WO2008115051A2

WO2008115051A2 - Vehicle, dynamo for use therein and method for driving an external load

Info

Publication number: WO2008115051A2
Application number: PCT/NL2008/000085
Authority: WO
Inventors: Jos Frits Van Breemen-Schneider
Original assignee: Rekker, Fokke; Bakker, Piet
Priority date: 2007-03-19
Filing date: 2008-03-19
Publication date: 2008-09-25
Also published as: NL1033557C2; WO2008115051A3

Abstract

The invention relates to a vehicle, dynamo and method, the vehicle comprising: - a frame provided with displacing means; - an electric drive connected to the frame for driving the displacing means; - an energy buffer connected operatively to the drive; - a generator connected directly to the energy buffer for the purpose of generating electric energy and charging the energy buffer. The generator is herein connected to the frame for free-running separately of the drive.

Description

VEHICLE, DYNAMO FOR USE THEREIN AND METHOD FOR DRIVING AN EXTERNAL LOAD

The present invention relates to a vehicle provided with, among other parts, an electrical drive.

Vehicles driven by a combustion engine wherein fossil fuels are used are generally known. Using the combustion engine the energy generated from the fuel is converted into kinetic energy for the vehicle. The kinetic energy is herein transmitted by means of a drive. The combustion engine is usually connected by means of a V-belt to a dynamo for charging a battery with which diverse secondary functions can be performed. These functions are, among others, having lights on, the use of air-conditioning and sound installations and so forth. Also known are vehicles wherein the kinetic energy required to displace the vehicle is obtained directly from the combustion engine and/or from one or more batteries. A switching mechanism is provided here in order to switch between these two energy sources. Also known are electric cars which only make use of batteries to provide the desired kinetic energy. The batteries are charged at a charging station. An example of such vehicles are the transport vehicles used for instance on factory premises.

Problems with the known devices include, among others, inefficient use of the fossil fuel.

The present invention has for its object, among others, to provide an improved vehicle with which more efficient use can be made of energy. The present invention provides a vehicle, comprising:

- a frame provided with displacing means;

- an electric drive connected to the frame for driving the displacing means;

- an energy buffer connected operatively to the drive;

- a generator connected directly to the energy buffer for the purpose of generating electric energy and charging the energy buffer, wherein the generator is connected to the frame for free-running separately of the drive.

Connecting the generator formed by the combustion engine directly to the energy buffer, and not directly to the drive, achieves that the kinetic energy required for displacement of the vehicle is supplied by the energy buffer. The energy buffer is preferably formed by at least one battery. Because the generator does not have to provide directly for driving of displacing means such as wheels, caterpillar tracks, propellers etc., the generator can be operated at its most efficient working point. No additional power need be supplied by the generator for acceleration of the vehicle. This power is supplied by the energy buffer. This has the advantage that the generator, or combustion engine, is operated more efficiently, whereby a more energy-saving vehicle is obtained. An additional advantage is that a combustion engine can be specifically designed for the relevant working point. It is possible here to suffice with, among other things, a smaller cylinder capacity for the combustion engine. A combustion engine can also be used which is suitable for natural fuels, such as a self-ignition engine. An advantage of for instance such a self-ignition engine is that it does not make any distinction as to the origin of a specific oil. A further additional advantage of a configuration wherein the generator is not coupled directly to the drive is that, among others, the number of components required for driving of the vehicle can be greatly reduced. It is possible here to envisage cardan shafts, gearbox, differential and so on. This has the advantage for instance is that the vehicle is less susceptible to breakdown and requires less maintenance. In addition, the mass of the vehicle is reduced. This also achieves that less energy is required to displace the vehicle. It is also the case that a vehicle will hereby have less impact on other road users in the case of collision. In addition, this also increases the safety of passengers in the vehicle. Another additional advantage of the absence of the direct coupling between the generator and the propulsion of the vehicle is that the generator can be placed at any desired position in the vehicle, whereby more efficient use can be made of the space in the vehicle. A different design of the vehicle can hereby also be realized, resulting in more space or a smaller vehicle. Another advantage of a generator which is free-running separately of the drive is that the whole requires a less rigid construction compared to conventional drives, whereby vibrations can be better insulated, and consequently damped. In addition, the safety of the passengers in the vehicle can be improved due to a less rigid construction since the impact of collisions can be better absorbed due to the less rigid construction. hi a preferred embodiment according to the invention the vehicle is provided with a direct external connection for driving an external load and/or charging an external energy buffer with the generator.

