Claims:WE CLAIM:

1. A powertrain (100) for a vehicle (200), said powertrain (100) comprising:
an engine (102);
a transmission assembly (158) being enclosed in a crankcase (110), said transmission assembly including:
a crankshaft (112);
a first drive unit (116) and a first driven unit (118) wherein the first drive unit (116) is operatively connected to the crankshaft (112) and the first driven unit (118) is operatively connected to a driven shaft (124), said driven shaft (124) being operatively connected to a rear wheel (228) of the vehicle (200);
an endless transmission (132) for transmitting power from the first drive unit (116) to the first driven unit (118);
a one-way clutch assembly (126) operatively connected to the driven shaft (124) and the first driven unit (118) wherein the one-way clutch assembly includes: a one-way clutch plate (128) configured to be attached to the first driven unit (118); and a back plate (130) configured to be attached to the driven shaft (124) and to the one-way clutch plate (128) such that power is transmitted from the first driven unit (118) to the driven shaft (124); and
a speed sensor assembly (139) having a first member (140) and a second member (142) wherein the first member (140) is configured to be coupled to the driven shaft (124) and the second member (142) is configured to be placed on a transmission cover (114) such that the second member (142) detects the number of rotations of the first member (140).

2. The powertrain (100) as claimed in claim 1, wherein the second member (142) is placed in an opening (144) on the transmission cover (114).

3. The powertrain (100) as claimed in claim 2, wherein the second member (142) is arranged directly above or below the first member (140) in a vehicle upward-downward direction.

4. The powertrain (100) as claimed in claim 1, wherein the first member (140) is a circular plate (154) having a plurality of notches (156) on its circumference.

5. The powertrain (100) as claimed in claim 1, comprising a second drive unit operatively connected to the driven shaft (124) and a second driven unit operatively connected to the rear wheel (228) of the vehicle (200).

6. The powertrain (100) as claimed in claim 1, wherein the first member (140) is configured to be attached to the back plate (130).

7. A hybrid vehicle (200) comprising:
a motor integrated with a rear wheel (228) of the vehicle (200) and a powertrain (100) wherein the motor and an engine (102) of the powertrain (100) are operatively coupled with each other to power the vehicle (200) individually or simultaneously, said powertrain (100) comprising:
the engine (102);
a transmission assembly being enclosed in a crankcase (110), said transmission assembly including:
a crankshaft (112);
a first drive unit (116) and a first driven unit (118) wherein the first drive unit (116) is operatively connected to the crankshaft (112) and the first driven unit (118) is operatively connected to a driven shaft (124), the driven shaft (124) being operatively connected to the rear wheel (228) of the vehicle (200);
an endless transmission (132) for transmitting power from the first drive unit (116) to the first driven unit (118);
a one-way clutch assembly (126) operatively connected to the driven shaft (124) and the first driven unit (118) wherein the one-way clutch assembly (126) includes: a one-way clutch plate (128) configured to be attached to the first driven unit (118); and a back plate (130) configured to be attached to the driven shaft (124) and to the one-way clutch plate (128) such that power is transmitted from the first driven unit (118) to the driven shaft (124); and
a speed sensor assembly (139) having a first member (140) and a second member (142) wherein the first member (140) is configured to be attached to the driven shaft (124) and the second member (142) is configured to be placed on a transmission cover (114) such that the second member (142) detects the number of rotations of the first member (140).

8. The hybrid vehicle (200) as claimed in claim 7, wherein the second member (142) is placed in an opening (144) on the transmission cover (114).

9. The hybrid vehicle (200) as claimed in claim 8, wherein the second member (142) is arranged directly above or below the first member (140) in a vehicle upward-downward direction.

10. The hybrid vehicle (200) as claimed in claim 7, wherein the first member (140) is a circular plate (154) having a plurality of notches (156) on its circumference.

11. The hybrid vehicle (200) as claimed in claim 7, comprising a second drive unit operatively connected to the driven shaft (124) and a second driven unit operatively connected to the rear wheel (228) of the vehicle (200).

