Rotary Electric Machine Crossover Wire Separation for Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rotary electric machines experience temperature increases due to confined heat within the stator, leading to rotor demagnetization, as the circumferential regions occupied by crossover wires overlap, reducing air passages and hindering efficient cooling.
Innovation Solution
The crossover wires are configured such that the circumferential regions they occupy are separated in the circumferential direction, increasing air passages and improving cooling by allowing efficient heat exchange between the stator and rotor, and external air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the circumferential regions occupied by transition parts overlap with each other in the circumferential direction, then the structure is compact, but air passages are reduced and heat is confined inside the stator
Solution Approach 1:
The patent applies dimensionality change by arranging crossover wires in the axial direction (third dimension) rather than only in the circumferential direction. Specifically, crossover wires are positioned at different axial locations to connect conductor terminals, which separates their circumferential regions and creates air passages without compromising structural compactness.
2Temperature
If the circumferential regions occupied by crossover wires are separated in the circumferential direction, then air passages are increased and cooling is improved, but the structural arrangement becomes more complex
Solution Approach 1:
The patent applies segmentation by dividing the stator winding into multiple independent phases (U-phase, V-phase, W-phase), with each phase having its own dedicated crossover wire. This segmentation allows each crossover wire to be positioned independently in the axial direction, simplifying the overall arrangement while ensuring proper circumferential separation for cooling.
3Reliability
If crossover wires are arranged to connect conductor terminals of same-phase electric power, then electrical connectivity is ensured, but heat confinement occurs when circumferential regions overlap
Solution Approach 1:
The patent introduces air passages as an intermediary medium between the crossover wires and the external environment. By positioning crossover wires at different axial locations, air can flow through the created passages to carry heat away from the stator, effectively using air convection as a heat transfer intermediary to prevent heat confinement while maintaining electrical connectivity.
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 cooling efficiency, suppresses temperature increases in the rotor, and prevents demagnetization of permanent magnets, enabling the use of less expensive magnets and reducing material usage while improving electrical insulation and productivity.
Implementation Method 1
air passages are increased in groups of the crossover wires. Cooling of the stator is thereby improved, suppressing temperature increases in the stator. Because heat is less likely to be confined inside the stator, the rotor and external air can exchange heat efficiently
Data Source
AI summary
Conductor terminals of a plurality of conductor wires that constitute a stator winding each extend outward at a first axial end of a stator core, and among the conductor terminals, conductor terminals through which same-phase electric power flows are respectively connected by crossover wires, and circumferential regions that are occupied by the crossover wires are separated from each other in a circumferential direction.