GB2483272A

GB2483272A - Electric vehicle with H shaped chassis

Info

Publication number: GB2483272A
Application number: GB1014582.9A
Authority: GB
Inventors: John William Anderson Paterson; Arthur Thomas Wolstenholme; Timothy Peter Martin
Original assignee: LIGHTNING CAR Co Ltd
Current assignee: LIGHTNING CAR Co Ltd
Priority date: 2010-09-02
Filing date: 2010-09-02
Publication date: 2012-03-07
Anticipated expiration: 2030-09-02
Also published as: GB2483272B; GB201014582D0

Abstract

An electric motor vehicle is provided with a chassis 201 for supporting operational components of the motor vehicle and a vehicle body-shell defining an overall appearance of the motor vehicle. The chassis comprises a substantially H-shaped box 201, having a central longitudinal section 204, a forward transverse section 205 and a rear transverse section 206. A lower floor of the chassis 201 may include conduits for a coolant. The chassis may be manufactured as an aluminium structure with an aluminium honeycomb core. The invention allows rechargeable batteries to be housed within the H-shaped box. The chassis may be provided with dimensions corresponding to vehicle size and the number of battery modules required. A substantial proportion of the stiffness provided by the chassis may be provided by a plurality of battery modules. This is advantageous for avoiding additional weight.

Description

Electric Motor Vehicle

CROSS REFERENCE TO RELATED APPLICATIONS

This application represents the first application for a patent directed towards the invention and the subject matter.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electric motor vehicle having a chassis for supporting operational components of the motor vehicle.

2. Description of the Related Art

Electric motor vehicles have become more attractive in recent times, partially due to a desire by many consumers to drive more environmentally friendly vehicles which reduce pollution to the atmosphere by creating fewer harmful emissions. Most currently available electric vehicles are desigried primarily for this purpose, while concentrating less on performance and often using heavy and bulky blocks of batteries, such as lead-acid batteries. Thus, problems exist in terms of designing electric powered vehicles that meet the performance of conventional hydrocarbon fuelled vehicle designs, while making use of available battery technology.

BRIEF SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided an electric motor vehicle having a chassis for supporting operational components of the motor vehicle and a vehicle body-shell defining an overall appearance of the motor vehicle, wherein: said chassis comprises a substantially H-shaped box, having a central longitudinal section, a forward transverse section and a rear transverse section; and re-chargeable batteries housed within said substantially H-shaped box.

In an embodiment, the H-shaped box houses a plurality of battery modules. These modules may be of the type disclosed in the applicant's co-pending British patent application number 10 14 173.7, filed 25 August 2010.

According to a further aspect of the present invention, there is provided a method of assembling a motor vehicle, comprising the steps of: constructing a substantially H-shaped chassis defining a central longitudinal section, a forward transverse section and a rear transverse section, wherein the beam strength of said substantially H-shaped box is enhanced by the inclusion of a plurality of re-chargeable battery modules.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Figure 1 shows an example of an electric motor vehicle; Figure 2 shows a schematic plan view of the electric vehicle of Figure 1; Figure 3 shows a schematic structure of the H-frame chassis of Figure 2; Figure 4 shows a schematic cross-sectional front view of a body-shell; Figure 5 shows a schematic plan view of an alternative embodiment of the present invention; Figure 6 shows a schematic plan view of a further alternative embodiment of the present invention; Figure 7 shows an alternative embodiment of the present invention in schematic plan view; and Figure 8 shows an example of a battery module for an electric motor vehicle of the type described herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figure 1 An example of an electric motor vehicle is shown in Figure 1. The electric motor vehicle 101 comprises a vehicle body-shell 102 and a chassis for supporting operational components of the motor vehicle, detailed in Figure 2. The chassis comprises a substantially H-shaped box which is shown further in the schematic plan view of the electric motor vehicle shown in Figure 2.

