DE3026339A1 - FLYWHEEL ENERGY STORAGE - Google Patents

Description

302633S

- 4 - 8

Flywheel energy storage

The invention relates to a flywheel energy storage device with an extremely fast rotating one for energy conversion Synchronous disk rotor and an axial and / or radial magnetic bearing, consisting of an extremely fast rotating body of revolution for generating axially and / or radially acting magnetic forces.

It is known that conventional energy converters (electric motor / generator) between the rapidly rotating flywheel and the energy converter require the engagement of gears. Such gears, however, cause high energy losses and are subject to mechanical wear subject. The same applies roughly to the mechanical mounting of these embodiments. Also make it difficult the systems for cooling and lubrication of the aforementioned components generate a vacuum in the flywheel housing. To these problems takes the DE-OS 24 30 141 detailed position, but without to give special lessons for the practical solution of the problem.

In DE-PS 25 58 422 a flywheel energy storage device is the initially described type, from which the present invention is based and it is based on the task of a flywheel energy storage device of the type mentioned at the beginning, which allows an almost loss-free energy conversion and a contact-free one The flywheel and energy converter run in the evacuated flywheel housing.

This object is achieved in an optimal and reliable manner by the measures laid down in the claims. In the following Description of embodiments of the invention are explained and shown in the drawing.

Show it:

1 shows a section through a rotor designed as a double disk with a hollow shaft,

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Flg. 2 shows a section along the line I-I according to FIG. 1,

3 shows a computational model for determining the voltage curves in the exemplary embodiment according to FIGS. 1 and 2,

4 shows a further computational model for determining the voltage profiles in the embodiment according to FIG. 1 and 2 when using a high carbon fiber Ε module (e.g. THORNEL 100),

5 shows a longitudinal section through a double disk design the fiber composite synchronous disk rotor,

6 shows a cross section through the rotor with arranged in a circle Excitation magnets,

7 shows a section through the pitch circle of the magnets in the disk of the rotor,

Fig. 8 shows an embodiment in cross section through a Energy converter with separately excited rotor magnets,

9 shows a cross section through an exemplary embodiment of a Synchronous disk rotor,

10 shows a cross section through a magnetic radial bearing, 11 shows a section along the line II-II according to FIG. 10,

12 shows a cross section through a combined axial-radial magnetic bearing,

13 shows a cross section through an axial magnetic bearing, FIG. 14 shows a section along the line III-III according to FIG. 13,

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15 shows a cross section through a further exemplary embodiment.

The embodiments of asynchronous, Restricting synchronous, direct and alternating current motors and generators respective energy converter either in the power and in the torque at high to very high speeds or in the Speed at high powers and torques. The demand on the energy converter to provide high performance and directly on the to be coupled to a high-speed fiber material flywheel met by the present invention. This is characterized by the installation of cylindrical ones for reasons of strength permanent or coil wound cylindrical soft iron magnets in corresponding bores in a metal disc, axially and uniformly distributed over the circumference of the disc. A typical embodiment with permanent magnets is shown in FIGS. 1 to 7. The metal body 1 of the rotor consists of a shaft and one or more disks. In the example shown, the shaft carries two Discs. In the disk or disks, cylindrical permanent magnets 2 are distributed uniformly over the pitch circle radius e in bores 1a pressed in or glued in. The metal body 1 is preferably made of titanium alloy and with a fiber or Thread material 3 wrapped around. These latter materials should a modulus of elasticity that is at least twice as high as that of titanium, have twice the strength and less than 0.5 times the specific weight. These demands correspond, for example, to carbon and carbon fiber composite materials e, as well as burr thread composites.

