of the wheel may be in proximity to the disc caliper. Therefore, the disc caliper may interfere with the wheel rim during assembly or disassembly procedure.

[00017] Hence, there exist challenges to provide a rear disc brake in a motor vehicle having a support structure that supports a rear wheel in a compact manner. The present subject matter is aimed at addressing the aforementioned and other problems in the prior art.

[00018] In an exemplary implementation, the present subject matter provides a motor vehicle comprising a support structure. A first-shaft is rotatably supported by the support structure. In one implementation, the first-shaft is disposed in a cantilevered fashion. One or more bearing members are provided to rotatably support the first-shaft on the support structure. The one or more bearing members includes a first-bearing member. A first-wheel is supported on the first-shaft. The first-wheel is provided such that the first-wheel rotates along with the first-shaft. [00019] In one implementation, the motor vehicle comprises a first-brake corresponding to the first-wheel and the first-brake comprises a first-disc member. The first disc -member is independently located on the first- wheel. The first discmember is not integrated or fastened to the first-wheel. It is independently located to rotate along with the first-wheel.

[00020] In one embodiment, the first-disc member is supported by the first-wheel without the need for any fasteners. The first-disc member is disposed between the first wheel and the first-bearing member. The first-disc member, which is supported by the first-wheel rotates along with the first-wheel. The first-disc member is securely supported by axial disposition between the first-wheel and the first-bearing member without the need for any fasteners. There is no requirement of providing bolts with threads and corresponding nuts or vice-versa. The part count is reduced. [00021] In one embodiment, the first-shaft supports a first-flange member. The first-flange member is disposed between the first-bearing member and the first-disc member. The first-disc member is an axial sandwich between the first-bearing member through the first-flange member and the first-wheel. The first-disc member that is supported by the first-wheel is further in an axial sandwich between the first- flange member and the first- wheel. Thus, the first-disc member will be aligned with the wheel as well as the first-flange member without the need for individual fastening of fasteners on to the first-wheel. Further, the first-wheel can be independently removed without disturbing the first-disc member as there is a supporting engagement therebetween.

[00022] In one embodiment, the first-flange member is supported by the first- shaft. Thus, the first-wheel, the first-flange member, and the first-disc member that is axial sandwich therebetween rotate along with the first-shaft. Therefore, when the first-wheel is passing through pot-holes or through uneven road conditions, an effect of any tensile stress, due to road impact, that may be induced on wheel is minimal. Especially, effect of the tensile stress at the wheel-hub is reduced due to compressive forces acting on the wheel due to the axial force acting on the proposed mounting. Therefore, crack initiation or formation is reduced in the wheel, which improves life of the wheel. The compressive forces act as pre-stress that counters the fatigue load.

[00023] In one embodiment, the first-flange member comprises a first-contact region provided in an axial contact with the first-bearing member that supports the first-shaft. Axial movement of the first-flange member is restricted by the first- bearing member. The first-disc member is secured by the axial sandwich mounting as the axial movement of the first-flange member is restricted by the first-bearing member on one side and the axial movement of the first-wheel would be restricted by a main fastening member to clamp the first-flange member, the first-disc member, the first-wheel against the first-bearing member. In effect, a single main fastening member like a nut is used for fastening the aforementioned components. The present subject matter provides ease of assembly and disassembly without any compromise on secure mounting.

[00024] In one embodiment, the first-bearing member comprises an outer race and an inner race. The outer race is fixedly connected or press-fitted to the support structure. The inner race is fixedly connected to the first-shaft and rotates therewith. The first-contact region is disposed to abut the inner race. There is no relative movement between the first-flange member and the inner race as they rotate together with the shaft.

[00025] In one embodiment, the first-flange member comprises a second-contact region. The second-contact region is disposed radially outward at a pre-determined distance with respect to the first-contact region. The second-contact region is configured to abut and engage with the first-disc member. In one implementation, the engagement of the second-contact region is to further support the first-disc member.

[00026] In one embodiment, the first-flange member and the first-wheel are axially spaced apart with a pre-determined gap therebetween. The pre-determined gap helps in maintaining the axial sandwich with the first-disc member as there is no direct effect of one component on another, the axial sandwich being between the first-wheel and the first-flange member.

