Flywheel Energy Storage Materials Patents: Top Filers & Trends 2026
- Filing has cooled since its 2017 peak of 7 records, with the 2022 midpoint at zero — this is a corpus with a concentrated historical burst rather than sustained annual growth.
- H02K electric motor and generator claims sit under all 57 families, while forging and heat-treatment classes (B21K, C21D, B21J) show rotor manufacturing is claimed almost as densely as the electromagnetics.
- The US receives more than half of all filings (29 of 57), with Europe, WIPO and Canada trailing far behind and China holding just a single record — a strong signal on where enforcement risk actually concentrates.
What this dataset covers
This landscape tracks 57 patent families at the intersection of flywheel energy storage systems and their structural materials — composite rotors, high-strength rims and the forging and heat-treatment routes used to build them. The search combines flywheel-specific title/abstract terms with rotor-material language and IPC codes spanning B29C70 (composite layup), H02K7/02 (flywheel-integrated electric machines) and F16F15 (vibration/inertia dampers), so the corpus captures both the mechanical rotor and its electromagnetic integration.
Coverage runs from 2015 through the 2026 data cut-off. Because publication typically lags filing by around 18 months, the most recent one to two years will always look thinner than they eventually turn out to be once pending applications publish.
Filing trend and technology composition
Two views of the same 57 families: how filing activity moved year over year, and which IPC subclasses carry the claim weight.
A 2017 peak, then a flat-to-declining line
Filings hit their highest point in 2017 at 7 records, then trended down; by the 2022 midpoint, annual filings had dropped to zero. That pattern points to an early cluster of foundational filings rather than a technology still building momentum — treat any post-2022 uptick with caution given publication lag.
Electromagnetics dominate, but manufacturing IPCs are close behind
Every one of the 57 families touches H02K (electric motors and generators), confirming the search's flywheel-integration core. F16F (springs and vibration dampers, 15 records) and the forging/heat-treatment cluster — B21K, C21D and B21J, each in the 12-14 range — show that a meaningful share of the claim activity is about how the rotor is made and damped, not just how it is driven.
Shares are the percentage of the 57 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Flywheel Energy Storage Advanced Materials with Eureka
This page is one run against one query. Ask Eureka your own question about flywheel energy storage advanced materials and every answer comes back with the patent numbers behind it.
Try EurekaThe records anchoring this space
Constant stress solid disk rotor of flywheel for flywheel energy storage system and design method thereof
The filing describes a solid disk rotor shaped to hold constant stress across its radius: a thickness-decreasing region from the rotation centre out to a connection radius, followed by a constant-thickness outer band running to the rotor's outer circumference. The shape parameters — outer radius, centre thickness, connection radius and outer edge thickness — are set by a design method rather than fixed geometry.Filed by NEXFI TECHNOLOGY INC., published 2024-09-19.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5462402A | Flywheel energy storage system with integral molecular pump | 78 |
| 2 | US20150008778A1 | Method for producing a kinetic energy storage system | 25 |
| 3 | US20180152076A1 | Integrated flywheel energy storage system | 24 |
| 4 | US20170279335A1 | High power flywheel system | 18 |
| 5 | US20130260999A1 | Open-core flywheel architecture | 15 |
| 6 | US20150007686A1 | Method for producing a kinetic energy storage system | 14 |
| 7 | US9136741B2 | Method for producing a kinetic energy storage system | 12 |
| 8 | US20200212762A1 | Method for pre-conditioning a kinetic energy storage system | 10 |
| 9 | US20150013148A1 | Method for producing a kinetic energy storage system | 10 |
| 10 | WO2015006136A2 | Method for producing a kinetic energy storage system | 9 |
Citation counts favour older filings simply because they have had more time to accumulate references — read them as a signal of influence on the field, not of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
Put your own technology through the same analysis
Eureka on the web
When you want the answer in the next five minutes.
The agent works the prompt against patents and technical literature, citing every source.
Run your analysis now →MCP server & REST API
When it has to run inside your own pipeline.
Patent search, landscape analysis and assignee resolution as MCP tools. Drop them into any agent framework, or call REST directly.
Browse MCP servers →What the numbers say about this field
Three read-outs from the filing data that matter more than the raw counts.
A burst, not a build
The corpus peaked early at 7 filings in 2017 and had fallen to zero by 2022. That shape — an early spike followed by a long flat stretch — is more consistent with a technology that had one foundational filing wave than one that is still being actively claimed year over year.
Enforcement risk sits mostly in the US
More than half of all families in this dataset were filed at the USPTO, with Europe, WIPO, Canada and Austria dividing most of the remainder. A single Chinese-received record suggests this technology's IP contest has so far played out almost entirely outside China.
