Chain and Belt Power Transmission Patents: Leaders & Trends 2026
- Filings have cooled since 2018. the peak year (42 families) has given way to a flat-to-declining trend through the 2022 midpoint of 21, well before the 2026 data cut-off understates the last year or two of filings.
- Claim density concentrates in gearing, not just belts. F16H gearing & transmissions accounts for 1,477 of 1,619 records, nearly five times the dedicated F16G belts-and-chains class, meaning tensioner and drive claims are more often filed as transmission subsystems than as standalone belt art.
- The most-cited prior art is decades old. the top five most-cited records include a 1979 sprocket patent cited 226 times and a 1985 tensioner patent cited 168 times, both still anchoring freedom-to-operate analysis today.
Filing growth compares 2021 (22 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 1,619 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This landscape tracks patent families filed against chain drives, belt drive transmissions and timing belts, filtered to claims addressing wear elongation, tensioning, noise, efficiency and service life under IPC classes F16G, F16G13 and F16H7. The corpus spans 1,619 published families from 2015 through the 2026 cut-off, giving a view of how tensioner, sprocket and drive-belt claim space has filled in over a full product-development cycle.
Because publication lags filing by roughly eighteen months, the most recent one to two years in any trend line are structurally undercounted; treat the tail of the filing curve as a floor, not a ceiling. Patent families, not raw document counts, are used for assignee ranking so that multi-jurisdiction filing and continuations do not inflate any single player's apparent footprint.
Filing trends and technology composition
Annual filing counts and IPC composition show where chain and belt transmission claim activity actually sits, and how that has shifted since 2017.
A flat-to-declining filing curve since 2018
Filings ran at 38 in 2017 and peaked at 42 in 2018. By the 2022 midpoint the annual count had fallen to 21, and it stays flat or declines from there through the partial 2026 figure. That pattern is consistent with a mature, well-occupied claim space rather than an emerging one — new entrants are filing into art that has already been staked out, not opening new ground.
Gearing dominates the classification mix
F16H (gearing & transmissions) covers 1,477 of the 1,619 records, dwarfing the 311 filed under the dedicated F16G belts-and-chains class. Adjacent activity in F02B (internal-combustion engines, 269) and F01L (valve gear, 136) confirms that a large share of this art is filed in the context of engine timing-drive systems rather than as general power-transmission hardware. Smaller pockets in G03G (34), F16F (31), F16D (28) and B29D (27) mark narrower application niches — photocopier drive belts, damping springs, clutch integration and belt moulding — that sit outside the main engine-timing cluster.
Shares are the percentage of the 1,619 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Chain and Belt Power Transmission with Eureka
This page is one run against one query. Ask Eureka your own question about chain and belt power transmission and every answer comes back with the patent numbers behind it.
Try EurekaThe prior art still shaping freedom-to-operate
Chain Drive Tensioner System with Translating Pivot Point (US20100022336A1)
The application describes a chain drive tensioner assembly moveable between two tensioner positions, paired with a tensioner arm that carries an internal gear and a rotatably mounted external gear whose concurrent rotation shifts the pivot point as the assembly moves. That translating-pivot mechanism is offered as a way to manage chain slack across the tensioner's range of travel rather than relying on a fixed pivot.Filed by GM Global Technology Operations, this record illustrates how automotive engine-timing tensioner claims layer geometric mechanisms — here, a moving pivot via paired internal/external gears — onto the tensioning function that dominates this landscape's most-cited art.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4174642A | Chain drive including sprocket having alternate wide and narrow teeth | 226 |
| 2 | US4583962A | Timing belt tensioner with damped constant spring tensioning and belt tooth disegagement prevention | 168 |
| 3 | US4822322A | Tensioning device for timing belt or chain in automotive engine applications | 117 |
| 4 | US5919107A | Belt tensioner for motor vehicle | 114 |
| 5 | US6375588B1 | Tensioner with viscous coupled one way wrap spring anti-kickback clutch | 105 |
| 6 | US4917655A | Self adjusting timing belt tensioner | 105 |
| 7 | US3377875A | Chain drive power transmitting mechanism | 103 |
| 8 | US3888217A | Camshaft belt drive for variable valve timing | 101 |
| 9 | US4867733A | Chain drive system | 97 |
| 10 | US6422962B1 | Timing belt tensioner with a backstop device with controlled one-way mechanism | 92 |
Citation counts reflect influence within this searched corpus and skew toward older filings; they are not a measure of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns matter more than the raw counts: where claim density sits, how old the controlling art is, and how filing pace has moved.
Gearing subclass carries the bulk of the art
Nearly all activity in this dataset is classified under gearing and transmissions rather than the dedicated belts-and-chains class. A filer targeting belt or chain hardware in isolation is still likely to run into F16H-classified prior art, because most applicants describe tensioners and drives as transmission subsystems.
Activity has roughly halved since the 2018 peak
The filing count fell from a 2018 peak of 42 to 21 by 2022 and stays flat or declining from there, before the usual publication lag further understates the final years. That trajectory points to a claim space where the core mechanisms are largely staked out rather than one still expanding.
