Architecture for a propulsion system of a helicopter including a hybrid turboshaft engine and a system for reactivating said hybrid turboshaft engine
US-2017305541-A1 · Oct 26, 2017 · US
Direct drive between power plant and rotor hub
Direct drive between power plant and rotor hub · Cooperative Patent Classification (CPC)
Separating, mixing, shaping, printing, and transporting materials.
Related technology areas
Mapped technology topics for this CPC code.
| Metric | Value |
|---|---|
| CPC code | B64C27/14 |
| Official title | Direct drive between power plant and rotor hub |
| Display label | Direct drive between power plant and rotor hub |
| Total patents | 534 |
Filing trend
Year-over-year patent counts classified under this CPC code.
Filing activity over the last five years is rapidly declining.
| Year | Patents |
|---|---|
| 2015 | 14 |
| 2016 | 31 |
| 2017 | 85 |
| 2018 | 60 |
| 2019 | 69 |
| 2020 | 83 |
| 2021 | 55 |
| 2022 | 57 |
| 2023 | 43 |
| 2024 | 18 |
| 2025 | 17 |
| 2026 | 2 |
Representative patents
Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.
Aircraft and method of orienting an airframe of an aircraft
US-2017308101-A1 · Oct 26, 2017 · US
Noise modes for rotary wing aircraft
US-2017305540-A1 · Oct 26, 2017 · US
Unmanned aerial vehicle
US-2017283050-A1 · Oct 5, 2017 · US
Wind-Powered Recharging for a Weight-Shifting Coaxial Helicopter
US-2017284371-A1 · Oct 5, 2017 · US
Dual rotor, rotary wing aircraft
US-2017274994-A1 · Sep 28, 2017 · US
Rotorcraft operational altitude and airspeed
US-2017225775-A1 · Aug 10, 2017 · US
Aircraft design for air to air refueling
US-2017225797-A1 · Aug 10, 2017 · US
Dual rotor, rotary wing aircraft
US-2017217582-A1 · Aug 3, 2017 · US
Propulsion system assembly
US-2017217600-A1 · Aug 3, 2017 · US
Active vibration control of a rotorcraft
US-2017217575-A1 · Aug 3, 2017 · US
Rotor drive systems for rotorcraft
US-2017217576-A1 · Aug 3, 2017 · US
Feathering propeller clutch mechanisms
US-2017166302-A1 · Jun 15, 2017 · US
Self-tightening rotor
US-9630703-B2 · Apr 25, 2017 · US
Maximum Filter Flow Predictor
US-2017067814-A1 · Mar 9, 2017 · US
Method of regulating a three-engined power plant for a rotary wing aircraft
US-2016376017-A1 · Dec 29, 2016 · US
Method of activating an electric motor in a hybrid power plant of a multi-engined aircraft, and an aircraft
US-2016375994-A1 · Dec 29, 2016 · US
Unmanned helicopter
US-2016368599-A1 · Dec 22, 2016 · US
Lubrication systems for gearbox assemblies
US-2016369887-A1 · Dec 22, 2016 · US
Composite and metal hybrid gear
US-2016363206-A1 · Dec 15, 2016 · US
Frequently asked questions
Answers are generated from the same data shown on this page.
- What is CPC B64C27/14?
- CPC B64C27/14 is the Cooperative Patent Classification code for “Direct drive between power plant and rotor hub.”
- How many patents are filed under CPC B64C27/14 (Direct drive between power plant and rotor hub)?
- Our database includes 534 publications tagged with this CPC code.
- Is patent activity under CPC B64C27/14 growing?
- Publication counts under this code: 18 in 2024 vs 17 in 2025 (latest complete years).