The fiber or filament composite winding 3 is connected to epoxy binder resin laminated and preventing breakage of the outer ring of the disc from the stress caused by the rotating masses of the magnets 2. a prescribed embodiment, its calculations was prepared according represented in the calculation model of Fig. 3 and H. The calculation is based on the following materials and their characteristic values, etc.:

Il

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Titanium metal body 1 (element 4) with E = 1.125 x 10 daN / cm γ = 4.5 g / cm ³

Magnets (item 5) with

^Rms ° ^{'2 E} Titan ^{X 2' X 1} ^ ^{25 daN} '' ⁰ ^ rms ^{= 7} · ¹⁴ S ^{/ Cm3}

Fiber material winding (element 6) with E = 2.5 χ 10 daN / cm Ύ = 1.78 / cm ³

ρ breaking strength = 31,000 daN / cm

Binding resin of the fiber material winding 3 (element 7) with E = 60,000 daN / cm ² Ύ = 1.2 g / cm ³

The elements 8 serve as a separating layer and are made of epoxy resin: E = 60,000 da / cm ² γ = 0

A model according to FIGS. 1 and 2 with the following was used for the calculations Dimensions chosen:

Speed: η = 42,000 rpm.

Fiber material outer radius: a = 150 mm Inner radius of the hollow shaft: b = 78.8 mm Titanium disc outer radius: c = 108.8 mm Magnet diameter: d = 18.9 mm

Magnet pitch circle radius: E = 9.6 mm.

The critical stresses 9 in the circumferential direction would be in the Titanium discs - as the calculation shows - without fiber material winding 3 (elements 6 and 7 in the model) the breaking stress 11 of the

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Titanium disc by far exceed. In addition, the stresses in the circumferential direction 12 and in the radial direction 14 in the magnets and between the magnet and disk would possibly exceed the press-in stresses. The fiber material winding 3 made of carbon fiber - for example TORAYCA 300A - lowers the critical circumferential stress of the titanium disk by approx. 40% from the values of curve 9 below the breaking stress of titanium 11 to the values of curve 10. In magnet 2 or between magnet and disk 1 the circumferential stresses 12 are reduced to the values of the curve 13 and the radial stresses 14 to those of the curve 15. The circumferential stresses (tensile stresses) 16 in the carbon fiber are far below their breaking stress 17, as are the circumferential stresses in the epoxy resin 18 and the radial stresses 19 in the uncritical compressive stress range 20.

The synchronous rotor disks according to the invention can be even more powerful be carried out when - as shown in Fig. 4 - a Carbon fiber with a significantly higher modulus of elasticity is used will. 41 An example of this is the fiber THORMEL 100 - with the values:

E = 6.8 9 χ 10 daN / cm "

γ = 1.94 g / cm

Breakage soannune = 34,000 daM / cm

The rotor disks were made larger by a factor of 1.333 and received the values:

a = 200 mm

b = 105 mm

c = 145 mm
d = 25.2 mm

e = 130 mm

All other values including the speed of 42,000 rpm were taken from the example according to FIG. 3. The hoop stress 21 in the titanium disk is again below the breaking stress of titanium 22. The circumferential stress 24 and the radial stress 23 im Magnet and in the magnet / titanium disc area are within permissible limits.

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The prevention of the expansion of the titanium disk by a high Ε modulus of the carbon fiber generates high internal stresses 25 and a steep increase in the circumferential stresses to the inside diameter c of the fiber winding. The maximum hoop stress or the tensile stress reaches the breaking stress 26 of the selected fiber. The radial compressive stress 27 in the resin also increases sharply and causes compressive stresses 28 in the resin in the circumferential direction. However, radial and tangential compressive stresses 27, 28 are within the fracture compressive stress 29 of the epoxy resin.

Fig. 5 shows a longitudinal section through a double disk design of the proposed rotor with hollow shaft and disks 1, the magnet 2 and the wrapping of the disks with carbon fiber or boron thread 3. The two disks with the magnets are made of the E-shaped excitation magnet 30 includes. The excitation of the magnets takes place through the coils 31 (magnetic field lines marked with B) .

Fig. 6 shows a cross section through the described before Rotor with the exciter magnets arranged uniformly in the pitch circle 30th

The coils 31 of the exciter magnets are of three-phase current with the three Phases R, S, T flowed through. Four of the twelve excitation magnets are each symmetrically εη one phase connected. The examples according to Figs. 2 and 5 show 12 excitation magnets and 12 magnets in the rotor disk. Versions with 6 or 24, 48 etc. magnet pairs are due the pane sizes and design possible. The excitation magnets 30 are held and centered by the parts 32 and 33. Fig. 7 illustrates in a partial section through the pitch circle of the magnets 2 in the disc 1 the well-known operation of a synchronous electric motor and Generators.

