Coaxial Direct Drive System Eliminates Nested Shafts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing coaxial drive systems are hindered by the need for large, expensive, and complex nested drive shafts, which increase weight, cost, and mechanical complexity, making them fragile and difficult to maintain, especially in applications like helicopters and drones.
Innovation Solution
A coaxial direct drive system featuring at least two prime movers with electrical stators and rotors affixed to a motor carrier member, allowing the rotors to rotate about a common axis, with driven members attached to the rotors, eliminating the need for nested shafts and simplifying the system by using brushless DC ring motors and a support mast for linear movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If nested drive shafts are used to connect prime movers to driven members in a coaxial arrangement, then torque can be transmitted to both driven members, but the drive shaft becomes large, expensive, and complex to fabricate, increasing weight and device complexity
Solution Approach 1:
The patent extracts the drive shaft from the system entirely by directly coupling the prime movers to the driven members. The motor carrier member serves as a mounting structure rather than a torque transmission shaft, eliminating the need for complex nested drive shafts while maintaining the coaxial arrangement and torque transmission capability.
Solution Approach 2:
The patent replaces the mechanical nested drive shaft system with a direct electrical-mechanical coupling system. Electric prime movers (motors) are directly coupled to the driven members, substituting the mechanical torque transmission through nested shafts with direct motor-driven rotation, thereby eliminating the complex drive shaft configuration.
2Power
If nested drive shafts are used in a coaxial arrangement, then both driven members can be rotated about a common axis, but the weight and mass of the drive shafts become large
Solution Approach 1:
The heavy nested drive shafts are extracted from the system and replaced with lightweight motor assemblies. The motor carrier member and support structure provide the necessary coaxial alignment and rotation capability without the excessive mass of nested drive shafts, significantly reducing the overall weight of the moving components.
3Power
If complex transmissions and linkages are used to transfer torque from electric motors to drive shafts and then to rotors, then torque can be transmitted effectively, but cost, weight, and complexity increase, reducing reliability
Solution Approach 1:
The patent replaces the complex mechanical transmission and linkage system with direct electrical-mechanical coupling. Electric motors are directly coupled to the driven members, eliminating transmissions, linkages, and intermediate torque transfer mechanisms, thereby reducing complexity, cost, and weight while improving reliability through fewer moving parts.
Solution Approach 2:
The complex transmission and linkage components are extracted from the system entirely. The direct coupling of electric motors to driven members eliminates the need for intermediate torque transfer mechanisms, simplifying the system architecture and improving reliability by removing potential failure points.
4Adaptability or versatility
If nested drive shafts and complex linkages are employed, then the coaxial drive system can be constructed, but the system becomes fragile and difficult to service and maintain
Solution Approach 1:
The patent replaces the fragile nested drive shaft and complex linkage system with a robust direct-coupled electric motor system. The simplified architecture with fewer moving parts and connections makes the system more durable, easier to service, and simpler to maintain while preserving full coaxial drive functionality.
Solution Approach 2:
The fragile nested drive shafts and complex linkages are extracted from the system, leaving only the essential motor-carrier-member assembly. This extraction eliminates the fragile components that were difficult to service and maintain, while the core functionality of coaxial drive is preserved through the direct motor-to-driven-member coupling.
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 configuration reduces weight, cost, and complexity, enhancing reliability and ease of maintenance by directly connecting prime movers to driven members through a common axis, while maintaining effective propulsion and reducing gyroscopic forces.
Implementation Method 1
each prime mover including an electrical stator and rotor; each stator affixed to a motor carrier member to define a common axis of rotation; each rotor encircling a respective stator and rotating about the common axis
Data Source
AI summary
A coaxial direct drive system includes at least two prime movers mounted to a motor carrier member about a common axis. Each prime mover includes a stator affixed to the motor carrier member, and each prime mover further includes a rotor which can rotate about the common axis. Each rotor has a driven member affixed to it, which rotates with the respective rotor, and to which driven objects, such as aero foil blades, etc. can be affixed. The motor carrier member can be directly mounted to an object to be propelled by the coaxial direct drive system, or can be hollow to receive a support mast which is mounted to the object to be driven. The driven objects can have different rotational senses, such that when the prime movers counter rotate, the driven objects generate trust in the same direction.