Brushless Motor Coil-to-PCB Solder Layout for Shorter Axial Length
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Solution Overview
Problem
Existing brushless motors face challenges in miniaturization due to the need for space to connect driving coils and circuit boards via terminal pins along the rotor's axial direction, limiting the reduction of the motor's overall size.
Innovation Solution
The on-vehicle brushless motor device integrates a direct connection between the electronic substrate and coil wire using a soldering portion, eliminating the need for rigid terminal components, and incorporates a holder unit with a guide hole to facilitate smooth assembly and reduce the axial dimension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If terminal pins are used to connect driving coils and circuit boards along the axial direction, then reliable electrical connection is achieved, but the axial length of the motor increases
Solution Approach 1:
The patent transitions the connection arrangement from the axial direction to the radial direction. The terminal pins are arranged radially outward from the rotor axis, and the circuit board is positioned in the radial direction rather than extending axially. This dimensional change allows electrical connection while reducing axial length.
Solution Approach 2:
The terminal pins are nested within the radial space between the rotor and stator, utilizing the existing radial clearance. The circuit board is positioned in the radial direction, nesting the connection structure within the motor's radial envelope rather than extending axially, thus achieving connection without increasing axial length.
2Reliability
If terminal pins are arranged along the axial direction for soldering connection, then electrical connectivity is ensured, but the space for arranging terminal pins and soldering increases the overall device size
Solution Approach 1:
The connection structure moves from axial arrangement to radial arrangement. Terminal pins extend radially rather than axially, and the circuit board is positioned in the radial plane. This redistributes the connection volume from the axial dimension to the radial dimension, reducing overall device volume.
Solution Approach 2:
The terminal pin arrangement merges with the rotor structure, where terminal pins are positioned to extend from the rotor body. The circuit board is integrated into the radial space, combining the connection function with the existing motor structure rather than adding separate axial components.
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
This configuration allows for a more compact design, improved assembly efficiency, and reduced welding points, enhancing the miniaturization and assemblability of the motor device.
Implementation Method 1
a soldering portion that electrically connects the electronic substrate and an end portion of a terminal pin of the coil or the vicinity thereof
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
[Subject] To provide an on-vehicle brushless motor device capable of being downsized with respect to an axial direction of a rotor and a method of manufacturing the same. [Solution] The on-vehicle brushless motor device 1 includes a brushless motor 10 and an electronic substrate 30. The brushless motor 10 includes a rotor 12 and a stator 16 including a plurality of coils 18 arranged around the rotor 12. The electronic substrate 30 is arranged on a side opposite to an output side of the brushless motor 10 along a plane P intersecting an axial direction X. The on-vehicle brushless motor device 1 further includes a soldering portion 40 that connects a coil wire 20 of the coil 18 and the electronic substrate 30.