BLDC Motor Housing with Screw Grounding for Static Dissipation
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Solution Overview
Problem
Conventional BLDC motors face issues with resin molding damaging printed circuit boards during high-temperature injection, increased manufacturing costs due to complete component replacement, and static electricity damaging bearings.
Innovation Solution
A motor design with a housing formed by insert injection molding that separates the stator assembly from the printed circuit board, includes a hollow portion with exposed power terminal pins, and uses screws and grounding pins to manage static electricity, enhancing assembly ease and heat radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If insert injection molding is performed with the printed circuit board disposed on the stator, then the housing can be molded together with the stator and printed circuit board, but the devices mounted on the printed circuit board are broken or damaged due to high temperature conditions
Solution Approach 1:
The patent divides the manufacturing process into separate stages: first molding the housing with the stator only, then separately assembling the printed circuit board onto the stator after the housing has cooled. This segmentation prevents the high-temperature injection molding process from damaging the electronic devices on the printed circuit board while still achieving integrated housing-stator construction.
Solution Approach 2:
The printed circuit board is pre-assembled onto the stator before the housing injection molding process begins, but the housing is molded separately in a first stage without the printed circuit board. This preliminary arrangement allows the board to be in position for final assembly while avoiding exposure to damaging molding temperatures.
2Ease of manufacture
If the printed circuit board is disposed on the stator before insert injection molding, then electrical activation can be performed, but the entire assembly must be thrown away and manufacturing cost increases when damage occurs
Solution Approach 1:
The patent separates the housing molding process from the printed circuit board assembly, allowing the housing and stator to be molded together as one unit while the printed circuit board is assembled separately. This segmentation enables replacement of only the printed circuit board if damaged, rather than discarding the entire assembly, thereby reducing manufacturing costs.
Solution Approach 2:
The patent enables recovery and reuse of the housing and stator assembly by allowing separate replacement of the printed circuit board. When the printed circuit board is damaged, only that component needs to be discarded and replaced, while the expensive housing and stator components are recovered and reused, reducing overall manufacturing costs.
3Strength
If a cover of the housing is made of metal material, then the housing structure is strengthened, but static electricity generated during motor rotation damages the bearing
Solution Approach 1:
The patent introduces a grounding pin as an intermediary element between the metal housing cover and the stator core. This grounding pin acts as a mediator that provides a controlled path for static electricity to dissipate from the bearing area to the stator core, preventing static accumulation that would damage the bearing while maintaining the structural benefits of the metal cover.
Solution Approach 2:
The patent extracts the static electricity management function from the housing cover structure itself by adding a separate grounding pin component. This extraction allows the metal cover to maintain its strength-providing function while the grounding pin handles the static electricity dissipation, preventing bearing damage without compromising the cover's structural integrity.
4Loss of energy
If radiation plate is mounted after electrical connection of the printed circuit board, then heat radiation can be achieved, but assembly work becomes difficult and manufacturing process is complicated
Solution Approach 1:
The patent merges the radiation plate with the housing structure, making the housing itself serve as the radiation surface. This integration eliminates the need for a separate radiation plate component and simplifies the assembly process, as the housing is already molded with the necessary heat radiation features built in, while still achieving effective heat dissipation.
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
The design facilitates easy assembly, prevents bearing damage from static electricity, reduces manufacturing costs, and improves heat radiation efficiency.
Implementation Method 1
a housing formed by means of insert injection molding in such a manner as to locate a stator assembly inside a mold
Implementation Method 2
at least one or more screws adapted to be inserted into screw holes formed on the top peripheral portion of the housing and having screw heads formed thereon, the screw heads being engagedly coupled to the peripheral portion of the end cover and the end portions of the screws being brought into contact with the stator core
Implementation Method 3
the static electricity, which is generally generated during the rotation of the motor, is generated from a bearing inside the cover
Data Source
AI summary
Disclosed is a motor including: a housing formed by means of insert injection molding in such a manner as to locate a stator assembly inside a mold, the stator assembly having a stator core, an upper insulator adapted to be coupled to the upper side of the stator core, and a lower insulator adapted to be coupled to the lower side of the stator core; a printed circuit board adapted to mount an integrated circuit device thereon; and at least one or more screws adapted to be inserted into screw holes formed on the top peripheral portion of the housing and having screw heads formed thereon, the screw heads being engagedly coupled to the peripheral portion of the end cover and the end portions of the screws being brought into contact with the stator core.