The present invention generally relates to a frame chassis for three-wheel electric vehicle. Particularly, relates to a lightweight tubular frame chassis for three-wheel electric utility vehicle.
BACKGROUND OF THE INVENTION
[002] Presently, the chassis frames for the electric vehicle are designed using plate material with multiple welds hence resulting in higher manufacturing steps as well as multiple wildings. Further, the force configurations acting on the tubular structure are mitigated by structural arrangement that deals with one dynamic drive train that is driving rear wheel.
[003] In the existing state of the arts, the chassis is a plate material based design, which is bulky, heavy, low flexibility, and low customization and designed to house the vehicle components in a specific manner. This result in a non-sustainable approach, because a bulky chassis being heavy in weight consumes more fuel (fossil fuel mainly) or energy while driving, as well as consumes more energy in manufacturing with more welds and multiple manufacturing steps.
[004] Several manufacturers have developed different chassis assembly for electric vehicles. US20130056293 discloses a tubular frame structure for a three-wheeled motor vehicle with an top upper frame extending in the vehicle longitudinal and vehicle transverse direction, and with a lower frame extending in vehicle longitudinal direction and vehicle transverse direction, which is structurally connected with the upper frame via several connecting tubes extending substantially in the vehicle vertical direction, to form at least one energy absorption structure. However, this publication lacks in structural flexibility as it does not have an independent wheel swing arms that generates motion flexibility against all dynamics.
[005] IN1354/MUM/2005 relates to an improved chassis with suspension for three wheelers and automobiles that distribute load evenly throughout the vehicle. Further, this publication relates to an improved chassis with suspension for three wheelers and automobiles that distribute load evenly throughout the vehicle.

[006] In view of the above problems associated with the state of the art, there is a need of a tubular frame chassis for three-wheel electric utility vehicle which has single tubular structure for complete vehicle and offers integrity, flexibility, stability, lean and lightweight dynamics. Further, there is a need of a chassis assembly which is lean and offers extra space for cargo box installation
OBJECTIVE OF THE INVENTION
[007] The primary objective of the present invention is to provide a tubular frame chassis for three-wheel electric utility vehicle.
[008] Another objective of the present invention is to provide a tubular frame chassis for three-wheel electric vehicle which has single tubular structure for complete vehicle.
[009] Another objective of the present invention is to provide a tubular frame chassis for three-wheel electric vehicle which has two independent motors to drive the rear wheels independently.
[0010] Yet another objective of the present invention is to provide a tubular frame chassis for three-wheel electric vehicle which demands reduced number of manufacturing steps.
[0011] Yet another objective of the present invention is to provide a tubular frame chassis for three-wheel electric vehicle which offers integrity, flexibility, stability, lean and lightweight dynamics.
[0012] Other objectives and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, wherein, by way of illustration and example, the aspects of the present invention are disclosed.
BRIEF DESCRIPTION OF DRAWINGS
[0013] The present invention will be better understood after reading the following detailed description of the presently preferred aspects thereof with reference to the appended drawings, in

which the features, other aspects and advantages of certain exemplary embodiments of the invention will be more apparent from the accompanying drawing in which:
[0014] Figure 1 illustrates various views of the tubular frame chassis for three-wheel electric vehicle;
[0015] Figure 2 illustrates various views of the tubular frame chassis attached with rectangular swing arms; and
[0016] Figure 3 illustrates various views of the three-wheel electric vehicle mounted above the tubular frame chassis.
SUMMARY OF THE INVENTION
[0017] The present invention relates to a lightweight tubular frame chassis for three-wheel electric utility vehicle which includes a base structure with three curved tubes extending from the front to the rear end of the vehicle, one on right side, one on middle, and one on left side for structural integrity. The tubular frame chassis further includes two front payload frame mounting points, four rear payload mounting points, two motor mounting rectangular swing arms, one rear sway bar for dynamic stability of swing arms, two rear shock absorbers mountings, two independent swing arms for each rear wheel, housing for batteries, one or more foot rest plate and atleast one seat mounting.
[0018] The proposed three wheel electric vehicle tubular chassis frame is designed to accommodate seating, front payload, read payload, independent wheel drive using non-interacting swing arms, without common rear wheel shaft, without differential gear box, offering flexible mountings for rear carry boxes and front carry box, housing for batteries and electronics, integrated mountings for steering frame in total achieving safe vehicle dynamics, turning and drivability.
DETAILED DESCRIPTION OF EMBODIMENTS
[0019] The following detailed description and embodiments set forth herein below are merely exemplary out of the wide variety and arrangement of instructions which can be employed with