Rotor material claims ride on the motor/generator class
Every family in the set carries an H02K classification, meaning composite rotor and rim claims are almost never filed in isolation from the electric machine they sit inside. Manufacturing-side classes (B21K, C21D, B21J) appear in roughly a quarter of records each, marking forging and heat treatment as a secondary but real claim front.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to flywheel energy storage advanced materials, with the prior art for and against each one.
Who is filing, and where the gaps sit
Assignee activity in this corpus is thin and largely historical: recent-year momentum across the tracked entities reads at zero, which is typical of a field with a founding generation of filers and few active successors so far.
No assignee shows current-year activity
Every entity in the recent-momentum view — from corporate filers to individual inventors — shows zero filings in the latest tracked year. Combined with the 2022 midpoint drop to zero, this points to a corpus dominated by an earlier filing generation rather than live competitive jockeying.
A small, tightly linked inventor cluster
Only three co-assignee pairs appear in the dataset, and they overlap around the same three names, suggesting a compact team behind several of the foundational filings rather than a broad, distributed set of collaborators.
One 1990s filing still anchors the field
The most-cited record in the corpus is a molecular-pump-integrated flywheel system, cited 78 times — nearly triple the next most-cited filing. That gap suggests foundational architecture claims from this early filing still shape how later applicants frame their own rotor and containment designs.
| Assignee | Recent year | YoY |
|---|---|---|
| HELIX POWER CORP | 0 | — |
| QUANTUM ENERGY STORAGE CORP | 0 | — |
| Boeing | 0 | — |
| St. Augustin Canada Electric Inc. | 0 | — |
| NexFi Technology Inc. | 0 | — |
| STRASIK MICHAEL | 0 | — |
| MITTLEIDER JOHN A | 0 | — |
| HULL JOHN R | 0 | — |
Where to take this analysis
The filing and citation patterns above raise questions that are worth running down before committing to a filing or freedom-to-operate position.
Map the manufacturing-class overlap
Cross-reference which families carry both H02K and the forging/heat-treatment IPCs (B21K, C21D, B21J) to see whether rotor material and rotor manufacturing are being claimed by the same assignees or split across different filers.
Explore in EurekaTrack the founding inventor cluster
The three identified co-assignee pairs share overlapping names; tracing their full filing history clarifies whether the foundational architecture claims are still enforceable or have lapsed.
Explore in EurekaWatch for post-2022 publication catch-up
Because publication lags filing by roughly 18 months, the apparent drop to zero by 2022 may partly reverse as pending applications from 2023-2025 publish; re-run the trend view periodically.
Explore in EurekaCommon questions about flywheel rotor material patents
Patent claims in this space centre on composite rotor construction and high-strength rim materials, with filings drawing on IPC classes for composite layup (B29C70) alongside forging and heat-treatment routes (B21K, B21J, C21D). This mix shows that rotor material claims cover both the composite fibre-wound designs and metal-forged alternatives, rather than one dominant material approach. A freedom-to-operate check should look across both manufacturing routes, not just composite claims.
The dataset shows filings peaking at 7 records in 2017 before falling to zero by the 2022 midpoint, a pattern consistent with an early cluster of foundational filings rather than sustained year-over-year investment. Some of the apparent decline in the most recent years is also a publication-lag artefact, since filings typically take about 18 months to appear in the public record. Even accounting for that lag, the multi-year flat stretch through 2022 suggests reduced new filing activity in this specific niche compared to the mid-2010s.
The United States receives the largest share of filings in this corpus, 29 of 57 records, well ahead of Europe (11), WIPO/PCT filings (9) and Canada (4). China holds only a single receiving-office record in this dataset. Anyone assessing enforcement or freedom-to-operate risk in this technology should prioritise US prosecution and litigation history, then check European filings, before treating China as a lower-priority jurisdiction for this specific niche.
The most-cited record in this dataset is a 1990s filing describing a flywheel energy storage system with an integral molecular pump, cited 78 times — nearly three times the next most-cited filing on an integrated flywheel system. High citation counts in a historical corpus like this typically reflect age and foundational status rather than current commercial dominance, since older records simply have had more time to accumulate references. New entrants should treat these as architecture references to design around, not necessarily as active competitive threats.
Filing density is thin relative to the H02K electromagnetic core in areas like composite-to-hub interface joints, in-situ rotor damage sensing, and vacuum housing integration for containment systems. These branches touch adjacent IPC classes (G01L for force sensing, H10N for solid-state devices) that appear in under 20% of the corpus, compared with the H02K class present in every single family. A first claim in these areas would likely combine a rotor-material limitation with a sensing or interface feature not yet densely claimed together in this dataset.
Research Flywheel Energy Storage Advanced Materials in depth with Eureka
Go past this page: query the whole flywheel energy storage advanced materials corpus yourself, in your own scope.
Every answer comes back with patent numbers you can open.
Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.