DE3026339C2 - Flywheel energy storage - Google Patents

Description

The invention relates to a flywheel energy storage device with a / ur energy conversion 'extremely fast rotating synchronous disc 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, with permanent magnets evenly In a Mctallschcibe are arranged distributed.

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. The same applies roughly to the mechanical mounting of these embodiments. In addition, the systems ^r ÜR cooling and lubrication of the aforementioned components complicate the generation of a vacuum in the Schwungradgehiluse These problems take the DE-OS 24 30 141 in depth position, without giving special teachings but the practical solution of the problem.

DE-AS 10% 473 has made known a rotor assembly for an electrical machine with an axial air gap, in which cylindrical permanent magnets are evenly distributed in a metal disk and are pressed into bores, the metal disk on the circumference by a wire connection or by a / usilt / The same tube is protected against centrifugal vibration at high speeds. Due to these protective measures, however, a not inconsiderable increase in the total weight is necessary 2i) | "In DE-PS 25 58 422 a flywheel energy Si'speieher of the type mentioned is described, from ! Jicm the present invention and its task For example, to create a flywheel energy storage device of the type mentioned at the outset, in which disc breakages due to the stress of the rotating magnetic masses are prevented without the strength and the modulus of elasticity being impaired and weight savings being achieved.

This issue is reflected in the claims

jo deranged measures in more optimal and reliable

Catfish solved. In the following description are

Embodiments of the invention explained and in the Drawing shown. It shows

I ig. I a section through a rotor designed as a double disk i ^r > with a hollow shaft;

Fiu. 2 shows a section along the line 1-1 according to FIG Fig. Ϊ;

3 shows a computational model for determining the voltage distribution in the embodiment according to Fig. 1 and 2;

I ig. 4 a further calculation model for the determination the stress level in the embodiment according to FIGS. 1 and 2 when using a carbon fiber with a high Ε module (for example THORNEL 100);

5 shows a cross section through an exemplary embodiment of a synchronizing disk rotor;

6 shows a cross section through a magnetic radial bearing;

Flg. 7 shows a section along the line II -11 according to FIG. 10;

8 shows a cross section through a combined A xial -Radial-M agnel bearing;

9 shows a cross section through an axial magnetic bearing. The designs of asynchronous, synchronous, DC and AC motors commonly used today and generators limit the respective energy converter either in terms of power or 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 high-speed fiber material flywheel being coupled are met by the present invention. It is characteristic of this the installation of cylindrical permanent or coil wound cylindrical shafts for reasons of strength Wcichelsenmagneten In corresponding bores of a metal disc, axially and uniformly over the

Circumference of the disk distributed, tine typical embodiment with permanent magnets show the Flg. 1 Ms 7. The metal body 1 of the rotor consists of a shaft around. one or more slices. In the example shown, the shaft has two disks. In the b7w. the disks are evenly distributed on the Tellkrelsradlus e cylindrical permanent magnets 2 pressed or glued into bores la. The metal body 1 is preferably made of titanium alloy and wrapped with a fiber or thread material 3. These last-mentioned materials should have a modulus of elasticity that is at least twice as high as the titanium material, twice as high a strength and less than 0.5 times the specific weight. These requirements are met, for example, by carbon and carbon fiber composite materials as well as boron thread composite materials.

The fiber or thread composite material winding 3 is laminated with epoxy resin and prevents breakage of the outer ring of the disk from the stress caused by the rotating masses of the magnets 2. A previously described exemplary embodiment! was presented according to separate calculations in the arithmetic model of Figs. 3 and j . The following materials and their characteristic values etc. were used as the basis for the calculation:

"Tltin metal body 1 (element 4> with

E - 1.125 χ JO ⁶ daN / cm ²

y = 4.5 g / cm ³
'Magnets (item 5) with

Etfekn » = O · ^{2 E} Tiwn x 2.25 χ 10 ^s daN / cm ²

y _e / Miiv = ^{7 '14} g ^{/ ctT} > ³
Fiber material winding (element 6) with

E = 2.5 χ 10 ⁶ daN / cm ²

γ = 1.78 g / cm ³

Breaking strength = 31,000 daN / cm ²

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

γ = 1.2 g / cm ³

The elements 8 serve as a separating layer and are made of epoxy resin:

E = 60,000

A model according to Flg. 1 and 2 selected with the following dimensions:

Rotational speed:

Fiber material outer radius:
Inner radius of the hollow shaft:
Titanium disc outer radius:
Magnet diameter:
Magnet pitch circle radius:

10

15th

20th

25th

30th

40

45

η = 42,000 rpm.

a = 150 mm

b = 78.8 mm

c = 108.8 mm

d = 18.9 mm

E - 91.6 mm.

The critical voltages 9 würijl ff circumferentially <in the titanium disks - such as the bill is without Faserwerksioffwicklung 3 (elements 6 and 7 in the M% model), the breakdown voltage 11 of the titanium disk in WEL 'exceed tem. In addition, the stresses in the circumferential direction 12 and in the radial direction 14 in the 6Oj 'magnets and between the magnet and the 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 Π 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 RadUlspannungen 14 to those of the curve 15. Rle circumferential stresses (tensile stresses) 16 in the carbon fiber Hegen well under their breaking stress 17, as are the circumferential stresses in epoxy resin 18 and the radial stresses 19 in the uncritical compressive stress range 20.

