GB2349621A

GB2349621A - Electrically-powered vehicle

Info

Publication number: GB2349621A
Application number: GB9910475A
Authority: GB
Inventors: Christopher Powell Wilkins
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-05-07
Filing date: 1999-05-07
Publication date: 2000-11-08
Anticipated expiration: 2019-05-07
Also published as: GB9910475D0; GB2349621B

Abstract

A vehicle 10a has at least three wheels including a pair of axially spaced wheels 15a, 20a and a single wheel steerable wheel 25a, the single wheel 25a being driven by an electric motor 70a. The electric motor is either mounted behinde the steering axis or is mounted on the hub of the steerable wheel 25a. Another single wheel may be provided on the opposite side of the axis of wheels 15a, 20a (Fig. 3).

Description

ELECTRICALLY POWERED VEHICLE This invention relates to electrically powered vehicles, and particularly-though not exclusively-to an electrically powered tricycle.

Electrically powered vehicles are known. In particular electrically powered tricycles having a single front wheel, and a pair of axially spaced rear wheels one of which is driven are known.

A number of problems exist with such known electrically powered vehicles with one driven rear wheel.

For example an insufficient power to weight ratio, such that known vehicles are limited to use on low gradient hills. The alternative is to drive both rear wheels either by means of two motors or one motor and a differential.

It is an objecc of the present invention to obviate or mitigate one or more of the aforementioned problems in the prior art.

It is a further object of at least one embodiment of the present invention to provide an electrically powered vehicle with improved manoevrability and/or road holding.

It is a yet further object of at least one embodiment of the present invention to provide an electrically powered vehicle with an improved power to weight ratio.

It is a yet further object of at least one embodiment of the present invention to provide an electrically powered vehicle which is relatively simple to manufacture, and wherein the number of parts is sought to be minimised.

The invention, therefore, provides a general solution of driving a single wheel of a tricycle by means of electrical power.

According to first aspect of the present invention there is provided a vehicle having at least three wheels including a pair of axially spaced wheels and a single wheel, wherein the single wheel is driven by electrically powered means.

This arrangement obviates a need for a differential mechanism.

The vehicle may, therefore, comprise a tricycle, the single wheel being positioned substantially along a first axis extending substantially perpendicularly from substantially midway along a second axis joining the pair of wheels.

The single wheel may advantageously comprise a front wheel of the vehicle.

This arrangement provides a particularly low tractive force layout.

The vehicle may include means for steering the single wheel.

The steering means may comprise handlebars operatively associated with a steering column or head. The steering head may include a fork or forks on which the single wheel is mounted for rotation.

The electrically powered means may include an electric motor.

In a first embodiment the electric motor may be mounted to the steering head, and preferably rearwardly thereof.

In a second embodiment the electric motor may be mounted on a hub of the single wheel.

It is, therefore, apparent that in the first and second embodiments the electric motor moves with the means for steering the single wheel.

In a modified embodiment the vehicle may include a fourth wheel comprising a balance wheel positioned substantially along the first axis but on an opposite side of the second axis to that of the single wheel.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, which are: Fig. 1 a view from one side of an electrically powered vehicle according to a first embodiment of the present invention; Fig. 2 a view from another side of the vehicle of Fig.

1; Fig. 3 a partial view from above of the vehicle of Fig. 1; Fig. 4 a detailed partial side view of the vehicle of Fig. 1 to an enlarged scale; Fig. 5 a view from one side of an electrically powered vehicle according to a second embodiment of the present invention; Fig. 6 a view from one side and forward of an electrically powered vehicle according to a third embodiment of the present invention; and Fig. 7 a detailed partial side view of an electrically powered vehicle according to a fourth embodiment of the present invention.

Referring initially to Figs. 1 to 3, there is shown a first embodiment of a vehicle, generally designated lOa, having three wheels including a pair of axially spaced wheels 15a, 20a and a single wheel 25a, wherein the single wheel 25a is driven by electrically powered means, as will be described hereinafter in more detail.

The vehicle lOa includes a chassis 30a to which the pair of wheels 15a, 20a, are suitably attached for rotational movement relative thereto. The chassis 30a supports a seat 35a for a driver 40a.

As can best be seen from Fig. 3, the single wheel 25a is positioned substantially along a first axis 40a extending substantially perpendicularly from substantially midway along a second axis 45a joining the pair of wheels 15a, 20a.

As is apparent from Figs. 1 to 3, the single wheel 25a of this embodiment comprises a front wheel of the vehicle lOa during normal forward motion.

Further the vehicle lOa includes means for steering the single wheel 25a. The steering means comprise handlebars 50a operatively associated with a steering head 55a by means of a rod linkage 50a, the steering head 55a including a fork (s) 65a on which the single wheel 25a is mounted for rotation. Movement of the handlebars 50a either to the left or to the right, therefore, produces a corresponding movement of the single wheel 25a.

The electrically powered means includes an electric motor 70a mounted to the steering column 55a and rearwardly thereof. The electric motor 70a is powered by means of batteries 75a, which in this embodiment are conveniently located upon the chassis 30a below the seat 35a. The batteries 75a supply electrical power to the motor 70a via cables 80a. The batteries 75a may comprise four 12v batteries providing around 80 Amp hours. Additional batteries (not shown) could be provided as a reserve power supply with a suitable change over switch (not shown).

This would increase the power supply by around 50%.

Further, as can be seen from Figure 2, an output shaft 85a of the motor 70a is operatively connected to a hub 90a of the single wheel 25a by means of a drive belt 95a or the like.

