Brushless Motor Terminal Fixing Blocks Radial Dimension Reduction
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Solution Overview
Problem
Existing brushless motors face issues with increased radial dimension, vibration, noise, and iron loss due to fractional slot winding, which affects efficiency and manufacturing complexity.
Innovation Solution
The design incorporates a stator with a specific arrangement of terminal fixing blocks and wire-through notches on the upper insulating bobbin, allowing the lead wire to be routed along the circumference, reducing the radial dimension and optimizing the winding structure to minimize harmonics and iron loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the terminal fixing block is located along the radial direction of the upper insulating bobbin with the terminal socket along the circumference, then the insulation displacement connection terminal can be connected, but the lead wire must be routed out along the radial direction which increases the radial dimension of the stator
Solution Approach 1:
The patent inverts the conventional arrangement by positioning the terminal socket along the radial direction instead of the circumferential direction, and the wire-through notch along the circumferential direction instead of radially. This inversion allows the lead wire to be routed circumferentially through the wire-through notch, eliminating the need for radial routing and thus reducing the radial dimension of the stator while maintaining terminal connection functionality.
2Productivity
If fractional slot winding is used to reduce slot area occupied by insulating bobbin, then the actual slot filling factor is improved and winding resistance is reduced, but armature reaction includes higher harmonics which increases iron loss
Solution Approach 1:
The patent changes the geometric parameters of the terminal fixing block, specifically the angle of the wire-through notch relative to the radial direction, and the position of the terminal socket. These parameter changes optimize the winding structure to minimize harmonics in the armature reaction, thereby reducing iron loss while maintaining the benefits of fractional slot winding for slot filling factor and winding resistance.
Data Source
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AI summary
A brushless motor includes a stator having a stator core; and an upper insulating bobbin connected to an upper face of the stator core, an upper surface of the upper insulating bobbin having a plurality of terminal fixing blocks and a plurality of wire through blocks, each terminal fixing block having a wire-through notch for positioning a wire and a terminal socket electrically connected with the wire. A first angle between a wire slot of each terminal fixing block and a radial direction of the upper insulating block is 50°-130°, and a second angle between a terminal socket of each terminal fixing block and a circumference direction of the upper bobbin is 50°-130°.