Limiting the use of a generator or combustion engine to use only for transport results in an inefficient use of this generator, in respect of use, lifespan and applicability among others. By also using the generator at times when the vehicle is stationary, for instance when it is parked at home, the use of the generator can be considerably increased during its whole lifespan, whereby the overall impact of the generator on its environment, including production and disposal of the generator, is minimized. By providing a direct external connection the generator can be used to drive external loads. It is possible here to envisage the use of for instance garden tools and the charging of external energy buffers such as batteries of other vehicles, or even supplying energy to the home. The combination of generator and dynamo functions here as it were as a mobile generator set. In an alternative preferred embodiment according to the invention the vehicle is provided with an indirect external connection for driving an external load and/or charging an external energy buffer from the energy buffer.

As a result of providing an indirect external connection, energy stored in the energy buffer can be used for external purposes other than to drive the vehicle. This has the advantage that more efficient use is made of the energy buffer or energy source. It is possible to envisage here, among other uses, the driving of electric tools and/or the charging of batteries of such tools.

In an advantageous embodiment according to the invention the generator is connected operatively to the energy buffer via a dynamo, wherein the dynamo is provided with a rotor which also functions as compressor for the generator.

By driving the dynamo with the generator energy is converted and subsequently stored in the energy buffer. Because the generator is connected to the frame for free-running separately of the drive, the generator can be connected directly to the dynamo. It is possible here to dispense with a V-belt or other transmission. This limits losses and, in addition, the number of components and therefore for instance maintenance costs. Embodying the rotor part of the dynamo as a blade-like element can achieve that the rotor also functions as compressor for the combustion engine, as embodiment of the generator. The rotor can also be used to cool for instance the battery. An efficient use of the dynamo is hereby achieved. A combination of these functions results in fewer components of the vehicle, whereby costs in respect of maintenance and for instance breakdowns can be reduced. The weight is also further reduced. The rotor is preferably made of aluminum and rotates in a preferably steel ring of 3 millimeter high and diameter of 200 to 300 millimeter, of course dependent amongst other things on available space. The diameter of the rotor is somewhat smaller as compared to the diameter of the steel ring, for example about 5 millimeter.

In an alternative preferred embodiment according to the invention the drive of the vehicle is provided as a PM motor. Through the use of motors with permanent magnets it is possible to equip each driven displacing means, such as a driven wheel, with an individual PM motor. This is possible because a driving with the PM motor is more compact than conventional drives since for instance gear transmissions are no longer required. This has the additional advantage that the losses in for instance the gearbox are avoided and, in addition, that less heat loss occurs. The controllability of the vehicle can also be further increased through the use of such PM motors per driven displacing means. The improved controllability is brought about by making driving of the individual PM motors partly dependent on the path followed by the vehicle, such as for instance bends, unevenness in the ground surface and differences in rolling resistance of the ground surface. This has the additional advantage that the safety of the vehicle is further enhanced. The controllability can be further improved through the use of instance an anti-lock braking system, power steering and so on. It is also possible to recover kinetic energy, for instance during braking of the vehicle. An energy converter is provided for this purpose. The recovered energy is preferably stored in the energy buffer. Alternatively, this recovered energy can for instance also be stored in an added flywheel, wherein a flywheel clutch is provided for extracting the energy stored in the flywheel.

In an alternative preferred embodiment according to the invention the energy buffer is provided with at least one lithium battery. The use of lithium batteries achieves that more efficient use can be made of the energy stored in the energy buffer. Such batteries are for instance already applied in laptops and telephones. Such equipment is used frequently and requires frequent discharging and recharging of the battery. It is also the case that such batteries are highly suitable for connection to external loads, such as garden tools, domestic appliances, although laptops and the like are also possible here. This has the additional advantage that such equipment can be used, even when the vehicle is stationary, without there being a battery or other energy source available.

