GB2305405A

GB2305405A - Electrical drive apparatus

Info

Publication number: GB2305405A
Application number: GB9519152A
Authority: GB
Inventors: David Henry Walugembe
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-09-19
Filing date: 1995-09-19
Publication date: 1997-04-09
Anticipated expiration: 2015-09-19
Also published as: GB9519152D0; GB2305405B

Abstract

Electrical drive apparatus (10) has an electrical motor (12) arranged to be driven by a power supply means (battery 17). An electrical generator (21) is operatively engaged to said motor (12) for rotation with the rotor (14) thereof. Means for initiating rotation of said motor (12) and said generator means (21) are provided. Electrical energy from said generator means (21) is selectively delivered to said electrical motor (12) to form at least part of said power supply means (17). The drive may be in a vehicle with the motor (12) driving one set of wheels and the generator (21) driven by another. The generator may be connected to a flywheel for energy storage and vehicle may additionally have an engine driving one set of wheels.

Description

ELECTRICAL DRIVE APPARATUS The present invention relates to electrical drive apparatus and in particular, but not exclusively, to electrical drive apparatus which is involved in the generation of electrical power and the provision of a mechanical drive by way of an electric motor.

Electrical drive apparatus is commonly found in situations where the motion of a particular piece of apparatus or machinery is required and, in particular, in situations where electrical power is to be generated so as to achieve operation of further apparatus requiring an electrical supply.

Such electrical drive apparatus involves the motion of at least one member under the influence of an electrical power supply so as to achieve the primary function of the apparatus.

However, such known apparatus can prove to be disadvantageous in that efficient use of the power generated is not generally made since the maximum power output obtained from the apparatus is not always required by the apparatus and so a portion of the power generated can in effect be wasted since it can be considered to be surplus to the general requirements of the apparatus.

Thus, in some instances, the electrical drive apparatus generates unnecessarily high levels of power having regard to the particular circumstances, and in some instances the instantaneous circumstances, in which the apparatus is operating.

The present invention seeks to provide for electrical drive apparatus which can assist in utilizing a power source, whether electrical or mechanical, and having advantageous over known such apparatus.

In accordance with the present invention there is provided electrical drive apparatus comprising an electrical motor arranged to be driven from power supply means, electrical generator means operatively engaged to said motor for rotation with the rotor thereof, means for initiating rotation of said motor and said generator means, and means for selectively delivering electrical energy from said generator means to said electrical motor to form at least part of said power supply means.

The invention is advantageous in that through the selective delivery of electrical energy from said generator means back to said electrical motor, the operation of the drive apparatus can be achieved in an altogether advantageously efficient manner, and in particular when the output requirements of the drive apparatus might, even instantaneously, exceed the input requirements of the apparatus being driven by the electrical drive apparatus.

The present invention generally exploits the advantage that a generally small amount of energy or power can be taken from a generally large power source without disadvantageously effecting the operation of any apparatus or equipment supplied by that power source and in a manner whereby the power taken off can be fed back within the electrical drive apparatus in a controlled manner so as to reduce the external power requirements of the electrical drive apparatus at particular instances.

Advantageously, said electrical motor can be arranged to assist in driving apparatus for locomotion. In particular, said apparatus can advantageously comprise apparatus for locomotion by land such as an automobile or otherwise.

Further, said power supply means may comprise a DC power source and, particularly if the apparatus is to comprise apparatus for locomotion, said DC power source can comprise an on-board battery.

Preferably, the rotor of said generator is operatively engaged to the rotor of said motor. The rotor and generator can then be advantageously provided as a single unit in which the respective rotors are arranged to rotate about a common axis. In particular, the respective rotors are advantageously directly connected by means of an insulating connector member.

According to a particular advantage of the present invention, the engagement between the respective rotors of the motor and generator is selectively releasable so that the driving engagement between the motor and the generator can be disconnected at any required time.

Thus, once rotation of the generator is achieved in a particular manner, the motor can be disconnected therefrom so that the motor is not then required to carry out any work in rotating the generator and wherein particular advantages can arise in that the continued rotation of the generator serves to provide for an electrical output which can at least assist in the continued operation of the motor.

