Patent US5905321A successfully refreshed from Google Patents.
US5905321A
Expired / Lapsed
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Energy storage flywheel apparatus and methods
Assignee: Piller USA Inc
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Filing: 1998-02-17
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Granted: 1999-05-18
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Expires: 2018-02-17
Abstract
Abstract A flywheel energy conversion device provides highly efficient conversion between kinetic and electrical energy. The flywheel produces increased output by providing armature coils in an air gap formed about the flywheel (both radial and axial embodiments are described). In preferred embodiments, field coils of a magnetic circuit are energized with DC drive current that creates homopolar flux within a rotating solid rotor having teeth cut from a flat disk. The total reluctance of the magnetic circuit and total flux remain substantially constant as the rotor rotates. The flux may travel radially outward and exit the flat disk through the teeth passing across an armature air gap. Airgap armature coils are preferably utilized in which the changing flux density (due to the rotating teeth) induces an output voltage in the coils. The flux is diffused before returning to the rotor in one of several ways such that core losses are effectively reduced, thereby enabling the flywheel to operate efficiently at high frequencies.
Inventors
- 👤 David B. Clifton
- 👤 Joseph F. Pinkerton
- 👤 James A. Andrews
- 👤 Scott R. Little
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:48
CPC Classifications
F; F16; F16C; F16C32/00; F16C32/04; F16C32/0406; F16C32/044; F16C32/0459; F16C32/0408; F16C32/0474; F16C32/0493; F16C32/0495; F16C39/00; F16C39/06; F16F; F16F15/00; F16F15/30; H; H02; H02K; H02K1/00; H02K1/06; H02K1/12; H02K19/00; H02K19/02; H02K19/10; H02K19/103; H02K19/16; H02K19/18; H02K19/20; H02K21/00; H02K21/38; H02K21/44; H02K3/00; H02K3/04; H02K7/00; H02K7/02; H02K7/025; H02K7/08; H02K7/09; F16C2361/00; F16C2361/55; H02K29/00; H02K29/06; H02K29/08; H02K3/28; Y; Y02; Y02E; Y02E60/00; Y02E60/16
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
143 words
An apparatus for converting between electrical and kinetic energy, said apparatus comprising: a solid rotor having a plurality of integral protrusions extending therefrom and forming and axial air gap, said rotor being constructed of substantially magnetic material and having an axial thickness that remains substantially constant or decreases when measured at increasing radial positions; a member that generates homopolar flux, said rotor and said flux generating member forming a magnetic circuit having a total reluctance that remains substantially constant while said rotor is rotated about an axis; and at least one stationary airgap armature coil mounted within said axial air gap with the active portion of said armature coil extends to substantially the entire axial length of said protrusions such that said flux induces an AC voltage in said at least one airgap armature coil when said rotor is rotated about said axis.
Claim 2
Independent Claim
143 words
An apparatus for converting between electrical and kinetic energy, said apparatus comprising: a solid rotor having a plurality of integral protrusions extending therefrom and forming and axial air gap, said rotor being constructed of substantially magnetic material and having an axial thickness that remains substantially constant or decreases when measured at increasing radial positions; a member that generates homopolar flux, said rotor and said flux generating member forming a magnetic circuit having a total reluctance that remains substantially constant while said rotor is rotated about an axis; and at least one stationary airgap armature coil mounted within said axial air gap with the active portion of said armature coil extends to substantially the entire axial length of said protrusions such that said flux induces an AC voltage in said at least one airgap armature coil when said rotor is rotated about said axis.
Claim 3
Dependent Claim
13 words
The apparatus of claim 1, wherein said rotor further includes an integral shaft.
Claim 4
Dependent Claim
59 words
The apparatus of claim 2, wherein said rotor is formed of a single piece of substantially high permeability material having first and second portions, said first portion being a substantially planar disk and said second portion being a shaft about which said disk portion rotates, said shaft having a radius less than the radially outermost edge of said protrusions.
Claim 5
Dependent Claim
50 words
The apparatus of claim 1 further comprising at least one ring having a substantially smooth surface, said ring being mounted concentric with respect to said rotor such that an armature air gap is formed between said protrusions and said smooth surface, said ring being constructed of substantially high permeability material.
Claim 6
Dependent Claim
54 words
The apparatus of claim 4, wherein said at least one ring comprises a pair of first and second rings mounted to a ring of non-magnetic material, said first ring being fixedly mounted to one side of said non-magnetic ring and said second ring being fixedly mounted to the other side of said non-magnetic ring.
Claim 7
Dependent Claim
49 words
The apparatus of claim 1, wherein substantially all of the axial length of said rotor forms said armature air gap and said armature coil is mounted within said air gap such that the active portion of said armature coil extends to substantially the entire axial length of said rotor.
Claim 8
Dependent Claim
21 words
The apparatus of claim 1, wherein said rotor further includes an integral lower portion that is substantially uniform about its circumference.
Claim 9
Dependent Claim
70 words
The apparatus of claim 1, wherein said rotor is a steel rotor that includes an integral shaft that said rotor is rotated about, said apparatus further comprising: a pair of upper and lower mechanical bearings that said shaft is rotatably mounted within; and an electromagnet mounted with respect to said rotor such that said electromagnet, when energized, removes a majority of the weight of said rotor from said mechanical bearings.