[00027] In one exemplary implementation, the first-wheel comprises a wheel-hub. The wheel-hub comprises a stem portion and an arm portion. The arm portion extends beyond the stem portion in an axial direction. The pre-determined gap is maintained between the stem portion and the first-flange member.

[00028] In one embodiment, the second-contact region engagingly supports the first-disc member in both radial and axial directions. Thus, even when the first- wheel is removed, the first-disc member is still supported by the first-flange member and there is no need for disturbing the first-brake.

[00029] As per one embodiment, in order to further reinforce the engaging support of the first-disc member with the first-flange member (the second-contact region) an interference fit is provided therebetween.

[00030] As per another embodiment, a clearance fit is provided between the first- flange member and the firs-disc member. In such a design, the first-disc member would be supported by a first-caliper member of the first-brake and by the first- flange member.

[00031] In one embodiment, the first-flange member is integrally formed with the first-disc member whereby the integrated first-disc member would be supported between the first-bearing member and the first- wheel. The part count is reduced in this implementation, without compromising on functionality.

[00032] In one embodiment, the first-disc member is clamped between the first- wheel and the first-flange member due to axial tightening (force) of a main fastening member on the first-shat. The first-shaft has a free-end and the main fastening member like a nut is secured to the first-shaft. The main fastening members exerts axial tension on the first-wheel, the first-disc member and the first- flange member whereby the mentioned components would be securely clamped between the first-bearing member and the main fastening member.

[00033] In one implementation, the first-wheel comprises an engaging structure forming a plurality of pins, as per one implementation. The plurality of pins is integrally formed (encasted in case of an alloy-type first-wheel) therewith. The plurality of pins is configured to engagingly support the first-disc member. During application of brake (exertion of frictional force by the first-caliper member), the braking force acting on the first-disc member is transferred directly to the first- wheel, say through the plurality of pins. The impact of the braking force on the first- shaft is smaller when compared to wheel assemblies that have the disc member fixed to axle.

[00034] In one embodiment, the plurality of pins protrude out from a wheel-hub in an axial direction so as to engagingly support the first-disc member.

[00035] In one embodiment, the first-brake comprises a first-caliper member. The first-caliper member is mounted to the support structure. The first-caliper member is mounted by two or more fastener members of which at least one being disposed on each lateral side.

[00036] In one embodiment, the support structure is mounted to a frame assembly of the motor vehicle. The support structure is configured to house a transmission system of the motor vehicle. The transmission system may include a continuously variable transmission (CVT), an automatic manual transmission (AMT), a belt drive, a geared drive, or any other known transmission system.

[00037] In one embodiment, the motor vehicle comprises a power unit. The power unit can be an internal combustion (IC) engine, an electric motor or both. In one implementation, the power unit is mounted to the frame assembly. The support structure is swingably mounted to the frame assembly and the transmission system is configured to couple the power unit to the first-wheel.

[00038] The support structure may be disposed on a left-side or a right-side of the first-wheel and the first-brake can be disposed accordingly depending on the position of the support structure.

[00039] In another implementation, the support structure is part of the power unit and the power unit is swingably mounted to the frame assembly. The support structure can be a crankcase in case of an IC engine or it can be structural member that at least partially supports the electric motor, which acts as a prime mover. [00040] These and other advantages of the present subject matter would be described in greater detail in conjunction with, the figures in the following description. The present subject matter is further described with reference to accompanying figures. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.

[00041] Wherever arrows are shown in the top right comer of the drawings, ‘FW’ indicates forward direction, ‘RW’ indicates rearward direction, ‘UP’ indicated upward direction, ‘DW’ indicated downward direction, ‘RS’ indicates right- side, and ‘LS’ indicates left-side, with reference to the motor vehicle/rider.

