Dielectric-Filled Electrostatic Machine for Arc-Free Torque Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrostatic machines face challenges with arcing between electrodes due to low breakdown voltage in air, and the selection of dielectric fluids with high permittivity and low conductivity is crucial for optimizing torque generation without premature dielectric breakdown.
Innovation Solution
The use of specific dielectric fluids such as carbonates, ethers, and fluorinated hydrocarbons between rotor and stator electrodes, along with a recirculation system to maintain fluid integrity and reduce drag, and the application of capacitive power converters like CSI and VSI to efficiently power these machines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air is used as the medium between electrodes, then the device complexity is low, but the breakdown voltage is low causing arcing between electrodes
Solution Approach 1:
The patent applies the inert atmosphere principle by introducing a dielectric fluid into the electrostatic machine to replace air as the medium between electrodes. This dielectric fluid creates an inert environment that prevents arcing and electrical breakdown, thereby improving reliability and breakdown voltage while managing the added complexity of fluid integration
2Reliability
If dielectric fluid is introduced between electrodes, then breakdown voltage increases preventing arcing, but fluid drag increases reducing efficiency
Solution Approach 1:
The patent applies parameter changes by carefully selecting and optimizing the physical and chemical parameters of the dielectric fluid, including its viscosity, density, and electrical properties. By adjusting these parameters, the system achieves high breakdown voltage for arc prevention while minimizing fluid drag that would otherwise reduce mechanical efficiency
Solution Approach 2:
The patent employs a recirculation system that copies and reuses the dielectric fluid continuously. This system collects fluid from the gap between electrodes, filters it to remove contaminants and degradation products, and returns it to the system, thereby maintaining low drag properties over extended operation periods
3Force
If high permittivity dielectric fluid is used, then torque generation is enhanced, but dielectric breakdown occurs prematurely
Solution Approach 1:
The patent applies composite materials by formulating a dielectric fluid that combines multiple chemical components with complementary properties. This composite fluid achieves high permittivity for enhanced torque generation while incorporating additives and selecting base materials that resist dielectric breakdown, thus balancing both requirements
Solution Approach 2:
The patent applies local quality by ensuring uniform distribution of the dielectric fluid throughout the electrode gap and optimizing its local properties in different regions. This ensures that high permittivity benefits are realized where needed for torque generation while maintaining breakdown resistance throughout the entire fluid volume
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 torque generation by maintaining high electric fields without arcing and minimizes fluid drag, improving the efficiency and performance of electrostatic machines.
Implementation Method 1
the dielectric fluid forms a passivation layer on a surface of the rotor electrode and on a surface of the stator electrode
Implementation Method 2
a capacitor including a rotor electrode and a stator electrode... Torque is proportional to the square of the applied electric field
Data Source
Figure 1A~2B
Figure 3A~3C
Figure 4A~4B
AI summary
An illustrative electrostatic machine includes a shaft that is configured to rotate about an axis, a rotor electrode, and a stator electrode. The rotor electrode and the stator electrode are separated by a gap and form a capacitor. The rotor electrode is fixed to the shaft. The electrostatic machine can also include a housing that is configured to enclose the rotor electrode, the stator electrode, and at least a portion of the shaft. The stator electrode is fixed to the housing. A dielectric fluid fills a void defined by the housing, the rotor electrode, and the stator electrode.