GB2120865A

GB2120865A - An electricity generator

Info

Publication number: GB2120865A
Application number: GB08308118A
Authority: GB
Inventors: Iorwerth Thomas
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-03-24
Filing date: 1983-03-24
Publication date: 1983-12-07
Also published as: GB2120865B; GB8308118D0

Abstract

The generator comprises a rotor comprising a shaft 10 and two axially spaced sets of windings 17,18. The windings 18 are wound in the opposite direction to the windings 17. The sets of windings 17 and 18 are associated with respective stators 27,28. The windings of stator 27 comprise a single winding per phase whilst the windings of the stator 28 comprise two single windings per phase one of which is wound in the opposite direction to the other. <IMAGE>

Description

SPECIFICATION An electricity generator The invention relates to an electricity generator and is particularly but not exclusively concerned with a generator for use in a vehicle.

It has been proposed to power vehicles by using hydrogen and oxygen gas derived from H2O. The gas is usually produced on the vehicle by electrolysis and the gases are subsequently fed in stoichiometric measurements to the cylinders of the vehicle to be burned as fuel. In known systems, the gas derived from H2O is produced over a period of time, separated and stored in tanks on the vehicle. The reason why it is necessary to store the gas is because with known electricity generators, insufficient gas can be produced economically by electrolysis to produce gas on demand. Therefore a gas reservoir is necessary, the reservoir taking up room in the vehicle and being undesirable in that it contains a large volume of highly inflammable gas.

An object of the invention is to provide an improved electricity generator one use of which is to produce gas from H2O by electrolysis to power a vehicle.

According to the invention there is provided an electricity generator comprising a rotor including axially spaced sets of windings, and a stator associated with each set of rotor windings.

Preferably, first and second sets of rotor windings are provided, the windings of the first set being wound in an opposite direction to the windings of the second set, the first and second rotor windings being associated with respective first and second stator windings. in use the two sets of rotor windings are of opposite polarity which results in less resistance to rotor movement and maximum available field for cutting the respective stator windings to produce current.

The windings of each said set may be wound on a bobbin, the bobbin being formed so that the radially innermost windings of the bobbin are close to the axis of the rotor. Such an arrangement enables the maximum number of turns to be wound on the bobbin for a given rotor diameter. Preferably the bobbin has a radial thickness of around 1/16 inches (1.59 mm) and absorbs minimum field.

Preferably each set of rotor windings is bounded by pole pieces comprising two intercalating claws defining a substantially sinusoidal wave form space therebetween, portions of the claws defining peaks of the wave form being flattened to increase the dimension of the space at the peaks in the axial direction of the rotor. Such flattening of those portions of the claws increases the available field at the periphery of the rotor.

The first set of stator windings may comprise a single winding per phase, and the second set of stator windings may comprise two windings per phase one of which is wound in the opposite direction to the other. The winding of the second stator in that way reduces hysteresis and, therefore resistance to rotation of the rotor as each winding tends to magnetize the second stator in an opposite sense.

The invention also includes an internal combustion engine powered at least partly by gas derived from electrolysis of H2O, the electrolysis being performed by generating electric current by means of an electricity generator according to any of the five immediately preceding paragraphs. Preferably the gas derived by electrolysis is fed directly from means in which the electrolysis is performed to the engine without entering an intermediate storage reservoir.

An electricity generator is accordance with the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is an axial cross-section through a generator in accordance with the invention in the form of an alternator, Figure 2 is a plan view of part of a rotor of the generator of Figure 1.

Figure 3 is a view of the rotor looking in the direction of arrow Ill in Figure 2, Figure 4 is a diagrammatic perspective view of part of the rotor, Figure 5 is a diagrammatic view of part of the aforesaid second stator, Figure 6 is a view of part of the second stator showing a compact method of winding, Figure 7 is a graph illustrating generator output, and Figure 8 is a diagrammatic view of a supply system for powering an engine of a motor vehicle by gas derived from H20.

In Figures 1 to 3 a shaft 10 of a rotor indicated generally at 9 is driven by an engine (not shown) through the usual fan belt 8 and pulley 11. A cooling fan for the generator is mounted on the shaft 10 as indicated at 12. The shaft 10 is journal led for rotation in bearings 13 mounted in ends of a casing 14.

The shaft 10, which is around 7/8 inches (22.23mm) diameter, carries two thin walled bobbins 15, 16 each having a radial thickness X of around 1/16 inches (1 -59mm). However, the dimension is not critical and may vary above or below that thickness provided that radially inner turns Tof windings 17, 18 on the respective bobbins lie closely adjacent the shaft 10. In normal alternators the bobbin is frequently around 1 inch (254 m) radial thickness. The thinner bobbins allow a large number of turns to be applied, e.g. 420 turns of 17 swg copper wire.

The windings 17 and 18 (constituting the aforesaid first and second sets of rotor windings respectively) are enclosed by sets of pole pieces 19,20 and 22,23 shown in end view in Figure 3. The pole pieces or claws of each set intercalate to define a substantially sinusoidal wave form space 24, the portions of the claws defining peaks being flattened at 26.

