Centrifugal Fan Aerodynamic Optimization Patents: Leaders & Trends 2026
- Concentration is moderate, not extreme. the top 5 assignees hold 50.0% of all 38 records in scope, and the top 10 hold 76.3% — a leader plus a real second tier, not a single dominant filer.
- Filing has cooled from its 2018 peak. 2021 filings of 3 fell to 1 by 2024, a -67% move over that span, though 2025-2026 counts are still filling in under publication lag.
- China now outpaces the US at the receiving-office level. 19 China filings versus 12 US filings, with Europe, the UK and Japan each in single digits.
Filing growth compares 2021 (3 records) with 2024 (1) — 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 38 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Centrifugal fan aerodynamic optimization spans the design choices that determine how efficiently a fan converts shaft power into airflow at pressure: backward-curved blade geometry, blade sweep, inlet cone clearance, scroll cutoff placement, and the flow-separation behaviour that governs static efficiency and specific fan power. These are incremental-improvement claims layered onto a mature machine type, filed by HVAC OEMs, appliance makers, and university labs working on computational fluid dynamics-driven blade profiles.
The 38 records in scope run from 2015 through the 2026-07-31 cut-off, concentrated in F04D (non-positive-displacement pumps) with secondary overlap into turbine and hydraulic-machine classifications where blade and casing geometry principles transfer.
Filing trend and technology composition
Two views of the same 38-record dataset: how filing activity has moved year over year, and how records distribute across IPC subclasses.
Filing trend, 2017-2026
Filings peaked at 3 in 2018 and have since run lower, with 2021 at 3 falling to 1 by 2024 (-67%). Treat 2025 and 2026 as undercounted: publication typically lags filing by around 18 months, so the most recent years always look thinner than they will eventually be.
IPC subclass composition
Every record in scope carries an F04D classification (38 of 38, 100.0%), confirming the search is centred correctly on non-positive-displacement pump/fan machinery. Smaller overlaps into F01D (5 records, 13.2%) and F03B (5 records, 13.2%) reflect blade and flow-path principles shared with turbines and hydraulic machines, and a record can sit in more than one class, so these shares do not sum to 100%.
Shares are the percentage of the 38 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Centrifugal Fan Aerodynamic Optimization with Eureka
This page is one run against one query. Ask Eureka your own question about centrifugal fan aerodynamic optimization and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records and a representative filing
US7001140B2 — Centrifugal fan diffuser
Describes a vaneless diffuser positioned extra-radially of a centrifugal fan that converts velocity pressure into static pressure by decreasing the impelled fluid's tangential velocity as it travels through the diffuser, without recirculating air back into the diffuser. The decrease is achieved by radially extending the interface through which air exits the diffuser into a downstream fluid-handling environment such as a scroll.Filed by Acoustiflo, Ltd.; granted 2006-02-21.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5478201A | Centrifugal fan inlet orifice and impeller assembly | 71 |
| 2 | US20150152875A1 | Air blower | 41 |
| 3 | US7246997B2 | Integrated high efficiency blower apparatus for HVAC systems | 41 |
| 4 | US3363832A | Fans | 32 |
| 5 | US20130323098A1 | Axial flow blower | 31 |
| 6 | US7001140B2 | Centrifugal fan diffuser | 18 |
| 7 | US7357621B2 | Centrifugal fan diffuser | 15 |
| 8 | EP0692637A1 | Centrifugal fan inlet orifice and impeller assembly | 13 |
| 9 | GB2114675A | Centrifugal fan impeller | 9 |
| 10 | CN105221479A | 离心风机叶轮、离心风机及空调 | 8 |
Citation counts reflect a searched corpus, not the full literature, and inherently favour older filings that have had more years to accumulate citations. Read them as markers of influence on later drafting, not as a ranking of current commercial importance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for a filing decision
Three read-throughs from the concentration, trend, and geographic data above.
A leader plus a genuine second tier
The top 5 assignees hold half of all 38 records in scope, and the leader alone accounts for 5. That is enough concentration to signal an active core of repeat filers, but the top 10 combined (76.3%) still leaves roughly a quarter of the field to single- or double-filing entrants — this is not a one-company field.
Activity has cooled from its 2018 peak
Filings dropped from 3 in 2021 to 1 in 2024. Combined with a 2018 peak of 3 and no year since exceeding it, the technology reads as a mature, incrementally-claimed space rather than one attracting fresh entrants — though 2025-2026 figures are still incomplete under normal publication lag.
