GENERATOR

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention refers to a process for generating electricity and devices implementing these methods, namely electric generators, synchronous motors, turning round.

2. Description of Related Art

The process known and used for generating electricity from mechanical energy is based on the fact that the magnetic flux variation induces a current in a conductor. The electric power is obtained from the work of turbines driven by water power, steam, wind or wave power for example. This electric power is obtained as alternative voltage with a shape close to sinusoid and proportional to the magnetic flux Φ and its variation rate. Usually the mechanical energy produces the variation of flux by rotating the induced and keeping the inductor fixed. The efficiency of the process is dependent on the absorbed energy to generate magnetic flux. As a result, using the superconductivity at "high temperatures", knows as HTS technologies begins to emerge as a serious alternative.

Various types of generators and electric motors are known and used as applications of this process. They are designed according to the power and rotation requirements of the application. In all cases, the electric generator and/ or motor consists in a rotor and a stator, each carrying at least one coil. The rotor possesses a magnetic field generated in almost all cases by an electromagnet, except for some low power versions that use permanent magnets. The magnetic field is induced in the stator, having the polarity controlled by the rotor angular position therefore alternative, the pulsation being proportional to the turning speed. The electric energy is obtained from the winding or windings of stator as AC voltage, close to sinusoidal shape and it is determined by the magnetic flux Φ produced by rotor and its variation speed, according to Faraday's law:

E = - d O / d t

The challenge is to get a magnetic flux Φ as high as possible in terms of minimal energy consumption, the energy consumed by the rotor participating in reducing yields as it is decreased from the produced energy. As a result, implementing superconducting coils on root is a current research area. Obviously, a solution with more coils on the rotor could optimize parameters, but this solution is not used because of technical complications related to the multiplication of the most delicate point of the machine, the carbon brushes. Power generators are made today in at least two ways: 1. Graphite brushes on wire rings, cheap solution, applicable for small and medium powers, being practically the most sensitive part of the machine and leading to a significant decrease in the average time for the good functioning

2. Additional generator mounted on the rotor, valid solution for high powers but with negative effects on the overall efficiency; moreover, it leads to additional loading of the rotor.

The implementation of superconducting coils in both cases requires the assembling of the cooling installation on the rotor because there is no valid technological procedure for transferring the liquid air from the stator to the rotor. This situation leads to huge technological complications.

Another aspect to consider is the shape of the generated voltage, in accordance with the application. If the generator debits on a rectifier, which is quite common in applications that do not allow speed control, the obtained waveform is not necessarily the best.

The disadvantages of the currently used process of generating electric power are the following:

1) The energy transfer to induce has low efficiency and becomes expensive case an auxiliary generator is used;

2) The shape of the output voltage is difficult to be controlled.

The disadvantages of current electric motors and generators are the following: 1) Low average life time case of graphite brush collectors are used

2) Design drastic restrictions involved case auxiliary generator is used;

3) Balancing problems due to the complexity of rotor;

4) Limited rotor speed due to its complexity;

5) Technologic difficulty in implementing superconducting elements;

6) Implementation of superconducting elements leads to overloading the rotor;

SUMMARY OF THE INVENTION

It is, accordingly, the primary object of this invention to provide a novel process for generating electrical power by so that to remove the disadvantage of the currently used process. The process allows the variation of the magnetic flux in induced preserving meantime both inductor and induced fixed. Moreover, the electromotive voltage generated form can be adapted to specific application requirements by adjusting the magnetic junctions' geometry of the inductor-induced coupling.

It is another object of this invention to provide a novel electric reversible generator wherein the process for generating electrical power according to the invention is applied so that to remove the disadvantage of current electric motors and generators. The reversible electric generator for applying the process according to the invention is characterized in that the induction coil responsible for the magnetic field of the rotor is jointly fixed along with the stator on housing facility, and the rotor is reduced to a piece of ferromagnetic material on which the work is applied

In one embodiment, the rotor consists in a component coaxial to the induction coil and two opposite discoid terminal components with teeth in opposite phases that provide the variation of the magnetic flux through the stator coils. In another embodiment, the rotor consists in a diamagnetic shaft joining two discoid ferromagnetic components with teeth in opposite phases. The discs are magnetically coupled to an outer induction coil that is fixed on the generator's casing along with the stator. The discs work as varying device of the magnetic flux through the stator coil. The induction coil means at least one coil winding. The stator has one winding.

By applying the process of physical detaching of the induction coil from the mobile piece in each of the above embodiments, the structure of the rotor becomes lighter and simpler from the geometric point of view, thus facilitating the balance and high speeds capacities.

