Description:TECHNICAL FIELD
[0001] The present subject matter relates to a power train assembly. In a preferred embodiment, said power train assembly is for a multi-wheeled vehicle, including but not limited to motor vehicles. Such powertrain assembly can also be employed in non-vehicular applications.
BACKGROUND
[0002] Generally, multi-wheeled vehicles function with the help of a power train assembly wherein the fundamental source of power is a prime mover. Such prime mover could include an internal combustion engine (petrol, diesel, gas like CNG, LPG and other types of fuels etc.), external combustion engine, rotary engine, other types of fuel based engines, electric motors propelled by energy sources of various types and combinations thereto.
[0003] More specifically, in one preferred embodiment, the present invention relates to a powertrain assembly including, but not limited to, an internal combustion engine as a prime mover and various illustrative embodiments. Even more specifically said engine can be a gasoline direction injection (GDI) engine. light of the existing prior art there was need for an improved engine, particularly, an improved GDI Engine assembly in order to overcome various shortcomings of the prior art.
[0004] In known GDI engine assemblies, the mounting of fuel pump has several drawbacks. In multi-cylinder engine assembly has a cylinder head, cylinder head cover which supports the GDI pump and a cam cover over it. GDI pump is fixed on the cylinder head cover underneath the cam cover. The structure on the cylinder head supports the pump mounting flange.
One of the drawbacks of the conventionally available GDI engines is that the stress developed on the cam shaft operating the fuel pump is very high. This is due to requirement of very high-pressure during GDI fuel pump operation and can lead to fatigue, stress and consequent failure of the shaft during due course of operation. It may also lead to reduced durability, component error, easy worn-out while functioning under demanding conditions that will affect the performance of the entire unit eventually loss in efficiency. Therefore, there is a need for an efficient and compact powertrain assembly which can avoid the above said disadvantages. Further conventionally, in case of direct injection engines, fuel rails are provided for multi-cylinder engines which are bulky and cumbersome. These are not applicable for smaller applications like single cylinder engines. Also, for a single-cylinder engine if the fuel pump output is directly connected to the injector which is injecting fuel in combustion chamber, it will result in high pressure fluctuations during fuel pumping and fuel injection. Further, fuel injection pressure needs to be closely monitored and the fluctuations must be minimized to avoid variations between cycles.
[0005] The present disclosure is further addressing to eliminate the pressure fluctuations while pumping high pressure fuel through the fuel pump. It addresses several issues regarding mounting of the high-pressure pump onto the powertrain. Particularly such challenges include a mechanical drive system for the high-pressure pump, phasing of the high-pressure pumping action and cam position driven electronic drive system for operation of the pump solenoid are being tried on a powertrain having a single-cylinder engine in pioneering way. Due to the small size of the powertrain having a single-cylinder engine, it is a challenge to mount the fuel pump onto the housing of a compact powertrain and to take a mechanical drive from a drive shaft of said powertrain. Further, the high-pressure fuel supply system must match the fuel flow requirement of the single-cylinder small bore engine while maintaining the requisite pressure. Lastly the location of the mounting of the fuel pump must have the requisite strength withstand the stresses and the drive means must have requisite torque to achieve the desired speed and efficiency of the pumping action. Therefore, the improvised mounting of the fuel pump for the powertrain in the present case specifically addresses the aforesaid issues present in the prior art which further result into improving the whole power train assembly in an efficient manner reducing the hardships of serviceability and maintainability along with increasing efficiency of the powertrain.
BRIEF DESCRIPTION OF DRAWINGS
[0006] The present invention relates to a powertrain assembly with an improved fuel pump mounting for direct injection of fuel into a combustion chamber of a prime mover. Such a powertrain assembly can be used in a multi-wheeled vehicle, such as two wheelers, three wheelers and other multi-wheeled vehicles. The present disclosure in a pioneering way discloses the method of mounting the high-pressure pump in a powertrain assembly. In one particular embodiment, said fuel pump is mounted specifically on the engine. Further the powertrain assembly includes a mechanical drive system for actuating the high-pressure pump. In one embodiment, the invention also helps in reducing the rail pressure fluctuation and maintains the pressure by phasing the pumping action before the injection event with the help of a cam position-based control mechanism. The detailed description is described with reference to the accompanying figures, which is related to a powertrain assembly, particularly where the prime mover includes an internal combustion engine with one cylinder being one embodiment of the present invention. However, the preset invention is not limited to the depicted embodiment(s). In the figures, the same or similar reference signs are used throughout to represent similar features and components.