[00042] Fig. 1 illustrates a right-side view of an exemplary motor vehicle, in accordance with an embodiment of the present subject matter. The motor vehicle 100 comprises a first wheel 101 and a second wheel 102. The present subject matter is not limited to the motor vehicle with two-wheels, as it is considered only for ease of explanation. The motor vehicle 100 comprises a frame assembly 130 (shown schematically). The frame assembly 130 comprises a head tube 131, a main tube 132 and one or more rear tube(s) 133. In accordance with the current embodiment, the head tube 131 is disposed in a front portion of the motor vehicle 100. The main tube 132 extends obliquely downward from the head tube 131 and the main tube 132 undergoes a bend. Subsequent to the bend, the main tube 132 extends substantially horizontally in a rearward direction. The one or more rear tube(s) 133 extend rearward from a rear end 134 of the main tube 132. In one implementation, the rear end 134 of the main tube 132 is connected to a cross-member (not shown) that extends in a lateral direction of the motor vehicle 100. The one or more rear tube(s) 133 has a front end connected to the cross-member. The one or more rear tube(s) 133 that extend inclinedly rearward may further comprise of one or more bends in order to adapt to a layout of the motor vehicle 100. [00043] In one embodiment, the frame assembly 130 comprises a pillion footrest mounting tube (not shown). The pillion footrest mounting tube extends downward from the one or more rear tube(s) 133. A brake oil-reservoir or a brake oil holder, which is corresponding to the first-brake/ rear brake, is mounted to the pillion footrest mounting tube. This ensures that oil level in the brake oil-reservoir is easily visible to the user without need of dismantling any parts from the vehicle and thereby enabling ease of maintenance and service.

[00044] The motor vehicle 100 comprises a steering system (not shown) and a front suspension 140 is part of the steering system. The steering system is rotatably journaled about the head tube 131. A handlebar assembly 150 is connected to the steering system for manoeuvring the motor vehicle 100. In another implementation, a pressure control valve (PCV) is provided for braking operation. The PCV is mounted to a bracket (not shown), which is fastened to the handlebar assembly 150. The bracket is a sheet metal bracket. Through the bracket, the PCV is directly fastened to handlebar assembly 150. Further, the handlebar assembly 150 may support a first-brake lever and a second-brake lever (both not shown). Correspondingly, a master cylinder (with reservoir) is provided for each brake lever. The front suspension 140 rotatably supports the second wheel 102. The second wheel 102 is provided with a front brake (not shown). The front brake can be any one of a drum brake or a disc brake. A power unit 120 is swingably mounted to the frame assembly 130. A seat assembly 165 is disposed above the power unit 120. In one implementation, the power unit 120 is swingably supported by the one or more rear tube(s) 133. In another implementation, the power unit 120 is swingably supported by the main tube 132. In the depicted embodiment, the motor vehicle 100 comprises a step-through portion 145. The power unit 120 is disposed rearward to the step-through portion 145. The rear wheel is rotatably supported by a support structure 205 (shown in Fig. 2 (a)). The rear wheel is provided with a first- brake 160, which is a disc brake. Further, a rear suspension 155 connects the support structure to the frame assembly 130 at the one or more rear tube(s) 133.

[00045] Fig. 2 (a) illustrates a right-side view of a rear structure of the motor vehicle, in accordance with an embodiment of the present subject matter. Fig. 2 (b) a left-side view of a rear structure of the motor vehicle, in accordance with an embodiment of the present subject matter. The rear structure comprises a rear wheel and other ancillary components mounted to a support structure. In one implementation, the support structure 205 is a housing configured to house a transmission system (not shown). The transmission system transfers power/torque generated by a power unit to the first-wheel 101. In one implementation, the power unit is an internal combustion (IC) engine. The support structure forms part of a crankcase of the IC engine. In one implementation, the power unit is an electric motor. The electric motor can be mounted to the support structure. In yet another implementation, the power unit may comprise both the IC engine and the electric motor, acting as hybrid power train.

[00046] The support structure 205 is disposed towards one lateral side of the first- wheel 101. In other words, since the first-wheel 101 is supported by the support structure 205, the first-wheel 101 is disposed towards one lateral side of the support structure 205. In the depicted implementation, the first-wheel 101 is disposed on a right-side thereof. The rear wheel may be disposed on a left-side of the support structure, as part of another implementation. A first-shaft 210 is rotatably supported by the support structure 205. The first-shaft 210 is disposed in a cantilevered fashion. A certain portion of the first-shaft 210 is rotatably supported by the support structure 205 and a free-end protrudes out from the support structure 205. In one implementation, the first-shaft 210 is rotatably supported by one or more bearing members. The bearing member can be a ball-bearing, a roller-bearing or a similar type of bearing. An inner race of the bearing member is secured to the first-shaft 210 and an outer race of the bearing member is secured to the support structure.