The most influential patents predate the current filing wave
The most-cited record in the corpus is a sprocket-tooth patent cited 226 times, followed by tensioner patents cited 168, 117, 114 and 105 times. All are legacy filings that continue to anchor citation chains for tensioner and sprocket geometry claims filed decades later.
Filing activity spreads across five major offices
The United States leads with 358 filings, followed by Japan (321), South Korea (193), the EPO (170) and China (158), with 86 routed through the WIPO PCT system. That spread means credible freedom-to-operate work in this space has to clear at least four jurisdictions, not one.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to chain and belt power transmission, with the prior art for and against each one.
Who holds the ground, and where the gate sits
Recent-year momentum shows the leading historical filers with zero filings in the latest year, consistent with a maturing claim space and a filing curve already in decline.
Historical leaders have gone quiet in the most recent year
Assignees including Tsubakimoto Chain, Hyundai Motor, BorgWarner, Litens Automotive, Cloyes Gear and IWIS Motorsysteme all show zero filings in the latest recorded year in this dataset. Given the publication lag, this likely overstates the slowdown, but it is consistent with the broader flat-to-declining filing trend since 2018.
Collaboration is limited and mostly OEM-to-OEM
The strongest co-assignee link pairs Cloyes Gear Products with an individual inventor across six shared filings; Hyundai Motor and Kia Motors share five. BorgWarner's pairing with an individual inventor appears three times. These are narrow, name-specific collaborations rather than a broad cross-licensing network.
Tensioner mechanics dominate the most-cited prior art
Four of the five most-cited records in the corpus claim tensioning mechanisms — spring-damped, viscous-coupled and one-way-clutch designs — rather than sprocket or belt-tooth geometry. Any new tensioner filing should expect prior-art searches to surface this cluster first.
| Assignee | Recent year | YoY |
|---|---|---|
| Tsubakimoto Chain Co. | 0 | — |
| Hyundai Motor Company | 0 | — |
| BorgWarner Inc. | 0 | — |
| Litens Automotive Partnership (Canada) | 0 | — |
| Cloyes Gear and Products, Inc. | 0 | — |
| IWIS Motorsysteme GmbH & Co. KG | 0 | — |
| Honda Motor Co., Ltd. | 0 | — |
| NTN Corporation | 0 | — |
Where to take this analysis
The filing trend and the assignee picture both point to a mature space; the open questions are about where thin coverage remains and how to design around the controlling tensioner art.
Map the white space in detail
Run the under-claimed branches above against a fresh full-text search to confirm how thin coverage actually is before committing engineering time to a filing there.
Explore white space in EurekaBuild a design-around for the tensioner cluster
The most-cited patents concentrate on spring-damped and viscous-coupled tensioning; a claim strategy needs to identify which mechanical approach sits outside that cluster.
Analyse claims in EurekaCommon questions about this landscape
The dataset's assignee ranking is led by automotive OEMs and dedicated drive-component makers including Tsubakimoto Chain, Hyundai Motor, BorgWarner, Litens Automotive, Cloyes Gear and IWIS Motorsysteme. All of these show zero filings in the latest recorded year, which reflects both the broader flat-to-declining filing trend since the 2018 peak and the roughly 18-month publication lag that understates the most recent years. Anyone evaluating competitive position in this space should treat the ranking as a picture of accumulated claim ownership rather than of who is filing fastest today.
Filings peaked at 42 in 2018, fell to 21 by 2022, and have stayed flat or declining since, though the final one to two years are always undercounted because publication lags filing by about 18 months. A declining count in a corpus this size usually signals that the core mechanisms — tensioning, sprocket geometry, belt-tooth profiles — are already well claimed, so new filings increasingly have to differentiate around the edges rather than stake fresh ground. It does not mean the underlying technology has stopped mattering commercially; chain and belt drives remain standard automotive hardware.
The core classes are F16G (belts, chains and cables) and F16H7 (gearing and transmissions involving flexible members), with this dataset's 1,619 records classified predominantly under F16H — 1,477 records versus 311 under F16G. Adjacent classes F02B (internal-combustion engines) and F01L (valve gear) appear heavily too, because a large share of chain and belt drive patents are filed in the context of engine timing systems. Smaller clusters sit in G03G, F16F, F16D and B29D, covering niche applications like photocopier belts and belt moulding processes.
US20100022336A1, filed by GM Global Technology Operations, claims a chain drive tensioner assembly that moves between two tensioner positions via a tensioner arm carrying paired internal and external gears, where the external gear's rotation shifts the pivot point as the arm moves. That specific mechanism — a translating pivot achieved through concurrent gear rotation — is what the claims cover, not tensioning generally. A design that tensions the chain through a fixed pivot, a different linkage, or a non-geared displacement mechanism sits outside this particular claim scope, though it may still run into the older, more heavily cited tensioner patents in this corpus.
The United States leads with 358 filings in this dataset, followed by Japan (321), South Korea (193), the European Patent Office (170) and China (158), with a further 86 filed through the WIPO PCT route. No single office holds a majority, so a freedom-to-operate review limited to one or two jurisdictions will miss a meaningful share of the controlling art. The concentration across US, Japan and Korea in particular reflects where the major automotive and drive-component manufacturers in this space are headquartered.
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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.