Three-Phase Brushless Fan Integrated Coil Assembly
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Solution Overview
Problem
Conventional three-phase brushless motor fans face challenges such as complex coil assembly processes, high defect rates, and increased assembly costs due to the need for welding multiple coils on the circuit board, as well as issues with thickness and vibration caused by the Hall sensor and cogging torque in single-phase brushless motor fans.
Innovation Solution
A three-phase brushless fan design featuring a metal seat and plastic outer frame for structural strength, with winding columns on the circuit board allowing conductive wires to form coils without individual welding, and a side plate to separate the driving element from the coils, reducing assembly complexity and height while preventing deformation during rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple coils are placed on the circuit board and welded one by one, then the three-phase brushless fan can be assembled, but the defect rate and assembly cost increase
Solution Approach 1:
The patent merges multiple separate coils into a single integrated coil structure. Instead of placing and welding multiple individual coils on the circuit board, the invention uses one coil that is divided into multiple winding sections, each section corresponding to a different phase. This integration eliminates the need for multiple separate welding operations, thereby reducing assembly cost and defect rate while maintaining the three-phase functionality.
2Ease of operation
If the Hall sensor is placed below the rotor, then the fan can sense magnetic field, but the fan thickness increases
Solution Approach 1:
The patent extracts and eliminates the Hall sensor from the fan structure. Instead of using a Hall sensor to detect magnetic field and rotor position, the invention employs a sensorless control method that uses the back-EMF signals from the coils to determine rotor position. This removal of the Hall sensor eliminates the need for additional space below the rotor, thereby reducing fan thickness while maintaining magnetic field sensing capability through alternative means.
3Ease of operation
If cogging torque is increased to avoid dead point, then the fan can start reliably, but vibration and noise increase
Solution Approach 1:
The patent employs dynamic control strategies to manage cogging torque during startup and operation. The sensorless control system dynamically adjusts the current waveform and switching timing based on rotor position estimation, allowing the fan to overcome dead points without relying on excessive static cogging torque. This dynamic approach reduces the harmful vibrations and noise that would result from high cogging torque, while maintaining reliable startup performance.
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 design reduces defect rates and assembly costs by simplifying coil formation, enhances structural integrity, and achieves a thinner profile by spacing the driving element from the coils, resulting in smoother operation and reduced vibration.
Implementation Method 1
a plurality of winding columns of a winding part are disposed around the axis part, and a fan of a rotating module is accommodated in the receiving groove... a circuit board of a circuit module is accommodated in the receiving groove, the circuit board is electrically connected to a plurality of coils formed by winding at least one conductive wire on the plurality of winding columns
Implementation Method 2
a magnetic element includes at least one set of south magnetic portions with south magnetic pole and north magnetic portions with north magnetic pole staggered in arrangement and disposed around the axis coupling part
Data Source
AI summary
A three-phase brushless fan is disclosed. In the three-phase brushless fan, an outer shell member includes an axis part, and winding columns are disposed around the axis part, and the rotating module includes a fan, an axis coupling part pivoted to the axis part, and a magnetic element having south and north magnetic portions; a circuit board electrically connected to coils formed by winding a conductive wire on the winding columns. The number of the coils is three or a multiple of three, and the number of the coils is not equal a total amount of the south and north magnetic portions. As a result, winding the conductive wire to form the multiple coils can omit the operation of placing coils on the circuit board and save labor cost in welding two head ends of conductive wires on the circuit board one by one.