Brushless Motor Thermal Management via Segmented Housing
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Solution Overview
Problem
Existing brushless motors with sealed electronics face issues of heat exposure affecting control electronics, unreliable connections between electronics and stator windings, and complex coupling with fan ducts, leading to inefficiencies and reliability problems.
Innovation Solution
A brushless motor design with open casing for heat dissipation, featuring sealed control electronics separate from the stator, using flexible and soldered connections with tubular seals to ensure reliability and protection from external agents, and a cap with a flange for easy mounting in a diffuser or fan duct, enhancing fluid dynamics and assembly precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the control electronics are positioned inside the motor housing close to the stator windings, then the motor structure is compact, but the electronics are affected by temperature increase from motor operation
Solution Approach 1:
The motor is divided into two separate housings: a first housing containing the stator and control electronics, and a second housing containing the rotor. This segmentation allows the electronics to be thermally isolated from the stator windings while maintaining a compact overall structure.
Solution Approach 2:
A heat sink is introduced as an intermediary thermal management component between the electronics and the motor environment. The heat sink actively manages thermal transfer, allowing the electronics to operate in a cooler environment while still being positioned close to the stator for compactness.
2Reliability
If connectors are used to connect stator windings to the printed circuit board, then assembly is simplified, but connection reliability decreases due to vibrations and wear
Solution Approach 1:
The stator windings are directly integrated with the printed circuit board through soldering, merging the electrical connection function into the manufacturing process itself. This eliminates separate connectors and their associated reliability issues while maintaining assembly efficiency.
3Object-affected harmful factors
If the casing is closed to protect electronics, then protection from outside agents is improved, but heat dissipation capability deteriorates
Solution Approach 1:
The motor housing is segmented into sealed and open portions. The first housing containing the electronics can be sealed for protection, while the second housing with the rotor remains open for heat dissipation. This allows simultaneous achievement of electronic protection and thermal management.
Solution Approach 2:
The electronics are extracted from the open motor housing environment and placed in a separate, sealed first housing. This extraction allows the main motor housing to remain open for effective heat dissipation while the electronics enjoy protected, sealed accommodation.
4Object-affected harmful factors
If the closing cap is oversized to accommodate a closed housing for electronics, then electronics protection is improved, but the motor dimensions increase
Solution Approach 1:
The housing is segmented into a first housing for electronics and a second housing for the rotor, allowing optimized sizing of each portion. The electronics housing can be compact and sealed without requiring an oversized overall motor structure.
Solution Approach 2:
The electronics are positioned in a different spatial arrangement within the segmented housing structure, allowing protection without requiring increased motor dimensions. The sealed first housing integrates efficiently within the overall motor footprint.
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 solution effectively protects electronics from heat, improves connection reliability, simplifies installation, and enhances the performance of ventilation units by maintaining electronic components outside the motor's temperature environment while ensuring airtight seals and reduced magnetic interference.
Implementation Method 1
sealing means at least partly inserted between the casing and the cap, wherein the sealing means comprise a first seal portion at the seat for the bearing, a second seal portion positioned between the casing and the cap, a substantially annular third seal portion associated with the second portion of the cap and facing towards the casing
Implementation Method 2
The motor is of the open type with sealed control electronics and preferably for driving a fan in a ventilation unit. One type of motor, called the open type, has apertures on the casing which allow the circulation of air for cooling the stator windings.
Data Source
AI summary
An electric motor including a casing; a cap coupled to the casing to form a housing of the electric motor; a stator, including a plurality of poles and a three-phase winding, each phase having one end, housed in the housing; a rotor inserted in the housing and rotatably constrained to it; a control printed circuit board connected to the stator; the outside of the housing including a seat for the printed circuit board in communication with the inside of the housing by means of at least one hole; the printed circuit board is housed in the seat and the electric motor includes a rigid system for sealed connection between the printed circuit board and the winding at the hole.