Centrifugal Pump Fastening Patents: Leaders & Trends 2026
- 27 families total. a small, tightly scoped corpus rather than a broad pump category — filing here concentrates almost entirely in casing bolting, impeller mounting, welded casing and flange joining.
- Filing peaked in 2019 at 5 and has not returned. the midpoint year (2022) sits at 3, and the trend from 2017 onward is flat to declining, not growing.
- China accounts for 21 of the filings. against 3 each from Japan and the United States, so the active filing geography has shifted decisively toward Chinese receiving offices even though the most-cited prior art is Japanese and American.
A narrow, mechanically specific niche inside pump patents
Centrifugal pump fastening and joining sits at the intersection of two well-worn patent classes: F04D for non-positive-displacement pumps and F16B for fasteners. Almost every record in this dataset carries an F04D classification, confirming that the corpus is built around pump structure rather than generic hardware — the fastening element (bolt, weld, shrink fit, keyway) is claimed as part of how the casing, impeller or shaft is held together, not as a standalone fastener invention.
The rest of the IPC spread is thin: single records touch engine cooling, clutches and brakes, balance testing, material analysis and electric motors, each suggesting a pump fastening claim written in service of an adjacent system rather than a dedicated joining innovation. That thinness is itself informative — this is a corpus where the claim space outside the F04D/F16B core is essentially open.
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Filing trend and technology composition
Two views of the same 27-family corpus: how filing activity has moved year over year, and how those filings distribute across IPC subclasses.
Filing has not grown since the 2019 peak
Filing rose to a peak of 5 families in 2019, fell back, and sat at 3 by the 2022 midpoint. With 2017 and 2026 both showing 0 (2026 is a partial year, and publication typically lags filing by around 18 months so its true count will rise), the honest read is a flat-to-declining filing curve rather than an emerging technology.
F04D dominates; everything else is residual
F04D appears in all 27 records, confirming the search is anchored correctly on pump structure. F16B (fasteners proper) appears in only 3, and five other subclasses — F01P, F16D, G01M, G01N, H02K — each appear exactly once, marking narrow crossover claims rather than sustained sub-fields.
Shares are the percentage of the 27 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Centrifugal Pump Fastening and Joining with Eureka
This page is one run against one query. Ask Eureka your own question about centrifugal pump fastening and joining and every answer comes back with the patent numbers behind it.
Try EurekaThe prior art anchoring this space
US4688987A — Split impeller centrifugal pump
A centrifugal pump having a split impeller which is directly mounted to an existing drive shaft and which is enclosed within a housing which is mounted in surrounding, spaced and non-contacting relationship with respect to the impeller and drive shaft so as to form annular fluid inlet openings between the housing and drive shaft through which fluids are directed by the impeller to an outlet from the housing.Filed by Wallace W. Ericson, granted 1987-08-25 — one of the two most-cited records in this corpus, alongside US20030059293A1, each cited 19 times.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20030059293A1 | Centrifugal pump | 19 |
| 2 | US4688987A | Split impeller centrifugal pump | 19 |
| 3 | US4890982A | Pump impeller and rotor shaft attachment construction | 11 |
| 4 | JP2011140954A | Horizontal shaft centrifugal pump | 3 |
| 5 | CN213205990U | 一种真空水泵叶轮安装结构 | 2 |
| 6 | JP1985134897U | The pump impeller of the slip-out preventing device | 2 |
| 7 | CN114439770A | 一种紧凑型船用水炮增压离心泵 | 1 |
| 8 | CN209818308U | 一种自吸式输油离心泵 | 1 |
| 9 | CN209800348U | 一种离心泵叶轮安装固定装置 | 1 |
| 10 | CN202732498U | 大型离心泵叶轮拆装平台 | 1 |
Citation counts reflect influence within the searched corpus and skew toward older filings; they are not a measure of current commercial relevance.
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 filing strategy
Three findings that shape where a new filing would land and how defensible it would be.
Activity peaked and has not recovered
The single peak year, 2019, produced 5 families; by the midpoint of 2022 filing had already dropped to 3, and the most recent completed years show no rebound. Applied over an 18-month publication lag, this reads as a mature, low-churn niche rather than one still being actively contested.
Filing activity has concentrated in China
China now accounts for the large majority of receiving-office filings, while Japan and the United States each hold a small, static share. That split does not match the citation record, where the most-cited prior art is Japanese and American — a sign that the foundational mechanical concepts were established elsewhere before Chinese filers began working the same claim space.