Moreover, since the induction coil is static, fixed to the housing, the electrical contacts are stable and the needed liquid air is easy to be injected, case superconducting induction coil(s) is used; the technological problems specific to the moving induction coil are no longer valid

In the rotor-stator coupling area, the stator' s heads shape is directly responsible for the appearance of the curve Φ = Φ(ί) and hence to its derivative, ultimately deciding the shape of electromotive voltage obtained in the stator' s coil.

The geometric shape of the stators increases the number of the embodiments of the invention.

According to the application's needs, one induced may consist in "b _s " stators.

For a single-phase generator, "b _s " is better to be an even number to minimize the momentum generated by the load balancing. In this case the number of teeth of each rotor disc is 2k, k = 3, 4...

To obtain three-phased current, it is sufficient to place three stators, arranged in such a manner so as to obtain the phase angle of 120°, so:

b _s = 3 stators.

In this case the number of teeth is 3k+l, k = 2,3...

If the applications strictly envisage obtaining continuous current, 5 stators can be mounted for example, arranged in such a way that the phase angle be 72°, so:

b _s = 5 stators.

In this case the number of teeth is5k+l, k = 2, 3....

Depending on application requirements, an industrial can be formed from a number "b _s " of stators.

The described generator is reversible; it works as a synchronous motor if an alternative voltage is applied on the stator.

The advantages of the process for obtaining electric power according to the invention are the following:

1) Eliminates power supplying of mobile elements, all components that are electrically connected being fixed. 2) The shape of the generated electromotive voltage is adaptable to specific application requirements.

The advantages of the power generator according to the invention are the following:

1) The induction coil is statically connected to the power source,

2) Allows multiple configurations to power supply the induction coil, with implications in improving the efficiency.

3) The rotor is easier to be equilibrated.

4) Allows a broad range of turning speed.

5) Superconductive elements can be implemented without major technical problems.

6) The implementation of superconductive elements does not lead to overloading the rotor.

These will be more fully understood from the following description of certain specific embodiments of the invention together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 reversible electric generator, 3D assembly drawing, side view

FIG. 2 rotor of one reversible electric generator, 3D assembly drawing, side view FIG. 3 housing of the induction coil of a reversible electric generator, 3D assembly drawing, side view

FIG. 4 stator of one reversible electric generator, 3D assembly drawing, side, view

FIG. 5 one reversible electric generator, 3D assembly drawing, bottom up view

FIG. 6 process of generating electric power, schematic representation of the mechanism of varying the magnetic flux in the induced of a reversible electric generator

FIG. 7 another stator for one reversible electric generator

FIG. 8 another stator for one reversible electric generator

FIG. 9 another reversible electric generator, bottom up view, without casing/ housing FIG. 10 another reversible electric generator without housing, longitudinal section view FIG. 11 rotor of another electric generator, representation from 3 sides - front, bottom- up and laterally

FIG. 12 core induction coil of another electric generator, representation from 3 sides - front, bottom-up and laterally

FIG. 13 stator of another electric generator representation from 3 sides - front, bottom- up and laterally

FIG. 14 housing element of another electric generator, representation from 3 sides - front, bottom-up and laterally

FIG. 15 another reversible electric generator, longitudinal section view

FIG. 16 process of generating electric power, schematic representation of the mechanism of varying the magnetic flux in the induced of another electric generator

FIG. 17 Simplified equivalent circuit for evaluating the magnetic flux through the induced DETAILED DESCRIPTION OF THE INVENTION

The process for generating electric power consists in converting mechanical energy into electrical energy on the classical principle based on Faraday's law only the inductor is detached from the mobile piece on which the work input is applied, both induced and inductor being fixed. The magnetic field flux produced by the inductor is directed to the induced by the mobile piece.

As any other inductive generator, the reversible electric generators wherein the process accordingly with the invention is used is based on Faraday's law that states that the electromotive energy induced in a turn is proportional to the variation speed of the magnetic flux.

Figures 1, 2, 3, 4 and 5 refer to one reversible electrical generator wherein the process accordingly with the invention is used.

Figure 1 shows a reversible electric generator that consists in a mobile piece referred as rotor 2, coaxial with a fixed housing 3, on which a induction coil is wrapped and a set of three identical stators 4, 5, 6, whose windings form the induced, all stators being fixed in a housing 7.

