Hydraulic Actuator Bearing Patents: Who Leads, Trends 2026
- Filing has cooled since a 2019 peak of 14. the midpoint year 2022 sits at 7, and the most recent full year is well below peak — this is a maturing claim space, not a growing one.
- F15B fluid-pressure actuator claims dominate at 157 records. against just 28 in F16C bearings and 18 in F16N lubrication systems, so the crowding is concentrated in the actuator body, not the tribological interface.
- China receives more than three times the filings of any single other office. 62 versus 36 in the United States and 19 in Japan, reshaping where freedom-to-operate risk actually sits.
Filing growth compares 2021 (7 records) with 2024 (3) — 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 197 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This landscape tracks 197 patent families filed between 2017 and mid-2026 that combine hydraulic actuator, hydraulic cylinder or servo-hydraulic terminology with tribology-specific language — seal wear, friction reduction, lubrication — under IPC classes covering fluid-pressure actuators, seals and gaskets, and bearings. The scope deliberately excludes general hydraulic system patents that do not address wear or lubrication directly, so the count reflects tribological engineering intent rather than hydraulic actuator patenting broadly.
Because publication typically lags filing by around 18 months, the last one to two years in any trend understate real filing activity; treat the tail of the chart as a floor, not a ceiling. The IPC split below shows where claim density actually sits — overwhelmingly in the actuator body and seal hardware, not in the bearing or lubrication subclasses that govern long-term wear performance.
Filing trend and technology composition
Two views of the same 197 families: how filing volume has moved year on year, and how those filings distribute across the mechanical subsystems they claim.
Filing trend, 2017-2026
Filings rose to a peak of 14 in 2019, held near the 2022 midpoint of 7, and have declined since — a flat-to-declining pattern rather than sustained growth, though the final year or two is likely undercounted due to publication lag.
IPC subclass distribution
F15B (fluid-pressure actuators) accounts for 157 of the records, roughly three times the combined total of F16J seals and F16C bearings. Smaller counts in F16N lubrication, E21D mine support, F16H gearing, B64C aerospace and C22C alloys mark adjacent application areas where tribological claims are comparatively rare.
Shares are the percentage of the 197 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Hydraulic Actuator Bearing and Tribology with Eureka
This page is one run against one query. Ask Eureka your own question about hydraulic actuator bearing and tribology and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited prior art and a representative filing
EP1270958B1 — Hydraulikzylinder (Hydraulic cylinder)
Filed by Kayaba Kogyo Kabushiki Kaisha, this cylinder claims a head member combining a sliding bearing against the rod body's outer circumference with an integrated dust seal and a defined lubrication path — a compact solution to the wear-and-contamination pairing at the rod/head interface.Granted 2007-05-09; still an active reference point for rod-seal-bearing integration claims.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20050132877A1 | Redundant flow control for hydraulic actuator systems | 48 |
| 2 | US4936197A | Dynamic seal construction | 47 |
| 3 | US5713578A | Hydraulic sealing device | 41 |
| 4 | US7121185B2 | Hydraulic cylinder having a snubbing valve | 40 |
| 5 | US3559540A | Hydraulic actuator | 37 |
| 6 | US7120523B2 | Hydraulic cylinder life prediction | 35 |
| 7 | JP2000009106A | Rod seal structure of hydraulic cylinder | 33 |
| 8 | JP2005337440A | Sealing structure and sealing structure of hydraulic cylinder | 30 |
| 9 | US6981439B2 | Redundant flow control for hydraulic actuator systems | 30 |
| 10 | US20060022412A1 | Two component seal | 22 |
Citation counts accumulate over time and favour older filings; read them as markers of foundational influence rather than 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 data tells you
Three findings that shape where to file, what to watch, and what the current filing pattern actually means for freedom to operate.
This is a cooling field, not a growing one
Filing peaked at 14 in 2019 and the 2022 midpoint sits at 7. Recent-year momentum across the tracked assignees shows zero new filings in the latest year for every one of the leading names, consistent with a claim space that has plateaued rather than one still being actively staked out.
Density sits in the actuator body, not the wear interface
F15B claims outnumber F16C bearing claims by more than five to one. Tribology-specific engineering — bearing materials, lubrication pathways — is claimed far less densely than the actuator systems that house it, which is where the open space actually is.
China is now the primary receiving office
China accounts for nearly a third of all records in this set, more than the United States and Japan combined. Any freedom-to-operate check that stops at US and European offices will miss the largest single cluster of filings.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to hydraulic actuator bearing and tribology, with the prior art for and against each one.