8 shows an energy converter based on the principle of the present invention Invention shown with separately excited rotor magnets. Instead of the permanent magnets 2, soft iron magnets are provided Core 35 and excitation coil 36 installed. The excitation current for the

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Coils 36 are generated by a generator 40 with the rotor magnet 41 and the excitation magnet 42 is generated. The exciter generator 40 on the stub shaft of the rotor body 1 works on the same principle like the rotor in generator mode.

The alternating excitation current is supplied by the generator 40 via the conductor 43 to rectifier unit 44. The rectified excitation current flows to the coils 36 via the conductor 39.

In Fig. 9, an embodiment is shown in which the Metal body of the rotor 1 consists of a solid disk 45, which is designed as a hyperbolic disk. Through this design it has a high energy density. With such a disk, the radial tensile stress is equal to the tangential tensile stress. In Such disks 45 are in turn evenly distributed around the circumference magnets 2 and carbon fiber windings are used upset. In the case of hyperbolic solid disks, high-strength aluminum alloys are also suitable for the in addition to titanium alloys Metal body 45 in connection with the carbon fiber winding 3.

In the case of a hyperbolic solid disk made of steel, the fiber material winding must 3 consist of a carbon fiber or burr thread winding with the double Ε module of steel. The rotor magnets themselves are to be stored in non-ferrous, high-pressure-resistant sockets 55, to prevent magnetic flux into the steel disc.

Two disks with the E-shaped stator magnet 56 and the winding 57 can be both an energy converter unit and at the same time due to the high energy storage capacity of the hyperbolic Solid disks 45 represent an energy storage unit. The connection of the disks 45 is made by the bolts 54 and the centering and bolt receiving rings 48,49. Prevent the carbon fiber windings 50.51 a breakage of the titanium rings 48,49. The space above these rings can be used for additional energy storage - such as through that Carbon fiber windings 52,53 shown - are exploited.

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A magnetic radial bearing is shown in FIG. 10. The bearing rotor from the parts 60,61,62,63 rotates without contact between the stator magnets 64,65. To make the eddy current losses small too hold, the rotor consists of the iron lamellas 61, which are centered by the titanium ring 60 and by the insulation 62 from each other are separated. To achieve the required magnetic forces or in order to keep the magnetic forces as small as possible, a correspondingly large circumferential surface of the lamellae 61 is necessary. the Tangential forces occurring in the high-speed rotor between the lamellae are taken up by the fiber winding 63 made of carbon or boron thread.

11 shows a section through the rotor according to FIG. 10. In FIGS. 12 and 13, combined axial-radial magnetic bearings as well as axial magnetic bearings are shown. For these embodiments is a structure of the winding from a thin soft iron strip and a carbon fiber or boron thread material strip characterizing the common are wound on the ring 66 and 71, respectively. The aforementioned bands isolate the soft iron band and take additional the tangential forces from the rotating masses of the soft iron strip and the fiber or thread material.

The combined axial-radial bearing has two soft iron strip windings 67 applied, which are separated by a fiber material winding or an air gap 69, whereby a magnetic flux from Magnet 70 to the opposing magnet 70 is prevented.

In the case of the axial bearing, the cover disks 74 take the bending stresses from the axial magnetic forces. The cover disks made of titanium alloy have a hyperbolic outer contour to absorb the bending moments and stresses from rotation.

In FIG. 14 there is also the induction B ₁ in the magnet 75 and the induction

represents.

Induction B in the soft iron strip of windings 67 and 72 shown

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A transfer of the invention to an energy converter unit in The form of a flywheel hollow roller 81 is shown in FIG. 15, the installation of the rotor 82 according to the invention being shown. The E-shaped Stator magnet 84 is in a housing provided with cooling fins stored. A cover 92 enables cooling air or cooling liquid to be guided in the annular channels 93 - the rotating bodies 81, 82 are mounted in contact-free radial magnetic bearings 83. the Radial magnetic forces are generated by the magnet 85. Due to the design of the lamellae 83 and the additional exciter magnets 86, the radial bearing also serves as an axial bearing.