[0007] Figure 1 illustrates perspective view of the power train assembly including an engine assembly, in accordance with an embodiment of the present subject matter.
[0008] Figure 2 exemplarily illustrates a side view of an internal combustion engine without the cylinder block of the powertrain, along with schematic mounting of the fuel pump in accordance with an embodiment of the present subject matter.
[0009] Figure 3(a) illustrates a top-side perspective view of the internal combustion engine of the present powertrain assembly without the cylinder block, along with a reservoir assembly mounted on the cylinder head schematic mounting of the fuel pump in accordance with an embodiment of the present subject matter.
[00010] Figure 3(b) exemplarily illustrates a top-side perspective view of the internal combustion engine of the present powertrain assembly without the cylinder block, along with the reservoir assembly mounted on the cylinder head schematic mounting of the fuel pump with high-pressure fuel supply pipe, in accordance with an embodiment of the present subject matter.
[00011] Figure 4 shows an exploded illustrative view of the reservoir assembly in accordance with an embodiment of the present subject matter.
[00012] Figure 5a and Figure 5b show an exploded view of a perspective view of the powertrain assembly along with the high pressure fuel pump assembly with high-pressure fuel supply pipe, and the fuel reservoir assembly in accordance with an embodiment of the present subject matter.
[00013] Figure 6 exemplarily illustrates in a graphical representation of high pressure pump phasing with respect to the engine cycle events, in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION
[00014] In known GDI Engine, one of the important components is the high-pressure fuel supply system. The high-pressure fuel is supplied in order to achieve the required injection characteristics such as droplet size, droplet penetration, atomization, fuel-air mixing characteristics and so on. In the exemplary embodiment of the present powertrain assembly disclosed herein, the gasoline direct injection high-pressure pump can be a single or multi cylinder, radial-piston pump. The powertrain assembly has a prime mover which can include a motor or an engine, a combination thereof or other means for supplying power to the powertrain. Said powertrain also includes a transmission assembly. In one embodiment, the prime mover includes an engine, whether alone or in combination with other power unit like a motor. The powertrain assembly also has at least two housings namely first and second housing. In one embodiment where the prime mover includes an engine, first housing includes cylinder head, cylinder block and combustion chamber among other components of said engine and other power units of the prime mover. In one aspect of the invention, the first housing has at least one opening for receiving a fuel injector to inject a fuel directly into a combustion chamber formed between inside the first housing. The fuel injector receives fuel from a fuel pump via a fuel pipe and a reservoir assembly. The fuel pump draws the fuel from a fuel storage means. Fuel can be selected from petrol, diesel, CNG, LPG or any other fluid based fuels suitable for a combustion engine. In one embodiment the fuel pump can be a high pressure fuel pump and said reservoir assembly is a multifunctional high-pressure fuel reservoir (MHPFR). The fuel pump is mounted on said second housing.