It is apparent from the foregoing that the electric motor 70a moves with the means for steering the single wheel 25a. Placement of the motor 70a behind fork (s) 65a provides a self centring steering mechanism.

The electric motor 70a may be a disc-armature DC motor, around llkg in weight and provided within a 200mm diameter case and may produce around 3.2 kw at 24V at 2560 rpm. Such a motor 70a is available from Lynch Motor Company of London, United Kingdom, and are described in EP 0 230 759, US 4,823,039, and JP 61-304083, the content of which is incorporated herein by reference.

The handlebars 50a are behind the steering head 55a, and have an offset joint 51a linked by a single rod 52a to a similarly offset joint 56a on the steering head 55a.

The steering head 55a turns on tapered roller bearings 57a.

This arrangement enables the driver 40a to sit behind the single front wheel 25a (rather than over it). This arrangement further provides space for mounting the motor 70a behind the steering head 55a.

As can be seen from Fig. 4, a motor mounting bracket 53a is attached to a top of the fork (s) 65a. Thus the motor 70a is substantially in line with the front of the single wheel 25a, and adjacent a line of the fork (s) 65a.

The motor 70a is geared with two gearwheels 71a, 72a, and belt 95a on a 3.3 to 1 reduction.

Cable operated drum breaks (not shown) may be provided to one or more and preferably all three wheels 15a, 30a, 25a.

The vehicle lOa including batteries 75a may be of the order of 140kg in weight, length approximately 1970mm, and width approximately 1050mm.

It is thus envisaged that the vehicle lOa could be operated for around 11/4 hour over 10 miles at an average speed of around 16 mph, and a top speed of 29 mph.

Referring to Fig. 3 there is shown in dotted outline a modification to the vehicle lOa, wherein the vehicle lOa is provided with a fourth wheel 26a comprising a balance wheel positioned substantially along the first axis lOa but on an opposite side of the second axis 45a to that of the single wheel 25a.

Referring now to Fig. 5 there is shown a view from one side of a second embodiment of an electrically powered vehicle, generally designated lOb according to the present invention. The vehicle lOb is similar in many respects to the vehicle 10a, like parts being designated by like numerals but suffixed with"b"rather than"a".

However, in vehicle lOb the electric motor 70b is mounted on top of fork (s) O 65b. Further, the vehicle lOb is provided with a partial cab 200b to seek to protect a vehicle occupant 40b.

Referring now to Fig. 6 there is shown a view from one side and forward of an electrically powered vehicle, generally designated lOc according to a fourth embodiment of the present invention. The vehicle lOc is similar in many respects to the vehicle lOa, like parts being designated by like numerals but suffixed with"c"rather than"a".

However, the vehicle lOc is provided with a modified steering mechanism including two rods 52c.

Referring now to Fig. 7 there is shown a detailed partial side view of a fourth embodiment of an electrically powered vehicle, generally designated lOd according to the present invention. The vehicle lOd is similar in many respects to the vehicle 10a, like parts being designated by like numerals but suffixed with"d"rather than"a".

However, in vehicle lOd the electric motor 70d is mounted on a hub 90d of the single wheel 25d so as to directly drive the wheel 25d.

The motor 70d may be a 4kW electric motor such as that designed by PML Flightlink Limited. The use of a hub mounted motor 70d allows for the provision of a pair of conventional forks 65d and steering head 55d.

It will be appreciated that the embodiments of the present invention hereinbefore described are given by way of example only, and are not meant to limit the scope thereof in any way.

In particular it will be appreciated that although in the disclosed embodiments the single wheel comprises a front wheel in normal operation, the electric motor could be provided with means to drive the motor in a reverse direction such that the vehicle may be reversed, in use.

It will further be understood that the vehicle may be provided with a cab or enclosure for a user and/or passenger.

Claims

CLAIMS 1. A vehicle having at least three wheels including a pair of axially spaced wheels and a single wheel, wherein the single wheel is driven by electrically powered means.
2. A vehicle as claimed in claim 1, wherein the vehicle is a tricycle.
3. A vehicle as claimed in claim 2, wherein the single wheel is positioned substantially along a first axis extending substantially perpendicularly from substantially midway along a second axis joining the pair of wheels.
4. A vehicle as claimed in any preceding claim, wherein there is provided means for steering the single wheel.
5. A vehicle as claimed in claim 4, wherein the steering means comprise handlebars operatively associated with a steering column or head.
6. A vehicle as claimed in claim 5 wherein the steering head includes a fork or forks on which the single wheel is mounted for rotation.
7. A vehicle as claimed in any preceding claim, wherein the electrically powered means includes an electric motor.
8. A vehicle as claimed in claim 7 when dependent upon claim 4, wherein the electric motor is mounted in association with the means for steering the single wheel so as to move therewith.
9. A vehicle as claimed in either of claims 7 or 8, wherein the electric motor is mounted to the steering head.
10. A vehicle as claimed in any of claims 7 to 9, wherein the electric motor is mounted rearwardly of the steering head.
11. A vehicle as claimed in either of claims 7 or 8, wherein the electric motor is mounted on a hub of the single wheel.
12. A vehicle as claimed in any of claims 2 or 3 to 11 when dependent upon claim 2, wherein there is provided a fourth wheel comprising a balance wheel positioned substantially along the first axis but on an opposite side of the second axis to that of the single wheel.
13. A vehicle substantially as hereinbefore described with reference to Figures 1 to 4, Figure 5, Figure 6 or Figure 7.