In a further alternative preferred embodiment according to the invention the vehicle is provided with positioning means for obtaining a low air resistance for the purpose of limiting extraction of energy from the energy buffer. By modifying the position of the vehicle, for instance in the height, to the external conditions during propulsion of the vehicle, such as wind, the air resistance (Cw value) can be adapted to the desired situation. Use can for instance be made for this purpose of a controllable air suspension. The streamlining of the vehicle can therefore be optimized in accordance with the situation. The possibilities hereof are further increased in that the generator is not directly coupled to the drive of the displacing means. Because the generator can be freely placed in the vehicle, different designs of the vehicle are possible. By modifying the resistance a more energy-efficient working point can be employed for displacement of the vehicle. The present invention also relates to a dynamo for use in a vehicle according to one or more of the appended claims.

Integration of the compressor with the rotor of the dynamo achieves that a separate compressor is not required for the generator, driven for instance by a toothed belt. This has the consequence that a more compact construction is obtained which requires less maintenance and can be produced more cheaply owing to the reduced number of components. The dynamo is preferably coupled with a ceramic coupling to the generator. A thermal separation between the two components is hereby obtained, whereby heat losses can be further limited.

The present invention also relates to a method for driving at least one external load with an electrically driven vehicle, comprising of:

- connecting the at least one external load to a generator and/or an energy buffer provided in the vehicle; and

- driving the at least one external load by means of the generator and/or the energy buffer. The method provides the same effects and advantages as those stated in respect of the vehicle.

Further advantages, features and details of the invention are elucidated on the basis of the preferred embodiment, wherein reference is made to the accompanying drawing, in which: - Figure 1 is a side view of the vehicle according to the invention; Figure 2 shows a block diagram of the whole drive of the vehicle; Figure 3 shows a view of a dynamo used in the vehicle of figure 1 ; and Figure 4 is a front view of the rotor of the dynamo of figure 3. A vehicle 2 (figure 1) has a frame 4 which moves on a number of wheels 6. The fuel for the generator is supplied via the fuel supply. Vehicle 2 is also provided with an external connection 10 to the energy buffer in the form of a battery (not shown). Vehicle 2 also has an external connection 12 directly coupled to the generator (not shown). Each driven wheel 6 is provided with a permanent magnet motor 14. The generator, for instance embodied as (biological) diesel engine 16, drives dynamo 18 during use. Dynamo 18 is connected to charging circuit 20 with which the battery/energy buffer 22 is charged. The drive 26 of vehicle 2 is driven from energy buffer 22 via control 24. An external load 28 can optionally be provided with energy from charging circuit 20. The load 28 herein receives energy directly from generator 16 via dynamo 18 and charging circuit 20. If generator 16 is not in operation, an external load 30 can be provided with energy from energy buffer 22 in which energy is stored. Generator 16 converts energy, stored in for instance biodiesel with the combustion density indicated with arrow 32 and supplied with flow 34, at an angular velocity 36 of the motor shaft with a torque 38 on this motor shaft. The mechanical power generated by the diesel engine is converted by dynamo 18 into electric power, wherein the dynamo generates a voltage 40 and charging circuit 20 takes up a current 42. Charging circuit 20 feeds energy buffer 22 at a voltage 44 with charging current 46. hi the case vehicle 2 is moving, control 24 draws a current 50 from energy buffer 22 at voltage 48. Control 24 then drives the drive 26 at voltage 52 with a current 54. The drive 26 then converts this power into an angular speed 56 at a torque 58. In the case an external load 28 is being provided with energy, charging circuit 20 can provide a current 60 at a voltage 62 in the situation where generator 16 is in operation, hi the case that generator 16 is not in operation, an external load 30 can be provided with energy from energy buffer 22 at a voltage 66 with a current 64. These external loads 28 and 30 may be not only loads outside vehicle 2, such as laptops and garden tools, but also external loads in vehicle 2 such as music installations, air-conditioning and so on.

