Harmonic Drive Backlash and Wear Patents: Who Leads, Gaps 2026
- One assignee dominates the record. Harmonic Drive Systems holds 29 of the ranked filings against a fifth-place count of just 2, leaving almost no mid-tier competitors in this dataset.
- Filing activity has cooled since its 2017 peak. The trend runs from 9 filings in 2017 down toward zero in the most recent, still-incomplete year — a pattern to read alongside normal publication lag.
- Claims cluster around gearing, not sensing. F16H gearing classes cover 87.9% of the 33 records in scope, while motor and generator control (H02K) touches just 3.0% — a visible gap between mechanical and electronic compensation.
What this patent landscape covers
Strain-wave gearing — commonly known by the trademark Harmonic Drive — delivers high reduction ratios in a compact envelope, which is why it shows up in robot joints, satellite actuators and precision positioning stages. Backlash and wear in these gears are not cosmetic defects: angular transmission error introduced by flexspline deflection or lubricant breakdown propagates directly into positioning accuracy, and compensating for it is where most of the inventive activity in this dataset sits.
This landscape covers 33 published records filed between 2015 and 2026, searched against strain-wave and harmonic gear drive terminology paired with backlash, fatigue, assembly error, transmission error, hysteresis stiffness and lubricant-selection language in the title and claims.
Filing trend and technology composition
Two views of the same 33-record dataset: how filing activity has moved year over year, and how those records distribute across IPC subclasses.
Filing trend, 2017–2026
Filings peaked at 9 in 2017 and have declined toward 0 in the most recent year. Because publication lags filing by roughly 18 months, the last one to two years understate real activity and should not be read as a hard drop-off yet.
Technology composition by IPC subclass
F16H (gearing and transmissions) appears in 87.9% of the 33 records, confirming that most inventive effort targets the mechanical gear train itself. F16C (shafts, bearings, couplings) and G05B/G05D (control systems) each cover a much smaller share, and H02K (electric motors and generators) appears in only 3.0% of records — since a record can carry multiple classes, these shares add up to more than 100%.
Shares are the percentage of the 33 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Harmonic Drive Backlash and Wear with Eureka
This page is one run against one query. Ask Eureka your own question about harmonic drive backlash and wear and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records in this landscape
Positioning control device of actuator provided with strain wave gearing using H-infinity control
A positioning control device for an actuator with strain-wave gearing that uses a full-closed control loop with an H-infinity compensator. The compensator is designed against a generalized plant where angular transmission error in the strain-wave gearing acts as a disturbance input, bounding the H-infinity norm of the disturbance-to-output transfer function to suppress mechanical vibration caused by that transmission error during positioning response.Filed by Harmonic Drive Systems Inc., published 2018-08-23 as US20180239327A1.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20200278017A1 | Rounded Strain Wave Gear Flexspline Utilizing Bulk Metallic Glass-Based Materials and Methods of Manufacture … | 17 |
| 2 | JP2010244343A | Method for compensating for angular transmission error in strain wave gearing | 17 |
| 3 | US20140203752A1 | Positioning control system for actuator provided with wave gear device | 15 |
| 4 | WO2010116607A1 | Method for compensating for angular transmission error in strain wave gearing | 13 |
| 5 | US20180246489A1 | Positioning control device for actuator provided with strain wave gearing using full-closed control with stat… | 6 |
| 6 | US20180239327A1 | Positioning control device of actuator provided with strain wave gearing using h-infinity control | 5 |
| 7 | US20170254403A1 | Wave generator and strain wave gearing | 5 |
| 8 | US20200032891A1 | Strain wave gearing | 4 |
| 9 | US20200040978A1 | Strain wave gearing and wave generator | 4 |
| 10 | US10816073B2 | Strain wave gearing | 3 |
Citation counts inside this corpus reward older filings, since they have had more time to accumulate citations — treat them as a signal of influence rather than current relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns stand out once the filing and citation data are read together.
One company set the technical agenda
Harmonic Drive Systems accounts for 29 of the records in the ranked assignee list, while the fifth-ranked entity holds only 2. The gap is wide enough that most of the field's controlling claims sit with a single filer rather than being contested across competitors.
Activity has cooled from its 2017 high
Filings peaked at 9 in 2017 and have trended down since, reaching 0 in the most recent, still-partial year. Publication lag means the last year or two is always undercounted, so this should be read as a slowdown signal, not a confirmed stop.
