Resolver Sheet Coils and Grooves for Inductance
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Solution Overview
Problem
Miniaturizing and micro-miniaturizing resolvers while maintaining sufficient detection accuracy, stability, and reliability is challenging due to the difficulty in securing necessary inductance, which leads to increased magnetic leakage flux and noise sensitivity.
Innovation Solution
The resolver design incorporates a combination of sheet coils with bore portions and coil-storing grooves in magnetic cores, along with amplitude-modulated excitation signals and magnetic flux correction functions, to enhance inductance, reduce magnetic leakage, and improve detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the size of the resolver is reduced for miniaturization, then the device becomes smaller and more compact, but the inductance becomes insufficient and magnetic leakage flux increases
Solution Approach 1:
The patent applies nesting by placing coil-storing grooves within the magnetic core structure and positioning multiple coil portions within confined spaces. The excitation windings and detection windings are nested within the magnetic core's groove structures, maximizing space utilization and maintaining sufficient inductance despite the reduced overall resolver size.
Solution Approach 2:
The patent transitions from planar coil arrangements to three-dimensional coil-storing grooves within the magnetic core. By utilizing the depth dimension of the magnetic core and creating grooves that extend into the core volume, the design achieves sufficient inductance in a compact footprint by exploiting spatial dimensions beyond the surface area.
2Speed
If the drive frequency is increased to compensate for small inductance, then the inductance effect is enhanced, but magnetic leakage flux increases and detection accuracy deteriorates
Solution Approach 1:
The patent changes the physical parameters of the magnetic circuit by introducing coil-storing grooves with specific geometric characteristics (depth, width, positioning). These parameter changes enhance the magnetic coupling and reduce leakage flux, allowing the system to operate at appropriate drive frequencies without sacrificing detection accuracy. The groove dimensions are optimized to balance inductance, flux containment, and frequency response.
3Volume of moving object
If dead space is removed to minimize size, then the resolver becomes more compact, but noise sensitivity increases and detection accuracy lowers
Solution Approach 1:
The patent applies local quality by providing magnetic shielding and flux containment specifically in regions where dead space previously existed. The coil-storing grooves are strategically positioned to concentrate and contain magnetic flux in critical areas, while magnetic shielding materials are applied locally to block external noise interference. This targeted approach maintains compact size while protecting against noise in specific sensitive regions.
4Reliability
If sheet coils with bore portions and coil-storing grooves are used to increase inductance, then sufficient inductance is achieved in miniaturized design, but manufacturing complexity increases
Solution Approach 1:
The patent employs thin-film sheet coils that can be flexed and conform to the three-dimensional groove structures within the magnetic core. These flexible thin-film coils are easier to manufacture and install compared to rigid traditional windings, as they can be precisely positioned within the complex groove geometries using standard thin-film fabrication techniques, thereby reducing overall manufacturing complexity despite the advanced coil structure.
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 allows for the micro-miniaturization of resolvers with improved detection accuracy, reduced noise influence, and cost-effectiveness, while maintaining sufficient inductance and stability.
Implementation Method 1
an excitation signal is input to an excitation winding and a detection signal is output from a detection winding, and detects the displacement amount of a passive body 4 based on a detection signal So which changes in accordance with the displacement amount
Data Source
AI summary
A resolver for detecting the displacement amount of a passive body is provided with an excitation winding or a detection winding. The detection is based on a detection signal outputted from the detection winding as a result of an excitation signal inputted to the excitation winding. The excitation winding and/or the detection winding are composed of a combination of one or more sheet coils having one or more bore portions. The sheet coils are arranged at prescribed intervals in the lengthwise direction of a magnetic core to which the sheet coils are attached. A plurality of coil-storing grooves formed in a direction perpendicular to the lengthwise direction are provided in the core surface of the magnetic core. The coil portions of at least two portions of the respective sheet coils are accommodated in the coil-storing grooves.