Oil-Immersed EC Motor Thermal Management via Partition Wall
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Solution Overview
Problem
Existing DC motors face challenges in manufacturing efficiency, axial length, weight, heat dissipation, and assembly complexity, particularly when integrating electronics within an oil-filled compartment.
Innovation Solution
The design features a stator with multi-phase winding, a permanent magnet rotor, and a housing component that includes a guide plate with press-fit contacts and a cooling plate for improved heat dissipation, using thermosetting materials for sealing and snap-fastening elements to simplify assembly and reduce weight, eliminating the need for external heat sinks and complex fastening systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If electronics are integrated into the oil-filled motor compartment, then the motor achieves compact design and reduced axial length, but the electronics are exposed to harmful oil effects
Solution Approach 1:
The motor is divided into two separate compartments: an oil-filled motor compartment containing the stator and rotor, and a separate electronics compartment housing the circuit board. These compartments are separated by an oil-tight partition wall, allowing the electronics to be protected from oil while maintaining a compact integrated design.
Solution Approach 2:
An oil-tight partition wall acts as an intermediary barrier between the oil-filled motor compartment and the electronics compartment. This partition wall with integrated sealing ensures complete oil tightness, preventing oil from reaching the electronics while allowing both compartments to function together in a compact motor structure.
2Device complexity
If traditional wiring methods are used in the stator region, then the motor structure is simple, but the wiring length is excessive and manufacturing complexity increases
Solution Approach 1:
Instead of bringing wiring from the stator region to the electronics, the invention inverts the approach by bringing contact elements from the electronics compartment through the partition wall directly to the stator windings. This eliminates excessive wiring length and simplifies the overall wiring structure.
Solution Approach 2:
The contact elements penetrate through the partition wall in the axial direction, creating a direct three-dimensional connection between the electronics compartment and the stator windings. This dimensional approach eliminates the need for long radial wiring paths through the stator region.
3Reliability
If conventional fastening methods with screws and pre-tensioning are used, then the assembly is reliable, but the manufacturing process becomes complex and time-consuming
Solution Approach 1:
The invention replaces complex mechanical fastening systems (screws, pre-tensioning mechanisms) with simple snap-fastening elements. These snap-fastening elements provide reliable mechanical connection through elastic deformation and geometric interlocking, simplifying the manufacturing process while maintaining assembly reliability.
Solution Approach 2:
The snap-fastening elements utilize elastic deformation parameters to achieve reliable connection. The elastic materials deform during assembly to engage with corresponding features, providing reliable mechanical connection without requiring complex fastening procedures or specialized assembly tools.
4Temperature
If heat dissipation is achieved through external heat sinks, then the heat removal is effective, but the motor axial length and weight increase
Solution Approach 1:
The cooling plate is merged with the partition wall separating the motor compartment and electronics compartment. This integration allows the partition wall to serve dual functions: oil-tight separation and heat dissipation. The cooling plate is tightly pressed onto the substrate by mounting bosses, enabling effective heat removal without external heat sinks.
Solution Approach 2:
The partition wall is designed with multi-functionality: it provides oil-tight separation between compartments, serves as a mounting structure for the cooling plate, and acts as a heat dissipation path. The mounting bosses integrated into the partition wall provide both mechanical support and thermal conduction to external heat-dissipating surfaces.
5Ease of manufacture
If the housing component is made entirely of plastic, then the manufacturing is economical and simplified, but the structural strength may be insufficient
Solution Approach 1:
The housing component uses composite construction with thermosetting plastic material providing the main housing structure and integrated metal inserts or reinforcement elements at critical locations. This composite approach maintains the economical plastic injection molding process while providing enhanced structural strength where required for mounting bearings and withstanding mechanical loads.
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 approach results in a compact, lightweight DC motor with enhanced heat dissipation and simplified manufacturing and assembly processes, ensuring reliable oil-tight sealing and efficient heat transfer, while reducing the number of parts and assembly complexity.
Implementation Method 1
Due to the heat removal through the cooling plate and the mounting bosses, the heat can be drawn away to a connected aggregate
Implementation Method 2
The heat dissipation from the circuit board to the cooling plate can be improved through elastic means
Implementation Method 3
The heat dissipation from the circuit board to the cooling plate can be improved through elastic means
Implementation Method 4
the heat dissipation from power components be passed via thermal vias in the circuit board to the cooling plate
Data Source
AI summary
An electronically commutated DC motor has a stator wound with a multi-phase stator winding, a permanent magnet rotor mounted rotatably about a motor axis, a circuit board, a guide plate electrically connected to the winding and a housing component. In one implementation, a DC motor can easily be manufactured with the fewest possible process steps, which exhibits a short axial length and a low weight as well as good heat-dissipation properties. It is also an object of the invention to create a DC motor with integrated electronics, whose motor interior can be filled with oil, and which holds the electronics sealed against this oil. For reasons of logistics, an attempt is also made for partial components, such as the electronics, to be designed such that they are capable of complete prior assembly and testing.