12. The hybrid vehicle (200) as claimed in claim 7, wherein the first member (140) is attached to the back plate (130).

13. The hybrid vehicle as claimed in claim 7, wherein the motor is mounted on a hub of the rear wheel (228).
, Description:FIELD OF THE INVENTION
[001] The present invention relates to a powertrain for a vehicle. More particularly, the present invention relates to mounting of a speed sensor assembly for measuring speed of the powertrain.

BACKGROUND OF THE INVENTION
[002] In a conventional vehicle having only an engine as a power source, speed of the vehicle is generally measured using one or more mechanically coupled sensor. The mechanically coupled sensors can be mounted in a transmission assembly or in a front wheel of the vehicle. However, in a parallel hybrid vehicle having both engine as well as a motor as a power source, it can be quite difficult to detect the speed of the vehicle at any instant unless the speed is measured at a wheel of the vehicle. Although measures have been taken in the prior art to measure the speed of the vehicle at a rear wheel, such provisions have not always been reliable. For example, in a parallel hybrid vehicle having a traction motor mounted on a hub of a rear wheel, the vehicle speed is obtained by a sensor such as hall sensor attached to the traction motor. One of the major disadvantages associated with such an arrangement is that both the sensor as well as the traction motor are exposed to an external environment and are prone to damages. Another disadvantage can be mechanical failure of the sensor and/or the traction motor. Owing to such damages/mechanical failure, no speed information is provided to the speedometer/odometer of the vehicle. Yet another disadvantage can be flaws in the wiring harness configured for sending the vehicle speed information from the sensor/motor to the speedometer/odometer. Yet another disadvantage is that the motor does not function when the vehicle is powered only by the engine and therefore no speed input is provided to the speedometer/odometer. Owing to incorrect and/or no vehicle speed inputs, both the speedometer and the odometer may record incorrect values of the vehicle speed and the distance travelled by the vehicle.
[003] In view of the foregoing, there is a need felt to provide alternative locations in both conventional as well as hybrid vehicles for placing the speed sensors/speed sensor assembly that overcomes the above-mentioned disadvantages.

