Integrated Electric Compressor Bus Bar Welding for Vibration Reliability
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Solution Overview
Problem
On-vehicle integrated electric compressors face reliability issues due to vibrations and heat changes affecting solder joints and screw connections, leading to potential electrical continuity impairment and variability in assembly quality.
Innovation Solution
Employing bus bars for electrical connections between the control board and polyphase motor, with resistance welding for stable joining, and using insulators with positioning means to improve workability and reliability, along with unitizing components like capacitors and reactors with bus bars for enhanced assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If soldering or screwing is used to attach electrical and electronic parts, then assembly is simple and flexible, but the connections become unreliable under vibration and heat changes
Solution Approach 1:
The patent merges the electrical connection function with the structural support function by integrating the bus bar directly into the housing structure. The bus bar is formed as an integral part of the housing, eliminating the need for separate mounting brackets or fasteners, thereby maintaining manufacturing simplicity while achieving reliable welded connections that resist vibration and heat changes.
Solution Approach 2:
The patent replaces mechanical fastening methods (screws, soldering) with resistance welding to join the bus bar to electrical terminals. Resistance welding creates strong, vibration-resistant metallurgical bonds that are more reliable than mechanical connections in harsh on-vehicle environments, while the welding process can be automated for efficient manufacturing.
2Reliability
If resistance welding is used to join bus bar and terminal, then connection reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent incorporates positioning protrusions on the bus bar that engage with corresponding positioning holes in the housing before welding. This preliminary positioning action ensures correct alignment and spacing between the bus bar and electrical terminals, preventing welding defects caused by misalignment and reducing the precision requirements during the welding process itself.
Solution Approach 2:
The positioning protrusions and holes create a self-aligning mechanism that automatically corrects minor positioning errors during assembly. The geometry of the positioning features guides the bus bar into the correct position relative to the terminals, reducing the need for high-precision manual adjustment and welding parameter control.
3Productivity
If bus bars are integrated by insulator with positioning means, then assembling workability is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple functions into the insulator component: electrical insulation between bus bars, mechanical support for the bus bars, and positioning guidance through integrated positioning protrusions. By merging these functions into a single insulator piece, the overall device complexity is reduced compared to using separate components for each function, while assembly workability is significantly improved.
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 bus bar connections with resistance welding enhance the reliability of terminal joints, reduce worker variability, and improve assembly workability, resulting in a more stable and consistent electrical connection within the integrated electric compressor.
Implementation Method 1
the bus bar and a terminal on the polyphase motor side can be joined to each other by resistance welding or the like. In resistance welding, if a welding current value and the like are controlled, the welding conditions can easily be kept constant
Data Source
AI summary
There is provided an integrated electric compressor that is improved in reliability. Bus bar connection is employed for electrical connection between a power board 16 and the power source side and between the power board 16 and the motor side, and welding is employed for joining a bus bar to a capacitor 13 and a reactor 14, for joining board-side terminal parts of the bus bar to PN terminals 20a and 20b, and for joining UVW terminals 25a, 25b and 25c to housing-side terminals 28a, 28b and 28c. By employing resistance welding for the welding, the terminals can be joined to each other with stabilized quality. Further, since flat joint plates are provided on one end side of the housing-side terminals 28a, 28b and 28c, and the UVW terminals 25a, 25b and 25c are welded thereto, reliable joints between terminals can also be attained in these portions.