China leads at the receiving-office level
China records 19 filings against 12 for the United States, with Europe, the UK and Japan each in single digits. That split points to where enforcement and freedom-to-operate checks matter most for anyone manufacturing or selling into those markets.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to centrifugal fan aerodynamic optimization, with the prior art for and against each one.
Who is filing, and where the gate sits
The ranked leaders span HVAC majors, appliance manufacturers and university labs — a mix that suggests both commercial defensiveness and academic exploration are active in this field.
A single leader ahead of a closely-packed field
The top-ranked assignee holds 5 of the 38 records in scope, roughly on par with the next several filers rather than dominating outright. Fifth place already sits at 3 records, and tenth place at 2 — the drop-off is gradual, not a cliff.
Co-filing is rare but present
Only 3 co-assignee pairs appear in the dataset, the strongest being a university-manufacturer pairing filing together twice. Most records carry a single assignee, suggesting this remains a field of solo corporate and academic filing rather than joint-venture R&D.
Two primary filing jurisdictions
China and the United States account for the large majority of receiving-office activity, with Europe, the UK, Japan and the WIPO PCT route each drawing only one or two filings. Anyone clearing freedom-to-operate should prioritise those two jurisdictions first.
| Assignee | Recent year | YoY |
|---|---|---|
| Xi'an Jiaotong University | 0 | — |
| ACOUSTIFLO | 0 | — |
| Midea Group Co., Ltd. | 0 | — |
| Carrier Corporation | 0 | — |
| Xi'an University of Technology | 0 | — |
| Gree Electric Appliances, Inc. of Zhuhai | 0 | — |
| General Electric Company | 0 | — |
| Zhejiang Sci-Tech University | 0 | — |
Where to take this next
The dataset points to specific next steps depending on whether you are clearing freedom-to-operate or scoping new claims.
Check freedom-to-operate against the leader's claim set
With the top assignee holding 5 records and citation leaders like US5478201A still active reference points, a claim chart against the leading filer's portfolio is the fastest way to see what is actually blocked before drafting.
Run a freedom-to-operate check in EurekaScope claims in the under-claimed sub-areas
Inlet cone clearance, scroll cutoff positioning and specific fan power reduction show thinner filing density than the core blade-profile claims, suggesting room for a differentiated first claim.
Explore white space in EurekaCommon questions on this landscape
The ranking covers 22 companies across 38 records in scope, with the leading assignee holding 5 records. The top 5 assignees combined hold 50.0% of all records, and the top 10 hold 76.3%, which means there is a genuine second tier of filers rather than one company controlling the field. The mix includes HVAC and appliance manufacturers alongside university research labs, so commercial and academic filing pressure are both present.
Filings peaked at 3 in 2018 and have since declined, with the 2021 count of 3 falling to 1 by 2024 — a -67% drop over that span. Figures for 2025 and 2026 are still incomplete because publication typically lags filing by around 18 months, so the most recent years will fill in somewhat but are unlikely to reverse the broader cooling trend visible since 2018.
China and the United States dominate receiving-office activity, with 19 and 12 filings respectively out of the tracked total. Europe (EPO), the United Kingdom and Japan each show only 2 filings, and the WIPO PCT route shows 1. Anyone manufacturing or selling centrifugal fans with optimized aerodynamic features should prioritise clearance in China and the US first, since that is where the bulk of enforceable rights sit.
US7001140B2, assigned to Acoustiflo, Ltd., claims a vaneless diffuser positioned extra-radially of a centrifugal fan that converts velocity pressure into static pressure by reducing the impelled fluid's tangential velocity as it passes through the diffuser, without recirculating exhaust air back into the diffuser. The mechanism works by radially extending the interface through which air exits into a downstream environment such as a scroll. Anyone designing a diffuser stage that manages tangential velocity recovery in a similar geometric arrangement should review this claim closely before finalising a design.
The technology composition shows near-total concentration in F04D (100.0% of the 38 records), with only secondary, thinner overlap into turbine (F01D, 13.2%) and hydraulic machine (F03B, 13.2%) classifications. Within that core, sub-areas such as inlet cone clearance tuning, scroll cutoff positioning, and specific fan power reduction methods show less filing density than blade-profile claims themselves, suggesting these are more open for a differentiated first claim. A full freedom-to-operate review is still recommended before relying on any apparent gap.
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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.