Stator Coil End Axial Size Reduction via Inner Bending
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Solution Overview
Problem
Conventional stators with concentrically wound coils experience an increase in axial size due to the bent lead-side coil end conductors being positioned on the axially outer side relative to the coil end peak portions, leading to a larger stator size.
Innovation Solution
The stator design includes a coil end portion with peak portions projecting axially outward and lead wire portions that have an extension and a bent portion, where at least part of the bent portion is positioned on the stator core side within the space between adjacent peak portions in the radial direction, preventing the axial size increase by bending the lead wire portion on the axially inner side.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the lead-side coil end conductor is bent on the axially outer side with respect to the peak portions of the coil end portion, then the coil end portion structure is simplified, but the axial size of the stator is increased
Solution Approach 1:
Instead of bending the lead-side coil end conductor on the axially outer side as in conventional designs, this patent inverts the bending direction to the axially inner side. Specifically, the bent portion is positioned on the stator core side with respect to the peak portions in the axial direction, which reduces the axial size while maintaining structural simplicity
Solution Approach 2:
The patent utilizes the radial dimension to resolve the axial size issue. By positioning the bent portion in the radial space between adjacent peak portions (closer to the stator core), the design effectively moves the problem from the axial dimension to the radial dimension, allowing compact axial configuration without compromising electrical connectivity
2Length of moving object
If the bent portion is positioned closer to the peak portions in the axial direction, then the lead wire portion length is reduced, but the risk of contact between the bent portion and peak portions increases
Solution Approach 1:
The patent applies local quality by precisely positioning the bent portion in a specific radial location between adjacent peak portions. The bent portion is placed on the stator core side with respect to the peak portions, creating a localized configuration that minimizes both the lead wire length and the risk of contact by utilizing the radial space efficiently
Solution Approach 2:
The space between adjacent peak portions acts as an intermediary region that accommodates the bent portion. This intermediate space serves as a buffer zone that allows the bent portion to be positioned close to the peak portions axially while maintaining radial separation, thus reducing lead wire length without increasing contact risk
Data Source
AI summary
A stator, wherein the coil unit includes a coil end portion projecting from an axial end face of the stator core; the coil end portion includes a plurality of peak portions projecting axially outward and arranged in a circumferential direction, and a plurality of lead wire portions for supplying electric power to the coils; and each of the lead wire portions includes an extension portion extending at least in an axial direction, and a bent portion that is bent at least from the axial direction to a radial direction, at least a part of the bent portion being disposed on a stator core side with respect to the peak portions in the axial direction, in a space between the peak portions that are closest to the extension portion in the radial direction and that are adjacent in the circumferential direction.