Electric Power Steering Drive Thermal Management
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Solution Overview
Problem
Existing electric drive devices for electric power steering systems in automotive vehicles face inefficiencies in heat dissipation and component distribution, leading to a larger number of parts and a less compact design.
Innovation Solution
The electric drive device incorporates a power board that covers the cross-section of the motor case, allowing for better distribution of elements and improved heat dissipation through a heat sink, reducing the number of parts and enhancing thermal efficiency while achieving a more compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the power board is arranged to cover the cross section of the motor case, then the number of parts is reduced and the design becomes more compact, but the heat dissipation capability may be compromised due to limited surface area for heat sink attachment
Solution Approach 1:
The heat sink transitions from a planar configuration to a three-dimensional finned structure, utilizing vertical space to increase heat dissipation surface area without expanding the horizontal footprint. This allows the heat sink to attach to the limited surface area of the power board while providing extensive heat dissipation capability through vertically extending fins.
Solution Approach 2:
The heat sink is integrated within the existing motor case structure, with the finned portion extending into the available internal space. This nesting approach allows the heat dissipation structure to utilize the motor case volume without requiring additional external space, thereby maintaining compactness while improving heat dissipation.
2Loss of energy
If the power board covers the cross section of the motor case, then the thermal efficiency improves by directing heat perimetrally towards the motor case, but the space for arranging other components is reduced
Solution Approach 1:
The power board is positioned to cover specific high-heat-generation areas of the motor, creating localized thermal management zones. The heat sink is strategically placed to contact these specific areas, concentrating heat dissipation efforts where they are most needed rather than distributing them uniformly throughout the motor case.
Solution Approach 2:
The heat sink utilizes the vertical dimension by extending fins upward from the power board surface, converting a two-dimensional attachment problem into a three-dimensional heat dissipation solution. This allows extensive heat dissipation surface area to be achieved within the limited horizontal space of the motor case cross-section.
3Ease of manufacture
If the heat sink, power board and control board are arranged after the motor in a linear sequence, then the assembly is straightforward, but the device occupies more axial space and becomes less compact
Solution Approach 1:
The heat sink is integrated with the motor case structure, merging the heat dissipation function with the existing motor housing. This consolidation eliminates the need for separate heat sink mounting space in the axial direction, as the heat sink becomes part of the motor assembly rather than a separate component in the sequence.
Solution Approach 2:
The control board and other components are arranged within the radial space of the motor case rather than extending the axial length. Components are nested within the available cross-sectional area, utilizing the motor case volume efficiently without increasing the overall axial footprint of the device.
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 configuration reduces the number of parts, improves thermal efficiency by directing heat peripherally towards the motor case, and results in a more compact device with enhanced heat dissipation, addressing the inefficiencies in existing technologies.
Implementation Method 1
a heat sink absorbing and dissipating the heat generated by the power board
Data Source
AI summary
Electric drive device for an electric power steering system that includes an electric motor with a motor case, and a motor shaft with a drive end, an electronic control unit that controls the drive of the motor, According to one embodiment the electronic control unit includes a power board and a heat sink. A connector coupled to a side of the electric drive device is at least partially maintained in its position with the use of one or more projections projecting from a first area of the connector that reside within one or more corresponding housings located in a peripheral region of the heatsink.