[00015] The second housing includes the transmission assembly. In one embodiment, the transmission assembly comprises various drive shafts rotated by the prime mover and ultimately transmits the torque transferred from the prime mover using various torque paths. In another embodiment, said fuel pump is actuated by a drive means installed on one of the said drive shafts of the transmission assembly. The drive means can be one of a cam member, eccentric disc, cam- gear or any other drive means for actuating the fuel pump. In another aspect of the invention, the second housing comprises at least one opening and one more bosses for receiving a portion of the fuel pump whereby the fuel pump is mounted on the second housing in such a way that a portion thereof is disposed inside the housing and another portion remains outside the second housing. The portion of fuel pump that remains inside the second housing can be a plunger that gets actuated by said drive means upon rotation of the drive shaft. The rotation of the drive means and actuation of the pump can be calibrated in a manner so that the fuel is injected by the injector at the appropriate cycle and/or stroke of the engine. In another embodiment, at least one of the drive shafts has unbalances mass(es) mounted on said drive shaft and said drive shaft actuates the fuel pump. In one embodiment where the prime mover includes an engine, a drive shaft including unbalanced masses can be a crankshaft which generates torque, whether alone or in combination with other power units of the prime mover, to be transferred to the transmission assembly for doing mechanical work. In one embodiment, said fuel pump is mounted on an opening on a portion of the second housing proximate with the crankshaft so that a portion of the fuel pump is disposed in proximity to the crankshaft and the drive means is installed on the crankshaft to actuate the fuel pump upon rotation of the crankshaft. In one aspect of the invention, the high-pressure pump volume flow rate of the pump is controlled by a flow control valve (FCV) located on the intake side of the pump. The operation of a high-pressure gasoline pump is unique in the way that the FCV has to operate synchronously to the cam position.
[00016] In one aspect of the invention, Fuel enters the pump through the open FCV during the downward stroke of the piston and FCV solenoid is kept in an open position through spring force. During the upward stroke of the piston the FCV solenoid is energized for a short duration closing the fuel back flow into the intake and pressure is developed inside the pump and opens the spring-loaded outlet of the pump. Fuel quantity delivered by the pump can be changed by changing the start of solenoid closing during the upward stroke of the piston. Earlier, the solenoid is closed higher the quantity of fuel delivered. The high-pressure pump is equipped with a non-return valve and a pressure relief valve on the outlet side of the high pressure pump.
[00017] In order to operate and optimize the operation of such a high-pressure pump, the present disclosure has developed an ergonomic mounting on the crankcase, a mechanical drive for the pump by a drive shaft of the transmission assembly as explained above. In one aspect said drive shaft is the crankshaft. The phasing and controlling of pumping action of the high pressure fuel pump is done through a control system mechanism. The disclosed system, in one embodiment, also consists of a multifunctional high-pressure fuel reservoir (MHPFR) for single cylinder engine, which stores high-pressure fuel from the high-pressure pump and delivers fuel to the injector. The mounting mechanism and system for the fuel pump are developed in such a way that it can be adapted onto an existing powertrain assembly with a prime mover, for example a single-cylinder engine design with minimum changes in the layout, wherein said engine may operate alone or in combination with an electric motor.
[00018] Further, the present disclosure, in one embodiment, also involves method for mounting the high-pressure pump onto the engine, a mechanical drive system for the high-pressure pump, phasing of the high-pressure pumping action and cam position driven electronic drive system for operation of the pump solenoid are being tried on a single-cylinder engine for the first time. In one embodiment, due to the small size of a single-cylinder engine, it is an ergonomic challenge to mount the pump onto the crankcase and to take a mechanical drive to the mounting position. Also, the high-pressure fuel supply system must match the fuel flow requirement of the single-cylinder small-bore engine while maintaining the MHPFR pressure. In prior art, problem exists over the base design, the stress developed on the cam shaft is very high due to requirement of very high-pressure GDI fuel pump operation, this can lead to fatigue failure of the shaft during due course of operation which further leads to reduced durability.
[00019] In order to lower the fuel pressure fluctuation in the reservoir assembly and maintain the required pressure the pumping action is phased during the exhaust stroke of the prime mover so that before each injection, there is pressurization of the fuel. This also ensures that the pumping work is drawn during the expansion stroke of the prime mover and reduces the torque fluctuation as well. The present invention, in one embodiment, discloses a novel cylindrical fuel reservoir assembly with its axis in line with the fuel injector. This ensures a compact design for the fuel reservoir assembly and further houses the fuel pressure sensor, inlet and outlet for the high-pressure fuel, holding the fuel injector towards the engine cylinder head of the prime mover and to serve as a reservoir of high-pressure fuel.