Figure 2 A schematic plan view of electric motor vehicle 101 is illustrated in Figure 2. The internals of the electric motor vehicle include the chassis 201, electric motor 202 and electric motor 203.

Chassis 201 comprises a substantially H-shaped box and, in an embodiment, is manufactured as an aluminium sandwich structure with an aluminium honeycomb core. It is to be appreciated that different composite structures could be used in alternative embodiments. Chassis 201 further has a central longitudinal section 204, a forward transverse section 205 and a rear transverse section 206 and the H-shaped box is configured to house a plurality of rechargeable batteries, such as those described with respect to Figure 8.

Electric motor vehicle 101 also has a front axle 207 and a rear axle 208.

Front axle 207 is supported in front of forward transverse section 205 and similarly, rear axle 208 is supported behind rear transverse section 206.

Furthermore, in front of forward transverse section 205 there is provided an engine compartment 209 which is configured to hold electric motor 202.

Similarly, a second engine compartment 210 is present behind rear transverse section 206 which is configured to hold electric motor 203.

In an alternative embodiment, electric motor 202 may not be required, and thus, engine compartment 209 can be alternatively configured to house battery modules such as the battery module shown in Figure 8. This has the added benefit of keeping the centre of gravity of the vehicle low.

At the rear of the vehicle, there is a cage 211 which is configured to house motor 203 and to support the suspension wishbones for electric motor vehicle 101.

The electric motors (such as electric motor 202 and electric motor 203) are twin AC electric motors which are produced for high power electric vehicles and, in an embodiment, are two separate AC synchronous induction motors that in turn drive reduction gearboxes. The reduction gearboxes and synchronous induction motors are housed together. In an embodiment, the speed of the motors is capable of reaching 12,000 rpm, with the gearing reducing the speed of the wheel to a maximum of 1654 rpm. This reduction allows for a geared maximum speed of up to 200 miles per hour. However, in most practical applications, this maximum speed will be reduced, possibly under electronic control.

Electric motor 203 is positioned between a left axle 212 and right axle 213 of rear axle 208. There is no direct connection between axle 212 and axle 213 but a differential effect is successfully achieved due to an increased load on the inside wheel of the vehicle giving rise to an automatic limited slip differential. Additional electronics are not required but torque vectoring may be used in order to specify the degree of torque required for each motor.

Figure 3 Figure 3 shows a schematic side view structure of H4rame chassis 201 in isolation from the body-shell 102 of electric motor vehicle 101. The aluminium composite chassis 201 provides beam stiffness and space in which to house the battery modules. Thus, chassis 201 provides beam strength in order to withstand the bending forces indicated by arrow 301 and arrow 302.

Chassis 201 is connected to body-shell 201. The body-shell lacks beam stiffness but has substantial torsional rigidity. The combination therefore provides a strong engineering solution.

The substantially H-shaped box of chassis 201 introduces minimal additional weight beyond that provided by the housed battery modules such that a substantial proportion of the beam stiffness provided by the substantially H-shaped box of chassis 201 is provided by the battery modules. In an embodiment, dimensions of the battery modules and that of their containing box defined by the H-shaped chassis, are such as to provide a substantiafly tight fit between the battery modules and their constraining box. Furthermore, in an embodiment, the batteries are constrained at their top and bottom surfaces, such that when so constrained, they enhance the overall stiffness and strength of the chassis. In some applications, this may allow the walls of the chassis to be made thinner with fewer cross braces, without risking instability to the beam-providing function of the chassis; it being appreciated that long and supported links have a tendency to become unstable and may ultimately flex.

In an embodiment, the batteries are solely contained within the H-frame, however, in alternative embodiments it may be desirable to place additional battery modules outside the H-shaped box section.

In this embodiment, however, by having the batteries housed within the H-frame, performance is enhanced by mass centralization; that is, the main weight of the vehicle is situated between front axle 207 and rear axle 208, thereby giving the vehicle enhanced inherent handling. This type of mass centralisation improves the performance of the vehicle; even when compared to a conventional mid-engined vehicle in which the engine is not actually at the centre of the vehicle, but positioned just in front of the rear wheels.