the present invention. The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. All the features disclosed in this specification may be replaced by similar other or alternative features performing similar or same or equivalent purposes. Thus, unless expressly stated otherwise, they all are within the scope of the present invention.
[0020] Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
[0021] The terms and words used in the following description and claims are not limited to the bibliographical meanings but are merely used to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention.
[0022] It is to be understood that the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.
[0023] It should be emphasized that the term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps, or components but does not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof.
[0024] The main embodiment of the present invention is a tubular frame chassis 100 for three-wheel electric vehicle having single tubular structure for complete vehicle. The various perspectives of this embodiment is shown in Figure 1. Further, figure 3 illustrates various views of the three-wheel electric vehicle mounted above the tubular frame chassis 100. Figure la illustrates the component of the single frame assembly for a three-wheel electric vehicle which includes three curved tubes 101 bended to form the main spine of the chassis. As shown in the

figure la and lb, one curved tube 101b is centrally aligned at the middle, while the other two 101a and 101c are symmetrically arranged in left and right side of the middle one. These three curved tubes 101 are extended from the front to the rear end of the vehicle and constitute the base structure of the frame assembly and provides structural integrity to the vehicle.
[0025] The frame assembly of the three-wheel electric vehicle further includes two front payload frame mounting points 102, four rear payload mounting points 103. The two front payload frame mounting 102 points are integrated at the front end of the curved tubes 101. The front payload frame mounting points 102 is designed to couple small cargo accessory which can carry payload of approximately 30 kgs. Similarly, the two rear payload mounting points 103 are integrated at the rear end of the curved tubes 101 and designed to offer the installation of a bigger cargo box which can carry payload of approximately 150 kgs. The loads are evenly distributed across the frame structure and offer a stable and reliable static and dynamic mechanical integrity.
[0026] In accordance with another embodiment, the tubular frame chassis 100 for three-wheel electric vehicle are attached with two motor mounting rectangular swing arms 104, each to incorporate a motor to drive the rear wheels independently as shown in figure 2. The motor mounting swing arms 104 are made of rectangular hollow sections which makes it a lightweight component. The two independent motor mounting rectangular swing arm are attached with chassis frames at swing arm attachment points both on the left and right side of the vehicle. The other end of each swing arm provides bearing housing for the motor shaft and hence a connection to motor 105. One rear sway bar is provided to attain dynamic stability of both swing arms. Further, the tubular frame chassis includes two rear shock absorber mounting 106 attachments one on each side left and right side of the chassis. One end of the shock absorber 111 is mounted on the rear shock absorber mounting 106 and another end is attached to the rectangular swing arms 104.
[0027] Another embodiment of the present invention is the incorporation of two independent swing arms 107 for each rear wheel. Independent swing arms 107 offers desired degree of freedom to the wheel movement by avoiding the mechanical interaction of both the rear wheels. The modular mechanism of the swing arm 107 for connecting the in-wheel motor housing provides