[00020] Thus, the objectives of the present subject matter are achieved by a system which provides a solution to the ergonomic challenge to mount the pump onto the crankcase and to take mechanical drive to the mounting position. This solution further solves the problem by creating a synergy between high pressure fuel supply system and the fuel flow requirement of the engine based prime mover while maintaining the desired pressure in the fuel reservoir assembly before the injector injects the fuel. In one embodiment, the reservoir is MHPFR. This synergistic configuration helps in dealing with the extremely high stress developed on the cam shaft in known engine configurations due to requirement of very high-pressure GDI fuel pump operation. Therefore, the present disclosure helps in overcoming the drawback of reduced durability in the conventionally available GDI engines along with enhancing the life of the engine as well by significantly reducing fatigue that may cause failure of the cam shaft during operation.
[00021] The aforesaid and other advantages of the present subject matter would be described in greater detail in conjunction with the figures in the following description.
[00022] The power train assembly may be implemented in any multi-wheeled vehicle such as two-wheeled, three-wheeled, a quadricycle or a multi-wheeled vehicle. However, the application of the invention is not limited vehicular applications only. However, for the purpose of explanation and by no limitation, the power train assembly, corresponding additional advantages and features are described through the following embodiments.
[00023] In one embodiment of, the power train assembly comprises a prime mover assembly. The present subject matter provides a power train assembly which further comprises a first housing assembly, combustion chamber for combustion of a fuel, a transmission assembly, a second housing assembly. The second housing assembly is being configured to substantially accommodate a transmission assembly. Further, at least one or more fuel pump unit is present. This fuel pump unit includes at least one fuel inlet which is connected to a fuel storage means and configured to supply fuel from fuel storage means to the fuel pump unit and at least one fuel outlet.
[00024] Further as per one illustrative embodiment of, the present inventive disclosure the first housing assembly is being configured to have one or more openings. The above stated opening is being configured to receive a portion of a fuel injector. The fuel injector is being configured to directly inject the fuel into a combustion chamber and said fuel injector being connected to said fuel pump unit via at least a fuel reservoir assembly, wherein the above stated fuel reservoir assembly is connected to said fuel pump unit on one end and the fuel injector on the other end and the fuel pump unit is mounted on said second housing assembly.
[00025] In one embodiment of, the present inventive disclosure the powertrain assembly includes at least one or more drive shafts and a drive means, said drive means being operably connected to one of the drive shafts. It is being configured to actuate the pump unit.
[00026] Further in another embodiment of, the present inventive disclosure the powertrain assembly comprises second housing assembly includes a first set of opening and one or more bosses. The opening is being configured to receive a portion of said fuel pump unit.
[00027] In another embodiment of, the present inventive disclosure related to powertrain which comprises boss that is configured to have internally threaded holes to facilitate the mounting of the fuel pump on the second housing assembly.
[00028] In another illustrative embodiment, of the powertrain assembly discloses the fuel reservoir assembly which further includes a plurality of connecting means and a fuel reservoir.
[00029] In an illustrative embodiment, of the present inventive disclosure the powertrain wherein the drive means is an unbalanced mass operably connected to said drive shaft and said drive shaft substantially faces the combustion chamber.
[00030] In an illustrative embodiment, of the present inventive disclosure the powertrain discloses the fuel pump which further includes a plunger. The driving means includes a cam member which is being installed on drive shaft, the cam member is being configured to rotate along with rotation of the drive shaft and actuate the mentioned plunger upon such rotation.
[00031] Further as per another embodiment of the present subject matter, the powertrain wherein the fuel pump includes a plunger and driving means includes a disc member having a mounting hole offset from a centre of the disc member. The disc member is being installed on drive shaft through the mounting hole and further disc member is configured to rotate along with rotation of the drive shaft and actuate the plunger of the fuel pump unit upon stated rotation. The fuel pump unit includes a plunger.