Preferably, inertia means are associated with said generator so as to maintain the generation of an electrical output therefrom. In particular, said inertia means may comprise flywheel means.

When employed for use with apparatus for locomotion, the electrical generator can, at least initially, be advantageously driven by means of the motion of the apparatus for locomotion. In particular, the generator can be driven from the engine of the apparatus for locomotion.

Preferably, the electrical motor can also be incorporated into the driving means of the apparatus for locomotion so as to assist in achieving the locomotion thereof. Thus, as and when required, the electrical supply generated by the generator can be used to provide an onboard electrical power supply for the apparatus for locomotion and, when appropriately selected, can also provide for a power source serving to improve the efficiency with which the apparatus for locomotion can achieve the required locomotion at any particular instance.

Preferably, the releasable engagement between the respective rotors of the generator and electrical motor can be advantageously achieved with regard to changes in the manner of motion of the apparatus for locomotion when the manner of motion of the apparatus for locomotion changes from one in which reduced power input is required, for example during a braking phase or a phase involving downhill motion, to a phase when increased power input to, and acceleration of, the apparatus for locomotion is required.

Thus, in a situation when increased input into the electrical drive apparatus might be required, electrical power can be returned by way of the aforementioned inertia means at an instance when further power to the electrical drive apparatus might be required and once the respective rotors of the generator and motor have been disconnected.

Advantageously, the means for initiating rotation of the motor and generator means comprises an electrical power source for the motor. In particular, the power source comprises a DC power source.

As mentioned above, the motor and generator can be driven by means of the motion of any apparatus for locomotion upon which the generator and motor are mounted.

Preferably, the means for selectively delivering electrical energy from the generator means to the electrical motor may comprise control means which can include cut out means for introducing the electrical energy retrieved from the generator means into the supply circuitry of the motor. If, for example, the supply circuitry of the motor comprises initiating means in the form of a DC supply circuit, said cut-out means can be arranged to interrupt, or at least enhance, the supply of current from that initiating means.

Preferably, the apparatus comprises control means which serves to achieve the accurately timed disconnection between the rotors of the generator and the motor and/or the selective delivery of the electrical energy from the generator means to the electrical motor.

As will then be appreciated, the apparatus can be controlled in a manner whereby at instances in which full power input to the electrical drive apparatus is not required, the generator means can be driven in a manner so as to increase the electrical energy retrievable therefrom, such that, when an increased supply to the electrical drive apparatus is required, the electrical energy retrieved from the generator can assist in the provision of this further supply requirement and at a time when the respective rotors of the generator and the motor are disconnected so that the generator does not represent a load requiring power from the motor.

Preferably, the control apparatus comprises control processor means.

Further, the apparatus may comprise a plurality of electrical motors and/or a plurality of electrical generator means whereby control means in the form of timing means can be arranged to achieve the selective operation or activation of the electrical motors and/or electrical generator means. In this manner, the control of the connection between the rotors of respective pairs of motors and generator means can advantageously allow for the simultaneous retrieval of power from each of the plurality of generator means or the time operation of each of the generator means separately so as to achieve a virtually continuous retrieval of power from the plurality of generator means.

Of course, it will be appreciated that the control means can provide for disengagement between the rotors of respective pairs of generator means and electrical motor means in any required manner, and also the selective delivery of electrical energy from said plurality of generator means to said electrical motor means, in any particular manner and order that is required for example which may include the delivery of the combined electrical energy from all of said generator means but the ordered reconnection of the means for achieving engagement between the generator means and the motor means.

Of course, it will be appreciated that the electromechanical properties of the generator means and/or the electrical motor, for example as regards the respective sizes and weights of the rotors, status and coils, and the strengths of the respective magnetic fields, can be varied so as to seek to optimize the efficiency of the apparatus of the present invention.

The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a schematic representation of electrical drive apparatus embodying the present invention; Fig. 2 illustrates the use of apparatus embodying the present invention in a motor car; Fig. 3 is a schematic representation of another embodiment of the present invention; and Fig. 4 is a schematic representation of a further embodiment of the present invention.

Turning now to Fig. 1, there is shown a schematic representation of electrical drive apparatus 10 embodying the present invention.

