Counter-Rotating Motor Assembly With Hollow-Shaft Slip Ring Nesting

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Solution Overview

Problem

Medium to large counter-rotating differential electric motor assemblies face challenges in efficiently powering horizontal flight and vertical take-off and landing aircraft due to increased mass and vibration issues, which lead to harmful resonances and reduced thrust, especially when trying to position the slip ring assembly close to the mounting base without interfering with propeller rotation.

Innovation Solution

A counter-rotating differential electric motor assembly design featuring a central hollow shaft with oppositely rotating members, where the slip ring assembly is positioned either above or within the rotational members, allowing for closer proximity to the mounting base and reducing vibrations, utilizing sintered/porous disks for efficient electricity transfer and minimizing rotational harmonics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the slip ring assembly is positioned between the rotational members and mounting base as in traditional designs, then electricity can be conveyed to the electromagnetic means, but the rotational members must be positioned at a distance from the mounting base, causing harmful resonances and vibrations in medium to large CR motors

Engineering Contradiction:
Improvereduction of harmful resonancesVSAvoidrepositioning of slip ring assembly
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The slip ring assembly is repositioned from a vertical arrangement (between rotational members and mounting base) to a horizontal arrangement (around the central hollow shaft). This dimensional change allows the rotational members to be positioned close to the mounting base without interfering with the slip ring assembly, thereby reducing harmful resonances while maintaining electrical connectivity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The slip ring assembly is positioned around the central hollow shaft, with the hollow shaft passing through the center of the slip ring assembly. This nested configuration allows the slip ring assembly to be integrated into the motor structure without occupying additional space that would prevent the rotational members from being positioned close to the mounting base.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Loss of energy

If the central shaft is made solid to accommodate the slip ring assembly, then electricity can be conveyed, but the slip ring assembly must be positioned away from the rotational members, increasing the distance from the mounting base and creating vibration issues

Engineering Contradiction:
Improveminimization of vibration energy lossVSAvoidhollow shaft configuration
Core Design Contradiction:
Loss of energyVSShape

Solution Approach 1:

The central hollow shaft serves as a structural core around which the slip ring assembly is positioned. The hollow configuration allows the shaft to maintain structural integrity while accommodating the slip ring assembly in the annular space, enabling the rotational members to be positioned close to the mounting base without requiring a solid shaft.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The motor is divided into distinct functional components: the central hollow shaft for structural support, the slip ring assembly for electrical connectivity, and the rotational members for mechanical rotation. This segmentation allows each component to be optimized independently, with the hollow shaft providing structural strength while accommodating the slip ring assembly without interfering with the rotational members' positioning.

Inventive Principle:
Principle #1Segmentation

3Reliability

If the slip ring assembly is repositioned around the central hollow shaft, then the rotational members can be positioned close to the mounting base reducing vibrations, but the electrical wire routing becomes more complex

Engineering Contradiction:
Improvereduction of harmful resonancesVSAvoidelectrical wire routing
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electrical wires are routed through the central hollow shaft, which acts as a protective conduit. The hollow shaft provides a dedicated pathway for the wires to reach the slip ring assembly, simplifying the routing process and protecting the wires from mechanical damage while allowing the slip ring assembly to be positioned around the shaft.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The central hollow shaft serves as an intermediary structure that facilitates the connection between the external electrical source and the slip ring assembly. By providing a dedicated routing path through the shaft, the system simplifies wire management and protects the electrical connections while enabling the slip ring assembly to be positioned in the optimal location for vibration reduction.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design enhances the motor's efficiency by reducing energy waste, increasing thrust, and extending battery life by minimizing vibrations and heat production, while maintaining the same space allocation as traditional motors, with synergistic differential coupling between the rotating members.

Implementation Method 1

electromagnetic means to power the rotation associated with the first and second rotational members

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

utilizing sintered/porous disks for efficient electricity transfer

Methodology Applied
Scientific EffectElectrical conduction through porous material: Conduction (electrical)

Data Source

PatentEP4022745B1Counter-rotating differential electric motor assembly
Publication Date: 2024.05.15 CR FLIGHT LLC
  • EP4022745B1 patent drawingFigure 1A
  • EP4022745B1 patent drawingFigure 1B
  • EP4022745B1 patent drawingFigure 1C

AI summary

An improved counter-rotating (CR) differential electric motor assembly is utilized to power an aircraft vehicle or fan for moving a gas and includes two oppositely rotating propellers that may be mounted to horizontal flight and vertical lift-off aircraft or a fan housing in spaces similar in size to mounting spaces for traditional motors having only one propeller and includes a hollow central shaft and slip ring assembly that is mounted either within, slight above, or total above oppositely rotating components and around the hollow central shaft.