[00032] In another embodiment of, the present inventive concept, the powertrain wherein mentioned prime mover is an internal combustion engine, the transmission assembly includes a crankshaft which is being configured to accommodate a crank mass and a drive means and the drive means is configured to actuate the fuel pump upon rotation of the mentioned crankshaft.
[00033] Further in another illustrative embodiment of, the present inventive concept, the powertrain wherein second housing has an opening which is being configured to receive a portion of the fuel pump unit which is in close proximity with the crank shaft and this portion of fuel pump unit includes a plunger, further this plunger is being configured to be actuated by the drive means.
[00034] One of the aspects of the powertrain specifically discloses that the fuel reservoir assembly includes a Multifunctional High-Pressure Fuel Reservoir, for maintaining a predetermined amount and pressure of the fuel before being injected into the combustion chamber through the fuel injector.
[00035] In one of the aspect of the present inventive concept, the powertrain assembly discloses that the power generating fuel is also gasoline and the prime mover includes an internal combustion engine for propelling a multi wheeled vehicle.
[00036] Further, in one of the embodiments of the present inventive concept the powertrain wherein the prime mover includes an internal combustion engine and an electric motor.
[00037] The aforesaid and other advantages of the present subject matter would be described in greater detail in conjunction with the figures in the following description.
[00038] Figure 1 illustrates a perspective view of the power train assembly (1000) including an engine assembly (10), in accordance with an embodiment of the present subject matter. For the sake of explanation, the powertrain assembly (1000) may be considered to be having a prime mover (10) comprising of a single cylinder engine assembly (10) as an exclusive power unit or in combination with an electric motor. The figures, for the sake of easier explanation only show the single cylinder engine assembly (10). Fig 1 specifically also depicts that the powertrain assembly (1000) with a first housing (701) which comprises a cylinder head (13) and a cylinder block (14) and a combustion chamber (713) (as shown in figure 2) formed therebetween. The powertrain assembly (1000) has a second housing (11) that houses the transmission assembly (101). The transmission assembly (101) comprises various drive and driven shafts and drive means that transfer the torque from the prime mover (10) to the output of the powertrain assembly (1000) or to actuate devices for various purposes. In this embodiment in Fig.1, the transmission assembly (101) has one drive shaft having unbalanced mass (12a). As per an embodiment, the drive shaft includes a crankshaft (12) of the engine assembly (10).
[00039] The first housing (701) has a first set of opening (not shown) to mount a fuel injector (500) for injecting fuel directly into the combustion chamber (713). In Fig.1 the fuel injector (500) shown is a gasoline direct injection (hereinafter “GDI”) fuel injector. A fuel reservoir (300) is mounted on the first housing (710) above the fuel injector (700) for holding a fuel at a predetermined pressure before being injected into the combustion chamber (713) by the injector (500). The fuel reservoir (300) is connected via a fuel pipe (400) to a fuel pump unit (100). The fuel pump unit (100) is mounted on the second housing (11). In one embodiment, said fuel pump unit (100) is a high pressure fuel pump assembly (100) mounted on the second housing (11), the fuel reservoir is a multifunctional High Pressure Fuel Reservoir (MHPFR) and the fuel pipe (400) is a high pressure fuel pipe connecting said pump and the said fuel reservoir. In one embodiment, the second housing is a crankcase (11) of the engine assembly (10). The fuel pump (100) must match the fuel flow requirement of the engine (10) of the prime mover assembly. The second housing (11) has an opening (11a) along with at least one boss member (11b). Holes are provided for mounting the fuel pump unit (100) using attachment means (100a; shown in Figure 2, 3(a), 5(b)) in such a manner that a portion of said fuel pump unit (100) is disposed inside the housing (11) and close the drive means (200) installed on the drive shaft/crankshaft (12). The portion of the fuel pump (100) inside the second housing (11) is a plunger (710) of the pump (100). The drive means (200), in Fig.1 is an eccentric cam (200) mounted on said drive shaft/crankshaft (12) of the transmission assembly (101). In Figure 1, the drive means (200) is shown as an eccentric cam or disc member with a mounting hole used to mount the same on the crankshaft (12). The mounting hole is offset from the centre of the eccentric disc (200). The orientation of fuel reservoir (300) is enabled in such an innovative way in close vicinity of the fuel injector (500) to further facilitate the compactness of the entire arrangement.