Figure 4 A schematic cross sectional front view of body-shell 102 is shown in Figure 4. As described in Figure 3, body-shell 102 has substantial torsional stiffness and when combined with the beam strength of the H-shaped chassis provides for a dynamically balanced vehicle.

Front axle 207 and rear axle 208, as illustrated in Figure 2, cause body-shell 102 to twist in the direction of arrow 401 and arrow 402, indicating the torsional forces the overall structure is subjected to.

With respect to the manufacture of the motor vehicle, the provision of a separate chassis and a separate body-shell allows for a method of manufacture that facilitates assembly and repair. Body-shell 102 can be lifted from chassis 201 providing access to the power-train for ease of maintenance.

The stiffest points of a motor vehicle are usually behind the front door and in front of the rear wheels. Therefore, in an embodiment, it is suitable to make use of these points for attachment of the chassis 201 to the body-shell 102.

In an alternative embodiment, body-shell 102 may be manufactured with greater strength than required for the complete structure, as this would aid transport of the body-shell when it is separated from the chassis. However, when the chassis and body-shell are combined, body-shell 201 does not require beam stiffness and this allows for weight reduction of the body-shell to improve overall performance of the vehicle.

Figure 5 Figure 5 shows a schematic plan view of an alternative embodiment of the present invention. Chassis 501 comprises a substantially H-shaped box, having a longitudinal central section 502, a forward transverse section 503 and a rear transverse section 504. Forward transverse section 503 and rear transverse section 504 are substantially similar to forward transverse section 205 and rear transverse section 206 depicted in Figure 2. However, in this embodiment, the H-shaped box is configured such that the number of battery modules contained within longitudinal central section 502 is variable, so as to vary the length of the vehicle. This allows for flexibility in terms of the wheel-base and overall length of the vehicle.

Figure 6 Figure 6 shows a schematic plan view of a further alternative embodiment of the present invention. Chassis 601 comprises a substantially H-shaped box, having a longitudinal central section 602, a forward transverse section 603 and a rear transverse section 604.

Longitudinal central section 602 is substantially similar to longitudinal central section 204 depicted in Figure 2. However, in this embodiment, the H-shaped box is configured such that the number of battery modules contained within forward transverse section 603 and rear transverse section 604 are variable so as to vary the width of the vehicle.

Figure 7 Figure 7 shows an alternative embodiment of the present invention in schematic plan view indicating the result of varying both the width and the length of the motor vehicle. Chassis 701 comprises a substantially H-shaped box, having a longitudinal central section 702, a forward transverse section 703 and a rear transverse section 704.

In this particular embodiment, longitudinal central section 702 is substantially similar to longitudinal central section 502 of Figure 5, showing an increase in the overall length of the vehicle. Furthermore, forward transverse section 703 and rear transverse section 704 are substantially similar to forward transverse section 603 and rear transverse section 604 of Figure 6, allowing for an increase in the overall width of the vehicle.

The modifications shown in Figure 7 allow for a greater number of battery modules to be included in the motor vehicle and allow for variations in a motor vehicle manufacturers' vehicle porffolio.

It is appreciated that alternative combinations of battery modules can be contained within the sections of the ftshaped box, other than those illustrated by example here, such that any suitable number of battery modules may be used to give a desirable width and/or length of a vehicle.

Figure 8 An example of a battery module for an electric motor vehicle of the type described herein is shown in Figure 8.

In this embodiment, the H-shaped box of chassis 201 houses a plurality of battery modules, such as battery module 801. Battery modules such as battery module 801 may be of the type disclosed in the applicant's co-pending British patent application 1014173.7 filed on 25 August 2010. However, it is appreciated that other suitable battery modules can be used in this application.