Who is filing, and where the field is open
The assignee list is a long tail rather than a single dominant player, with collaboration between named entities rare — only six co-assignee pairs appear across the full set.
Collaboration is the exception, not the norm
Most families in this set carry a single named assignee. The handful of co-assignee pairs that do appear are concentrated around specific mining and construction-equipment relationships, suggesting joint filing is driven by supplier partnerships rather than broad industry norms.
Even the most active filers have gone quiet recently
Every one of the leading named assignees shows zero filings in the most recent tracked year. Combined with the overall filing decline since 2019, this points to a field where established players are maintaining existing positions rather than expanding claim coverage.
Filing strategy is regionally concentrated
China, the United States and Japan together account for the large majority of filings, with Europe, the UK and India as secondary offices. A company weighing where to seek protection should treat China as a primary jurisdiction, not a defensive afterthought.
| Assignee | Recent year | YoY |
|---|---|---|
| KYB Corporation | 0 | — |
| Atgeirr Oy | 0 | — |
| Sulzer South Africa (Pty) Ltd. | 0 | — |
| Akashi Gokin Co., Ltd. | 0 | — |
| Xuzhou University of Technology | 0 | — |
| Clark Equipment Company | 0 | — |
| HR Textron Inc. | 0 | — |
| DBT DEUT BERGBAU TECH GMBH | 0 | — |
Where to take this analysis
This landscape is a starting point for a filing decision, not a substitute for one. The next steps depend on whether you are clearing a design or planning where to file.
Run a freedom-to-operate check on the most-cited records
The five most-cited patents in this set, including the rod-seal-bearing integration claims in EP1270958B1, are the ones most likely to constrain a new design. Check claim scope against your specific mechanism before committing to a bearing or seal architecture.
Explore citing art in EurekaModel the white-space branches against your own roadmap
Bearing alloy selection, lubrication pathway design and wear-detection claims all show lower filing density than the core actuator and seal subclasses. Test whether your planned claims sit inside that lighter-claimed space before drafting.
Map white space in EurekaTrack assignee momentum before assuming the field is settled
Zero recent-year filings across the leading assignees does not mean no one is working on this — it may mean filings are pending publication. Set up ongoing monitoring rather than relying on a single snapshot.
Set up monitoring in EurekaCommon questions about hydraulic actuator bearing and tribology patents
This landscape identifies 197 patent families filed between 2017 and mid-2026 that combine hydraulic actuator or cylinder terminology with tribology-specific language such as seal wear, friction reduction or lubrication, under IPC classes covering fluid-pressure actuators, seals and bearings. That is a narrower scope than hydraulic actuator patents in general, since it excludes filings that do not address wear or lubrication directly. The true current total is likely somewhat higher because publication typically lags filing by around 18 months.
Filing peaked at 14 records in 2019, held near a midpoint of 7 in 2022, and has declined since, with the most recent tracked year showing zero new filings across the leading assignees. This is a flat-to-declining pattern rather than sustained growth. The final one to two years in any trend of this kind are always undercounted due to publication lag, so the true recent trajectory is somewhat less steep than it appears.
The actuator body itself is by far the most heavily claimed, with 157 of 197 records falling under F15B fluid-pressure actuators. Seal and gasket claims under F16J follow at 51, and bearing-specific claims under F16C trail further at 28. Lubrication system claims under F16N are lower still at 18, meaning the tribological interface — where wear actually happens — is claimed less densely than the actuator system around it.
China is the leading receiving office in this dataset with 62 filings, well ahead of the United States at 36 and Japan at 19. Europe, the UK and India follow as secondary offices. Any competitive or freedom-to-operate review limited to US and European patent offices would miss the largest single cluster of activity in this field.
EP1270958B1, assigned to Kayaba Kogyo Kabushiki Kaisha, claims a hydraulic cylinder head member that integrates a sliding bearing against the rod body with a dust seal and a defined lubrication path in a single component. It does not block hydraulic cylinders generally, but it is a relevant reference for any design that combines bearing, seal and lubrication function at the rod/head interface in a similar arrangement. Anyone designing in that specific area should check the granted claim scope directly rather than relying on the abstract alone, since integration-style claims like this one tend to be drafted broadly around the physical arrangement rather than a specific material or dimension.
Research Hydraulic Actuator Bearing and Tribology in depth with Eureka
Go past this page: query the whole hydraulic actuator bearing and tribology 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.