Planetary Gearbox Fatigue & Micropitting Patent Landscape
The planetary gearbox fatigue and micropitting space is dominated by Japanese automotive OEMs and their transmission suppliers, with Toyota Motor Corporation and Aisin AW holding the top two positions in a moderately concentrated field of 204 patent families. Activity peaked in 2019 and has since eased, signalling a maturing core while adjacent branches in surface finishing, bearings, and electric-drive integration remain comparatively underserved.
Toyota and Aisin lead a Japanese-OEM-heavy field with a narrow tier gap at the top
Toyota Motor Corporation ranks first with 70 patent records, followed closely by Aisin AW Co., Ltd. at 64 and Hyundai Motor Company at 53, establishing a compact leading tier with no single player commanding an overwhelming majority.
The top five filers collectively account for 35% of the hundred largest filers’ combined total, indicating moderate concentration. Below the top three, REM Technology Inc. (44 records) and Pratt & Whitney Canada Corp. (39 records) represent meaningful specialist positions — one focused on surface-finishing process patents, the other on aerospace gas-turbine gearing.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Toyota Motor Corporation | 70 | |
| 2 | Aisin AW Co., Ltd. | 64 | |
| 3 | Hyundai Motor Company | 53 | |
| 4 | REM Technology Inc. | 44 | |
| 5 | PRATT & WHITNEY CANADA CORP | 39 | |
| 6 | OSRO GmbH | 36 | |
| 7 | Sumitomo Heavy Industries, Ltd. | 32 | |
| 8 | Ricoh Co., Ltd. | 21 | |
| 9 | Hitachi Construction Machinery Co., Ltd. | 21 | |
| 10 | JATCO Ltd. | 20 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | Honda Motor Co., Ltd. | 17 | |
| 12 | Enplas Corporation | 16 | |
| 13 | Mazda Motor Corporation | 15 | |
| 14 | NSK Ltd. | 15 | |
| 15 | Nissan Motor Co., Ltd. | 13 | |
| 16 | NTN Corporation | 11 | |
| 17 | JTEKT Corporation | 11 | |
| 18 | SCHAEFFLER TECHNOLOGIES AG & CO KG | 10 | |
| 19 | Subaru Corporation | 10 | |
| 20 | Archer Aviation Inc. | 8 |
The automotive OEMs’ dominance reflects decades of hybrid-drivetrain development, particularly around multi-speed planetary automatic transmissions, while specialists such as REM Technology and OSRO GmbH signal that surface-treatment and finishing routes are a strategically distinct sub-field with its own dedicated filers.
Filing counts for 2024–2026 are subject to publication lag and likely understate recent activity; treat recent-year totals as provisional. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
A 2019 peak followed by easing volume, with gearing patents vastly outnumbering adjacent branches
The annual trend chart reveals a clear peak in 2019 and a subsequent multi-year softening, while the technology-composition chart shows F16H (Gearing & transmissions) as the overwhelmingly dominant branch alongside a long tail of adjacent IPC classes.
Annual filing trend
Filings rose sharply to a peak of 43 records in 2019, then retreated to the low-to-mid twenties range through 2020–2024. The most recent years (2024–2026) are subject to publication lag and should not be read as confirmed decline; the underlying trend from 2020 onward is best described as stabilised at a lower plateau than the 2019 peak.
↗ Hover for values · click a bar to ask EurekaTechnology composition
F16H (Gearing & transmissions) accounts for the large majority of IPC taggings at 789 records, with B60K (Vehicle propulsion & drive) a distant second at 95. Branches including F16C (Shafts, bearings & couplings), B24B (Grinding & polishing), F16D (Clutches & brakes), H02K (Electric motors & generators), and B23F (Gear & thread cutting) each register between 27 and 46 records, confirming that micropitting mitigation is being addressed through both mechanical design and surface-process routes.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
Superfinishing large planetary gear systems
Disclosed herein is a new improved large planetary gear system used on the input stage of wind turbine power generators. This improved planetary gear system reduces or eliminates lubricant debris traditionally generated from the gear teeth, thereby eliminating an initiating source for bearing failure. To achieve these results, some and preferably all of the… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | In-line reversing mechanism | 1,415 |
| 2 | Star gear system with lubrication circuit and lubr… | 997 |
| 3 | Transmission assembly with four planetary gear set… | 514 |
| 4 | Epicyclic gear train integral sun gear coupling de… | 427 |
| 5 | Integral sun gear coupling | 363 |
| 6 | Epicyclic gearbox | 119 |
| 7 | Gear train of automatic transmission for vehicles | 93 |
| 8 | In-wheel motor with high durability | 86 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
What the patent structure means for R&D investment decisions
Four structural reads — maturity, concentration, collaboration, and geography — together define where defensible space exists and where the field is already crowded.