[00040] Figure 2 exemplarily illustrates a side view of an internal combustion engine (10) without the cylinder head (13) and without cylinder block (14), along with schematic mounting of the fuel pump (100) in accordance with an embodiment of the present subject matter. Fig. 2 specifically shows the fuel pump assembly (100), drive means/eccentric cam (200) used to drive the fuel pump (100) and the crankshaft assembly (12) of the engine assembly (10) on which the eccentric cam (200) is disposed. The cylinder block (14) is also shown in the Fig. 2. The figure shows the relative orientation and placement of the drive means (200) with respect to the crankshaft (12). It particularly shows that the drive shaft (12) is substantially facing the combustion chamber (713). In one embodiment, the drive shaft (12) can have unbalanced mass (12a) installed thereon. In another embodiment, the drive shaft can be a crankshaft with a crank web or lobes as unbalances masses (12a) for cranking and running the engine of the prime mover assembly (10).
[00041] Figure 3(a) illustrates a top-side view of the internal combustion engine (10) of the present powertrain assembly (1000) without the cylinder block (14), along with reservoir assembly (300) mounted on the cylinder head (13). Figure 3a clearly shows how the plunger (710) interacts with the drive means eccentric cam (200) upon rotation of the crankshaft (12). Figure 3(b) exemplarily illustrates a top-side view of the internal combustion engine (10) of the present powertrain assembly (1000) without the cylinder block (14), along with reservoir assembly (300) mounted on the cylinder head (13). Figure 3(b) shows how the fuel pipe line (400) connects the fuel pump (100) with the fuel reservoir (300) in a top view.
The drive means/eccentric cam (200) used to drive the fuel pump is mounted on the crankshaft assembly (12) of the engine (10). The drive means/eccentric cam (200) advantageously positioned in between the primary drive gear (122) and the sprocket cam chain drive (121) on the crankshaft (12).
[00042] Fig. 4 depicts an exploded illustrative view of the fuel reservoir assembly (300). In this figure the fuel reservoir (300) is a Multifunctional High Pressure Fuel Reservoir (MHPFR) for a single cylinder engine (10). Multifunctional high pressure fuel reservoir (MHPFR) (300) consists of a volume (301) for storing high-pressure fuel coming from the high-pressure pump (100), fuel inlet (302), fuel outlet (303) to the high-pressure fuel injector (500). Threaded provision on the top portion (304) is provided for mounting a fuel pressure sensor (not shown). The high pressure inlet connector (305) to the MHPFR (300) is made separately and is attached to the main body of said MHPFR (300) using known means in the art, for example by welding or other adhesion techniques. A through-hole (306) is provided which opens to the reservoir volume (301) of the MHPFR (300), which holds the high-pressure fuel. The top portion (308) of the MHPFR (300) and the bottom part (309) of the MHPFR (300) are joined after fabrication using a welded or threaded joint with necessary sealing. A bottom portion (310) of the cylindrical MHPFR (300) fits on to the high-pressure fuel injector (500). The primary function of the MHPFR (300) is to serve as a reservoir for high-pressure fuel going to the high-pressure fuel injector (500). This also must house the fuel pressure sensor (not shown). High pressure fuel from the pump (100) is directly connected to the MHPFR (300) using a threaded connection and the outlet of the MHPFR (300) is directly connected to the injector (500). As an alternative embodiment, the MHPFR assembly (300) can also include a holder (not shown) consisting of a holding plate (not shown) and mounting bolts (not shown). The MHPFR is pressed onto the cylinder head (13) using said holding plate (not shown) . Said mounting bolts (not shown) are fixed on the provision provided on the cylinder head (13). This gives additional stability to the mounting of the fuel reservoir assembly (300).