The rotor disks according to the invention can still run more efficiently if - v / Ie In HI g. 4th shown - a carbon fiber with much higher Young's modulus is used. An example of this is the THORNEL 100 fiber - with the values:

E - 6.89 χ 10 ° daN / cm ²
γ = 1.94 g / cm ³
breaking stress = 34,000 daN / cm ²

The rotor disks became larger by a factor of 1.333 dimensioned and received the values

a = 200 mm
b = 105 mm
c = 145 mm
\ d = 25.2 mm
e = 130 mm

. Fig. 3, all remaining values including the speed of 'Al 000 U / min were taken from the example of FIG. The hoop stress 21 in the Titanschelbe Hegt back 22 under the breakdown voltage of titanium hoop stress 24 and the radial stress 23 Xm magnet and are in the field magnet / Titanschelbe in permissible limits.

The prevention of the expansion of the titanium disk by a high Ε modulus of the carbon fiber generates high circumferential stresses 25 and a steep increase in the circumferential stresses towards the inside diameter c of the fiber winding. The maximum circumferential 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.

In the wing. 5 An embodiment is shown at which the metal body of the rotor 1 consists of a full disk '45, which is designed as a hyperbolic disk. As a result of this configuration, it has a high energy density. With such a disc, the wheel tension is radial equal to the tangential tensile stress. In turn, disks 45 configured in this way are uniform Distributed on the circumference magnets 2 are used and carbon fiber windings 3 are applied. With hyperbolic full disks In addition to titanium alloy, high-strength aluminum alloys are also suitable for the metal body 45 in connection with the carbon fiber winding 3.

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

Zwe, disks with the E-shaped stator magnet 56 and the winding 57 can both be an energy converter and at the same time due to the high energy storage capacity of the hyperbolic full disks 45 represent an energy storage unit. The connection of the disks 45 is carried out by the bolts 54 and the centering and bolt receiving rings 48, 49. The carbon fiber windings 50, 51 prevent the titanium rings 48, 49 from breaking. The space above these rings can be used for additional

Lent energy storage - like through the carbon fiber windings 52, 53 shown, are exploited.

In FIG. 6 and in section along the line II-II of this FIG. 7 shows a magnetic radial bearing. The bearing rotor from the parts 60, 61, 62, 63 rotates without contact between the stator magnets 64, 65. To the To keep eddy current losses small, the rotor consists of the iron lamellas 61, which are supported by the titanium ring 60 are centered and separated from one another by the insulation 62. To achieve the required magnetic forces or in order to keep the magnetic forces as small as possible, a correspondingly large l'mlauffläche is the Lamellae 61 necessary. The tangential forces occurring in the high-speed rotor between the lamellas are taken up by the fiber winding 63 made of carbon or boron thread / i.

In FIGS. 8 and 9, combined axial-radial magnetic bearings and axial magnetic bearings are shown. Aulbau the winding from a thin soft iron strip and a carbon fiber or carbon fiber. Characteristic Borliidenwerkloffband, which are jointly on the ring 66 b / v /. 71 are wound. The aforementioned bands isolate the soft iron band and also absorb the tangential forces from the rotating masses of the soft iron band and the fiber or thread material.

In the case of a combined axial-radial bearing, there are two

Iron tape windings 67 are applied, which are separated by a fiber material winding or an air gap 69 are, whereby a magnetic flux from the 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 to absorb the bending moments and stresses from rotation

"To hyperbolic outer contour.

The induction B ₁ in the magnet 75 and the induction B ₂ in the soft iron strip of the windings 67 and 72 are also shown.

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

For this purpose 4 sheets of drawings

Claims (5)

Patent claims: 1. Flywheel energy storage device with an extremely fast rotating one for energy conversion Synchronous pulley 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, wherein Permanent magnets are arranged evenly distributed in a metal disk, characterized in that that the Melallschcibe (s) (1. 45) and the one or more magnetic bearings (100, 101, 102) with windings (3, 50, 51, 63, 68) from Fa.-ierverbundwerkloll, consisting made of carbon fibers or boron shutters, umwlkkell are. 2. Energy storage device according to claim I. characterized in that two volume disks (45) are formed into a pair of screws and are closed by the fiber or thread loops (50, 51) Bolzenaiifnahmerlnge '/ (48, 49) are connected.
t 3. Energy store according to claim I and 2, characterized characterized in that the rotary body of the radial 'magnetic bearing (100) is made of Weichelsen lamellae (61) 'exists, which is radially around a non-clamp bushing (ήΟ) arranged and covered by insulating glass or carbon fiber panels impregnated with epoxy resin * (62) connected and with a fiber or thread weave winding (63) are provided. 4. Energy store according to one or more of claims 1 ms 3. characterized in that at a combined axial and radial magnetic bearing (IOD a soft iron strip together with a Carbon fiber or boron tape and epoxy plastic tape in two equal turns (67) separated by one l.ultspall or an isolicria.ser- or thread winding (69) applied to the metal sleeve (66) and with a closure (68) made of carbon fiber or Borladcnband is provided and the two windings (67) rope with symmetrical phases to achieve the desired magnetic force and direction of force are provided. 5. Energy store according to one or more of claims I to 4, characterized in that at a winding (72) from an axial magnet bearing (102) a carbon fiber or boron tape with epoxy adhesive applied to the bushing (71) and with a termination winding (73) made of the same materials is provided and on the parallel side surfaces disks (74) with hyperbolic outer contour made of titanium alloy are glued on with epoxy resin.