Propeller Energy Saving Devices Patents: Top Companies & Trends 2026
Propeller Energy Saving Device Patents: Who Leads and Where the Filings Sit
Concentrated at the top. The five leading assignees hold 115 of 211 records in scope (54.5%), and the leading ten hold 163 (77.3%) — a field with a short list of repeat filers and a long tail behind them. Volume climbed to 7 filings in 2018, the high point of the window, then settled onto a lower plateau; the 2021-to-2024 comparison the dataset supports shows filings falling from 4 to 2, a 50% decline over that span. Because publication lag means 2025 and 2026 are still filling in, that fall should not be read as a definitive slowdown — only as the clearest complete-year comparison available.
- 1EMBERTEC40
- 2MITSUI O S K LINES LTD22
- 3NAGRAVISION SA22
- 4KOREA INSTITUTE OF OCEAN SCIENCE & TECHNOLOGY18
- 5REDDING JOHN13
See the full propeller energy saving devices analysis in Eureka
- The complete ranking, not just the top five
- Every IPC branch with its share of the corpus
- The most-cited records, and where claim space is still thin
Common questions about propeller energy saving device patents
Who holds the most patents on propeller energy saving devices?
One assignee leads the ranked field with 40 of the 211 records in scope, well ahead of the fifth-ranked filer’s 13 and the tenth-ranked filer’s 8. The top five assignees combined hold 54.5% of all records, and the top ten hold 77.3%, so the field is concentrated among a small group of repeat filers even though 61 companies appear in the ranking overall. Anyone entering this space should check that leading portfolio first, since it is the most likely source of blocking prior art.
Is patent filing activity in this field growing or slowing?
Filings peaked at 7 in 2018 and have not returned to that level since. The clearest complete-year comparison available, 2021 to 2024, shows a drop from 4 filings to 2 — a 50% decline over that span. Because publication typically lags filing by around 18 months, 2025 and 2026 figures are still incomplete and should not yet be read as confirming a continued slowdown.
What is a propeller boss cap fin and why does it get patented separately from ducted propellers?
A propeller boss cap fin (PBCF) is a fin structure fitted to the hub cap behind a propeller to reduce hub vortex cavitation and recover rotational energy lost in the wake, while a ducted propeller wraps a nozzle or duct around the propeller to change the flow field ahead of the blades. They solve the same efficiency problem through different mechanical routes, which is why the search scope for this landscape treats both as core device terms alongside the flow-physics language — wake field, hub vortex, cavitation risk — used to justify each design.
Disclaimer. This analysis is based on Patsnap Eureka data drawn from a limited snapshot of global patent records and is provided for general information and reference only. Patent data carries inherent limitations — recent filings are under-counted because of publication lag, counts may be on a record or family basis, classification and applicant-name data may contain errors or duplicates, and the underlying search query defines the scope shown — so the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing here is an exhaustive prior-art, novelty, freedom-to-operate or validity search, nor does it constitute legal, financial or professional advice, and it should not be relied upon as such. Verify independently and review with qualified patent and legal professionals before acting on it.
Method: Filing trend and technology composition. Derived from a Patsnap search on Propeller Energy Saving Devices covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish. Every share divides by all records in scope. Data: Patsnap Eureka. See the full landscape report.