[00047] The first-brake 160 comprises a first-disc member 215 and a first-caliper member 220. The first disc-member 215 is independently located on the first-wheel 101. The first disc-member 215 is neither integrated nor fastened to the first-wheel 101. It is independently located to rotate along with the first-wheel 101. In one implementation, the first disc -member member 215 can be removed along with the first-wheel 101 as it is located on the first-wheel 101. Alternatively, the first- wheel 101 can be independently removed without the need for removal of the first-disc member 215 as the first-disc member 215 is just located on the first-wheel 101 and in such a condition, the first-disc member 215 would still be supported on the vehicle through other ancillary components (elaborated subsequently).

[00048] The first-disc member 215 is securely supported on the first-wheel 101 without the need for any fasteners. Further, the first-caliper member 220 is mounted to the support structure 205. The first-caliper member 220 is configured to engage with the first-disc member 215 upon application of brake. The first-disc member can be a circular disc member or petal-shape disc member (as shown). The petalshaped disc member provides larger surface for effective cooling thereof. In one embodiment, the first-disc member 215 is provided with a plurality of cooling apertures that are selectively provided on the first-disc member, again, for effective and quick cooling thereof. In one implementation, as shown in Fig. 2 (b), the support structure 205 is an elongated member in a longitudinal direction FW-RW. The first-caliper member 220 is disposed at an upper-rear diagonal portion of the support structure 205. A first-brake hose 225 is connected to the first-caliper member 220 and for actuating one or more pistons thereof. The first-brake hose 225 is securely routed from an upper portion of the support structure 205 towards a front portion thereof. The first-brake hose 225, in one implementation, is a combination of a flexible brake hose and rigid brake hose.

[00049] Fig. 2 (c) illustrates a sectional (top) view of a rear structure, the section being taken along axis A-A’ as shown in Fig. 2 (a), in accordance with an embodiment of the present subject matter. The first-wheel 101 comprises a wheelbody 250 that support on a tyre 251. In one implementation, the wheel-body 250 is made of any alloy, not by way of limitation. The wheel-body 250 may include a wheel-rim 252, a plurality of arms 253, and a wheel-hub 254. Further, the first- wheel 101 may include a wheel-insert 255, which is provided at the wheel-hub 254. The wheel-insert 255 is configured to engage with a plurality of splines 212 provided on a periphery of the first-shaft 210. Due to the engagement between the wheel-insert 255 and the plurality of splines 212, the first-shaft 210 and the first- wheel 101 rotate together. [00050] In one implementation, the support structure 205, configured to house a transmission system (not shown), is formed of at least two -sub parts. In the depicted embodiment, the support structure 205 is formed by a first -sub part 206 and a second -sub part 207 that are laterally connected to each other to form the housing. A first-bearing member 230 is provided on the first -sub part 206 and the second- bearing member 232 is disposed on the second -sub part 207. The first-shaft 210 is rotatably supported by the first-and the second-bearing member 230, 232 and receives rotational force form the transmission system. The first-shaft 210 is rotatably supported by the first-bearing member 230 and the second-bearing member 232. The first-shaft 210 extends from the support-structure 205 in a cantilevered fashion. The first-shaft 210 has a free-end 211 through which the first- wheel 101 is mounted thereto.

[00051] The rear structure comprises the first-disc member 215 and the first-caliper member 220. The first-disc member 215 is supported by the first-wheel 101 without the need for any fasteners. The first-disc member 215 being supported by the first- wheel 101. The first-disc member 215 is located on the first-wheel 101 and disposed in close vicinity of the first-bearing member 230. The rear structure comprises a first-flange member 240. The first-flange member 240 is supported on the first-shaft 210. In one implementation, the first-flange member 240 is in an axial contact with an inner race (not marked) of the first-bearing member 230. Further, the first-disc member 215 is disposed in an axial sandwich configuration denoted by 245 between the first-flange member 240 and wheel-hub 254 of the first-wheel 101. A main fastening member 260 like a nut secures the first-wheel 101, the first-disc member 215 and the first-flange member 240 on the first shaft 210 by exerting axial tension thereon.

