Internal Rotor Motor with Integrated Plastic Bushing
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Solution Overview
Problem
Existing electric motors for fluid-handling systems, such as oil separators in vehicles, face challenges in providing a hermetic seal and efficient cooling while maintaining cost-effectiveness and compactness.
Innovation Solution
An internal-rotor electric motor design featuring a complex injection-molded plastic structure with a bushing and winding supports, which creates a sealed boundary between the rotor and stator regions, allowing fluid circulation for cooling and lubrication, and integrates electronic components for reliable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hermetic seal between rotor and stator regions is implemented using traditional sealing methods, then sealing reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines multiple sealing functions into a single integrated plastic structure that is injection-molded onto the pole pieces. This bushing structure integrates the sealed boundary between rotor and stator regions, eliminating the need for separate sealing components and reducing overall device complexity while maintaining hermetic sealing reliability.
Solution Approach 2:
The plastic bushing structure serves multiple functions simultaneously: it provides hermetic sealing between the rotor and stator regions, supports the rotor bearing, and enables fluid circulation for cooling. This multi-functional design reduces the number of separate components needed and simplifies the overall motor structure.
2Temperature
If fluid circulation for cooling is implemented, then thermal management is improved, but sealing complexity increases
Solution Approach 1:
The plastic bushing structure simultaneously provides hermetic sealing and enables fluid circulation channels for cooling the rotor bearing. The integrated design allows cooling fluid to flow through the bushing structure without requiring separate sealing mechanisms, thus improving thermal management while avoiding increased sealing complexity.
3Ease of manufacture
If traditional separate component assembly is used for stator and rotor regions, then manufacturing flexibility is improved, but manufacturing cost and assembly complexity increase
Solution Approach 1:
The patent integrates the sealing structure, rotor support, and stator region boundary into a single plastic component that is injection-molded onto the pole pieces. This reduces the number of separate parts and assembly steps, lowering manufacturing cost and simplifying assembly while maintaining the functional separation between stator and rotor regions.
4Volume of moving object
If a compact motor design is implemented, then space utilization is improved, but cooling efficiency may deteriorate
Solution Approach 1:
The cooling fluid circulation channels are integrated within the bushing structure itself, nesting the cooling function inside the existing sealing and support component. This allows effective cooling of the rotor bearing without requiring additional external cooling components, thus maintaining compact motor volume while ensuring adequate thermal management.
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 achieves a durable hermetic seal, efficient cooling, and cost-effective manufacturing, enabling the motor to be compact and lightweight while maintaining reliable operation in fluid environments.
Implementation Method 1
the said bushing of the plastic structure is suitable for a durably and absolutely reliable sealed boundary between two regions of the external stator
Implementation Method 2
The possibility exists of effective cooling of the electric motor by the fluid circulating inside the bushing (in the rotor space)
Implementation Method 3
the fluid circulating inside the bushing (in the rotor space)
Implementation Method 4
it may contribute to lubrication of the rotor bearing
Data Source
AI summary
An electric motor, especially for a fluid-handling system, comprises an external stator and an internal rotor mounted to rotate around an axis. The said external stator comprises a multiplicity of ferromagnetic pole pieces disposed around the axis and having winding cores extending substantially radially, an injection-molded plastic structure having a bushing and, molded thereon, winding supports enveloping the winding cores, as well as stator windings received on the winding supports. The bushing comprises a sleeve having a closed inner face extending radially inside the pole pieces and an end piece that closes the sleeve in the end region. The rotor is disposed inside the sleeve and mounted in a bearing disposed in the end piece.