Flywheel energy accummulator

• US 6,236,127 B1
• Filed: 08/16/1999
• Issued: 05/22/2001
• Est. Priority Date: 03/11/1997
• Status: Expired due to Fees

• Current Assignee: Forschungszentrum Karlsruhe Gmbh
• Original Assignee: Forschungszentrum Karlsruhe Gmbh
• Inventors: Bornemann, Hans
• Primary Examiner(s): Enad, Elvin
• Application Number:
  US09/375,209
• Time in Patent Office: 645 Days
• Field of Search: 310/74, 310/90.J, 310/178
• US Class Current: 310/74
• CPC Class Codes: F16C 2361/55 Flywheel systems in general F16F15/00
• CPC Class Codes: F16C 32/0438 with a superconducting body, e.g. a body made of high temperature superconducting material such as YBaCuO
• CPC Class Codes: F16F 15/31 characterised by means for varying the moment of inertia
• CPC Class Codes: H02K 7/025 for power storage
• CPC Class Codes: H02K 7/09 with magnetic bearings
• CPC Class Codes: Y02E 60/16 Mechanical energy storage, e.g. flywheels or pressurised fluids

Abstract

In a flywheel energy accumulator including, in a vacuum-tight housing, a vertical shaft with a rotor of an electric motor/generator arranged in the axial center of the shaft and flywheels mounted on the shaft at opposite sides of the rotor, the electric motor/generator and the flywheels are included in modules, each with a housing ring, which are mounted on top of one another and receive bearing modules including support discs mounted between, and adjacent, the housing rings with superconductive magnetic bearings disposed in the center thereof around the shaft for supporting the shaft with the flywheels and the rotor. The number of superconductive bearings is twice the number of flywheels. The bearing module discs between adjacent flywheels have upper and lower superconductive magnetic bearings and the bearing modules at the axial ends of the shaft and adjacent the rotor carry each only one superconductive magnetic bearing so that the number of superconductive magnetic bearings is greater, by two, than the number of flywheels.

Claims

1. A flywheel energy accumulator including, disposed in a vacuum-tight housing, a vertical shaft, supported on superconductive magnetic axial bearings (SMB), an electric motor/generator having a stator mounted in said housing and a rotor mounted on said vertical shaft so as to be disposed within said stator, and a number of flywheels also mounted on said shaft at opposite sides of said rotor, said energy accummulator having the following features:

a) the flywheels are disposed on said shaft at opposite sides of said electric motor/generator on top of one another in axially spaced relationship and said rotor of said electric motor/generator is disposed centrally between said flywheels,

b) an annular permanent magnet of a first, lower superconductive passive axial bearing is disposed below the lowermost flywheel forming an axial thrust bearing and an annular permanent magnet of a second upper superconductive passive axial bearing is disposed above the uppermost superconductive axial bearing in the form of an axial pull bearing, and

c) disc-like superconductors are supported on said housing so as to be disposed opposite said annular magnets in spaced relationship therefrom,

d) the stator which extends around said rotor includes windings capable of generating a rotating magnetic field effective on the rotor,

e) said flywheel energy accumulator consists of individual modules which are disposed on top of one another and are interconnected by spacer shaft members, each module including a housing section surrounding a respective one of said electric motor/generator and said flywheels, and bearing modules are mounted between adjacent housing sections and between the uppermost and lowermost housing section and upper and lower housing covers respectively.

f) each of said bearing modules includes a superconductive magnetic axial bearing (SMB) for each of the adjacent flywheels such that the total number of SMB'"'"'s is twice the number of flywheel modules and each flywheel has an upper and a lower SMB associated therewith,

g) each bearing module includes one or two SMB'"'"'s, respectively, and

h) the number of bearing modules is greater, by two, than the number of flywheel modules.

2. A flywheel energy accumulator according to claim 1, including the following additional features:

i) each of the bearing modules disposed between two adjacent flywheels has an SMB mounted at each of its upper and lower sides,

j) the bearing modules disposed adjacent the rotor and at the upper and lower ends of the accumulator include each only one bearing module disposed opposite the respective adjacent flywheel.

3. A flywheel energy accumulator according to claim 2, including the following additional features:

k) each of the bearing modules disposed between adjacent flywheels comprises an annular hollow disc with upper and lower sides in which a respective upper and a lower superconductor is disposed and has a hollow space receiving a cryostat for cooling said upper and lower superconductors, said superconductors having rear inner surfaces directly exposed to the hollow space.

4. A flywheel energy accumulator according to claim 1, including the following additional features:

l) said bearing modules disposed adjacent only one flywheel comprises an annular hollow disc having a superconductor disposed in one of its sides and having a hollow space receiving a cryostat for cooling said superconductor, said superconductor having a rear inner surface directly exposed to said hollow space.

5. A flywheel energy accumulator according to claim 1, including the following additional features:

m) said housing consists of a number of housing rings each extending around one of said flywheels, a center housing ring extending around said electric motor/generator and top and bottom covers, said housing rings and said top and bottom covers being flanged together in a vacuum-tight manner and having said bearing modules clamped therebetween for firmly supporting said bearing modules.

6. A flywheel energy accumulator according to claim 1, including the following additional features:

n) said flywheels are positioned on said shaft in spaced relationship by spacer members and are exchangeably mounted on said shaft above and below said electric motor/generator.