A particular feature of the electrical drive apparatus 10 of the present invention is that it comprises a combined motor/generator having rotors which are arranged for engagement so as to rotate together about the same axis of rotation.

In Fig. 1, there is illustrated an electrical motor 12 having a rotor coil 14 supplied by way of a DC current supply line 16 from a battery 17 and which rotor 14 achieves rotation within the magnetic field generated by motor magnets 18, 20.

A generator 21 is illustrated which has a rotatable coil 22 arranged so as to generate an electrical output by way of supply lines 24 due to the rotation of the coil 22 in the magnetic field produced by the magnets 26, 28.

As mentioned above, the rotors of the motor 12 and the generator 21 are engaged for rotation together about a common axis of rotation by way of an insulating connecting member 30. Thus, operation of the motor 12 by way of the current supplied by supply line 16 serves to effect rotation of the rotor 22 of the generator 21 and thereby achieve the generation of an electrical current which can be delivered by way of supply lines 24 to a cut-out member 32.

The cut-out member 32 is arranged, in the illustrated embodiment, to replace the battery 17 as the source of power for the electrical motor 12 in a selective manner.

As will of course be appreciated, in the illustrated embodiment, the motor 12 comprises a DC motor and the generator 21 comprises a DC generator. Thus, the DC current delivered from the generator 21 by way of the supply lines 24 is employed to replace the current derived from the battery 17 and supplied to the motor 12 by way of the supply lines 16.

The disconnection of the battery 17 from the supply lines 16 and its replacement by way of the supply lines 24 is advantageously achieved by way of central control means (not shown).

Further, the insulating connector member 30 connecting the respective coils 14, 22 of the motor 12 and the generator 21 is advantageously arranged to provide for releasable connection between the rotors 14, 22. The release of the connection between the rotors 14, 22 is also controlled by way of said central control means in a manner which allows for the rotation of the coil 22 in the generator 21 at a time when the rotor coil 14 has been disconnected from the rotor 22 of the generator so that work is not required by the motor 12 to drive the generator 21 but current can nevertheless be supplied by way of the supply lines 24 to the supply lines 16 of the motor 12. Of course, the current supplied by way of the supply lines 24 can be used to replace, or at least combine with, the current provided by the battery 17.In this manner, the cut-out 32 can be arranged to completely isolate the battery 17 from the supply 16 of the motor 12 or to introduce the supply lines 24 into the supply circuitry from the motor 12 in combination with the battery 17.

It should be appreciated that the electrical drive apparatus 10 of Fig. 1 can be used as drive apparatus for a principal equipment/apparatus requiring such a supply but that, when required, a possibly small fraction of the power generated by the apparatus can be fed back within the apparatus so as to achieve more efficient operation of the apparatus as a whole. The manner in which electrical power is fed back within the electrical drive apparatus 10 is dependent upon the nature of the power to be supplied externally of the electrical drive apparatus 10.

In one particular embodiment, the rotor 22 of the generator 21 is arranged to rotate with inertia means, such as a fly wheel, so that, once the rotor 22 has become disengaged from the motor rotor 14, the length of time for which the rotor 22 of the generator 21 continues to rotate is increased.

Advantageously, the insulating connector member 30 can be arranged to provide for driving connection between the rotors 14 and 22 during times in which the external power requirement of the apparatus 10 is reduced but, once the external power requirement of the apparatus 10 increases, the connection between the rotors 14, 22 can be controllably broken so that the motor 12 does not need to produce extra work to continue the rotation of the generator 21 but, particularly in view of the continued rotation achieved by use of the aforementioned flywheel (not shown), the generator 21 can continue to generate a current and supply as current by way of supply lines 24 and which current is combined with the current supplied by the battery 17 so as to maintain the required operation of the motor 12.

Of course, it will be appreciated that the principal apparatus being driven by the electrical drive apparatus 10 can be driven by way of a current generator within the apparatus or by way of a chemical power take-off derived from the motor 12.

Turning now to Fig. 2, one particular use of apparatus embodying the present invention is illustrated. Fig. 2 illustrates a motor car 34 in which the electrical drive apparatus 10 of Fig. 1 is employed. The motor car 34 comprises an engine 36 which serves to drive the rear wheels 37 of the motor car 34. From a comparison with Fig.