[00043] Figure 5a and 5b show an exploded perspective illustrative view of of the powertrain assembly (1000) along with the fuel pump unit (100), with high-pressure fuel supply pipe (400), and the fuel reservoir assembly (300) in accordance with an embodiment of the present subject matter.
[00044] The engine assembly (10) is having the crankshaft (12) disposed along with a drive means/eccentric cam (200). Figure 5(b) clearly shows the opening (11a) along with the boss member (11b) on the second housing (11). The fuel pump unit (100) is mounted on the second housing (11) using attachments means (100a) through said opening (11a) such that the portion of the fuel pump unit (100) with the plunger (710) (shown in Figure 2 and 3(a)) is disposed which is the crankcase. The eccentric cam (200) acts as the drive means (200) to drive the fuel pump (100) upon rotation of the crankshaft (12) during operation of the engine (10). The present disclosure is addressing an ergonomic challenge to mount the pump onto the crankcase (11) and to take a mechanical drive from the engine crankshaft (12).
[00045] Fig. 6 depicts an exemplary graphical representation of phasing of the drive means for the fuel pump unit (100) with respect to the engine cycle events, in accordance with an embodiment of the present subject matter. This graphical representation plots the high pressure lift vs. engine crankcase angle and further represents the intake, compression, expansion and exhaust cycle of the engine of the prime mover (10) graphically. Typically, as the vehicle’s speed increases so does the engine RPM with it. The drive means (200), which in this case is the eccentric disc (200), is phased in such a way that the high-pressure pump’s (100) piston/plunger (710) is operated during the expansion and exhaust stroke of the engine. Since the fuel injection event for the engine is scheduled during the intake and compression stroke of engine operation, the fuel is pressurized each time before the fuel injection event. This helps in developing the required pressure for the fuel injection right before the fuel injection event. Further, the fuel pumping event is offset from the injection event, this helps in minimizing the pressure fluctuations in the MHPFR. The timing of the pumping event during the expansion stroke which is the power stroke of a 4-stroke engine helps in reducing the torque fluctuations as well.
[00046] It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein. Many modifications and variations of the present subject matter are possible in the light of above disclosure.

List of reference numerals:
10: Prime Mover Assembly/Engine assembly
11: Second Housing/Crankcase
11a: Opening on second housing
11b: Boss member
12: Drive Shaft/Crankshaft
12a: Unbalanced mass on drive shaft/Crank web/lobe
13: Cylinder head
14: Cylinder block
100: Fuel Pump Unit/High pressure fuel pump assembly
100a: Attachment means for fuel pump
101: Transmission Assembly
121: Sprocket cam chain drive
122: Primary drive gear
200: Drive Means/Eccentric Cam
300: Fuel Reservoir/ Multifunctional High Pressure Fuel Reservoir (MHPFR)
301: Volume for storing high pressure fuel coming from high pressure pump
302: Fuel inlet to the high pressure fuel injector
303: Fuel outlet to the high pressure fuel injector
304: Top of portion with threaded provisions
305: High-pressure inlet connector
306: Through Hole for fuel reservoir
308: Top of portion of multifunctional High Pressure Fuel Reservoir (MHPFR)
309: Bottom of portion of multifunctional High Pressure Fuel Reservoir (MHPFR)
310: Bottom portion of cylindrical MHPFR fits to the high pressure fuel injector
400: Fuel Pipe/High-pressure fuel supply pipe
500: Fuel injector
701: First housing assembly
710: Plunger
713: Combustion chamber
1000: Powertrain Assembly
, Claims:1) A powertrain assembly (1000) comprising
a prime mover assembly (10), said prime mover assembly (10) including
a first housing assembly (701),
a combustion chamber (713) for combustion of a fuel,
a transmission assembly (101),
a second housing assembly (11), said second housing assembly (11) being configured to substantially accommodate said transmission assembly (101);
at least one or more fuel pump unit (100), said fuel pump unit (100) configured to pump a fuel from a fuel storage means to a fuel injector (500);
characterised in that
said first housing assembly (701) is configured to have at least one opening, said opening being configured to receive a portion of said fuel injector (500);
said fuel injector (500) is configured to directly inject the fuel into said combustion chamber (713), said fuel injector (714) being connected to said fuel pump unit (100) via at least a fuel reservoir assembly (300); wherein
said fuel reservoir assembly (300) is connected to said fuel pump unit (100) on one end and the fuel injector (500) on the other end; and the fuel pump unit (100) is mounted on said second housing assembly (11).