Field is in decline from its 2019 peak
The lifecycle evidence classifies this field as Decline, with annual filings easing back from the 2019 peak of 43 records. Core planetary-gearing design patents appear to be in a harvesting phase for the leading OEMs. New entrants or R&D teams looking for white space should focus on adjacent process and application branches rather than replicating mature gearing architecture claims.
Lifecycle: DeclineModerate concentration with a specialist tier below the OEM leaders
The top five filers hold 35% of the hundred largest filers’ combined total — meaningful but not dominant. Below the automotive OEM cluster, REM Technology Inc. and OSRO GmbH form a specialist surface-treatment tier at 44 and 36 patent records respectively. This two-tier structure means that surface-finishing and process-chemistry routes are contestable by focused entrants without having to match the OEMs’ transmission-design portfolios.
Concentration: ModerateREM Technology–OSRO and Toyota–Aisin are the dominant co-filing pairs
The most active co-filing pair is REM Technology Inc. and OSRO GmbH with 33 joint records, reflecting a deep supplier–partner relationship around isotropic superfinishing for gear fatigue mitigation. Hyundai Motor and Kia form the second pair at 18 records, and Toyota Motor Corporation and Aisin AW follow at 17. These alliances indicate that cross-company co-development is concentrated in surface-treatment and hybrid-drivetrain sub-segments, leaving multi-party collaborations in bearings or wind-turbine gearing comparatively sparse.
Collaboration: ClusteredUS is the primary filing office; Japan and Europe are secondary markets
The United States leads all jurisdictions with 342 patent records, with Japan second at 153 and Europe (EPO) third at 107. China, at 55 records, is notably smaller given its manufacturing scale in both automotive and wind-energy gearboxes — suggesting either a strategic decision by incumbents to under-file there or a gap that local players have not yet fully filled. WIPO (PCT) filings at 18 records indicate selective international prosecution rather than broad global campaigns.
Geography: US-centricGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| REM Technology Inc. | OSRO GmbH | 33 |
| Hyundai Motor Company | Kia Corporation | 18 |
| Toyota Motor Corporation | Aisin AW Co., Ltd. | 17 |
| Toyota Motor Corporation | Toyota Motor Corporation | 12 |
| Aisin AW Co., Ltd. | Toyota Motor Corporation | 8 |
| Toyota Motor Corporation | Aisin Seiki Co., Ltd. | 3 |
| Toyota Motor Corporation | Aisin AW Industries Co., Ltd. | 2 |
| Aisin AW Co., Ltd. | Aisin AW Industries Co., Ltd. | 2 |
| Toyota Motor Corporation | DENSO Corporation | 1 |
| REM Technology Inc. | ORSO LLC LLC | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Toyota and Aisin anchor a gearing-design core; REM Technology defines the surface-treatment flank
The top two players share nearly identical technology profiles concentrated in multi-speed transmission architecture, while REM Technology and OSRO GmbH occupy a distinct niche built entirely on gear-surface finishing processes.
Toyota Motor Corporation
Toyota Motor Corporation holds 70 patent records, the highest in the corpus, concentrated in F16H57 (transmission housings and lubrication, 51 records), F16H3 (multi-stage planetary gear trains, 36 records), and F16H1 (epicyclic gearing, 13 records). Its close co-filing relationships with Aisin AW and Aisin Seiki confirm a vertically integrated development ecosystem for hybrid-drivetrain planetary systems. Momentum data does not flag a notable recent surge, consistent with the field’s post-2019 maturation.
patent records: 70REM Technology Inc.
REM Technology Inc. holds 44 patent records and is the only top-five player whose primary focus lies outside pure gearing design: its portfolio centres on B24B31 (mass finishing and isotropic superfinishing, 39 records) and F16H55 (gear tooth geometry and surface, 39 records), with OSRO GmbH as its principal co-development partner (33 joint records). This surface-treatment specialisation gives REM Technology a differentiated position relative to the OEM-dominated gearing-architecture cluster and makes it the dominant player in micropitting mitigation through post-process surface conditioning.
patent records: 44| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Hyundai Motor Company | 2 | ▲ new entrant |
Under-served branches at the intersection of gearing, surface engineering, and electric drives
Five IPC branches sit adjacent to the dominant F16H core with comparatively low filing density; two stand out for their plausible technical relevance to gear fatigue and micropitting alongside realistic entry paths.
