Electric Coolant Pump PCB Cooling With a Constant Thermal Gap

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Solution Overview

Problem

Existing electric coolant pumps face challenges in effective heat dissipation due to production-related dimensional variations and non-uniform heat transfer, leading to inefficiencies and increased costs.

Innovation Solution

A brushless electric coolant pump design with a plane separating can bottom wall and a parallel printed circuit board, supported by height-adjusted supporting means, ensuring a constant axial gap filled with a heat conductive material, allowing efficient heat transfer to the coolant.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a heat conductive paste is used to fill the axial gap between the printed circuit board and the separating can bottom wall, then heat transfer efficiency is improved, but production-related dimensional variations cause non-uniform heat transfer

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoiddimensional variations
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The supporting means are designed with adjustability, allowing the axial gap height to be individually adjusted for each pump unit. This dynamic adjustment compensates for production-related dimensional variations in the separating can and pump housing body, ensuring uniform heat transfer across all manufactured pumps despite variations in manufacturing precision.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the parameter of axial gap height from a fixed value to an individually adjustable value. By trimming the supporting means to different heights, the axial gap can be optimized for each specific pump configuration, ensuring consistent heat transfer performance despite variations in separating can and pump housing body dimensions.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If the axial gap height is individually adjusted for each pump, then heat transfer uniformity is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveheat transfer uniformityVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The supporting means are segmented into multiple discrete units, each capable of independent height adjustment. This segmentation allows individual trimming of each supporting means to compensate for dimensional variations in the separating can and pump housing body, achieving uniform heat transfer without requiring complex overall redesign.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The supporting means are trimmed to the required height before final assembly. This preliminary action ensures that the axial gap is correctly configured before the printed circuit board is installed, simplifying the overall manufacturing process by preparing components in advance rather than requiring complex adjustments during final assembly.

Inventive Principle:
Principle #10Preliminary action

3Temperature

If the printed circuit board is in direct contact with the separating can bottom wall, then heat transfer is maximized, but production variations cause non-uniform heat transfer

Engineering Contradiction:
Improveheat transfer maximizationVSAvoiddimensional consistency
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The heat conductive paste serves as an intermediary material between the printed circuit board and the separating can bottom wall. This paste fills the axial gap and provides a compliant thermal interface that compensates for dimensional variations, allowing heat transfer to be maximized without requiring direct rigid contact that would be sensitive to manufacturing tolerances.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The axial gap between the printed circuit board and separating can bottom wall is maintained at a controlled height rather than being eliminated entirely. This dynamic gap, filled with heat conductive paste, provides flexibility to accommodate production variations while maintaining effective heat transfer, avoiding the rigidity issues of direct contact.

Inventive Principle:
Principle #15Dynamics

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 design achieves reliable heat dissipation and reduced production costs by normalizing manufacturing tolerances and enhancing heat transfer efficiency, while eliminating the need for separate cooling circuits.

Implementation Method 1

The axial gap between the separating can bottom wall and the printed circuit board is filled with a heat conductive means, in particular with a heat conductive paste

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

The separating can bottom wall surface transfers heat to the circulating coolant at the wet side of the separating can

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 3

heat is transferred to the coolant circulating in the wet zone of the coolant pump and is thereby dissipated from the pump housing

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4240975B1Electric coolant pump
Publication Date: 2025.12.31 PIERBURG PUMP TECH
  • EP4240975B1 patent drawingFigure 1
  • EP4240975B1 patent drawingFigure 2~3

AI summary

The invention is directed to an electric coolant pump (10) for providing an automotive cooling circuit with coolant. The electric coolant pump (10) is provided with an electric motor (50) for driving the electric coolant pump (10), a pump housing (30) defined by a pump housing body (32), a separating can (20) comprising a substantially plane separating can bottom wall (25) lying in a cross plane, and a substantially cylindrical separating can shell (28) for fluidically separating a wet zone (12) from a dry zone (14) within the pump housing (30) of the electric coolant pump (10), and a printed circuit board (40) provided with electronic components for driving the electric motor (50). The plane printed circuit board (40) is arranged substantially parallel to and not in direct contact with the separating can bottom wall (25), so that a small axial gap (75) is defined between the separating can bottom wall (25) and the printed circuit board (40). The printed circuit board (40) is axially supported by at least three permanently height-adjusted supporting means (70) whereas the distal tip (71) of every supporting means (70) has been trimmed to define a height-constant axial gap (75) with a nominal gap height (h) between the printed circuit board (40) and the separating can bottom wall (25). The axial gap (75) is filled with a heat conductive means (77) to effectively transfer the heat generated by the electronic components to the circulating coolant in the wet zone (12).