Brushless Motor Stator Terminal Radial Inversion for Axial Compactness
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Solution Overview
Problem
Existing brushless motors face challenges in miniaturization due to the need for space between the stator core and circuit board, as the joining portion of the connecting terminal is positioned between them, limiting the motor's axial compactness.
Innovation Solution
A stator design with a connecting terminal that includes a fixing portion, an outward projecting portion, and a joining portion positioned outside the stator core in the radial direction, allowing the circuit board to approach the stator core and reducing axial space, while the joining portion is opened outward to securely connect the coil ends without inward movement, enhancing reliability and yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the joining portion of the connecting terminal is positioned between the stator core and circuit board in the axial direction, then the connecting terminal can be securely fixed, but the circuit board cannot approach the stator core closely, preventing miniaturization in the axial direction
Solution Approach 1:
The joining portion is repositioned from the axial direction to the radial direction, specifically positioned outside the stator core in the radial direction. This dimensional change allows the circuit board to approach the stator core closely in the axial direction while the joining portion extends radially outward to securely connect the coil ends, resolving the contradiction between miniaturization and connection reliability.
2Volume of moving object
If the joining portion is positioned inside the stator core, then the structure is compact, but the coil ends cannot be securely connected without risk of loosening
Solution Approach 1:
Instead of positioning the joining portion inside the stator core as in conventional designs, the joining portion is inverted to be positioned outside the stator core in the radial direction. This inversion allows the joining portion to be opened outward to securely connect the coil ends, preventing inward movement and loosening, while maintaining compact radial space utilization.
3Device complexity
If the connecting terminal uses a conventional structure with separate terminal base, then the assembly is simple, but it requires additional axial space for positioning the joining portion
Solution Approach 1:
The terminal fixing base is merged with the insulator, forming an integrated structure. The connecting terminal is fixed to this merged structure, eliminating the need for a separate terminal base. This merging reduces the axial length of the stator assembly while maintaining structural simplicity and ease of assembly.
Data Source
AI summary
A stator of a brushless motor includes: a stator core; a coil that is formed by winding a conducting wire around the stator core; a connecting terminal that is electrically connected to an end portion of the coil; and a terminal fixing base that has an electrical insulation property, is attached to an end portion of the stator core on one side in an axial direction thereof, and fixes the connecting terminal. The connecting terminal includes a fixing portion that is fixed to the terminal fixing base, an outward projecting portion that extends from the fixing portion toward outside in a radial direction than the stator core, and a joining portion that overlaps with the outward projecting portion in the axial direction and is positioned outside the stator core in the radial direction. The joining portion is opened outward in the radial direction.