Field of the invention:

[0001] The present invention relates to a rolling chassis of an electric vehicle.

Background of the invention:

[0002] A patent 324887 discloses common underbody platform for front engine front wheel drive and rear engine rear wheel drive vehicles. The various embodiments of the present invention provide a common underbody for vehicles. The common underbody comprises a lower sub-structure having a front extended frame, firewall, front floor and a modular rear floor to accommodate common aggregates to define the underbody of the vehicle. The common aggregates are selectively mounted on said lower sub-structure to manufacture vehicle variants with desired location of engine at front end or rear end of the vehicles. A cradle provided at rear end of said lower sub-structure. A frame extension elements and a mid-floor is provided at rear end for manufacturing front engine variant. A modular front suspension mounting point is provided for manufacturing vehicle variants.

Brief description of the accompanying drawings:

[0003] An embodiment of the disclosure is described with reference to the following accompanying drawing,

[0004] Fig. 1 illustrates a perspective view of the rolling chassis, according to an embodiment of the present invention;

[0005] Fig. 2 illustrates a perspective view of a converted rolling chassis, according to an embodiment of the present invention;

[0006] Fig. 3 illustrates different views of rear wheel drive of the rolling chassis, according to an embodiment of the present invention, and

[0007] Fig. 4 illustrates body of the rolling chassis, according to an embodiment of the present invention.

Detailed description of the embodiments: [0008] Fig. 1 illustrates a perspective view of the rolling chassis, according to an embodiment of the present invention. The rolling chassis 100 comprises a front module 110, a rear module 130 and an intermediate module 120. A drive motor (not shown) mountable in any one of the front module 110 and the rear module 130 to provide any one of a front wheel drive configuration and a rear wheel drive configuration, and plurality of battery packs assembled in the intermediate module 120 for supplying power to the drive motor. The battery packs are any one of swappable and chargeable through On-Board Charger (OBC). The other components such as circuits, harness etc. are not discussed for simplicity and for being known in the art, and must not be considered as limitation for the present invention. The rolling chassis 100, characterized by the front module 110 and the rear module 130 are interconvertible to each other. The interconvertible feature is achieved based on common provisions in each of the front module 110 and the rear module 130. The rolling chassis 100 is shown with the wheel hubs 114 and a gearbox 108.

[0009] In the present invention, the front wheel drive configuration corresponds to the drive motor positioned in the front module 110 and configured to drive the front wheels either directly or through the gearbox 108. Similarly, the rear wheel drive configuration corresponds to the drive motor mounted in the rear module 130 and configured to drive the rear wheels directly or through the gearbox 108. Further, either a single drive motor is provided or multiple based on the requirement of the vehicle type or torque output. Further, an all-wheel drive configuration is also possible, where each of the front wheels and the rear wheels are provided with at least one drive motor. In conventional vehicle chassis design, the steering assembly 102 is designed to be mounted in only the front module 110. Thus, in the rear wheel drive configuration, a provision for the steering assembly 102 is absent.

[0010] In accordance to an embodiment of the present invention, both of the front module 110 and the rear module 130 comprises a first provisions 404 (shown in Fig. 4) for mounting the steering assembly 102. The provision signifies the structure and points provided on the rolling chassis 100 for mounting of a sub system/components. The sub-system is selected from a group comprising steering assembly 102, gearbox 108, suspensions, a drive motor (not shown), a Motor Control Circuit (MCU), other control units, a crash module and the like. Further, the steering assembly 102 comprises a steering wheel, a steering column, a rack, a pinon, tie rods, and optionally a steering assist motor.

[0011] Each of the front module 110 and the rear module 130 comprises a provision for mounting/fixing a firewall 104. Still further, each of the front module 110 and the rear module 130 comprises a second provision 202 (shown in Fig. 2) for mounting the drive motor. A mounting position of the drive motor is swappable between the front module 110 and the rear module 130. A support 122 is shown only in the front module 110, but is avoided in the rear module 130 to show the underlying components, which must not be understood in limiting sense. In the final rolling chassis 100, the support 122 is provided in both of the front module 110 and the rear module 130.