flexible and independent drive assembly for electric vehicles. Since, there is no interaction between the rear wheels and both are operated independently via two separate motors, hence this eliminates the requirement of a common rear shaft for vehicle rear wheels.
[0028] The proposed three wheel electric vehicle tubular chassis frame is designed to accommodate seating through a seat mounting 108, front payload through front payload mountings 102, read payload through rear payload mountings 103, independent wheel drive using non-interacting swing arms 107, without common rear wheel shaft, without differential gear box, offering flexible mountings for rear carry boxes and front carry box, one or more foot rest plate 110, mountings 109 to house batteries and electronics, integrated mountings 102a for steering frame in total achieving safe vehicle dynamics, turning and drivability. The design of the tubular chassis frame confirms the overall mechanical integrity, flexibility, stability, lean and lightweight, and required dynamics.
[0029] The various embodiments of the present invention provides following advantages:
• Optimized production cost: Lower number of manufacturing steps and components leads to optimized cost for production. The optimized production cost is achieved without compromising with the quality, features, functionality or strength.
• Environment Friendly: Environmental friendly because of reduced number of manufacturing steps (reduced number of welds, reduced bending and cutting steps), which allows low consumption of electrical energy while production, low number of manufacturing steps.
• Negligible mechanical losses: The rear wheels are attached directly to the chassis frame via a swing arm. Hence, eliminates the requirement of common drive shaft and differential gear mechanisms. This resulted in almost negligible mechanical losses while the power is transferred from motors to the wheels. The vehicle frame offers a solution that can provide dynamic functionality, independent housing and mountings to avoid mechanical losses during movement.

• Light weighted robust vehicle frame: To be able to gain more space as well as avoid mechanical losses the vehicle frame is made to house different elements in place that interact with each other as well as and remain intact from any relative movement effects. This also resulted in a light weighted robust vehicle frame.
• Increased space for payload/cargo: This frame supports two independent motors that drive the wheels independently. Hence removing completely the differential gear box as well as single shaft. Therefore there is no rear shaft for connecting two wheels hence wheels are independent, there is no differential unit. This offers extra space for cargo box installation.
[0030] While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

We Claim:

1. A tubular frame chassis 100 for an electric vehicle, comprising:
• atleast three curved tubes 101 extending from the front to the rear end of the vehicle;
• two front payload frame mounting points 102;
• two rear payload mounting points 103;
• two mountings for rectangular swing arms 104;
• one rear sway bar for dynamic stability of swing arms;
• one or more rear shock absorbers mountings 106;
• two independent swing arms 107 for each rear wheel;
• battery mounting 109 for housing batteries;
• one or more foot rest plate 110; and
• atleast one seat mounting 108,
wherein, all the said housings and mountings (101, 102, 103, 106, 107, 108, 109, 110) are integrated into a single tubular structure;
each motor mounting rectangular swing arms 104 incorporate a motor to drive the rear wheels independently;
the rear wheels are operated independently via two separate motors;
the independent swing arms 107 for each rear wheel offers desired degree of freedom to the wheel movement by avoiding the mechanical interaction of both the rear wheels.
2. The tubular frame chassis 100 for an electric vehicle as claimed in claim 1, wherein the said electric vehicle is three wheeled electric vehicle.
3. The tubular frame chassis 100 for an electric vehicle as claimed in claim 1, wherein one curved tube 101b is centrally aligned at the middle, while the other two 101a and 101c are symmetrically arranged in its left and right side

4. The tubular frame chassis 100 for an electric vehicle as claimed in claim 1, wherein the front payload frame mounting points 102 are integrated at the front end of the curved tubes 101 to couple small cargo accessory to carry payload of approximately 30 kgs.
5. The tubular frame chassis 100 for an electric vehicle as claimed in claim 1, wherein the two rear payload mounting points 103 are integrated at the rear end of the curved tubes 101 to couple big cargo box which can carry payload of approximately 150 kgs.
6. The tubular frame chassis 100 for an electric vehicle as claimed in claim 1, wherein the motor mounting swing arms 104 are made of rectangular hollow sections.
7. The tubular frame chassis 100 for an electric vehicle as claimed in claim 1, wherein the two shock absorber 111 are mounted on rear shock absorbers mountings 106 on left and right side of the rear end of chassis.