SUMMARY OF THE INVENTION
[004] In one aspect of the invention, a powertrain for a vehicle having a speed sensor assembly is disclosed. The powertrain comprises an engine and a transmission assembly. The transmission assembly is enclosed in a crankcase and includes a first drive unit and a first driven unit. The first drive unit is operatively connected to a crankshaft and the first driven unit is operatively connected to a driven shaft. The driven shaft is operatively connected to a rear wheel of the vehicle. The power from the first drive unit is transmitted to the first driven unit by an endless transmission. The powertrain further comprises a one-way clutch assembly which is operatively connected to both the driven shaft and the first driven unit. The one-way clutch assembly comprises a one-way clutch plate and a back plate. The one-way clutch plate is configured to be attached to the first driven unit. The back plate is configured to be attached to both the driven shaft and the one-way clutch plate. The power is transmitted from the first driven unit to the one-way clutch plate. As the back plate is attached to the one-way clutch plate, the power is transmitted from the one-way clutch plate to the driven shaft via the back plate. In other words, the power is transmitted from the first driven unit to the driven shaft via the one-way clutch assembly including the one-way clutch plate and the back plate. The powertrain further comprises a speed sensor assembly. The speed sensor assembly comprises a first member and a second member. The first member is configured to be coupled to the driven shaft. The second member is configured to be placed on a transmission case such that the second member detects number of rotations of the first member.
[005] In an embodiment, the second member is placed in an opening provided on the transmission case. The second member is placed such that it can detect the number of rotations of the first member. In one non-limiting example, the second member is placed/arranged directly above or below the first member in a vehicle upward/downward direction. In another non-limiting example, the second member is placed/arranged on a right side/left side of the first member in a vehicle front rear direction. In another non-limiting example, the second member is placed on the transmission case at a radial distance from the rotational axis of the second member.
[006] In an embodiment, the first member is a circular plate having a plurality of notches on its circumference.
[007] In an embodiment, the powertrain comprises a second drive unit and a second driven unit. The second drive unit is operatively connected to the driven shaft and the second driven unit is operatively connected to the rear wheel of the vehicle. It is to be understood that there can be multiple drive units and driven units in the transmission assembly and the above-mentioned embodiments should not, in any way, be construed as limiting to the scope of the invention.
[008] In an embodiment, the first member is configured to be attached to the back plate.
[009] In another aspect of the invention, a hybrid vehicle having a powertrain and a motor is disclosed. The hybrid vehicle comprises both engine as well as a motor as the source of power. The motor is integrated with a rear wheel of the vehicle. The motor and engine are operatively coupled with each other to power the vehicle individually or simultaneously. The powertrain comprises an engine and a transmission assembly. The transmission assembly is enclosed in a crankcase and includes a first drive unit and a first driven unit. The first drive unit is operatively connected to a crankshaft and the first driven unit is operatively connected to a driven shaft. The driven shaft is operatively connected to a rear wheel of the vehicle. The power from the first drive unit is transmitted to the first driven unit by an endless transmission. The powertrain further comprises a one-way clutch assembly which is operatively connected to both the driven shaft and the first driven unit. The one-way clutch assembly comprises a one-way clutch plate and a back plate. The one-way clutch plate is configured to be attached to the first driven unit. The back plate is configured to be attached to both the driven shaft and the one-way clutch plate. The power is transmitted from the first driven unit to the one-way clutch plate. As the back plate is attached to the one-way clutch plate, the power is transmitted from the one-way clutch plate to the driven shaft via the back plate. In other words, the power is transmitted from the first driven unit to the driven shaft via the one-way clutch assembly including the one-way clutch plate and the back plate. The powertrain further comprises a speed sensor assembly. The speed sensor assembly comprises a first member and a second member. The first member is configured to be coupled to the driven shaft. The second member is configured to be placed on a transmission case such that the second member detects number of rotations of the first member.