The corpus is correctly anchored, and thin outside its core
Every record touches F04D, but only 3 also carry F16B, and five further subclasses appear just once each. That pattern says the fastening and joining claim space is being worked almost exclusively as an extension of pump design, with very little cross-pollination from dedicated fastener, motor or testing patent families.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to centrifugal pump fastening and joining, with the prior art for and against each one.
Who is filing, and where the field is still open
The assignee list is a long tail: no single filer shows sustained latest-year momentum, and several show 0 filings in the most recent year, consistent with the flat overall trend.
A dispersed field with no dominant filer
Recent-year momentum data shows multiple assignees — including Furukawa Metals & Machinery Co., Ltd. and several Chinese pump and fitting manufacturers — sitting at 0 filings in the latest year, one with a -100% YoY drop. This is a fragmented corpus of small, often single-family filers rather than a market led by one or two large portfolios.
China-based filers now drive volume
With Chinese receiving-office filings outnumbering Japan and the US combined by a wide margin, most new activity in casing bolting and impeller mounting claims is coming from Chinese manufacturers and research institutes, even as the most historically influential patents remain Japanese and American.
Influence sits with a handful of older US filings
The two most-cited records in the corpus, both cited 19 times, are US filings from the 1980s and early 2000s. Newer entrants are filing into a space where the foundational mechanical concepts — split impellers, shaft attachment — were already claimed decades ago, which narrows the room for a broad structural claim.
| Assignee | Recent year | YoY |
|---|---|---|
| Furukawa Metals & Machinery Co., Ltd. | 0 | — |
| Qingdao Runwei Huaneng Technology Co., Ltd. | 0 | — |
| Shaanxi Aerospace Power Hi-Tech Co., Ltd. | 0 | — |
| Yingkou Jingyi Metal Products Co., Ltd. | 0 | — |
| Huai'an Pachun Huaxin Plastic Products Co., Ltd. | 0 | -100% |
| Zhejiang Shoufei Pump Industry Co., Ltd. | 0 | — |
| Zhejiang Sci-Tech University | 0 | -100% |
| Jiangsu Leike Machinery Co., Ltd. | 0 | — |
Where to take this next
The dataset points to specific follow-up work rather than a single conclusion.
Check freedom-to-operate on the under-claimed branches
Shrink-fit attachment, welded seam design and split-impeller keyway variants show thin coverage in this corpus. Before assuming that means open space, run a targeted freedom-to-operate search on each branch specifically — thin coverage in a 27-family topical corpus is not the same as thin coverage globally.
Explore in EurekaMap the citation chain behind the two most-cited US patents
US4688987A and US20030059293A1 each carry 19 citations and anchor much of what followed. Tracing who cites them, and what those citing claims add or narrow, clarifies exactly how much room remains around impeller mounting and casing attachment.
Explore in EurekaCommon questions on centrifugal pump fastening patents
Not currently. The filing trend in this dataset peaked at 5 families in 2019 and had fallen to 3 by the 2022 midpoint, with no rebound in later completed years. Because publication lags filing by roughly 18 months, the most recent year is always undercounted, but even allowing for that the overall shape is flat to declining rather than growing. Anyone evaluating this space should treat it as a mature niche, not an emerging one.
The assignee base is a long tail of small filers rather than a market led by one or two dominant portfolios. Recent-year momentum data shows several assignees, including Furukawa Metals & Machinery and multiple Chinese pump manufacturers, at zero filings in the latest year. No single organisation in this 27-family corpus shows sustained year-over-year growth.
China, by a wide margin: 21 of the 27 records in this corpus came through Chinese receiving offices, compared with 3 each from Japan and the United States. That said, the most historically influential prior art — the two records cited 19 times each — are Japanese and American filings, so the geography of current volume and the geography of foundational IP are not the same.
US4688987A claims a centrifugal pump with a split impeller mounted directly on an existing drive shaft, enclosed in a housing held in spaced, non-contacting relationship to the impeller and shaft so as to form annular fluid inlet openings. It is one of the two most-cited records in this corpus, so any design using a split impeller mounted directly to a shaft with that non-contacting annular-inlet housing arrangement should be checked against it specifically. It does not block impeller attachment methods that avoid a split impeller or that use a contacting, sealed housing geometry.
The IPC composition shows the corpus is almost entirely F04D with only a thin F16B fastener overlay, and five other subclasses — including motor and testing classes — appear just once each. That points to under-claimed branches such as shrink-fit shaft attachment, welded casing seam design, and split-impeller keyway variants, none of which show dense coverage in this 27-family set. These are starting points for a freedom-to-operate search, not confirmed open space.
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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.