1, it should be appreciated that the mechanical connection between the rotors 14, 22 of the motor 12 and generator 21 is achieved by way of the frictional engagement between the electrical motor 12 and the front wheels 37', the road surface, the back wheels 37 and the generator 14. The disconnection achieved by the disconnection of the connecting member 30 in Fig. 1 is achieved in Fig. 2 by way of the disconnection of the rear wheels 37 from the dynamo 14.

The present invention can be employed in an advantageous manner in the motor car 34 of Fig. 2 in that the rotational output from the electric motor 12, whether achieved by way of the on-board motor 17 and/or by way of the current generated by the generator 14 as discussed above, is arranged to drive the rotation of the front wheels 37' which can serve to assist the efficiency of the motion of the motor car 34. The engine 36 of the motor car 34 advantageously serves to achieve at least intermittent motion of the motor vehicle 34 and the electric motor 12 can then be employed to assist with the movement of the motor car 34 dependent upon the manner of motion of the motor car 34, in particular whether or not the motor car 34 is required to decelerate or is perhaps moving down-hill under the influence of gravity.It should be appreciated that the electrical drive apparatus in Fig. 2 corresponds to that of Fig. 1 in that a mechanical power take-off is derived from the motor 12 of Fig. 1 and serves to drive the rotation of the front wheels 37' of the motor vehicle 34 as discussed above.

Turning now to Fig. 3, there is provided a schematic representation of another embodiment of the present invention in which a heavy duty motor is driven by way of the current supplied by the electrical drive apparatus, and which heavy duty motor is associated with a flywheel which can in turn serve to assist in achieving the continued rotation of the rotor of the generator.

The apparatus of Fig. 3 comprises an electrical motor 38 having a rotor (not shown) releasably connected to the rotor (not shown) of a generator 40 by means of an insulating connector 42 such that, as before, the motor and generator can be provided as a combined unit in which the respective rotors rotate together about a common axis of rotation. The motor 38 is arranged to be supplied by way of a DC supply means such as a battery 44 and the generator 40 is arranged to deliver an electrical current by way of the supply line 46. The supply line 46 delivers electrical current to a heavy duty motor 48 although a feed-back line 50 is also provided from the output of the generator 40 to the input of the motor 38.The opening and closing of the fed-back supply line 50 is controlled by way of the central control means (not shown), as is the disconnection between the rotors of the motor 38 and the generator 40. Although inertia means may be associated with the generator 40, it should also be appreciated that inertia means in the form of a flywheel 52 is associated with the heavy duty motor 48 and is mechanically coupled via coupling 53 to the generator 40 in a manner so as to maintain the rotation of the rotor of the generator 40 and thus the output of a supply current from the generator 40.

Thus, it will be appreciated that the central control (not shown) can be arranged to provide for the feed-back of electrical power derived from the generator 40 to the input of the motor 38 as and when required and can also allow for the feed-back of mechanical power from the flywheel 52 to the generator 40 so as to maintain the output of current from the generator 40.

It will be appreciated that, when incorporated into principal apparatus requiring an electrical and/or mechanical power input, the embodiment of the present invention as illustrated in Fig. 3 provides for drive apparatus in which the operation of the means providing for the power output of the apparatus can be controlled in a manner so as to effectively store energy during periods of low power output requirement and then effectively retrieve that stored energy during periods of increased power output requirement in a manner which serves to reduce the power supply requirement of the drive apparatus itself during such periods of increased power output requirement.

Fig. 4 illustrates a further development of the present invention and, in particular, a further development of the embodiment illustrated with reference to Fig. 3.

Fig. 4 shows electrical drive apparatus 54 having motor/dynamo pairs 56, 58; 56', 58' which have their respective rotors connected by way of respective connecting members 60, 60' which can, as and when required, provide for a releasable connection between said rotors as discussed above in connection with the previous embodiment.

The electrical energy generated by the dynamos 58, 58' is delivered by way of supply line 62, 62' to principal apparatus 64 which can provide for the drive of a flywheel 66 which, if required, can advantageously also serve as an entry point for external mechanical power, for example that provided by the motion of a vehicle and the rotation of its wheels etc.