[010] In an embodiment, the second member is placed in an opening provided on the transmission case. The second member is placed such that it can detect the number of rotations of the first member. In one non-limiting example, the second member is placed/arranged directly above or below the first member in a vehicle upward/downward direction. In another non-limiting example, the second member is placed/arranged on a right side/left side of the first member in a vehicle front rear direction. In another non-limiting example, the second member is placed on the transmission case at a radial distance from the rotational axis of the second member.
[011] In an embodiment, the first member is a circular plate having a plurality of notches on its circumference.
[012] In an embodiment, the powertrain comprises a second drive unit and a second driven unit. The second drive unit is operatively connected to the driven shaft and the second driven unit is operatively connected to the rear wheel of the vehicle. It is to be understood that there can be multiple drive units and driven units in the transmission assembly and the above-mentioned embodiments should not, in any way, be construed as limiting to the scope of the invention.
[013] In an embodiment, the first member is configured to be attached to the back plate.
[014] In an embodiment, the motor is mounted on a hub of the rear wheel.
[015] To further clarify the advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended Figures. It is appreciated that these figures depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS
[016] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a schematic view of a vehicle 200, in accordance with an embodiment of the present invention.
Figure 2 and Figure 3 illustrate a perspective view and side view of the powertrain 100 respectively, in accordance with an embodiment of the present invention.
Figure 4 illustrates a cut section of Figure 3 taken along plane A-A of the powertrain 100 in accordance with the embodiment of the present invention.
Figure 5 illustrates a top view of the powertrain 100 in accordance with the embodiment of the present invention.
Figure 6 illustrates a cut section of Figure 5 taken along plane B-B of the powertrain 100 in accordance with the embodiment of the present invention.
Figure 7 illustrates a speed sensor assembly 139 provided in the powertrain in accordance with the embodiment of the present invention.
Figure 8 illustrates an exploded view of the transmission assembly 158, in accordance with the embodiment of the present invention.
Figure 9 illustrates a perspective view of the transmission assembly 158, in accordance with the embodiment of the present invention.
Figure 10 illustrates a cut section of Figure 5 taken along plane C-C of the powertrain100 in accordance with the embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[017] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder.
[018] Figure 1 illustrates a schematic view of a vehicle 200, in accordance with an embodiment of the present invention. Arrows provided in the top left corner depicts direction with respect to the vehicle, wherein an arrow F denotes front direction, an arrow R indicates rear direction, an arrow Up denotes upward direction, an arrow Dw denotes downward direction, an arrow Rt denotes right direction and an arrow Lt denotes left direction.
[019] The vehicle in Figure 1 has been depicted as a scooter-type vehicle. However, the vehicle 200 depicted in Figure 1 should not be construed as limiting and the term “vehicle” includes all vehicle having a transmission assembly operatively connected to a crankshaft and a rear wheel of the vehicle. In one non-limiting example, the vehicle is a conventional vehicle which is powered only by an engine as a power source. In another non-limiting example, the vehicle is a parallel hybrid vehicle powered by both engine and motor as power source. In another non-limiting example, the vehicle is a series hybrid vehicle powered by both engine and motor as power source. In another non-limiting example, the vehicle is a three wheeled vehicle or a four wheeled vehicle.
[020] The vehicle 200 has a powertrain 100 that is disposed behind a floorboard 204 and below a seat assembly 222 and/or a storage compartment underneath the seat. The powertrain 100 has an internal combustion engine 102 (Refer to Figure 4) and a transmission assembly 158 (Refer to Figure 4). The vehicle 200 has a front wheel 226, a rear wheel 228, frame member (not shown) and a fuel tank (not shown).
[021] A head pipe (not shown) connects to the frame member (not shown). The head pipe supports a steering shaft (not shown) and a front suspension (not shown) attached to the steering shaft through a lower bracket (not shown). The front suspension support the front wheel 226. The upper portion of the front wheel 226 is covered by a front fender 230 mounted to the front suspension. In an embodiment, the front fender 230 is movable along with the front wheel 226, during travel over undulations on a road surface. A handlebar 232 is fixed to upper bracket (not shown) and can rotate about the steering shaft for turning the vehicle 200. A headlight (not shown), a visor guard (not shown) and instrument cluster (not shown) is arranged on an upper portion of the head pipe.
