Rotating Electric Machine Axial Neutral Point Arrangement
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Solution Overview
Problem
The existing circuit arrangement in rotating electric machines using three-phase alternating currents results in increased size due to the wire connection parts at the neutral point, causing the coil ends to be piled high.
Innovation Solution
A rotating electric machine design with a stator featuring salient poles and windings where lines from one end of each phase are connected in parallel and lines from the other ends are connected at a neutral point, with fewer turns of the winding around a radially closer area to reduce height and accommodate protection tubes, and neutral points arranged along the stator periphery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the neutral point wire connection part is arranged on the windings of the stator together with three-phase lines, then the circuit connection is achieved, but the coil ends become piled high and the machine size increases
Solution Approach 1:
The patent applies dimensionality change by moving the neutral point connection from the radial direction (pile-up at coil ends) to the axial direction (along the periphery). The neutral points are arranged to extend in the axial direction along the periphery of the stator, transforming a two-dimensional planar arrangement into a three-dimensional spatial arrangement that utilizes the axial dimension, thereby reducing coil end height while maintaining all necessary connections.
Solution Approach 2:
The patent segments the neutral point connections into multiple discrete connection points arranged along the periphery of the stator. Instead of concentrating all neutral point connections at a single location or pile, they are distributed and segmented along the axial direction, with each phase's neutral point connected at different axial positions, preventing pile-up and reducing overall height.
2Power
If the number of winding turns is increased to improve magnetic field strength, then the magnetic field creation capability is enhanced, but the radial distance from the axis of rotation increases
Solution Approach 1:
The patent applies local quality by creating non-uniform winding distributions where different radial areas have different numbers of turns. Specifically, the inner radial area (closer to the axis) has fewer turns while the outer radial area has more turns. This localized differentiation allows the machine to maintain adequate magnetic field strength in the outer region while keeping the overall radial footprint compact, as the inner region does not require the same number of turns.
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 a compact rotating electric machine that operates on three-phase alternating currents without increasing the height of the coil ends, maintaining a thin profile and ensuring reliable operation.
Implementation Method 1
passing three-phase alternating currents through windings on a stator to create magnetic fields
Implementation Method 2
a rotor rotatable about the axis of rotation in response to magnetic field created upon passing three-phase current through the plurality sets of three phase windings
Data Source
AI summary
A rotating electric machine includes: a stator 11 including a plurality of salient poles 13, and a plurality sets of three windings 31 for three phases wound around the plurality of salient poles 13, and a rotor 21. Lines 31a from one ends of the windings 31 for each of the three phases are connected in parallel, and lines 31b from the other ends of the windings 31 of each of the plurality of sets are connected at a neutral point. The number of turns of the winding 31 around a first area on each of the salient poles 13 is less than the number of turns of the winding 31 around a second area on the salient pole 13. The neutral points are arranged on one side of the windings 31 to follow the periphery of the stator 11.