The rotor 2 shown in Figure 2 is composed of a metal axis 21 dressed in a high magnetic permeability material 24, such as ferrite, fixed between two discs 22 and 23. Discs 22 and 23 are of the same material with high magnetic permeability. They have toothed edges, a tooth 25 being figured, and the discs are assembled in such a way that each tooth 25 on one disc has as perpendicular correspondent a window 26 on the other disc.

In Figure 3, the fixed housing 3 of the induction coil of the rotor consists in a cylinder 31 fixed between two flanges 32 and 33 through fasteners 34. Cylinder 31 has a inner diameter larger than the outer diameter of the rotor shaft 21 but its length is smaller than the distance between the rotor's teethed discs. Flanges 32 and 33 can be made in several variants, their geometry approaching more or less the shape of a circle, depending on the width of rotor teeth and thus of the stator profile. So, the narrower are the teeth and hence denser, the smaller cut out area the circle of flange may have. The fixed housing 3 of the induction coil is mounted coaxially with the rotor and is fixed jointly to the generator housing 7, therefore three holes in each flange were provided. Housing 3 is entirely made of a insulated and diamagnetic material e.g. plastic. The cylinder 31 of fixed housing 3, the induction coil is wrapped, which produces a magnetic field into the axis 21 of the rotor having the magnetic poles on the two toothed discs 22 and 23.

The stator 4 in Figure 4 has two branches 41 and 42 and one or more in series windings on traverse 43. The thickness of the branches is same with the depth of the teeth 24 of the rotor 2. The stator is made of a material with high magnetic permeability. The stator is fixed to the generator housing 7 through fixing elements 44 made of mechanically resistant material, in order to prevent the magnetic field closing throughout the stator. During the rotation of the two rotor discs, the magnetic flux closes alternatively through the diagonally opposite extremities 45 and 46 of the branches of the stator, resulting in alternating direction through the induced coil core represented by the traverse 43, thus to inducing an alternative electric voltage in the stators' windings. Figure 5, which is a 3D assembly drawing of the electric generator 1, bottom up view, shows how the magnetic coupling is achieved between a pole 50 of the rotor and one end 51, 52 and 53 of a branch of each stator 54, 55 and 56. It is also apparent that both housing 57 of the induction coil and the three stators 54, 55 and 56 are jointly attached to a housing 58 of the generator and the rotor is attached through a pair of bearings or bearing 59.

If the load is of continuous current, then the binding of a winding in series with the load inductors can improve the performance / efficiency conversions.

Starting from the observation that the reluctance of the magnetic coupling area is:

ί

μ - S

there are two ways to control the reluctance and, consequently, the electric voltage generated shape.

1. Correcting the surface while maintaining 1 constant.

2. Varying the distance 1 between the magnetic coupling elements.

Figure 6 shows schematically the mechanism of driving the magnetic field flux into the induced by the rotor. For simplicity, the analysis is carried out on the in-time image of a pair of discs 61 and 62 and one stator 63. As one can see, magnetic flux crosses the stator on the diagonal line, changing the coupling extremities at each angular displacement φ of the rotor, with φ - 360 / n, where n is the total number of teeth.

The number of teeth n is chosen according to the turning speed to be applied on the rotor considering that the frequency of the induced electric voltage is proportional to the number of teeth and the rotor turning speed.

Following a complete passage of a pair "tooth - space" over the extremities of the stator 63, it is found that the magnetic flux in the stator coil is the resultant of the summation of two components having opposite signs, coming from the two diagonals:

O _s = <£>i + <3>2

In the drawing, the magnetic field intensity H highlighted which is a vector, directly proportional to the flux Φ:

Φ = μΗ8

where μ - magnetic permeability

S - Vector of the surface area meaning the surface of a branch section multiplied with the normal to the surface.

Figures 7 and 8 refer to other stators for one reversible electric generator wherein the process accordingly with the invention is used. Stators are made of sheets for reducing Eddy current losses. The sheets are perpendicular to the discs 22 and 23surface.

Figures 9, 10, 11, 12, 13, 14, 15 and 16 refers to another reversible electric generator wherein the process accordingly with the invention is used.