[022] Further, a rear suspension (not shown) is provided to the rear wheel 228 for dampening the vibrations induced during travel of the vehicle 200 over undulations on the road surface. A taillight unit 236 is disposed at the end of the vehicle 200 and at the rear of the seat assembly. A grab rail 238 is also provided for facilitating the grip and/or balance to the rider on the vehicle 200 during movement. The rear wheel 228 is arranged below the seat assembly 222 and adapted to receive the motive force from the powertrain 100. The transmission assembly 158 of the powertrain 100 is provided for transferring the drive force from the internal combustion engine 102 to the rear wheel 228 for driving the vehicle 200. A rear fender 240 is disposed above the rear wheel 228. An exhaust pipe 242 is also provided that extends therefrom towards the rear end of the vehicle 200.
[023] Figure 2 and Figure 3 illustrate a perspective view and side view of the powertrain 100 respectively, in accordance with an embodiment of the present invention. Arrows provided in the top left corner depicts direction with respect to the powertrain 100, wherein an arrow F denotes front direction, an arrow R indicates rear direction, an arrow Up denotes upward direction, an arrow Dw denotes downward direction, an arrow Rt denotes right direction and an arrow Lt denotes left direction.
[024] As mentioned, the powertrain 100 comprises the engine 102 (Refer to Figure 4) and the transmission assembly 158 (Refer to Figure 4). In a non-limiting example, the engine 102 is an internal combustion engine. The internal combustion (IC) engine 102 comprises a cylinder block 160 (Refer to Figure 4) including a cylinder bore, a piston 164 (Refer to Figure 4) reciprocating inside the cylinder bore, a cylinder head 162 (Refer to Figure 4) and a combustion chamber disposed between the cylinder head 162 and the cylinder block 160. During operation of the internal combustion (IC) engine 102, the burning of an air fuel mixture occurs in the combustion chamber of the engine 102. The forces generated due to combustion of the air fuel mixture is transferred to a piston 164 (Refer to Figure 4) which is capable of reciprocating inside the cylinder block 160 and this reciprocating motion is transferred to rotary motion of the crankshaft 112 (Refer to Figure 4) though a connecting rod 166 by a crank mechanism. The cylinder head 162 is covered by a cylinder head cover 104.
[025] The transmission assembly 158 forms a part of the internal combustion engine 102 and extends from the internal combustion engine 102. The transmission assembly 158 is enclosed in a crankcase 106,110 which extends from the internal combustion engine 102 and extends rightward and leftward in the vehicle width direction when viewed from a rear side of the vehicle 100. The crankcase RH 106 comprises a cooling system which includes a shroud 108 and a cooling fan 168 (Refer to Figure 4). The crankcase LH 110 comprises a transmission assembly 158 operably coupled to the crankshaft 112 (Refer to Figure 4) of the internal combustion engine 102 (Refer to Figure 4) and operably coupled to the rear wheel 228 of a vehicle 200. The crankcase LH 110 is covered by a transmission cover 114.
[026] Figure 4 illustrates a cut section of Figure 3 taken along plane A-A of the powertrain 100 in accordance with the embodiment of the present invention. As illustrated, the transmission assembly 158 of the powertrain 100 comprises a first drive unit 116 and a first driven unit 118. The first drive unit 116 is operatively connected to the crankshaft 112 via a first one-way clutch assembly 120. A spacer 122 is placed between the first drive unit 116 and the first one-way clutch assembly 120. The transmission assembly 158 further comprises a first driven unit 118 which is operatively connected to a driven shaft 124 by means of a second one-way clutch assembly 126. The driven shaft 124 is operatively connected to the rear wheel 228 of the vehicle 100. The second one-way clutch assembly 126 comprises a one-way clutch plate 128 and a back plate 130. The one-way clutch plate 128 is configured to be attached to the first driven unit 118. The back plate 130 is configured to be attached to both the one-way clutch plate 128 and the driven shaft 124 such that power is transmitted from the first driven unit 118 to the driven shaft 124 via the one-way clutch plate 128 and the back plate 130. The first drive unit 116 and the first driven unit 118 are operatively connected by an endless transmission 132 such as chain, belts and the likes.
[027] Figure 5 illustrates a top view of the powertrain 100 in accordance with the embodiment of the present invention. As illustrated, the crankcase 106,110 extends rightward and leftward in width direction of the internal combustion engine 102. The crankcase RH 106 comprises a cooling system which includes the shroud 108 and the cooling fan 168. The crankcase LH 110 have the transmission assembly 158 operably coupled to the crankshaft 112 of the internal combustion engine 102 and operably coupled to the rear wheel 228 of the vehicle 100.The crank case LH 110 is covered by a transmission cover 114.