[00052] In other words, the first-shaft 210 supports the first-flange member 240. The first-flange member 240 is disposed between the first-bearing member 230 and the first-disc member 215. The first-disc member 215 is in an axially sandwiched configuration 245 sandwiched between the first-bearing member 230 through the first-flange member 240 and the first-wheel 101. The first-disc member 215 is clamped between the first- wheel 101 and the first-flange member 240 by axial tightening of the main fastening member 260 on the first-shaft 210. The first-disc member 215, the first-flange member 240, and the first-wheel 101 are secured between the first-bearing member 230 and the main fastening member 260.

[00053] Fig. 2 (d) illustrates a sectional (rear) view of a rear structure, the section being taken along axis B-B’ as shown in Fig. 2 (a), in accordance with another embodiment of the present subject matter. Fig. 2 (e) illustrates an enlarged view of a portion of the rear structure, in accordance with this embodiment of the present subject matter. The first-wheel 101 is provided with an engaging structure. In one implementation, the engaging structure is a plurality of pins 270 that are integrally formed along with the first- wheel 101. In one embodiment, the plurality of pins is encasted along with the alloy wheel (first- wheel 101). The first disc-member 215 is independently located on the first- wheel 101 through the plurality of pins 270. Each pin of the plurality of pins 270 comprises a substantially cylindrical structure with non-uniform radius. A portion of the plurality of pin 270 that is encasted comprises a larger radius when compared to a portion that is protruding out. As per the exemplary construction depicted, the portion of the pin 270 that is encasted is provided with a circumferential depression that enables it be securely seated in the alloy wheel.

[00054] Correspondingly, the first-disc member 215 is provided with a complementary-engaging portion in order to engage with the engaging structure of the first-wheel 101. In one implementation, the complementary-engaging portion is a plurality of apertures 275 that are selectively provided on the first-disc member 215. Through the plurality of apertures 275 the first-disc member 215 engages with the plurality of pins 270. The engagement between the plurality of pins 270 and the plurality of apertures 275 is such that the first-disc member 215 makes contact with the first-wheel 101. The resulting engagement joint is such that the first-wheel 101 provides support to the first-disc member 215. When the first-wheel 101 is rotated by the first-shaft 210, the first-disc member 215 also rotates along with the first- wheel 101. In one implementation, the engagement can be a transition fit. In another implementation, the engagement can be a minor-interference fit. [00055] In one implementation, the first-flange member 240 comprises a solidumbrella structure. The solid-umbrella structure is provided with an aperture at the centre, in axial direction, for mounting on to the first-shaft 210. The first-flange member 240 comprises a first-contact region 241 and a second-contact region 242. The first contact region 241 is provided on one-axial face, which is disposed towards the first-bearing member 230. The first-flange member 240, which is supported by the first-shaft 210, is in an axial contact 244 with the first-bearing member 230 through the first-contact region 241. The first-bearing member 230 comprises an outer race 233 and an inner race 234. The outer race 233 is fixedly press-fit to the support structure 205 and the inner race 234 is press-fit to the first- shaft 210. The first-contact region 241 protrudes in the axial direction and abuts the inner race 234. The second-contact region 242 is radially outward with respect to the first-contact region 241 at a predetermined distance/ radius 243. The predetermined distance is not limited to any specific value as it is dependent on parameters like a diameter of the wheel, a diameter of the first-flange member etc. The second-contact region 242 is configured to abut and engage with the first-disc member 215. The second-contact region 242 engagingly supports the first-disc member 215 in both radial and axial directions. The engagement between the first- flange member 240 and the first-disc member 215 can be by a clearance fit or an interference fit.