A generator 16 is connected to a dynamo 18 (figure 3) by a ceramic coupling 68. Dynamo 18 is provided with a shaft 70 on which a bearing 72 is situated at the outer end furthest away from generator 16. This means that shaft 70 is supported on one side by bearing 72 and on the other side by generator 16. In this way the number of bearings required can be limited in the shown embodiment. Bearing 72 is placed in a housing 74, wherein stator 76 is arranged on the outer side. On the inner side of housing 74 the rotor 78 is placed rotatably around shaft 70 and moving relative to stator 76. Arranged on the outer ends of the rotor blades of rotor 78 are magnets 80 which are coupled via a steel connection 82 to an aluminum outer end 84 of rotor blade 86. Rotor blade 86 (figure 4) rotates inside housing 74, wherein rotor blades 86 are formed or placed at an angle relative to shaft 70. In the illustrated embodiment has shaft 70 an outside diameter of about 30 millimeter that fits in the inside of the aluminum rotor 78. Rotor 78 is placed with a case-like part with an outside diameter of about 40 millimeter over shaft 70.

The present invention is by no means limited to the above described preferred embodiment; the rights sought are defined by the following claims, within the scope of which many modifications can be envisaged. Vehicle 2 can thus also be a boat 2, wherein wheels 6 are replaced by a propeller. It is also possible, through suitable placing of generator 16 and dynamo 18, to use possible heat generation by these components in efficient manner for the purpose of heating vehicle 2, if desired. Due to the absence of a direct coupling between generator 16 and the associated drive components it is also possible to provide for sound damping in addition to the low bandpass filter effect of a free suspension. This will contribute towards the comfort of the users of vehicle 2 and moreover a reduction in noise nuisance for people in the vicinity as well as other users of a (paved) road. The present invention further provides the option of also making use of energy in efficient manner at relatively remote locations. An optionally mobile hospital can for instance thus be provided with energy. The vegetable oil used as fuel for the combustion engine can for instance also be used to prepare food during travel in such areas. In addition, it is a possible option to place the generator, owing to the possibility of free placing thereof, at for instance two thirds of the distance from the front, at the position of the greatest underpressure. This improves for instance the road-holding. This can be further enhanced by applying for instance a substantially flat base plate. This is also possible due to the reduction in components and freer placing of some remaining components. Further enhanced by the positioning means, this for instance provides a better streamlining of the vehicle.

Claims

1. Vehicle, comprising:

- a frame provided with displacing means; - an electric drive connected to the frame for driving the displacing means;

- an energy buffer connected operatively to the drive;

2. Vehicle as claimed in claim 1, wherein a direct external connection is provided for driving an external load and/or charging an external energy buffer with the generator.

3. Vehicle as claimed in claim 1 or 2, wherein an indirect external connection is provided for driving an external load and/or charging an external energy buffer from the energy buffer.

4. Vehicle as claimed in claim 1, 2 or 3, wherein the generator is a combustion engine.

5. Vehicle as claimed in one or more of the claims 1-4, wherein the generator is connected operatively to the energy buffer via a dynamo, wherein the dynamo is provided with a rotor, which rotor functions as compressor for the generator.

6. Vehicle as claimed in one or more of the claims 1-5, wherein the drive comprises at least one PM motor.

7. Vehicle as claimed in claim 6, wherein the displacing means comprise wheels, wherein at least the wheels steerably connected to a steering device of the vehicle are individually provided with a PM motor.

8. Vehicle as claimed in one or more of the claims 1-7, wherein an energy converter is provided for converting surplus energy into available energy.

9. Vehicle as claimed in claim 8, wherein the energy converter comprises a recovery circuit for storing the surplus energy in the energy buffer.

10. Vehicle as claimed in claim 8, wherein the energy converter is provided with a flywheel for storing the surplus energy, and a flywheel clutch for extracting the energy stored in the flywheel.

11. Vehicle as claimed in one or more of the claims 1-10, wherein the energy buffer comprises at least one lithium battery.

12. Vehicle as claimed in one or more of the claims 1-11, wherein the vehicle is provided with positioning means for obtaining a low air resistance for the purpose of limiting extraction of energy from the energy buffer.

13. Dynamo for use in a vehicle as claimed in one or more of the claims 1-12, wherein the dynamo is provided with a rotor, which rotor also functions as compressor.

14. Dynamo as claimed in claim 13, wherein the dynamo is coupled with a ceramic coupling to the generator.

15. Method for driving at least one external load with an electrically driven vehicle, comprising of:

- driving the at least one external load by means of the generator and/or the energy buffer.