A power take-off line 68 is arranged to provide for a selective driving force to the two dynamos 58, 58' so as to assist in the rotation thereof as and when required and to thereby maintain the generation of electrical power which is delivered to the principal apparatus 64 by means of the supply lines 62, 62'.

A pair of batteries 70, 70' are also provided and are generally only called upon to supply power in a back-up manner or when the energy generated within the apparatus 54 is substantially reduced. In particular, in emergency situations, the batteries 70, 70' can be arranged to supply power directly to the principal apparatus 64 by way of the supply line 72. As will also be appreciated, the selective supply of electrical power from the batteries 70, 70' to the motors 56, 56' is achieved by means of respective cutout means 73, 73' Further cut-out means 74 is provided in the electrical power supply lines 62, 62' extending between the dynamos 58, 58' and the main apparatus 64. The cut-out 74 allows for the feed-back of electrical power generated by the dynamos 58, 58' to drive the respective motors 56, 56' in accordance with a principal operation of the apparatus 54 for serving to increase the efficiency thereof. Thus, the dynamos 58, 58' can be arranged to momentarily provide power to the motors 56, 56' by way of the cut-out 74 and supply lines 76, 76' and, further, the dynamos 58, 58' can be arranged if continuously supply the main apparatus 64, such as a heavy duty motor. Likewise, the flywheel 66 can momentarily be arranged to provide for rotational drive to the dynamos 58, 58' by way of the power take-off arrangement 68.

During operation, the flywheel 66 can also be provided so as to achieve further work output by way of a further power take-off (not shown).

Switching and control arrangements may also be provided so that the electrical power generated by the dynamos 58, 58' and delivered by way of the supply lines 62, 62' to the cut-out 74 is then delivered to only one of the motors 56, 56' at a time.

The circuit arrangement of Fig. 4, and in particular any control and switching arrangement can be further enhanced by the use of coils, transformers, AC-DC converters/rectifiers, circuit breakers, circuit parameter measuring devices so as to enhance the control and efficiency of operation of the apparatus. Further, additional electronic circuits, speed governors and particular materials, such as particular alloys, can be chosen for the motor/dynamo pairs in order to further enhance the efficiency of the apparatus 54.

The electrical drive apparatus of the present invention therefore provides for means for improving the efficiency with which apparatus having power requirements that can vary with time can operate.

It should be appreciated that the present invention is not restricted to the details of the foregoing embodiment.

For example, any appropriate number of motors and/or generators can be provided so that, with use of appropriate control means, one or more of the pairs of motors/generators can be caused to supplement the power provided by the electrical drive apparatus either simultaneously or independently in a switched manner.

Conversely, the operation of the plurality of generators so as to effectively store potential energy of the drive apparatus can be achieved in a simultaneous manner or in a switched separate manner. Further, with the provision of a plurality of pairs of generators/motors, each pair can advantageously be arranged to assist, or substitute for, the operation of another such pair of generators, motors of the apparatus. Also, each of the aforementioned pairs of the generators/motors could be arranged for operation with respective plurality of deep electrical power supplies, or a single central electrical power supply.Also, the control and connection/disconnection of the respective rotors of the generator/motor pairs of the present invention need not necessarily be achieved by way of a mechanical connection/disconnection but can also be achieved by the control of any one or more of the magnetic fields of the generator/motor pair.

The invention can, in particular, employ a powerful battery which produces a current which is strong enough to run a motor. The power of the motor would be adequate to overcome Eddy currents, back EMF and actual load or work required (i.e. load and rotation required to produce a current).

Assuming a battery has a power unit of 10 for practical purposes it can be assured that in the motor 2 units would be used so as to get a power output of about 8 units at the connecting rod.

It is further assumed that all the total resistance will equate into about 5 units. Therefore, the motor with about 6 units will run the generator whose coil will also be connected to a PTO (Power Take Off arrangement) assuming the work requirement is about 2 units and in the power transfer we lose 1 unit it will be possible to generate electricity of about 2 units at the point of entry in the motor point. So when 2 units (of course this can be higher if the system is efficient) is being transferred into the motor the connecting rod will be disconnected at this time.