[0012] The rolling chassis 100 further comprises a third provision for mounting a crash end module 112 in each of the front module 110 and the rear module 130. In the Fig. 1, the crash end module 112 is already shown mounted. Still further, each of the front module 110 and the rear module 130 comprises a third provisions 402 (shown in Fig. 4) for mounting of at least two suspensions. The at least two types of suspension are selected from an integrated strut assembly 118, an independent suspension assembly 116, a single wishbone suspension, a double wishbone suspension and the like. The integrated strut assembly 118 is also referred to as a MacPherson strut comprising a lower control arm and shock absorber integrated inside a spring, mounted onto a knuckle and the rolling chassis 100, respectively. The independent suspension assembly 116 comprises a trailing arm, a shock absorber and a spring. [0013] The third provision 402 comprises fixed points, and pivot points of suspension components in both the front module 110 and the rear module 130. The front module 110 and the rear module 130 are made identical to enable mounting of components in an interchangeable manner. In another embodiment, the front module 110 and the rear module 130 are non-identical to each other, but still enables swapping of components. The non-identical manner corresponds to the alignment of beam structures of the rolling chassis 100 which are in different manner (different heights as well) in each of the front module 110 and the rear module 130 but providing the third provisions 402 as required. Further, the rolling chassis 100 comprises common provisions for pillar structures (not shown) of a vehicle body frame. The pillar structures are maintained in same position irrespective of a change in the positioning of the front module 110 and the rear module 130.

[0014] Fig. 2 illustrates a perspective view of a converted rolling chassis, according to an embodiment of the present invention. The rear module 130 is converted to or used as the front module 110, due to the provisions of mounting the steering assembly 102 and the firewall 104. In other words, the rear module 130 is now used as front part of the vehicle to be manufactured. Consequently, the front module 110 now acts as the rear module 130, or rear part of the vehicle to be manufactured. The second provision 202 enables the mounting of the drive motor in both of the front module 110 and the rear module 130. The suspension are interchangeable, however the Fig. 2 shows the rolling chassis 100 retaining the suspensions in the same place in comparison to Fig. 1. Only the steering assembly 102 is moved to the rear module 130. Further, the suspensions are shown decoupled from the rolling chassis 100 for clarity in illustration, and the same must not be understood in limiting manner.

[0015] Fig. 3 illustrates different views of rear wheel drive of the rolling chassis, according to an embodiment of the present invention. A side view 310 shows the rear wheel drive configuration of the rolling chassis 100. A top view 320 shows the same rear wheel drive configuration of the rolling chassis 100. In accordance to an embodiment of the present invention, the intermediate module 120 is modular in structure, allowing adding or removing the segment 106 to and from the intermediate module 120. Based on the required wheel base of the required type of the vehicle, the number of segments 106 are added or removed. The scalability of the intermediate module 120 as per the wheel base requirement makes the rolling chassis 100 modular. The scalability or the modularity is made possible due to I- beam or H-beam or inverted C-beam frames of the intermediate module 120. Other forms frames are possible without departing from the scope of the scalability or modularity of the intermediate module 120. The segment 106 is fastened to the adjacent segments 106 through bolts, screws and the like. Further, as per the change in the number of segments 106 added or removed, the other components of the vehicle such as but not limited to, brake lines are also adjusted.

[0016] In accordance to another embodiment, the front module 110 and the rear module 130 are detachable from the intermediate module 120 and thus offer swappable with each other. This is further enabled by having a poke-yoke feature to avoid/prevent mounting of the front module 110 and the rear module 130 in upside down manner, which may result in delay in the assembling/ manufacturing process.