Claim 10
Dependent Claim
27 words
The apparatus of claim 8, wherein said electromagnet acts directly upon said rotor to remove a majority of the weight of said rotor from said mechanical bearings.
Claim 11
Dependent Claim
17 words
The apparatus of claim 8, wherein said mechanical bearings are one of ball bearings and roller bearings.
Claim 12
Dependent Claim
28 words
The apparatus of claim 8, wherein one of said upper and lower bearings are roller bearings and the other of said upper and lower bearings are ball bearings.
Claim 13
Dependent Claim
31 words
The apparatus of claim 8, wherein said electromagnet is energized in response to signals obtained from at least one strain gauge that monitors the amount of weight on said mechanical bearings.
Claim 14
Dependent Claim
22 words
The apparatus of claim 1, wherein said flux generating member comprises at least one permanent magnet that induces said flux to flow.
Claim 15
Dependent Claim
22 words
The apparatus of claim 1, wherein said flux generating member comprises at least one field coil that induces said flux to flow.
Claim 16
Dependent Claim
40 words
The apparatus of claim 14, wherein said at least one field coil comprises a pair of upper and lower field coils, said upper field coil being mounted above said rotor and said lower field coil being mounted below said rotor.
Claim 17
Dependent Claim
95 words
The apparatus of claim 15, wherein said rotor further includes a shaft, said apparatus further comprising: a pair of upper and lower mechanical bearings that said shaft is rotatably mounted within; an upper bearing coil; a lower bearing coil; and a control circuit that controls said upper and lower bearing coils such that said flux driven by said upper field coil is varied by a given amount and said flux driven by said lower field coil is inversely varied by said given amount resulting in a change in the net axial force on said rotor.
Claim 18
Dependent Claim
54 words
The apparatus of claim 16, wherein said flux driven by said upper field coil is varied by increasing said flux said given amount and said flux driven by said lower field coil is varied by decreasing said flux said given amount resulting in an upward change in said net axial force on said rotor.
Claim 19
Dependent Claim
77 words
The apparatus of claim 15, wherein said rotor further includes a shaft, said apparatus further comprising: a pair of upper and lower mechanical bearings that said shaft is rotatably mounted within; and a control circuit that independently controls said upper and lower field coils such that the net axial force on said rotor is a function of the difference between said flux driven by said upper field coil and said flux driven by said lower field coil.
Claim 20
Dependent Claim
31 words
The apparatus of claim 18, wherein said upper and lower field coils are controlled by said control circuit to produce an upward change in said net axial force on said rotor.
Claim 21
Dependent Claim
25 words
The apparatus of claim 1, wherein each of said at least one armature coil is an airgap coil being formed of substantially low permeability material.
Claim 22
Independent Claim
155 words
A method for converting between electrical and kinetic energy, said method comprising the steps of: rotating a solid rotor about an axis, said rotor having a plurality of integral protrusions extending therefrom and forming and axial air gap, said rotor being constructed of substantially magnetic material and having an axial thickness that remains substantially constant or decreases when measured at increasing radial positions; generating homopolar flux in a member such that said rotor and said flux generating member form a magnetic circuit having a total reluctance that remains substantially constant while said rotor is rotated about said axis; and causing an AC voltage to be induced in at least one airgap armature coil mounted in said axial air gap with the active portion of said armature coil extends to substantially the entire axial length of said protrusion when said rotor is rotated about said axis by exposing said airgap armature coil to said generated flux.
Claim 23
Independent Claim
155 words
A method for converting between electrical and kinetic energy, said method comprising the steps of: rotating a solid rotor about an axis, said rotor having a plurality of integral protrusions extending therefrom and forming and axial air gap, said rotor being constructed of substantially magnetic material and having an axial thickness that remains substantially constant or decreases when measured at increasing radial positions; generating homopolar flux in a member such that said rotor and said flux generating member form a magnetic circuit having a total reluctance that remains substantially constant while said rotor is rotated about said axis; and causing an AC voltage to be induced in at least one airgap armature coil mounted in said axial air gap with the active portion of said armature coil extends to substantially the entire axial length of said protrusion when said rotor is rotated about said axis by exposing said airgap armature coil to said generated flux.
Claim 24
Dependent Claim
67 words
The method of claim 21, wherein said step of rotating a solid rotor comprises rotating a rotor formed of a single piece of substantially high permeability material having first and second portions, said first portion being a substantially planar disk and said second portion being a shaft about which said disk portion rotates, said shaft having a radius less than the radially outermost edge of said protrusions.
Claim 25
Dependent Claim
30 words
The method of claim 21, wherein said step of generating comprises the step of: driving at least one field coil with a drive signal to induce said flux to flow.
Claim 26
Dependent Claim
32 words
The method of claim 23 further comprising the step of: monitoring a source of primary power and automatically varying said drive signal to said field coil when said primary power is disrupted.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-05-17 | 2002-11-16 | 2003-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-05-17 | 2006-11-16 | 2007-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-05-17 | 2010-11-16 | 2011-05-18 | $7700.00 | Window Closed / Lapsed |