Turbine Tip Clearance Patents: Who Leads, Where Gaps Are 2026
- 65.6% of all 961 records sit with just five assignees, so most of the claim space around blade tip clearance and sealing is already staked out by a small group of engine OEMs and coating specialists.
- Filing fell 38% from 2021 to 2024 (24 to 15 records), the last span the dataset treats as complete once publication lag is accounted for.
- F01D carries 78.6% of records but coating deposition (C23C, 6.6%) and dimensional measurement (G01B, 4.3%) are comparatively thin, pointing to where claim space is still open.
Filing growth compares 2021 (24 records) with 2024 (15) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 961 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Turbine tip clearance and sealing technology governs how tightly a rotating blade can run against its casing without rubbing, and what happens to that gap as the casing heats, cools and grows through a duty cycle. The search underlying this page pulls together blade tip clearance, abradable coatings and squealer tips against the control and sealing hardware that manages them: active clearance control, casing thermal growth, tip leakage vortex behaviour, brush seals, honeycomb seals and rub incursion. That combination captures both the mechanical hardware and the control logic used to hold clearance tight across the flight or duty envelope.
The scope spans 961 published records filed between 2015 and mid-2026, with the most recent year necessarily partial since publication typically lags filing by around 18 months. Records are drawn from six receiving offices, led by the United States and the European Patent Office, giving a reasonably global view of where this technology is being protected rather than just where it is invented.
Let an AI agent run this analysis on your own technology
Pick a task. Every answer cites the patents behind it.
Filing trend and technology composition
Two views of the same 961 records: how filing activity has moved year over year, and which IPC subclasses carry the underlying claims.
Filing activity, 2017-2026
Filings rose to a peak of 59 in 2019, then eased back; the 2021-to-2024 span shows a 38% decline (24 to 15 records), the most recent period the dataset treats as complete. Later years understate true filing activity because publication has not yet caught up.
Technology composition by IPC subclass
F01D (turbines and non-positive engines) touches 78.6% of the 961 records, confirming this is fundamentally a turbine-hardware field. Gas-turbine plants (F02C, 20.6%) and pump machinery (F04D, 13.1%) are the next-largest overlaps, while seals and gaskets (F16J, 7.7%) and coating deposition (C23C, 6.6%) sit further down — a record can carry more than one class, so these shares do not sum to 100%.
Shares are the percentage of the 961 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Turbine Tip Clearance and Sealing with Eureka
This page is one run against one query. Ask Eureka your own question about turbine tip clearance and sealing and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records in this landscape
US7891938B2 — Multi sensor clearance probe
A multi sensor clearance probe with at least longitudinally and transversely spaced apart first and second sensors operable to measure first and second distances respectively between the sensors and a longitudinally spaced apart rotating rotor. The sensors measure blade tip clearances between radially outer turbine blade tips and an annular stator shroud circumscribing the blade tips, including squealer tip configurations, and the probe connects to a controller for signal reporting.Filed by General Electric Company, granted 2011-02-22.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US7219490B2 | Nested core gas turbine engine | 216 |
| 2 | US20080053107A1 | Slidable spring-loaded transition-to-turbine seal apparatus and heat-shielding system, comprising the seal, a… | 145 |
| 3 | US20080112798A1 | Compound clearance control engine | 131 |
| 4 | US6273671B1 | Blade clearance control for turbomachinery | 125 |
| 5 | US4571935A | Process for steam cooling a power turbine | 121 |
| 6 | US5562408A | Isolated turbine shroud | 113 |
| 7 | US4326804A | Apparatus and method for optical clearance determination | 111 |
| 8 | US5879753A | Thermal spray coating process for rotor blade tips using a rotatable holding fixture | 106 |
| 9 | US5641267A | Controlled leakage shroud panel | 104 |
| 10 | US4781388A | Brush seal | 102 |
Citation counts favour older records inside any searched corpus; treat them as a signal of past influence on subsequent filings, 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 data that matter for deciding where to file, who to watch, and where claim space is genuinely open.
The field is concentrated at the top
The top five assignees account for 630 of the 961 records in scope, a level of concentration that means most core clearance-control and abradable-coating claims are already occupied by established engine OEMs and coating suppliers. The leader alone holds 287 records, well ahead of fifth place at 21.
Activity has cooled from its 2019 peak
Filings peaked at 59 in 2019 and had fallen to 15 by 2024, a 38% decline from the 24 filed in 2021. That is the most recent span the dataset can treat as complete; 2025 and 2026 figures will rise as publications catch up.
