Variable/Collective Pitch Rotor System
- Two direct drive motors drive two coaxial driveshafts.
- Driveshafts control pitch of two or more primary rotors.
- Corotation of motors drives rotor system.
- Non-corotation of motors alters blade pitch.
SCOPIC (Shaft Controlled Pitch Change) Technology
U.S. Patent Pending · Electron Flight LLC
The future of rotor hub mechanics. SCOPIC technology is a software-defined virtual swashplate. It delivers collective and cyclic pitch control using nothing more than driveshafts and drive motors, with no swashplates, actuators, linkages or complex mechanisms required.
Coaxial driveshafts carry cogs that mesh with a cog on each blade. When the shafts turn together, they drive the rotor; when one shaft rotates relative to the other, blade pitch changes.
- Software-defined virtual swashplate
- No swashplates, pitch actuators or linkages
- Collective and cyclic pitch via coaxial driveshafts
- Independent blade pitch control, with lead-lag optimization in multi-hub configurations
- Applies to rotary-wing, fixed-wing, tiltrotor, eVTOL and watercraft
- Regenerative braking enables pitch control for autorotation and for hydro and wind generators
- Design option: mechanical stops let a rotor continue at a fixed pitch if one drive motor fails
SCOPIC Technology
Cyclic Pitch Rotor System
- Two direct drive motors drive two coaxial driveshafts.
- Driveshafts control pitch of one primary rotor which is coupled to a secondary rotor.
- Corotation of motors drives rotor system.
- Non-corotation of motors alters blade pitch.
Collective and Cyclic Pitch Rotor System
- Four direct drive motors drive four coaxial driveshafts.
- Driveshafts control pitch of two completely independent primary rotors.
- Corotation of motors drives rotor system.
- Non-corotation of motors alters blade pitch.
SCOPIC vs. Conventional Pitch Control
| Feature | Conventional | SCOPIC technology |
|---|---|---|
| Cyclic pitch | Swashplate plus actuators and linkages | Relative rotation of coaxial driveshafts |
| Collective pitch | Actuator and linkage set per rotor | Relative rotation of coaxial driveshafts |
| Rotor head parts | Swashplate, pitch links, bearings, actuators | Cogged coaxial driveshafts, hub and cogged blades |
| Blade-level control | Requires added rotating-frame actuators | Built in: independent blade pitch control |
| Control definition | Mechanical geometry | Software |
| Maintenance | Wear-prone linkages and swashplate bearings | Fewer moving parts in the rotor head |
| Blade lead-lag control | Passive dampers | Lead-lag optimization possible in multi-hub configurations |
| Drive motor failure | Loss of pitch control | Design option: mechanical stops hold a fixed pitch on the remaining motor |
What SCOPIC Technology Makes Possible
Capabilities
- Software-defined virtual swashplate: Collective and cyclic pitch defined in software, not mechanical geometry.
- Independent blade control: Blade pitch set by the drive motors, with lead-lag optimization in multi-hub configurations.
- Regenerative braking for pitch control: Enables pitch control during autorotation, and in hydro and wind generators.
- Fault-tolerance option: With mechanical stops, a rotor can continue at a fixed pitch if one drive motor fails.
- Unlimited range of motion: Enables automated blade folding for stowage and articulating stopped blades on stop-rotor aircraft.
Applications
- Rotary-wing: Helicopters and multirotors with full collective and cyclic control and simpler rotor heads.
- Fixed-wing: Variable-pitch propellers driven straight from the motors.
- Tiltrotor: Pitch control across hover and forward flight without swashplates on the nacelles.
- eVTOL: Distributed rotors with pitch control.
- Autogyro: Rotor pre-rotation and in-flight pitch control.
- Stop-rotor: Blades that can be articulated while stopped.
- Watercraft: Variable-pitch marine propulsion.
- Energy: Pitch control for hydro and wind generators via regenerative braking.
How SCOPIC Technology Works
- Cogged coaxial driveshafts: Two nested driveshafts carry cogs that mesh with a cog on the blade, and the hub sits between them.
- Drive: When both shafts turn together, they turn the hub and blade around the rotor axis.
- Pitch: When one shaft rotates relative to the other, the blade rotates about its pitch axis.
- Motors: Each shaft is driven by its own electric motor, directly or through a gear or belt, so the drive motors also provide pitch control.
- Configurations:
- Multi-blade: A single shaft pair pitches two or more blades together, replacing per-rotor pitch actuators and linkages.
- Opposed-blade: The shaft pair pitches a cogged blade linked to an opposing blade, so the two pitch in opposition, replacing the swashplate and its actuators.
- Multi-hub: Nested shaft pairs, each driving and pitching its own hub and blade, give full helicopter-style collective and cyclic pitch control from the drive motors alone, with no swashplate or linkages.
Development Status
SCOPIC technology is at the engineering-model stage, and a subscale demonstrator is in development.
R&D Roadmap
- Subscale bench build and spin-up
- Collective pitch validation
- Cyclic pitch validation
- Integration and reliability testing
- Flight demonstration
- Scale-up and partnering
Intellectual Property
U.S. Patent Pending · Provisional Application No. 64/110,081 · Assigned to Electron Flight LLC
SCOPIC technology is currently under review in federal R&D programs.
FAQ
How does SCOPIC technology change blade pitch?
Coaxial driveshafts carry cogs that mesh with the blade. Turning together drives the rotor; rotating one shaft relative to the other changes blade pitch.
How is cyclic achieved without a swashplate?
Pitch comes from relative driveshaft rotation, so cyclic is defined in software rather than by swashplate hardware.
What happens if a drive motor fails?
As a design option, mechanical stops let the rotor continue at a fixed pitch on the remaining motor.
Where can SCOPIC technology be used?
Rotary-wing, fixed-wing, tiltrotor, eVTOL, autogyro, stop-rotor and watercraft, plus hydro and wind generators, where regenerative braking enables pitch control.
What is the current status?
SCOPIC technology is at the engineering-model stage, and a subscale demonstrator is in development.
Advance SCOPIC Technology With Us
We're seeking agency, research and industry partners to validate and mature SCOPIC technology from subscale testing to flight.