Stepped Bus Bar Assembly for Compact Motor Insulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional bus bar assemblies in motors require a significant axial distance for insulation, leading to increased motor size due to the need for separation between bus bar end edges and windings.
Innovation Solution
A bus bar assembly with a bus bar holder made of insulating material that holds multiple bus bars in a non-contacting state, featuring overlapping base portions and extending connecting portions with stepped sections, allowing for reduced insulation distance between the stator and connecting portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bus bar assembly with protruding end edges is used, then insulation between bus bar and winding is ensured, but motor axial size increases
Solution Approach 1:
The bus bar configuration transitions from a conventional linear arrangement with protruding end edges to a folded structure where the base portion extends in the axial direction and the connecting portion folds back radially inward. This dimensional reconfiguration allows the bus bar to achieve adequate insulation clearance through spatial folding rather than axial extension, thereby reducing motor axial size while maintaining insulation reliability
Solution Approach 2:
The connecting portion of the bus bar is positioned to overlap with the base portion of another bus bar in the axial direction, creating a nested arrangement. This nesting allows multiple bus bars to be compactly arranged within the stator core space, reducing the overall axial dimension required for insulation clearance while maintaining electrical isolation between adjacent bus bars through the insulating member
2Length of moving object
If stepped portion is added to bus bar, then insulation distance is reduced, but bus bar structure complexity increases
Solution Approach 1:
The bus bar is segmented into distinct functional portions: a base portion extending in the axial direction and a connecting portion extending radially inward. This segmentation allows each portion to be optimized independently for its specific function, with the base portion providing structural support and electrical connection to the stator core, while the connecting portion provides the necessary insulation clearance. The stepped configuration emerges naturally from this segmentation rather than adding unnecessary complexity
Solution Approach 2:
The stepped portion creates local variations in the bus bar structure where different sections serve different purposes. The base portion maintains a consistent cross-section for structural integrity, while the connecting portion features a stepped configuration that locally reduces the axial dimension. This local quality change allows insulation distance reduction without compromising the overall structural strength of the bus bar
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 reduces the motor's axial size by minimizing the insulation distance and improves manufacturing ease by allowing closer proximity of bus bars to windings, while maintaining insulation integrity.
Implementation Method 1
a bus bar holder that is made of an insulating material and holds the plurality of bus bars in a non-contacting state
Data Source
AI summary
A bus bar assembly includes bus bars and a bus bar holder that is made of an insulating material and holds the bus bars in a non-contact state. The bus bars include base portions that overlap with other bus bars in the axial direction, and connecting portions extending from the base portions along the radial direction. At least two of the bus bars include stepped portions extending toward the other bus bars between proximal ends of the connecting portions and connection ends connected to windings. The bus bar holder molds the base portions and the stepped portions in a state where the connection ends are exposed.