F16C · Shafts, bearings & couplings
With 46 patent records, the F16C branch is sparsely populated relative to the scale of the gearing corpus. Bearing-raceway micropitting is a documented failure mode in planetary carriers and sun-shaft interfaces, yet dedicated bearing-surface fatigue patents appear underrepresented. Teams working on bearing-integrated planetary modules or hybrid ceramic-steel bearing solutions for high-load epicyclic stages could find limited prior art to navigate. Entry is most tractable for bearing specialists with existing F16C portfolios who can extend into planetary-carrier integration.
Search this in Eureka →H02K · Electric motors & generators
The H02K branch registers 32 patent records, reflecting the early-stage integration of electric-motor stages directly into planetary gearboxes for EV and hybrid applications. As integrated motor-gearbox units face compacted gear meshes at higher torque densities, micropitting risk at the ring-gear interface increases, yet the patent landscape here remains thin. The momentum data flags Hyundai Motor and Kia as new entrants in the broader corpus, suggesting OEMs are beginning to address this intersection; the surface-treatment and lubrication sub-problems remain largely unclaimed. Wind-turbine and eVTOL drivetrain developers (Vestas Wind Systems and Archer Aviation appear in the corpus) represent additional demand-side context for this branch.
Search this in Eureka →How leaders differ by technology route across gearing design, surface treatment, and drive integration
Route coverage across the main technology branches in the current evidence set.
| Player | F16H 57 · Gearing & transmissions | F16H 1 · Gearing & transmissions | F16H 3 · Gearing & transmissions | F16H 55 · Gearing & transmissions | B60K 17 · Vehicle propulsion & drive |
|---|---|---|---|---|---|
| Aisin AW Co., Ltd. | Strong · 54 | Moderate · 11 | Strong · 46 | Emerging · 6 | Emerging · 3 |
| Toyota Motor Corporation | Strong · 51 | Moderate · 13 | Strong · 36 | Emerging · 6 | Absent |
| Hyundai Motor Company | Strong · 49 | Absent | Strong · 27 | Absent | Emerging · 9 |
| REM Technology Inc. | Strong · 34 | Absent | Absent | Strong · 39 | Absent |
| Pratt & Whitney Canada Corp. | Strong · 38 | Strong · 26 | Absent | Absent | Absent |
| OSRO GmbH | Strong · 30 | Absent | Absent | Strong · 33 | Absent |
| Sumitomo Heavy Industries, Ltd. | Strong · 17 | Strong · 30 | Absent | Strong · 16 | Absent |
Frequently asked questions
The corpus contains 204 patent families in scope. The United States is the primary filing office with 342 patent records, reflecting multi-jurisdiction prosecution of many of those families.
Toyota Motor Corporation leads with 70 patent records, followed by Aisin AW Co., Ltd. at 64 and Hyundai Motor Company at 53. All three are concentrated in F16H gearing and transmission sub-classes.
The field is classified as Decline, with annual filings easing back from a peak of 43 records in 2019. Core planetary-gearing architecture patents appear to be in a harvesting phase, though publication lag means 2024–2026 counts are provisional.
The most active co-filing pair is REM Technology Inc. and OSRO GmbH with 33 joint records, centred on isotropic superfinishing processes. Hyundai Motor and Kia follow at 18 joint records, and Toyota Motor Corporation and Aisin AW at 17.
While Toyota, Aisin AW, and Hyundai focus on multi-speed planetary transmission architecture (F16H), REM Technology’s portfolio is anchored in B24B31 (mass finishing and isotropic superfinishing) and F16H55 (gear tooth surface geometry), making surface-treatment process patents its primary differentiator rather than gearing design.
F16C (Shafts, bearings & couplings) at 46 patent records and H02K (Electric motors & generators) at 32 patent records are the most notable adjacent branches with plausible technical relevance to gear fatigue and micropitting but comparatively low filing density. B24B (Grinding & polishing) at 44 records and F16D (Clutches & brakes) at 38 records are also relatively sparse.
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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.
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