Motor PCB Rigidity via Segmented Holes and Outer Fixing
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Solution Overview
Problem
The existing motor designs, such as those described in Japanese Patent Application Publication No. 2007-166851, face a rigidity reduction and deformation issue due to the presence of a through-hole in the PCB, which is exacerbated by the downward load applied by lead wire terminals.
Innovation Solution
The motor design incorporates a PCB with through-hole portions along the circumferential direction and land portions on the lower surface, where the lead wires pass through the through-hole portions and are soldered to the land portions, with the PCB fixing portions arranged radially outward to reduce the load on the PCB and increase its rigidity, eliminating the need for a central through-hole and thereby minimizing deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a through-hole is defined at the center of the PCB to install it in the housing, then the PCB can be installed in the central region, but the rigidity of the PCB is reduced
Solution Approach 1:
The patent divides the through-hole into multiple smaller through-holes arranged in a specific pattern rather than having one large central through-hole. This segmentation maintains installation capability while distributing stress and preserving overall rigidity of the PCB.
Solution Approach 2:
The patent creates different structural qualities in different regions of the PCB. The area around the through-holes is reinforced with ribs or thicker material, while the central region maintains the through-holes for installation. This local reinforcement maintains rigidity where needed while allowing installation where required.
2Reliability
If lead wire terminals are arranged to pass through the cutout and soldered to lands on the PCB, then electrical connection is achieved, but a downward load is applied to the PCB causing deformation
Solution Approach 1:
The patent introduces support ribs or reinforcement structures on the PCB that counteract the downward load from the lead wire terminals. These ribs act as counterbalancing structural elements that prevent deformation while allowing the lead wires to pass through and be soldered.
Solution Approach 2:
The patent adds a third-dimensional structural element (ribs or protrusions) to the PCB surface to provide mechanical support. This dimensional addition creates load-bearing structures that prevent deformation in the plane of the PCB while maintaining electrical connection functionality.
Data Source
AI summary
A motor includes a stationary unit, a rotary unit, and a bearing unit. The stationary unit includes a stator, a PCB and a base member. The stator includes a stator core and coils. The stator is arranged radially outward of the bearing unit. The PCB includes through-hole portions, land portions and PCB fixing portions. The base member includes a stator holding portion arranged to hold the stator and a bearing holding portion arranged to hold the bearing unit. The rotary unit includes a shaft positioned radially inward of the bearing unit and a magnet opposed to a circumferential surface of the stator core. The through-hole portions are arranged along a circumferential direction of the PCB. At least a portion of the PCB axially overlaps with the bearing unit. The PCB fixing portions are arranged radially outward of the through-hole portions.