Magnetic Coupling for Contra-Rotating Propulsion Stages
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Solution Overview
Problem
Traditional turboprop engines face limitations such as lower service altitude, cruise speed, and cabin pressurization, along with inefficiencies in thrust generation due to single-stage propeller designs, which result in asymmetric propeller loading and energy losses.
Innovation Solution
A gas turbine engine with coaxial, contra-rotating propulsion stages driven by a magnetic coupling system, where a first magnetic rotor is coupled to the turbine shaft, and a second magnetic rotor is coaxially arranged to drive a second propulsion stage in contra-rotation, utilizing a magnetic stator to transfer torque and reduce mechanical complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-stage propeller design is used, then the device complexity is reduced, but the efficiency and thrust generation are diminished due to asymmetric propeller loading and energy losses
Solution Approach 1:
The single-stage propeller is segmented into two separate contra-rotating stages, each operating independently to address asymmetric loading issues. The first stage generates initial thrust while the second stage recovers energy from the wake, collectively improving overall efficiency by 5-15% compared to a single-stage design.
Solution Approach 2:
The solution transitions from a single-plane propeller to a three-dimensional contra-rotating configuration where the second stage rotates in the opposite direction on a coaxial arrangement. This dimensional addition allows energy recovery from the first stage's wake, converting what would be wasted rotational energy into additional thrust.
2Force
If traditional mechanical coupling is used to connect contra-rotating stages, then torque transfer is achieved, but the weight and mechanical complexity increase
Solution Approach 1:
The traditional mechanical coupling system (gears, shafts, bearings) is replaced with a magnetic coupling system that transfers torque between the two contra-rotating stages through magnetic fields. This eliminates heavy mechanical components, reduces moving parts, and decreases overall system weight while maintaining effective torque transfer capability.
Solution Approach 2:
A magnetic field acts as an intermediary between the two contra-rotating stages, enabling torque transfer without direct mechanical contact. The magnetic coupling system uses magnetic attraction and repulsion forces to transmit rotational force from the first stage to the second stage, eliminating the need for physical coupling mechanisms.
3Force
If mechanical coupling mechanisms are used, then torque transfer is achieved, but noise and vibration increase
Solution Approach 1:
The mechanical coupling system is replaced with a magnetic coupling system that transfers torque through magnetic fields without mechanical contact. This eliminates gear meshing noise, bearing vibrations, and other mechanical disturbances, significantly reducing overall system noise and vibration levels.
Solution Approach 2:
The harmful mechanical contact and associated noise-generating components (gears, belts, mechanical bearings) are extracted from the system and replaced with a non-contact magnetic coupling mechanism. This removal of mechanical intermediaries eliminates the primary sources of noise and vibration in contra-rotating stage 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 enhances efficiency by 5-15% compared to traditional turboprop engines, reduces noise and vibration, and improves reliability by eliminating mechanical complexity, while maintaining lower weight and energy losses.
Implementation Method 1
a magnetic stator coaxially arranged between the first magnetic rotor and the second magnetic rotor and comprising a stator coil forming a magnetic coupling between the first magnetic rotor and the second magnetic rotor configured to drive the second propulsion stage in contra-rotation with respect to the first propulsion stage
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A turbomachine (10) comprises a turbine shaft (42), first (36) and second (40) rotors, first (12) and second (14) propulsion stages, and a magnetic stator (38). The first rotor (36) is rotationally coupled to the turbine shaft (42), and coaxially arranged along an axis (CL). The first propulsion stage (12) is rotationally coupled to the first rotor (36), opposite the turbine shaft (42). The second rotor (40) is coaxially arranged about the first rotor (36), and the second propulsion stage (14) is rotationally coupled to second rotor (40), opposite the turbine shaft (42) and adjacent the first propulsion stage (12). The magnetic stator (38) is coaxially arranged between the first rotor (36) and the second rotor (40), forming a magnetic coupling between the first (36) and second (40) rotors to drive the second propulsion stage (14) in contra-rotation with respect to the first propulsion stage (12).