Mechanical gearing claims dominate over control-side claims
F16H gearing and transmission classifications appear in 87.9% of the 33 records, well ahead of control-system classes like G05B (18.2%) and G05D (12.1%). Electric motor and generator control under H02K reaches only 3.0%, suggesting compensation approaches rooted in motor-side control are comparatively thin.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to harmonic drive backlash and wear, with the prior art for and against each one.
Who is filing, and where they collaborate
The ranked assignee list is short and top-heavy, with one clear collaboration pattern between a company and a university partner.
Harmonic Drive Systems
Holds the large majority of the ranked filings in this dataset, spanning transmission-error compensation, flexspline design and actuator positioning control. Its strongest co-assignee link is with a Nagoya-area technical university, appearing together in 9 records.
Nagoya Institute of Technology
The strongest co-assignee pair in the dataset links this university with Harmonic Drive Systems, pointing to a sustained joint research relationship on transmission-error compensation rather than one-off co-filings.
Okitsu Yoshifumi and Iwasaki Makoto
This inventor pair appears together on 3 records, with a secondary link to a third named inventor on 2 further filings, indicating a small, stable engineering team working the same technical thread across several applications.
| Assignee | Recent year | YoY |
|---|---|---|
| Harmonic Drive Systems Inc. | 0 | — |
| Nagoya Institute of Technology | 0 | — |
| OKITSU YOSHIFUMI | 0 | — |
| IWASAKI MAKOTO | 0 | — |
| California Institute of Technology (Caltech) | 0 | — |
| YAMAMOTO MASAFUMI | 0 | — |
| YAJIMA TOSHIO | 0 | — |
| SASAKI KOZO | 0 | — |
Where to take this analysis
The filing and citation patterns above point to specific next steps depending on whether you are scoping freedom to operate or looking for open claim space.
Check freedom to operate against the leader's claim set
With one assignee holding 29 of the ranked records, any new positioning-control or transmission-error compensation filing should be checked directly against that portfolio before drafting.
Run a freedom-to-operate check in EurekaProbe the control-side white space
Motor and generator control classes are thin relative to the gearing classes that dominate this dataset, which is where a first claim may face less prior art.
Explore white space in EurekaCommon questions on harmonic drive backlash and wear patents
Harmonic Drive Systems is the clear leader in this dataset, holding 29 of the records in the ranked assignee list against a fifth-place count of only 2. Its filings cluster around transmission-error compensation and positioning control for actuators using strain-wave gearing, often co-filed with Nagoya Institute of Technology. Anyone evaluating freedom to operate in this space should start by reviewing that portfolio directly rather than assuming the field is fragmented.
The patent literature in this dataset points to flexspline fatigue, assembly error and hysteresis stiffness as the recurring mechanical causes, alongside lubricant selection for wear life. These mechanical factors manifest as angular transmission error, which several of the most-cited filings address through compensation algorithms rather than purely mechanical redesign. Both routes — mechanical hardening of the flexspline and control-side compensation — appear in the record, though mechanical gearing claims (F16H) are far more numerous than motor-control claims.
Filings in this dataset peaked at 9 in 2017 and have trended downward since, reaching 0 in the most recent, still-partial year. Because publication typically lags actual filing by around 18 months, the last one to two years understate true activity and should not yet be read as a firm decline. A clearer read on 2024-2026 filing levels will only be possible once those applications finish publishing.
The technology composition data shows F16H gearing classes covering 87.9% of the 33 records in scope, while motor and generator control under H02K appears in only 3.0%. That gap suggests compensation approaches driven from the motor-control side, rather than mechanical flexspline redesign, are comparatively under-claimed. Lubricant-selection claims tied specifically to wear life also appear thin relative to the volume of mechanical and control-system filings.
US20180239327A1, assigned to Harmonic Drive Systems and published in 2018, claims a positioning control device that uses an H-infinity compensator to suppress vibration caused by angular transmission error in strain-wave gearing. It affects anyone designing full-closed-loop position control for actuators built on strain-wave gears, particularly where the control architecture treats transmission error as a disturbance input. Designing around it would likely mean using a different control-theoretic framework than H-infinity bounding, or targeting the mechanical source of transmission error instead of compensating for it in the control loop.
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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.