Battery module 801 includes a plurality of substantially planar rechargeable electric cells such as electric cell 802. In this embodiment, each individual module comprises 16 cells, although any suitable number of cells may be used.

The lower floor 803 of the H-shaped box of chassis 201 may further include conduits, such as conduit 804 and conduit 805 for the transmission of cooling fluid.

The plurality of battery modules contained within the H-shaped box of chassis 201 and their mass also provides damping for the suspension of the electric motor vehicle 101. In a motor vehicle, it is desirable to absorb vibrations, in particular those of second order frequencies, and the weight of the batteries can be arranged such that the batteries provide an effective damper for the overall structure thereby improving ride and handling.

Claims

Claims t An electric motor vehicle having a chassis for supporting operational components of the motor vehicle and a vehicle body-shell defining an overall appearance of the motor vehicle, wherein: said chassis comprises a substantially H-shaped box, having a central longitudinal section, a forward transverse section and a rear transverse section; and re-chargeable batteries are housed within said substantially H-shaped box.
2. The electric motor vehicle of claim 1, including a front axle and a rear axle, wherein said front axle is supported in front of said forward transverse section and said rear axle is supported behind said rear transverse section.
3. The electric motor vehicle of claim 1, wherein an engine compartment is provided in front of said forward transverse section and/or behind said rear transverse section.
4. The electric vehicle of claim 1, wherein said H-shaped box houses a plurality of battery modules.
5. The electric vehicle of claim 4, wherein each said battery module includes a plurality of substantially planar rechargeable electric cells.
6. The electric vehicle of claim 4, wherein the number of battery modules contained within said central longitudinal section is variable so as to vary the length of the vehicle.
7. The electric vehicle of claim 4, wherein the number of battery modules contained within the forward transverse section and the rear transverse section are variable so as to vary the width of the vehicle.
8. The electric vehicle of claim 1, wherein said substantially H-shaped box introduces minimal additional weight beyond that provided by the housed batteries such that a substantial proportion of the beam strength and/or stiffness provided by the substantially H-shaped box is provided by the battery modules.
9. The electric vehicle of claim 8, wherein torsional stiffness for the vehicle is provided substantially by said body-shell.
10. The electric vehicle of claim 1, wherein a lower floor of said H-shaped box includes conduits for the transmission of cooling fluid.
11. A method of assembling a motor vehicle, comprising the steps of: constructing a substantially H-shaped chassis defining a central longitudinal section, a forward transverse section and a rear transverse section; wherein the beam strength of said substantially H-shaped box is enhanced by the inclusion of a plurality of re-chargeable battery modules.
12. The method of claim 11, wherein said motor vehicle includes a front axle and a rear axle, and said front axle is supported in front of said forward transverse section and said rear axle is supported behind said rear transverse section.
13. The method of claim 11, wherein an engine compartment is provided in front of said forward transverse section and/or behind said rear transverse section.
14. The method of claim 11, wherein said H-shaped box houses a plurality of battery modules.
15. The method of claim 14, wherein each said battery module includes a plurality of substantially planar rechargeable electric cells.
16. The method of claim 14, wherein the number of battery modules contained within said central longitudinal section is variable so as to vary the length of the vehicle.
17. The method of claim 14, wherein the number of battery modules constrained within the forward transverse section and the rear transverse section are variable so as to vary the width of the vehicle.
18. The method of claim 14, wherein said substantially H-shaped box introduces minimal additional weight beyond that provided by the housed batteries such that a substantial proportion of the beam stiffness provided by the substantially H-shaped box is provided by the battery modules.
19. The method of claim 18, wherein torsional stiffness for the vehicle is provided substantially by said body-shell.
20. The method of claim 11, wherein a lower floor of said H-shaped box includes conduits for the transmission of cooling fluid.
21. An electric motor vehicle as substantially described herein with reference to the Figures.
22. A method of assembling a motor vehicle as substantially described herein with reference to the Figures.