The cylindrical housing 89, which accommodates the flywheel hollow roller 81 running in a vacuum, is made of high-strength aluminum alloy with integral ribs to ensure sufficient stability against external pressure with minimal weight.

The shoulder roller bearings 87 serve as emergency supports in the event of a possible Failure of the magnetic bearings. The bearing bushes with the spring damping element 88 made of rubber must be placed in such a way that the system is almost exclusively in the supercritical speed range.

The extremely high performance that the proposed energy converter has at maximum speeds opens up new application possibilities for it in both the civil and military sectors. High-performance surge generators according to the one proposed here Principle can, due to their high energy / weight and power / weight ratio, be used in the field of Find nuclear fusion and laser weapon technology. As a drive system for vehicles it is battery drives in terms of performance Energy absorption and output far superior.

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Claims (1)

PATENT CLAIMS Flywheel energy storage device with an extremely fast rotating synchronous disk rotor for energy conversion and an axial and / or radial magnetic bearing, consisting of an extremely fast rotating body of revolution for generating of axially and / or radially acting magnetic forces, characterized in that cylindrical permanent magnets (2) or soft iron magnets (35) with excitation coil (36) pressed into axial bores (1a) evenly distributed over the circumference of metal disks M) are, the metal disc (η) (1) on the circumference with a Winding (3) made of fiber composite material is provided and that or the magnetic bearings (100,101,102) with fiber composite material windings (63, 68, 73) are provided. Energy storage device according to claim 1, characterized in that g e k e η η ζ e i c h η e t that the material of the disc (1) des Synchronous disc rotor made of titanium alloys and the Windings (3) of the discs made of carbon fibers or Boring threads exist. 12th 130065/0366 SUBMITTED 3026333 - 2 -; 8774 3. Energy storage device according to Claims 1 and 2, characterized in that the single-pane design of the synchronous disk rotor U- or C-shaped and, in the case of double-disk design, E-shaped soft iron magnets (30) with the excitation coil (31) the discs (1) with fiber material winding (3) and magnets (2.35). 4. Energy store according to claims 1 to 3, characterized in that the synchronizing disk rotor works as the rotor of an electric synchronous motor when the motor is running, with the help of alternating current synthesis Power transistors a magnetic field running synchronously with the rotor is generated in the exciter magnet (39) and at The rotating magnets (2.35) are operated as a generator generate electrical voltage in the coils (31) of the soft iron magnets (39). 5. Energy store according to one or more of claims 1 to 4, characterized in that the disk (1) of the rotor is a solid disk (45) with a hyperbolic contour is trained. 6. Energy store according to one or more of claims 1 to 5, characterized in that two solid disks (45) are combined to form a pair of disks and due to the fiber or thread material windings (50,51) provided washer centering and bolt receiving rings (48,49) are connected. 130065/0366 Energy store according to one or more of Claims 1 to 6, characterized in that the rotary body of the radial magnetic bearing (100) made of soft iron lamellas (61), which is arranged radially around a non-metal bushing (60) and is impregnated with insulating epoxy resin or glass Carbon fiber prepreg sheets (62) connected and with a fiber or thread material winding (63) are provided. Energy store according to one or more of Claims 1 to 7, characterized in that in a combined Axial and radial magnetic bearings (1C1) a soft iron tape together with a carbon fiber or boron thread tape and epoxy resin adhesive in two identical windings (67) separated by an air gap or an insulating fiber or thread winding (69) applied to the metal sleeve (66) and with a final winding (68) is made of carbon fiber or burr thread tape and the two windings (67) laterally with symmetrical Phases to achieve the desired magnetic force and direction of force are provided. Energy storage device according to one or more of Claims 1 - 8, characterized in that, in the case of an axial magnetic bearing (102), a winding (72) made of a carbon fiber or boron thread tape with epoxy resin adhesive is applied to the socket (71) and with a final winding (73) from the The same materials are provided and discs (7 ¹ O with a hyperbolic outer contour made of titanium alloy with epoxy resin are glued to the parallel side surfaces. 130065/0366