Vehicle Drive Resolver Shielding Near the Motor Air Gap
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Solution Overview
Problem
The adverse effect of leakage magnetic flux from the gap between the stator coil and rotor of a motor on the resolver in vehicle drive systems is not adequately addressed, leading to potential interference with the resolver's detection signals.
Innovation Solution
A shielding member made of a nonmagnetic material is positioned between the gap and the resolver, comprising a first shielding plate extending radially and a second shielding plate approaching the rotor, to minimize the impact of leakage magnetic flux on the resolver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the resolver is disposed inside the motor coil end to reduce its outer diameter, then the resolver can be separated radially inward of the gap between coil and rotor, but the adverse effect of leakage magnetic flux on the resolver increases when the stator of the resolver reaches a vicinity of the gap
Solution Approach 1:
A shielding member made of nonmagnetic material is introduced as an intermediary between the gap (source of leakage magnetic flux) and the resolver (affected object). The shielding member includes a first shielding plate disposed in the space between the gap and resolver rotor, and a second shielding plate extending in a direction approaching the rotor from the first shielding plate, thereby blocking the harmful magnetic flux path while allowing the resolver to maintain its compact positioning inside the coil end.
2Measurement precision
If the resolver is positioned close to the gap between stator coil and rotor to improve detection accuracy, then the resolution of rotation state detection is enhanced, but the interference from leakage magnetic flux increases
Solution Approach 1:
The shielding member acts as a mediator that allows the resolver to be positioned close to the gap for improved detection precision while simultaneously blocking the harmful leakage magnetic flux. The nonmagnetic material of the shielding member does not interfere with the resolver's detection function but effectively suppresses the magnetic flux interference.
Solution Approach 2:
The shielding member is strategically positioned only in the specific region where leakage magnetic flux interferes with the resolver, rather than providing universal shielding throughout the entire motor structure. This localized approach maintains measurement precision while suppressing harmful effects only where necessary.
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 shielding member effectively suppresses leakage magnetic flux, reducing interference with the resolver's detection signals and allowing for precise rotation state monitoring while maintaining a compact vehicle drive system design.
Implementation Method 1
a shielding member made of a nonmagnetic material which suppresses leakage magnetic flux discharging from the motor to the resolver
Data Source
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AI summary
A vehicle drive system is provided, which includes a shaft, a motor (3) which rotates the shaft, a resolver (4) which detects a rotation state of the motor, and a shielding member made of a nonmagnetic material which suppresses leakage magnetic flux from the motor discharging to the resolver. The resolver includes a resolver stator (40) extending to a vicinity of a gap formed between a stator coil and a rotor of the motor, and a resolver rotor which rotates with the rotor of the motor. The shielding member (5) includes a first shielding plate (51) disposed in a space between the gap and the resolver rotor so that the first shielding plate extends in the radial direction of the shaft, and a second shielding plate (52) extending in a direction approaching the rotor of the motor from the first shielding plate.