[00056] In an assembled condition, the first-disc member 215 is securely mounted between the first-wheel 101 and the first-flange member 240. A first-axial side 216 of the first-disc member 215, which is facing the first-wheel 101, is disposed in contact with the wheel-hub 254 and a second-axial side 217, which is facing away from the first- wheel 101 (which is facing the flange member 240) is supported by the first-flange member 240. In one implementation, the wheel-hub 254 has a Y- shaped section as shown in Fig. 2 (d), when viewed in a radial direction. A stem portion 265 of the Y -shaped section accommodates the wheel-insert 255 and an arm portion 266 of the Y-shaped section supports the plurality of pins 270. The arm portion 266 extends beyond the stem portion 265, in an axial direction, to support the first-disc member 215. A pre -determined gap 248 is maintained, in axial direction, between the first-flange member 240 and the stem portion 265 (of the wheel-hub 254). The pre-determined gap 248 enables the first-wheel 101 to exert axial engaging force on the first-disc member 215 without any undesirable hindrance from the first-flange member 240 and the stem portion 265.

[00057] Fig. 2 (f) illustrates an exploded perspective view of the rear structure, in accordance with an embodiment of the present subject. Fig. 2 (g) illustrates an isometric view of a portion of the rear structure, in accordance with an embodiment of the present subject matter. As per one implementation and not by way of any limitation, during the process of assembly, the first-flange member 240 is mounted to the first-shaft 210 along a wheel-axis W-W’. The first-disc member 215 is then supported on the first-flange member 240, through the second-contact region 242 (as shown in Fig. 2 (e)). In next step, the first-wheel 101 is mounted to the first- shaft 210 whereby the plurality of pins 270 are aligned with the plurality of apertures 275 (shown in Fig. 2 (e)) of the first-disc member 215. Then a washer 261 is inserted and then all the aforementioned components are secured together by using the main fastening member 260. The main fastening member 260 exerts axial force because of which the first-disc member 215 is securely supported through the first-flange member 240 and first-wheel 101 in an axial sandwich region 245 therebetween.

[00058] The first-shaft 210 comprises a transmission engagement portion 213, which is used for engaging the first-shaft 210 with a gear, a belt drive, a chain drive, a pulley or the like.

[00059] In another implementation, instead of mounting the first-disc member 215 on to the first-flange member 240, the first-disc member 215 and the first-wheel 101 can be first assembled together whereby the first-wheel 101 gets mounted to the first-shaft 210 and subsequently the first-disc member 215 engages with the first-flange member 240 during assembly.

[00060] Further, the first-caliper member 220 is mounted to the support structure 205. The first-caliper member 220 comprises one or more pots 221. The first-caliper member 220 includes a slit-portion or opening wherein the first-disc is slid in the slit and the first-caliper member 220 gets aligned with the first-disc member 215. The support structure 205 is provided with a first-mounting portion 208 for securing the first-caliper member 220 thereat using a first-fastener 209. Further, in one implementation, the first-caliper member 220 is disposed at an upper-rear diagonal portion i.e. the first quadrant when viewed in an axial view and seen from side where the support structure 205 is disposed with respect to the wheel axle centre as origin.

[00061] When the first-wheel 101 is to be removed for servicing or for any other requirement, the main fastening member 260 can be removed and only the first- wheel 101 can be removed without disturbing the first-brake 160. An interference fit may be provided between the first-flange member 240 and the first-disc member 215. In yet another implementation, the first-flange member 240 and the first-disc member 215 are integrated to form a single component. In one implementation, the first-disc member 215 comprises a disc-body 218. The disc-body 218 is configured to be disposed on a first-flange member 240. The first-flange member 240 is integrally formed with the disc -body 218. In another implementation, the first-disc member 215 is supported on the first-flange member 240 and by the first-caliper member 220. In one implementation, a frictional contact is available between frictional pads (not shown) of the first-caliper member 220 and the first-disc member 215. Further, the present subject matter enables use of a larger outer diameter of the caliper member thereby maximising the braking strength of the system. This configuration enables designing an improved disc brake system for a motor vehicle by maintaining a minimal radial clearance ‘C’ (shown in Fig.2 (d)) between an outer diameter of the disc member 215 and the inner diameter/ surface of the wheel-rim 252 of the first-wheel 101. As a result, the need for removing the caliper member for removing the wheel is completely eliminated.

