Gyroscopic Boat Stabilizer Cooling for Faster Flywheel Spin-Up
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Solution Overview
Problem
Existing control moment gyroscopes (CMGs) for boat roll stabilization face challenges such as heat buildup in bearings due to inefficient cooling, leading to potential failure, and a lengthy 'spin up' period, making them unsuitable for short trips.
Innovation Solution
The proposed solution involves a gyroscopic roll stabilizer with an enclosure mounted on a gimbal, maintaining below-ambient pressure, and a flywheel assembly with a motor cooling circuit that uses a closed fluid pathway to recirculate cooling fluid and efficiently dissipate heat from the motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the flywheel is contained in a vacuum enclosure to achieve high spin rate, then the CMG can provide effective roll stabilization, but heat dissipation becomes problematic leading to bearing failure
Solution Approach 1:
The patent divides the CMG system into separate functional zones: a vacuum enclosure for the flywheel to minimize drag and maintain high spin rates, and a separate cooling circuit system with radiators positioned outside the vacuum environment. This segmentation allows the flywheel to operate in vacuum while heat is dissipated through dedicated cooling channels that do not compromise the vacuum integrity.
Solution Approach 2:
The patent introduces a thermal management intermediary system consisting of cooling fluid channels and radiators that act as a mediator between the heat-generating flywheel bearings and the external environment. The cooling fluid circulates through channels in the flywheel housing, absorbing heat internally, then dissipates it externally through radiators positioned away from the vacuum enclosure, thus protecting bearings from overheating without compromising vacuum conditions.
2Reliability
If the flywheel is contained in a vacuum enclosure for efficient operation, then the CMG achieves desired performance, but the motor cooling becomes inefficient
Solution Approach 1:
The patent extracts the motor cooling function from the vacuum enclosure environment and positions radiators and major cooling components outside the vacuum seal. The motor itself remains inside the vacuum enclosure for reliable operation, but its heat is conducted through dedicated cooling channels to radiators positioned externally, where heat dissipation occurs efficiently without the constraints of vacuum conditions.
Solution Approach 2:
The patent resolves the cooling efficiency problem by transitioning the heat dissipation function to a different spatial dimension - moving radiators and heat exchange surfaces from the internal vacuum environment to the external atmospheric environment. This dimensional relocation allows the motor to operate reliably in vacuum while heat is dissipated in the third dimension through externally positioned cooling components with access to ambient air for convection and radiation.
3Loss of time
If a larger motor is used to reduce spin up time, then the CMG becomes suitable for short trips, but more heat is generated requiring better cooling
Solution Approach 1:
The patent implements preliminary thermal management by pre-positioning extensive cooling channels and externally mounted radiators before the motor needs to deliver high power. The cooling infrastructure is already in place and operational, allowing the motor to be sized for rapid spin-up without concern for heat generation, since the thermal management system is prepared in advance to handle the increased heat load.
Solution Approach 2:
The patent employs composite thermal management structures combining internal cooling channels with externally mounted radiator assemblies. The cooling system uses a composite approach with fluid conduits integrated into the motor housing and external radiators positioned for optimal heat dissipation, allowing the motor to operate at higher power levels for reduced spin-up time while the composite cooling structure handles the increased thermal load efficiently.
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 heat dissipation, allowing for the use of larger, more powerful motors, reducing the time to engage the CMG and enabling its use on shorter trips, while also significantly reducing the spin down time and associated noise.
Implementation Method 1
The motor cooling circuit is configured to transfer heat away from the motor. The motor cooling circuit has a closed fluid pathway for recirculating cooling fluid therein... The gyroscopic roll stabilizer is configured to transfer heat away from the motor to the cooling fluid.
Implementation Method 2
The motor cooling circuit is configured to transfer heat away from the motor... The fluid pathway includes a fluid channel jointly defined by the motor and the enclosure and having the cooling fluid therein.
Implementation Method 3
Gyroscopic boat stabilization is another technology for roll suppression that is based on the gyroscopic effect. A control moment gyroscope (CMG) is mounted in the boat and generates a torque that can be used to counteract the rolling motion of the boat.
Implementation Method 4
The energy used to counteract the rolling motion of the boat comes from the angular momentum of the rotation of the flywheel at a high rate of speed.
Data Source
AI summary
A gyroscopic roll stabilizer for a boat includes an enclosure mounted to a gimbal for rotation about a gimbal axis and configured to maintain a below-ambient pressure, and a flywheel assembly including a flywheel and flywheel shaft, with the flywheel assembly rotatably mounted inside the enclosure for rotation about a flywheel axis. The gyroscopic roll stabilizer also includes a motor operative to rotate the flywheel assembly and disposed inside the enclosure. A motor cooling circuit is configured to transfer heat away from the motor. The motor cooling circuit has a closed fluid pathway for recirculating cooling fluid therein. The fluid pathway includes a fluid channel jointly defined by the motor and the enclosure and having the cooling fluid therein. The gyroscopic roll stabilizer is configured to transfer heat away from the motor to the cooling fluid. Related methods are also disclosed.