2) The powertrain assembly (1000) as claimed in claim 1, wherein said powertrain assembly (1000) includes at least one or more drive shafts (12), and a drive means (200), said drive means (200) being installed on one of said drive shafts (12) and being configured to actuate said pump unit (100).
3) The powertrain assembly (1000) as claimed in claim 2, wherein said second housing assembly (11) includes at least one opening (11a), and one or more bosses (11b), said opening (11a) being configured to receive a portion of said fuel pump unit (704).
4) The powertrain assembly (1000) as claimed in claim 1, wherein each of said boss (11b) is configured to have internally threaded hole to mount the said fuel pump unit (100) on said second housing assembly (11) using attachment means (100a).
5) The powertrain assembly (1000) as claimed in claim 1, wherein said fuel reservoir assembly (300) includes a plurality of connecting means and a fuel reservoir (301).
6) The powertrain assembly (1000) as claimed in claim 2, wherein said drive means (200) is an unbalanced mass (12a) operably connected to said drive shaft (12) and said drive shaft (12) substantially faces the combustion chamber (713).
7) The powertrain assembly (1000) as claimed in claim 6, wherein said fuel pump unit (100) includes a plunger (710) and said driving means (200) includes a cam member being installed on said drive shaft (12), said cam member (200) being configured to rotate along with rotation of said drive shaft (12) and actuate said plunger (710) of said fuel pump unit (100) upon said rotation.
8) The powertrain assembly (1000) as claimed in claim 2, wherein
said fuel pump unit (100) includes a plunger (710) and said driving means (200), said driving means (200) includes a disc member, said disc member having a mounting hole, said mounting hole being provided at an offset from a centre of said disc member, said disc member being installed on said drive shaft (12) through said mounting hole; and
said disc member (200) is configured to rotate along with rotation of said drive shaft (12) and actuate said plunger (710) of said fuel pump unit (100) upon said rotation.
9) The powertrain assembly (1000) as claimed in claim 1 wherein said prime mover (10) is an internal combustion engine, said transmission assembly (101) includes a crankshaft (12), said crankshaft (12) being configured to accommodate a crank web or lobe (12a) and a drive means (200) and said drive means (200) is configured to actuate said fuel pump unit (100) upon rotation of said crankshaft (12).
10) The powertrain assembly (1000) as claimed in claim 9 wherein the eccentric disc (200) is phased to actuate the fuel pump (200) at least during an exhaust stroke of said internal combustion engine of said prime mover (10).
11) The powertrain assembly (1000) as claimed in claim 9 wherein
said second housing (11) comprises at least one opening (11a), said opening (11a) being configured to receive a portion of said fuel pump unit (100) in close proximity with the crank shaft (12); and
said portion of said fuel pump unit (100) includes a plunger (710), said plunger (710) being configured to be actuated by said drive means (200) installed on said crankshaft (12).
12) The powertrain assembly (1000) as claimed in claim 1, wherein a fuel reservoir assembly (300) includes a Multifunctional High-Pressure Fuel Reservoir (300), for maintaining a predetermined amount and pressure of the fuel before being injected into said combustion chamber (713) through the fuel injector (500).
13) The powertrain assembly (1000) as claimed in claim 1, wherein said fuel is gasoline and said prime mover (10) includes an internal combustion engine for propelling a multi wheeled vehicle.
14) The powertrain assembly (1000) as claimed in claim 1 wherein said prime mover (10) includes an internal combustion engine (10) and an electric motor.
15) A multi-wheeled vehicle comprising a powertrain assembly as claimed in any of the preceding claims.