[00062] Further, when braking force is applied, the first-caliper member 220 exerts frictional force on the first-disc member 215, which further transfers the braking force to the first-wheel 101. The impact of braking operation on the first-shaft 210 is reduced as the direct torque transfer engaging contact between the first-shaft 210 and the first-disc member 215 is eliminated and the torque is now routed to the first- flange 254 of the first-wheel 101 to the first-shaft 210 through coupling wheel insert 255.

[00063] Fig. 2 (h) illustrates an enlarged view of a portion of the rear structure, in accordance with an embodiment of the present subject matter. This enlarged view illustrates a second-fastener 280, which is for mounting the first-caliper member 220 to the support structure 205. On a wheel facing side of the support structure 205, a mounting portion (not shown) is provided for securing the first-caliper member 220 thereat.

[00064] Further, the first-wheel 101 is provided with the plurality of arms 253. The first-caliper member 220 is so configured that the second-fastener 280 is accessible through the gaps between the plurality of arms 253. In case of a sheet-metal wheel, a wheel-disc that connects a wheel-hub to a wheel-rim is provided with access portions, say apertures, for accessing the second-fastener 280 through a tool or the like. The first-fastener 209 (shown in Fig. 2 (g)) and the second-fastener 280 are accessible only when the first-caliper member 220 needs to be removed. However, the present subject matter eliminates the need for removing the first-caliper member 220 for removing the first-wheel 101.

[00065] In one mentation, the motor vehicle includes an advanced anti-lock braking system (ABS) unit. The advanced ABS unit is configured to perform locking operation of wheels, in addition to a steering lock present in the motor vehicle for additional safety. This operation can be performed on user command.

[00066] The motor vehicle with the advanced ABS unit usually has a master cylinder. A valve connecting the master cylinder to a hydraulic electronic control unit (HECU) is usually a normally open valve and a valve connecting the HECU to a caliper member is usually a normally closed valve. When the motor vehicle is stationary with a pre-set condition (first-wheel speed = 0, second-wheel speed = 0, a side stand in engaged condition & a power unit status = OFF), the user of the motor vehicle can initiate a sequence of actions. Through the sequence of actions, a signal is sent to the ABS unit to operate in the brakes by creating pressure in the master cylinder. On the receipt of this signal, the HECU will start pumping brake fluid to the caliper members, locking the disc members of the wheels and preventing it from rotating. Since the valve connecting to the caliper member is a normally closed valve, even when the vehicle is in switched-off condition, no energy will be required to keep the vehicle in locked position. This will act as a secondary locking feature in addition to the steering lock. When the user wants to disengage the lock, another signal is sent to the HECU/ABS unit to disengage the brakes by releasing pressure.

[00067] Although the subject matter has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. It is to be understood that the appended claims are not necessarily limited to the features described herein. Rather, the features are disclosed as embodiments of the motor vehicle of the present subject matter.

List of reference signs:

100 motor vehicle

101 first wheel

102 second wheel

120 power unit

130 frame assembly

131 head tube

132 main tube

133 rear tube(s)

134 rear end (of main tube)

140 front suspension

145 step-through portion

150 handlebar assembly

155 rear suspension

160 first-brake

165 seat assembly

205 support structure

206 first-sub part

207 second-sub part

208 first-mounting portion

209 first-fastener

210 first-shaft

211 free-end (of first-shaft)

212 plurality of splines

213 transmission engagement portion

215 first-disc member

216 first-axial side

217 second-axial side

220 first-caliper member

225 first-brake hose

230 first-bearing member 232 second-bearing member

233 outer race

234 inner race

240 first-flange member

241 first-contact region

242 second-contact region

243 pre-determined distance (radially outward)

244 axial contact

245 axial sandwich

248 pre-determined gap

250 wheel-body

251 tyre

252 wheel-rim

253 plurality of arms

254 wheel-hub

255 wheel-insert

260 main fastening member

261 washer

265 stem portion

266 arm portion

270 plurality of pins

275 plurality of apertures

280 second-fastener

C radial clearance

W-W’ wheel axis