[028] Figure 6 illustrates a cut section of Figure 5 taken along plane B-B of the powertrain 100 in accordance with the embodiment of the present invention.
[029] As shown, the first drive unit 116 is operatively connected to the crankshaft 112 and the first driven unit 116 is operatively connected to the driven shaft 124. In a non-limiting example, the first drive unit 116 comprises a spring-loaded centrifugal clutch 134 attached to the crankshaft 112. The centrifugal clutch 134 has one or more clutch shoes 136 which are capable of expanding and engaging with an outer drum 138 on rotation of the crankshaft 112 beyond a predetermined speed. A sprocket is welded on the outer drum 138 of the centrifugal clutch 134. The first driven unit 118 also comprises a sprocket. The first drive unit 116 transmits power to the first driven unit 118 via a chain. In one non-limiting example, the first drive unit 116 and the first driven unit 118 are pulleys and the power is transmitted from the first drive unit 116 to the first driven unit 118 by a belt. In another non-limiting example, the first drive unit 116 and the first driven unit 118 are gears which are engaged with each other directly or via one or more intermediate gears.
[030] Figure 7 illustrates a speed sensor assembly 139 provided in the powertrain in accordance with the embodiment of the present invention.
[031] The speed sensor assembly 139 comprises a first member 140 and a second member 142. The first member 140 is configured to be operably coupled to the driven shaft 124. In an embodiment, the first member 140 is a circular plate 154 having a plurality of notches 156 on its circumference. The second member 142 is configured to be placed on a transmission cover 114 such that the second member 142 detects the number of rotations of the first member 140. It is to be understood that the driven shaft 124 is operatively connected to the rear wheel 228 of the vehicle 100. Hence, the speed of rotation of the driven shaft 124 shall be proportional to the speed of the rear wheel 228 of the vehicle 100. As the first member 140 is operatively coupled to the driven shaft 124, the speed of rotation of the first member 140 shall also be proportional to the speed of the rear wheel 228 of the vehicle 100. The second member 142 may be placed in an opening 144 on the transmission cover 114. The second member 142 can be placed on the transmission cover 114 at any location from where it can detect the rotations of the first member 140. In one non-limiting example, the second member 142 is placed/arranged directly above or below the first member 140 in a vehicle upward/downward direction. In another non-limiting example, the second member 142 is placed/arranged on a right-side RS/left-side LS of the first member 140 in a vehicle front/rear direction. In another non-limiting example, the second member 142 is placed on the transmission cover 114 at a radial distance from the rotational axis of the second member 142.
[032] Figure 8 illustrates an exploded view of the transmission assembly 158, in accordance with the embodiment of the present invention. As shown, the first driven unit 116, the second one-way clutch assembly 126 and the first member 140 of the speed sensor assembly 139 are operatively connected to the driven shaft 124. The power is transmitted from the first driven unit 116 to the driven shaft 124 via the second one-way clutch assembly 126. The second one-way clutch assembly 126 is configured to prevent the rotary motion drive from transferring back to the crankshaft 112 and the transmission assembly 158 from the driven shaft 124 during the ideal running of the vehicle 100 on road and when vehicle 100 is powered by an electric motor (in case of hybrid vehicles). The second one-way clutch assembly 126 comprises a one-way clutch plate 128 and a back plate 130. The one-way clutch plate 120 further comprises a cage 146 and a flange type shell 148. The one-way clutch plate 128 is configured to be attached to the first driven unit 118. The back plate 130 is configured to be attached to the one-way clutch plate 128. More particularly, the back plate 130 is configured to be attached to the flange type shell 148 of the one-way clutch plate 128. In one non-limiting example, the back plate 130 is removably attached to the flange type shell by one or more fasteners. In another non-limiting example, the back plate 130 is permanently attached to the flange type shell 148 by welding, riveting and the likes.
[033] The back plate 130 is further configured to be connected to the driven shaft 124. In one non-limiting example, the back plate 130 is internally splined and mounted on external splines provided on an end of the driven shaft 124. Owing to the attachment of the back plate 130 to both the one-way clutch plate 128 and the driven shaft 124, the power is transmitted from the first driven unit 118 to the driven shaft 124. The back plate 130 may further comprise one or more holes for housing cushioning members 150.
[034] The transmission assembly 158 further comprises a stopper plate 152 configured to be connected to the back plate 130 and sandwiched between the flange type shell 148 of the one-way clutch plate 128 and the back plate 130. The stopper plate 152 is configured to arrest the free axial movement of the cushioning members 150 provided in the back plate 130.