[0017] Fig. 4 illustrates body of the rolling chassis, according to an embodiment of the present invention. A first perspective view 410 and a second perspective view 420 shows just the body frame of the rolling chassis 100 without any subsystems or components mounted thereon. The intermediate module 120 is shown without battery packs in all the figures just to bring clarity in the structure of the rolling chassis 100. The firewall 104 is shown mounted in both the front module 110 and the rear module 130, but is mountable to one location as required. In comparison to previous figures, the third provision 404 for the suspension is shown in both the front module 110 and the rear module 130. The support 122 is also shown in both the front module 110 and the rear module 130. [0018] According to the present invention, a use case of the rolling chassis 100 is described. Considering the rolling chassis 100 as described in Fig. 1, is provided to a vehicle manufacturer. The rolling chassis 100 is a rear wheel drive configuration. Now, if the manufacturer intends to manufacture the vehicle with front wheel drive configuration, then only the components of the rolling chassis 100 provided on the rear module 130 need to be shifted to the front module 110, which are the drive motor and gearbox 108.

[0019] In another scenario, if due to any requirement in the assembly line during the manufacturing, the rear module 130 needs to be at front, then instead of completely shifting and rotating the rolling chassis 100, only the sub systems/components are shifted from the rear module 130 to the front module 110, thus saving time and efforts or any changes in the assembly line itself. A need to align the front module 110 and the rear module 130 in a specific direction on an assembly line is no more needed. The manufacturer is free to choose the orientation of the rolling chassis 100. Further, with respect to the intermediate module 120, the segments 106 are assembled and disassembled based on customer requirement. The segments 106 are further joined/assembled by I-Beam or Inverted C-Sections using fasteners (bolts/rivets, etc.). The torque requirement for fasteners are defined based on the load distribution.

[0020] According to the present invention, the rolling chassis 100 with an electric drive system (the drive motor and the gearbox) is a production ready and a modular platform solution for electric vehicles. The rolling chassis 100 with integrated functional subsystems enables the Original Equipment Manufacturer (OEM) to save on development time and testing, leading to quick penetration into series production. The rolling chassis 100 offers custom-made solutions for OEM’s considering the front module 110 and the rear module 130. Both the front module 110 and the rear module 130 are compatible for mounting drive motor with gearbox 108 to define front wheel drive configuration and rear wheel drive configuration. Both the front module 110 and the rear module 130 are compatible for redeployment of suspension and steering assembly 102 without changing the respective provisions. Both the front module 110 and the rear module 130 are equipped with mounting arrangement/provisions with the intermediate module as poke-yoke to ease the OEM in identifying the orientation of the front module 110 and the rear module 130. Both the front module 110 and the rear module 130 are equipped with structural crash end module 112 and no additional structure to be fitted by the OEM for vehicle safety. Both the front module 110 and the rear module 130 are equipped with pillar structure mounting points considering the load distribution which eases the OEM for upper body design freedom (compatible for both passenger and Light Commercial Vehicles (LCV), such as hatchback, sedan, utility vehicle, lorry, tempo, etc.).

[0021] According to the present invention, a modular flat rolling chassis 100 is provided to mount components/ subsystems for passenger, LCVs and other types of vehicles. The rolling chassis 100 is designed and analyzed under static and dynamic test conditions for the subsystems and body to withstand the different loading conditions. The subsystem integration to the rolling chassis 100 and tolerance analysis is performed for different possible variants of the required vehicle type. The tolerance analysis is performed in consideration with design positions of the sub-systems/components, maximum front and rear axle loads, max jounce and rebound, etc. The complete rolling chassis 100 is adapted with subsystem mounting feasibility. The rolling chassis 100 is usable for front or rear wheel drive configurations by swapping the respective modules. The rolling chassis 100 is common for different types of vehicle. Further, keeping the same position of the front module 110 and the rear module 130, the size, length of the intermediate module 120 can be increased or decreased based on the required wheel bases. For example, and the wheel base up to which the intermediate module 120 is scalable is 3.335m, and the maximum Gross Vehicle Weight (GVW) for higher wheelbase is two tons. This is just an example to bring out clarity in understanding, and the same must not be understood in limiting manner. [0022] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.