The reversible electrical generator 91 drawn in figure 9 consists in a mobile piece that we now refer to as a rotor 92, fixed core 93 on which a induction coil is wrapped 94 and one induced consisting in three identical stators 95, 96 and 97 also fixed. A cross section through the generator 91 is shown in figure 10. The rotor 92 shown in Figure 11 is composed of a non-magnetic shaft 111, fixed between two discs 112 and 113. Discs 112 and 113 are of a high magnetic permeability material. They have toothed edges and are assembled in such a way that each tooth on one disc has as perpendicular correspondent a window on the other disc. The fixed core of the induction coil 93 of the rotor is represented in Figure 12, representation from 3 sides - front, bottom-up and laterally. It is fastened through fixing elements for which some mounting holes 121, 122, 123 and 124 have been provided. Two parallel surfaces 125 and 126 provide the magnetic coupling to the rotor discs 112 and 113. The stator 95 shown in Figure 13, representation from 3 sides - front, bottom-up and laterally, consists in and two arms 131, 132 for magnetic contact with the rotor discs 112 and 113, an area 133 on which the coil is wrapped and two mounting holes 134 and 135. The stator 95 is made of a high magnetic permeability material, even ferromagnetic sheets. The sheets are parallel to the rotor discs surface.

Figure 14 is a representation from 3 sides - front, bottom-up and laterally of one of the two pieces of the housing for another reversible generator. There are mounting holes for each element of the generator, two holes 141 and 142, 143 and 144, 145 and 146 for each stator and two holes 147 and 148 for the fixed inductor core 93. In the center there is a bearing 149 for the rotor 92 axis. A longitudinal section through the generator 91 is shown in Figure 15. The rotor 92 is fastened on the housing through a pair of bearings 151 and 152. Fixed core 93 of induction coil 94 and the induced consisting in three identical stators 95, 96 and 97 are fixed to the generator housing by means of studs 153, 154, 155, 156 and 157 and spacing elements 158, 159, 160, 161, 162 and 163.

Figure 16 schematically shows the mechanism of driving the magnetic field flux in the stator by the rotor.

The examples that follow will illustrate an application of generator and process of generating electric power of this invention, together with the accompanying drawings 1 and 17 respectively.

EXAMPLE 1

Referring figure 1, the number of teeth for an application in which a three-phased generator is needed will be calculated.

Starting from the multiplication factor required by the application, n is chosen in terms of:

n ^■ φ = 360 ^c

and

360·° = 3k<p + 3—

3

Then:

ηφ = (3 k + ϊ)ψ

So:

n = 3k +- 1, k = 2,3,4 ....

If f _out = 50Hz is necessary, the rotation speed (rpm) will be evaluated in direct drive condition so that:

r = 50/7 r/s (k = 2); r = 50/10 r/s (k = 3) so on.

EXAMPLE 2

Kirchoff s law equivalent for the magnetic circuit shown in Figure 17 is:

r = . 4 = _έ (π^ + ¾ + ¾^ )

where:

T = Magneto motive force

J*f = Turns number of rotor coil

* = Current through rotor coil

Φ _Φ = Total magnetic flux through rotor

K = rotor reluctance

¾= stator reluctance

¾ _£ = air gap reluctance

Τ ~- Ή ^' "ί = Φ - R

where M ' = entire circuit reluctance

For simplicity, we consider the case of a single stator in the first constructive version of the generator shown in Figure 1.

In accordance to the equivalent circuit shown in Figure 17, the flow of magnetic flux depends on the figured reluctances.

The magnetic flux ₈ that flows through the stator coil divides into two components Φ ₁ and Φ ₂ . Thus,

φ ₅ = φ» _! + φ ₂

The two streams have a temporal variation Φ[ = Oj(t). This variation is dependent on the reluctances R _h i = R _h i(t) which, in turn, depend on the time variation of magnetic junction surfaces Si and S ₂ and also the distance between rotor and the extremities Si and S ₂ respectively of the stator.

To evaluate of the two components we consider an equivalent simplified scheme. It is found that the total flux _τ produced by the rotor divides into the two branches of the H-shaped, in accordance to the reluctances values involved in the circuit.

Knowing that:

i ^■

^■ R =

μ - S

where:

1 = length

μ = magnetic permeability

S = surface

Since the variable circuit components 3.Γ6 ^-g _^ cind. , we take for simplicity the linear variation of surface contacts on a half cycle:

s ₁ (e> = 5 ₀ - -— « e ( o - a = do + cot

Considering identical cross flows, the two components ₁ and Φ ₂ will become:

_ 3Ψ· - ^■

^{1 ~} 2 · ¾ + 2 ^■ ¾ _Λ

Φ, =

Therefore, the magnetic flux through the stator coil will be:

If the stator is composed by three pieces, the contribution of the magnetic flux generated by the rotor will be:

i

,φ, , = -

The magnetic flux <P _S will therefore be dependent on the contact surfaces S _± and 5 ₂ whose geometry allows the adjustment of the output voltage.