As mentioned earlier the load requirement at this period would be significantly reduced by 5 units to very low amounts. The power requirement will though still be deficient of the requirement by the motor.

So if part of the load to move the car was 2 units as already mentioned the car would gain speed it is assumed as usual. After attaining a certain velocity the momentum (mass velocity) would be momentarily transferred into the generator point at a time during power transfer. (The decrease in the speed of the of the car is not important).

It is assumed that this would be adequate to increase the power input in the motor to a level which would enable the motor to run efficiently, at this point it would be connected back to the generator as originally mentioned.

This cycle when continuously repeated leads to considerable energy savings and would be accomplished in systems that run for long periods especially those that use wheels or propellers and would therefore have un-utilised energy which could be fed back into the generator during power transfer when the motor would be in a disconnected condition.

Power need not be fed back into the battery which could be many in any case except at certain periods when their charge would be running out. It would be better to feed power directly into the coils via the cutout. This would require appropriate decisions relating to alternating and direct current transfers. When the invention is perfected the role or necessity of a normal engine in some systems would be minimised or actually excluded.

To diversify the invention further, several units of the invention can be placed next to each other. In this case it would not be necessary to get power from the wheels but rather tap power from these units during the time when they are transferring their power. All the units could rotate at the same time and phase and provide their power to a central large generator which serves to keep the entire system continuously serviced with energy or they could rotate at different phases and complement each other at appropriate well timed moments towards providing energy for one function.

Claims

1. Electrical drive apparatus, the apparatus comprising an electrical motor arranged to be driven from power supply means, electrical generator means operatively engaged to said motor for rotation with the rotor thereof, means for initiating rotation of said motor and said generator means, and means for selectively delivering electrical energy from said generator means to said electrical motor to form at least part of said power supply means.

2. Apparatus according to claim 1, wherein said power supply means comprises a DC power source.

3. Apparatus according to claim 2, wherein said DC power source comprises a battery.

4. Apparatus according to any of claims 1 to 3, wherein a rotor of said generator means is operatively engaged to a rotor of said motor.

5. Apparatus according to claim 4, wherein the motor and generator means are provided as a single unit in which the respective rotors are arranged to rotate about a common axis.

6. Apparatus according to any of claims 1 to 5, wherein the generator means and the motor have respective rotors which are directly connected by means of an insulating connector member.

7. Apparatus according to any of claims 1 to 6, wherein the engagement between respective rotors of the motor and generator means is selectively releasable so that the driving engagement between the motor and the generator means can be disconnected at any required time.

8. Apparatus according to any of claims 1 to 7, further comprising inertia means associated with said generator means so as to maintain the generation of an electrical output therefrom.

9. Apparatus according to claim 8, wherein said inertia means comprises flywheel means.

10. Apparatus according to any of claims 1 to 9, wherein said electrical motor is arranged to assist in driving apparatus for locomotion.

11. Apparatus according to any of claims 1 to 9, wherein said electrical motor is arranged to assist in driving apparatus for locomotion by land.

12. Apparatus according to claim 10 or claim 11, wherein the generator means is arranged to be driven from an engine of said apparatus for locomotion.

13. Apparatus according to any of claims 10 to 12, wherein the electrical motor is incorporated into the driving means of the apparatus for locomotion so as to assist in achieving the locomotion thereof.

14. Apparatus according to any of claims 1 to 13, wherein the means for initiating rotation of the motor and generator means comprises an electrical power source for the motor.

15. Apparatus according to claim 14, wherein the power source comprises a DC power source.

16. Apparatus according to any of claims 1 to 15, wherein the means for selectively delivering electrical energy from the generator means to the electrical motor comprises control means including cut out means for introducing the electrical energy retrieved from the generator means into the supply circuitry of the motor.

17. Apparatus according to any of claims 1 to 16, wherein the apparatus comprises control means for achieving accurately timed disconnection between rotors of the generator means and the motor and/or the selective delivery of the electrical energy from the generator means to the electrical motor.

18. Electrical-drive apparatus substantially as described with reference to any of Figures 1 to 4 of the accompanying drawings.