Resolver Coil Occupancy and Insulation Design
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Solution Overview
Problem
Resolvers used for detecting rotation angles in rotating devices, such as motors, face challenges with external noise interference and errors due to coil winding design, where excessive coil occupancy in slots leads to electric interference and reduced transformation ratios.
Innovation Solution
A resolver design with a stator and rotor made of magnetic materials, featuring insulation covers with tooth insulating units to manage coil occupancy, maintaining a coil occupying ratio per slot of 35% or below and ensuring a minimum 4 mm distance between adjacent coils, which reduces magnetic flux interference and enhances signal accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a coil is wound more on the teeth, then the transformation ratio of induced voltage is improved, but the area occupied by the coil at the slot increases causing electric interference between adjacent coils
Solution Approach 1:
The patent introduces insulation covers as intermediary components between adjacent coils wound on teeth. These insulation covers prevent direct electrical contact between coils from adjacent teeth, thereby eliminating electric interference while allowing sufficient coil turns to maintain transformation ratio. The insulation cover acts as a mediator that enables both high transformation ratio and low interference simultaneously.
2Object-affected harmful factors
If a coil is wound less on the teeth, then electric interference between adjacent coils is reduced, but the transformation ratio of induced voltage is lowered making it vulnerable to external noise
Solution Approach 1:
The insulation cover serves as a protective intermediary that allows the coil to be wound with sufficient turns on each tooth without causing electric interference. By providing electrical isolation between adjacent coils, the insulation cover enables the system to achieve both low interference and high transformation ratio, thereby maintaining reliability against external noise while minimizing harmful electric interference.
3Measurement precision
If the coil occupying ratio per slot is increased, then the transformation ratio is improved, but the distance between adjacent coils is reduced causing magnetic flux interference
Solution Approach 1:
The insulation cover acts as a spatial and magnetic intermediary between coils on adjacent teeth. By introducing this insulating structure, the patent enables coils to be positioned closer together (increasing slot occupancy and transformation ratio) while the insulation cover prevents magnetic flux interference between adjacent coils, thus resolving the contradiction between transformation ratio and magnetic interference.
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
The design results in a robust resolver that accurately measures rotation angles with reduced error rates and improved resistance to external noise, ensuring precise and reliable operation.
Implementation Method 1
If an excitation power is applied to the excitation coil and the rotary shaft is rotated, a sine signal and a cosine signal are output from the first output coil and the second output coil
Implementation Method 2
a stator made of a magnetic material and having a plurality of teeth and a plurality of slots alternately formed at an inner side thereof
Data Source
AI summary
Disclosed is a resolver, which includes a stator made of a magnetic material and having a plurality of teeth and a plurality of slots alternately formed at an inner side thereof; insulation covers respectively having a tooth insulating unit formed at an inner side thereof corresponding to the teeth and mounted to the stator at both upper and lower surfaces of the stator; and coils wound on the teeth with the tooth insulating unit being interposed therebetween, wherein a coil occupying ratio per slot, which is defined by the following equation and represents a ratio of area occupied by the coils in a slot to which the insulation covers are fixed, is 35% or below:Coil occupying ratio per slot=(area occupied by coils in a single slot)/(area of a single slot) Equation.