[035] The first member 140 of the speed sensor assembly 139 is configured to be coupled to the driven shaft 124. The first member 140 is a circular plate 154 having a plurality of notches 156 on its circumference. In one non-limiting example, the first member 140 is configured to be directly attached to the driven shaft 124. In another non-limiting example, the first member 140 of the speed sensor assembly 139 is configured to be attached to the back plate 130. In another non-limiting example, the first member 140 is configured to be attached to the stopper plate 152. It is to be understood that the first member 140 can be fixedly attached to the back plate/stopper plate 130,152 by welding, riveting and the likes known in the art. It is also to be understood that the first member 140 can be removably attached to the back plate/stopper plate 130, 152 by fasteners such as nut, bolts and the likes.
[036] Figure 9 illustrates a perspective view of the transmission assembly 158, in accordance with the embodiment of the present invention. As shown, the transmission cover 114 covers the crankcase LH 110 and has an opening 144 for placing the second member 142 of the speed sensor assembly. It is to be understood that the second member 142 can be placed on the transmission cover 114 at any location from where it can detect the rotations of the first member 140. In one non-limiting example, the second member 142 is placed/arranged directly above or below the first member 140 in a vehicle upward/downward direction. In another non-limiting example, the second member 142 is placed/arranged on a right-side RS/left-side LS (Refer to Figure 8) of the first member 140 in a vehicle front/rear direction. In another non-limiting example, the second member 142 is placed on the transmission cover 114 at a radial distance from the rotational axis of the second member 142.
[037] Figure 10 illustrates a cut section of Figure 5 taken along plane C-C of the powertrain100 in accordance with the embodiment of the present invention.
[038] As shown, the first member 140 is configured to be attached to the driven shaft 124 and the second member 142 is directly arranged above the first member 140.
[039] Although not shown, in an embodiment, the powertrain comprises a second drive unit and a second driven unit. The second drive unit is operatively connected to the driven shaft 124 and the second driven unit is operatively connected to the rear wheel 228 of the vehicle 200. It is to be understood that there can be multiple drive units and driven units in the transmission assembly and the above-mentioned embodiments should not, in any way, be construed as limiting to the scope of the invention.
[040] Also, it is to be understood the powertrain 100 disclosed in Figure 2-10 is capable of being fitted into conventional vehicles which uses only engine as a power source as well as hybrid vehicle which used both motor as well as engine as power sources. In an embodiment, the powertrain 100 is fitted in a hybrid vehicle 200. The hybrid vehicle 200 has a motor integrated with a rear wheel 228 and the powertrain 100 as shown in Figures 2-10 wherein the motor and the powertrain 100 are operatively coupled with each other to power the vehicle individually or simultaneously. The motor may be mounted on a hub of the rear wheel 228 or an axle of the rear wheel 228.
[041] Advantageously, the first member 140 of the speed sensor assembly 139 is configured to be attached to the driven shaft 124. The driven shaft 124 is operatively connected to the rear wheel 228 of the vehicle 200 and, therefore, the speed of the driven shaft 124 is proportional to the rear wheel of the vehicle. As the speed sensor assembly 139 is placed in the transmission assembly 158, the present invention overcomes the disadvantages associated with placing a sensor at the rear wheel 228 of the vehicle 200. More particularly, the speed sensor assembly 139 is not exposed to external environment which makes the speed sensor assembly less prone to damages. Also, the construction of the first member 140 and the second member 142 of the speed sensor assembly 139 unit is simple and reliable.
[042] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.

 
List of reference numerals

100- Powertrain
102-engine
104- cylinder head cover
106- crankcase RH
108-shroud
110-crankcase LH
112- crankshaft
114-transmission cover
116-first drive unit
118-first driven unit
120-first one-way clutch assembly
122- spacer
124-driven shaft
126- second one-way clutch assembly
128- one-way clutch plate
130- back plate
132-endless transmission
134- centrifugal clutch
136-clutch shoes
138- outer drum
139-speed sensor assembly
140- first member
142-second member
144-opening
146- cage
148- flange type shell
150-cushioning members
152-stopper plate
154-circular plate
156- notches
158- transmission assembly
160-cylinder block
162-cylinder head
164-piston
166- connecting rod
168- cooling fan
200-Vehicle
204- Floor Board
222-seat assembly
226-Front Wheel
228- Rear Wheel
230- Front Fender
232- Handlebar
236-Tail Light Unit
238- grab rail
240- rear fender
242- Exhaust pipe