Core turbine hardware dominates the classification mix
Nearly four in five records touch F01D (turbines and non-positive engines), while adjacent classes like coating deposition and dimensional measurement appear in a smaller minority of records, suggesting sensing and coating-process claims are comparatively less crowded than the mechanical hardware itself.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to turbine tip clearance and sealing, with the prior art for and against each one.
Who holds the claim space
A small group of engine manufacturers and coating specialists account for most of the filing volume, with a long tail of single- and few-filing entrants behind them.
One assignee sits well clear of the field
The leading assignee holds 287 of the 961 records in scope, more than ten times the count at fifth place (21), reflecting a long-running programme of clearance-control and sealing filings rather than a recent surge.
Ten assignees hold three-quarters of the field
The ranked leaders' top 10 combine for 719 of the 961 records, or 74.8% of everything in scope. That leaves roughly a quarter of records spread across a long tail of smaller filers, including forge and casting specialists alongside the major OEMs.
Filing is mostly solo, with a few tight OEM-subsidiary pairs
Only 10 co-assignee pairs appear in the dataset, and the strongest links are between an OEM and its own regional subsidiaries rather than cross-company joint filings, suggesting collaboration here happens inside corporate structures more than across competitors.
| Assignee | Recent year | YoY |
|---|---|---|
| General Electric Company | 2 | -50% |
| Raytheon Technologies Corporation | 2 | -50% |
| United Technologies Corporation | 0 | — |
| Rolls-Royce plc | 0 | — |
| Siemens AG | 0 | — |
| Sulzer Metco (US) Inc. | 0 | — |
| Rolls-Royce plc | 0 | — |
| CARLTON FORGE WORKS | 0 | — |
Where to take this analysis
The dataset points to a field where core mechanical claims are largely staked out but sensing, coating-process and measurement sub-areas remain comparatively open.
Map freedom-to-operate against the top holders
With 65.6% of records held by five assignees, a freedom-to-operate check should start with those portfolios before broader prior-art searching, especially around active clearance control and casing thermal growth claims.
Explore assignee portfolios in EurekaTrack the under-claimed sub-areas
Coating deposition, dimensional measurement and brush/honeycomb seal wear sit at lower record shares than the core turbine-hardware classes, which is where new claims are more likely to clear prior art cleanly.
Run a white-space search in EurekaCommon questions on this landscape
One assignee leads clearly with 287 of the 961 records in scope, well ahead of the fifth-place holder at 21. The top five assignees combined hold 65.6% of all records, and the top ten hold 74.8%, so this is a field where a small number of engine OEMs and coating specialists control most of the claim space. A newcomer should expect to design around, or license from, one of these established portfolios rather than file into open ground on the core mechanical concepts.
Filings peaked at 59 records in 2019 and had fallen to 15 by 2024, down 38% from the 24 filed in 2021. That 2021-to-2024 window is the most recent period the dataset can treat as complete, since publication typically lags actual filing by about 18 months. Figures for 2025 and 2026 will rise as those publications catch up, so the apparent recent drop should not be read as the field going quiet.
An abradable coating is a sacrificial layer applied to the casing or shroud that wears away preferentially when a blade tip rubs against it, protecting the blade and controlling the running clearance. A squealer tip is a thin-walled feature machined into the blade tip itself, often with internal cavities, that reduces the contact area and tip leakage vortex losses during any rub incursion. Both approaches appear throughout this dataset, frequently in the same records, because engine designs commonly combine a squealer-tip blade with an abradable casing coating to manage clearance and leakage together.
F01D, covering turbines and non-positive-displacement engines generally, appears in 78.6% of the 961 records in scope, making it by far the dominant classification. Gas-turbine plants (F02C) and non-positive-displacement pumps (F04D) follow at 20.6% and 13.1% respectively, reflecting how tip-clearance technology carries across turbine and compressor applications. Coating and surface deposition (C23C) and dimensional measurement (G01B) appear in noticeably smaller shares of records, which is a useful signal for where claim density is lighter.
Relative to the core mechanical hardware classes, coating deposition processes, tip clearance sensing and measurement, and honeycomb or brush seal wear mechanisms all carry noticeably smaller shares of the 961 records than the dominant turbine-hardware classes. That does not mean these areas are unpatented, but filing density is thinner, which typically means less crowded prior art for a well-drafted claim. Aircraft-specific integration of active clearance control systems is another comparatively thin branch worth checking before assuming it is blocked.
Research Turbine Tip Clearance and Sealing in depth with Eureka
Go past this page: query the whole turbine tip clearance and sealing 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.