Motor Bus Bar Assembly Sealability via Axial Circuit Board Layout
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Solution Overview
Problem
Conventional motors with bus bar assemblies face sealability issues due to deformation caused by heat during soldering, which compromises the sealing between the cover and bus bar holder, especially when electronic components are increased, leading to potential water or oil ingress.
Innovation Solution
A motor design featuring a bus bar assembly with a wiring member that includes an external power-supply connection terminal and a circuit board connection terminal, where the circuit board connection terminal is positioned closer to the cover than the external power-supply connection terminal, reducing heat-induced deformation and maintaining seal integrity through strategic placement and use of O-rings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the circuit board is mounted close to the bus bar holder to improve responsiveness and reduce motor size, then the motor becomes more compact and responsive, but the bus bar holder is deformed by heat during soldering, compromising sealability
Solution Approach 1:
The patent repositions the circuit board from a radial arrangement (close to the bus bar holder) to an axial arrangement (away from the bus bar holder along the motor axis). This dimensional change allows the circuit board to be mounted in a different spatial dimension, maintaining compactness while avoiding thermal interference with the bus bar holder during soldering operations
Solution Approach 2:
The patent introduces a holder as an intermediary component that supports the circuit board at a position away from the bus bar holder. This holder acts as a mediator, allowing the circuit board to be securely mounted while maintaining sufficient distance to prevent heat-induced deformation of the bus bar holder during soldering
2Ease of manufacture
If the wiring member is routed through the bus bar holder to connect external power supply to the circuit board, then electrical connection is achieved, but heat from soldering deforms the bus bar holder, creating gaps that reduce sealability
Solution Approach 1:
The patent performs preliminary positioning of the circuit board and wiring member before the soldering process. The circuit board is pre-mounted on the holder at a position that anticipates thermal expansion and heat distribution during subsequent soldering operations, ensuring that the bus bar holder remains undeformed and maintains proper sealing gaps
3Productivity
If electronic components are increased to improve motor performance, then responsiveness is enhanced, but the circuit board outer edge is located closer to the bus bar holder, increasing heat deformation risk
Solution Approach 1:
The patent resolves the spatial conflict between increased electronic components and heat deformation risk by transitioning from a radial layout to an axial layout. This dimensional reorganization allows more electronic components to be accommodated on the circuit board without placing the board edge closer to the bus bar holder, thereby reducing heat deformation risk while maintaining enhanced responsiveness
Data Source
AI summary
A motor includes a rotor, a stator, a housing, a bus bar assembly, a cover fixed to the housing, and a circuit board. The bus bar assembly includes a bus bar, a wiring member, and a bus bar holder. The bus bar holder includes a main body portion, a connector portion, and a connection terminal holding portion. The cover directly or indirectly contacts a second side of the main body portion. The wiring member includes a circuit board connection terminal fixed to the connection terminal holding portion and an external power-supply connection terminal. At least one other portion of the wiring member is located closer to a second side of the motor than the external power-supply connection terminal.