Flywheel rotor with conical hub and methods of manufacture therefor

• US 5,628,232 A
• Filed: 05/13/1994
• Issued: 05/13/1997
• Est. Priority Date: 01/14/1994
• Status: Expired due to Term

• Current Assignee: Beaver Aerospace And Defense, Inc.
• Original Assignee: Rosen Motors, L.P.
• Inventors: Rosen, Harold A., Bosley, Robert W., Bakholdin, Daniel, Grayer, William
• Primary Examiner(s): LUONG, VINH
• Application Number:
  US08/242,647
• Time in Patent Office: 1,096 Days
• Field of Search: 74/572, 74/573 R, 74/574, 74/573 F, 310/74, 310/90.5, 318/161, 322/4
• US Class Current: 74/572.12
• CPC Class Codes: B60L 50/30 using propulsion power stored mechanically, e.g. in fly-wheels
• CPC Class Codes: B62M 1/10 involving devices which enable the mechanical storing and releasing of energy occasionally, e.g. arrangement of flywheels
• CPC Class Codes: F16C 15/00 Construction of rotary bodies to resist centrifugal force flywheels, correction weights F16F15/30, F16F15/32
• CPC Class Codes: F16C 2361/55 Flywheel systems
• CPC Class Codes: F16F 15/302 comprising arrangements for cooling or thermal insulation
• CPC Class Codes: F16F 15/305 made of plastics, e.g. fibre reinforced plastics [FRP] , i.e. characterised by their special construction from such materials
• CPC Class Codes: F16F 15/315 characterised by their supporting arrangement, e.g. mountings, cages, securing inertia member to shaft F16F15/31 takes precedence
• CPC Class Codes: H02K 5/173 using bearings with rolling contact, e.g. ball bearings
• CPC Class Codes: H02K 7/025 for power storage
• CPC Class Codes: H02K 7/083 radially supporting the rotary shaft at both ends of the rotor H02K7/086, H02K7/09 take precedence
• CPC Class Codes: H02K 7/09 with magnetic bearings
• CPC Class Codes: Y02E 60/16 Mechanical energy storage, e.g. flywheels or pressurised fluids
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10S 903/96 having chargeable mechanical accumulator
• CPC Class Codes: Y10T 74/2119 Structural detail, e.g., material, configuration, superconductor, discs, laminated, etc.
• CPC Class Codes: Y10T 74/212 Containing fiber or filament

Abstract

A flywheel rotor used in a flywheel energy storage system providing a high energy storage capacity while providing an ample volume for a high power motor-generator within its envelope includes an outer, primarily cylindrical body having conically tapered end sections, a conical hub section attached to the outer body, and a relatively short inner cylinder, which cylinder connects shaft to the inner portion of the conical hub section. In an exemplary case, the individual components are predominantly constructed of filament wound fiber composites while allowing material choices to be driven by both cost and performance. According to one aspect of the rotor, the inner portion of the inner cylinder can be a slotted aluminum cylinder.

Claims

1. A flywheel rotor for a flywheel energy storage system, comprising:

an outer, primarily cylindrical portion including first fibers having a predetermined first tensile strength for storing the majority of total system energy; and

a hub portion including;

a conical member formed from second fibers of a second predetermined second tensile strength; and

a inner cylindrical member operatively connected to a rotatable shaft, said inner cylindrical member comprising;

a hexagonal aluminum cylinder;

a spring surrounding said hexagonal cylinder; and

a plastic annular member operatively connected to said hexagonal aluminum cylinder by said spring,

wherein said conical member operatively connects a first end of said outer cylindrical portion with said inner cylindrical member, and

wherein said first tensile strength is greater than said second tensile strength.

2. The flywheel rotor as claimed in claim 1, wherein said outer cylindrical portion comprises:

an outer cylindrical member including said first fibers; and

an inner cylindrical member comprising a material having a relatively high density and a relatively low modulus of elasticity with respect to said first fibers.

3. The flywheel rotor as claimed in claim 2, wherein said first end and a second end of said outer cylindrical portion are tapered.

4. The flywheel rotor as claimed in claim 3, wherein said first and second ends of said outer cylindrical portion are tapered so as to permit reduction of radial stresses at an intersection between said hub portion and said outer cylindrical portion.

5. The flywheel rotor as claimed in claim 4, wherein the radius of said inner cylindrical member is sized so as to permit said conical member to intersect said outer cylindrical portion to thereby form a conical angle.

6. The flywheel rotor as claimed in claim 3, wherein said first and second ends of said outer cylindrical portion are tapered so as to permit reduction of radial stresses at an intersection between said hub portion and said outer cylindrical portion and wherein said inner cylindrical member permits reduction in radial stress in a center region of said outer cylindrical portion.

7. The flywheel rotor as claimed in claim 1, wherein said first fibers and said second fibers are carbon fibers.

8. A flywheel energy storage system, comprising:

a motor-generator; and

a rotor, said rotor comprising;

an outer, primarily cylindrical portion including first fibers having a predetermined first tensile strength for storing the majority of total system energy; and

a hub portion including;

a conical member formed from second fibers of a second predetermined second tensile strength; and

an inner cylindrical member operatively connected to a rotatable shaft, said inner cylinder member comprising;

a hexagonal cylinder;

a spring surrounding said hexagonal cylinder; and

a plastic annular member, wherein said hexagonal cylinder and said plastic annular member are operatively connected by said spring,

wherein said conical member operatively connects a first end of said outer cylindrical portion with said inner cylindrical member,

wherein said first tensile strength is greater than said second tensile strength, and

wherein a portion of said motor-generator is disposed within a cavity defined by said conical member.

9. The flywheel energy storage system as claimed in claim 8, wherein said first fibers and said second fibers are carbon fibers.

10. The flywheel energy storage system as claimed in claim 8, wherein said hub portion is operatively connected to a first end of said outer cylindrical portion and wherein said first end is conically tapered in an axial direction so as to permit a reduction in radial stress in a region where said hub portion is connected to said outer cylindrical portion.