Electronic Fluid Pump Frame for EMC Shielding and Coaxiality
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Solution Overview
Problem
Existing automotive electronic fluid pumps face challenges in achieving high electromagnetic efficiency and compatibility due to the lack of a metal pump housing, which results in poor electromagnetic shielding and increased weight and cost, while maintaining precise coaxiality and dynamic sealing between the motor stator and rotor.
Innovation Solution
A deep-drawn metal sheet body is used to create a motor housing frame with a support collar and transversal separation wall, supporting a non-ferromagnetic separation tube, providing electromagnetic shielding and thermal conductivity, while maintaining coaxiality and separating wet and dry chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a metal pump housing is used to provide electromagnetic shielding, then electromagnetic compatibility is improved, but weight and cost increase
Solution Approach 1:
The motor housing is segmented into two functional parts: a plastic housing for structural enclosure and a separate metal frame (made via reverse-drawing of deep-drawn metal sheet) that provides electromagnetic shielding. This segmentation allows the shielding function to be provided only where needed without enclosing the entire housing in metal, thus reducing weight while maintaining EMC.
Solution Approach 2:
The metal frame is positioned locally around the motor stator where electromagnetic shielding is most critical, rather than using metal throughout the entire housing. The frame's cylindrical shape with radial support for the stator provides targeted shielding in the regions where electromagnetic interference would most affect motor performance.
2Object-affected harmful factors
If a metal pump housing is used to provide electromagnetic shielding, then electromagnetic compatibility is improved, but cost increases
Solution Approach 1:
The housing is divided into plastic and metal components, each manufactured by optimal processes (injection molding for plastic, deep-drawing and reverse-drawing for metal), then assembled. This avoids the high cost of manufacturing an entire metal housing while providing shielding only where necessary.
Solution Approach 2:
The metal frame is formed through reverse-drawing of deep-drawn metal sheet, a process that efficiently creates the required cylindrical shape with integrated support features. This manufacturing approach reduces material waste and processing steps compared to traditional metal housing fabrication methods.
3Weight of stationary object
If a plastic pump housing is used to reduce weight and cost, then weight and cost are improved, but electromagnetic shielding is insufficient
Solution Approach 1:
The metal frame acts as an intermediary component between the plastic housing and the electromagnetic field. It provides the necessary shielding function that plastic cannot provide, while the plastic housing provides the structural enclosure and cooling functions. The frame is electrically connected to ground to effectively shield the motor stator.
4Reliability
If dynamic sealings are used between wet and dry parts, then fluid separation is improved, but reliability decreases due to seal failure
Solution Approach 1:
The problematic dynamic sealing between wet and dry parts is completely removed from the design. Instead, a static fluid separation is achieved through the motor housing frame structure itself, which provides both mechanical support and fluid separation through integrated separation walls and sealed chambers.
Solution Approach 2:
The motor housing frame combines multiple functions: structural support for the motor stator, fluid separation between wet and dry chambers, and mounting for the separation tube. This integration eliminates the need for separate sealing components and reduces overall device complexity.
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 achieves good electromagnetic compatibility and efficiency by using a metal frame for shielding, reducing weight and cost, and ensuring precise coaxial alignment, with improved thermal conductivity and dynamic sealing-free operation.
Implementation Method 1
an electromagnetic motor stator (50, 52) with stator coils (52), a rotor (54, 30) with a motor rotor (54) and a pump rotor (34) and a rotor shaft (30), wherein the motor rotor (54) can be electromagnetically driven by the electromagnetic motor stator (50, 52)
Implementation Method 2
The motor housing frame is made from a deep-drawn metal sheet body. The support collar of the motor housing frame is made via a reverse-drawing of the deep-drawn metal sheet body
Data Source
AI summary
An automotive electronic fluid pump includes an electric pump motor. The electric pump motor includes a motor stator having stator coils, a rotor having a motor rotor, a pump rotor and a rotor shaft, a motor electronics arranged within a dry electronics chamber, a separation tube which fluidically separates a wet motor rotor chamber from a dry motor stator chamber, and a motor housing frame. The motor rotor is driven by the motor stator. The motor electronics has power semiconductors which energize the stator coils. The separation tube has a support section. The motor housing frame has a support collar, a frame bottom wall, and a frame side wall. The support collar directly supports the support section. The frame bottom wall defines a transversal separation wall which fluidically separates the wet motor rotor chamber from the dry electronics chamber. The frame side wall supports the electromagnetic motor stator