The flattening of those sections of the claws has been found to increase the available field at the periphery of the rotor which is highly desirable. The windings 17, 18 are wound in opposite directions as shown in Figure 4 and are connected to positive and negative sections of slip rings 25,26 at the right hand end of the shaft 10 through which electric current for energising windings 17, 18 is applied. In that way the polarity of the windings 17, 18 will be opposite. As shown in Figure 2, the adjacent pole pieces 20,22 are of like polarity so that the magnetic fields tend to repel each other. Fields are then formed as indicated in broken lines in the upper half of Figure 1. The pole pieces 20, 22 are spaced apart by a spacer 24, the space preferably being around 3/8 inches (9.53mm).

The rotor windings are associated with respective stator windings 27, 28 constituting the aforesaid first and second statorwindings respectively. The axial length of each stator winding correspond substan tiallywith the axial length of the associated rotor winding and pole pieces. The outputs from the stators are fed to respective rectifiers 29, 30 to provide a direct current for use in electrolysis as described below. The spacing of the rotor windings 17, 18 and the opposed polarity minimises the possibility of field from one set of windings interfering with the stator associated with the other set which would increase resistance to rotation.

The stator 27 is preferably a three phase type having three windings per phase formed from wire of 0.065 inches (1.65 mm) diameter. The stator 28 is preferably also a three phase type. However, the stator 28 has two windings 32,33 per phase as shown in Figure 5, one of which is wound in one sense and the other of which is wound in the opposite sense. The stator 28 has a former 34 formed with axial slots 35 for receiving the windings.

In Figure 5 windings in only two of the slots are shown for clarity. The wire of winding 32 is prefer ably 0.065 inches (1.65 mm) diameter and the winding 33 is preferably 0.085 inches (2.16 mm) diameter for reasons explained below. Figure 6 illustrates the way in which the wires of windings 32, 33 are bent substantially at right angles at their points of emergence from the slots in the stator former. In that way the windings do not extend by more than about 1/8 inches (3.15mm) from the former to minimise interference with the field of rotor winding 17. The windings of the stator 27 are bent in a similar manner to minimise interference with the field of rotor winding 18.

A typical output diagram from a generator in accordance with the invention is shown in Figure 7 where the solid line represents the output from stator 27 and the broken line represents output from stator 28. Following start up and up to around 3000 rotor RPM the output of the stator 28 is relatively small compared to that of stator 27. Stator 27 provides a maximum output of around 250 amps at approximatoly 5000 RPM. As rotor RPM increases further the output from stator 28 overtakes that of stator 27. Initially the current from stator 28 is provided predominantly by winding 32 and as RPM increases further an increasing amount of current is produced by the thicker winding 33.

Current of around 430 amps at around 21/2 volts (although it is envisaged that generators in accord ance with the invention will produce considerably higher currents e.g. 700 amps) is sufficient to produce large volumes of hydrogen and oxygen by electrolysis which can be fed as in Figure 4 to the carburettor 40 of an internal combustion engine 41 and thereby reduce the amount of liquid fuel 45 required. The gas is produced in an electrolysis unit 43 by current from the generator indicated at 44 and is sufficient to meet engine demand. Therefore, it is unnecessary to store a large volume of gas for subsequent use by the engine. With such an arrangement, production of gas begins when the engine is started and ceases when the engine stops, no gas storage with attendant explosion risk being necessary.

If desired a further stator 50 may be mounted as shown in broken lines in Figure 1 coaxial with stators 27,28. The further stator 50 is cut by any stray magnetic flux from the rotor and may provide sufficient output to charge a battery of the vehicle.

The hydrogen and oxygen obtained by the above method could also be used for welding or brazing or to provide a flame for heating water. It is also envisaged that an electrolysis system could be used to fire a boiler for central heating.

Claims

1. An electricty generator comprising a rotor including axially spaced sets of windings, and a stator associated with each set of rotor windings.

2. An electricity generator according to claim 1 in which first and second sets of rotor windings are provided, the windings of the first set being wound in an opposite direction to the windings of the second set, the first and second rotor windings being associated with respective first and second stator windings.

3. An electricity generator according to claim 1 or 2 in which the windings of each set are wound on a bobbin carried by the rotary member, said bobbin being formed so that the radially innermost windings of the bobbin are close to the axis of the rotor.

4. An electricity generator according to claim 3 in which the bobbin has a radial thickness of around 1/16 inches (1.59 mm).

5. An electricity generator according to any of claims 1 to 4 in which each set of rotor windings is bounded by pole pieces comprising two intercalating claws defining a substantially sinusoidal wave form space therebetween portions of the claws defining peaks of the wave form being flattened to increase the dimension of the space at the peaks in the axial direction of the rotor.

6. An electricity generator according to any of claims 2 to 5 in which the first set of stator windings comprises a single winding per phase, and the second set of stator windings comprises two windings per phase one of which is wound in the opposite direction to the other.

7. An electricity generator according to claim 6 in which one of the windings of the second stator is formed from wire of greater diameter than the wire forming the other winding.

8. An electricity generator according to any preceding claim in which windings of each stator are wound so that they lie in slots formed in the stator and are bent substantially at right angles at their points of emergence from the slots so as to lie closely adjacent side surfaces of the stator.

9. An internal combustion engine powered at least partly by gas derived from electrolysis of H2O, the electrolysis being performed by generating electric current by means of an electricity generator according to any preceding claim.

10. An internal combustion engine according to claim 9 in which the gas derived by electrolysis is fed directly from means in which the electrolysis is performed bo the engine without entering an intermediate storage reservoir.

11. An electricity generator constructed and arranged substantially as described herein with reference to the accompanying drawings.