Hydraulic Pump Unit Layout for Cooled In-Tank Solenoid Valves

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Solution Overview

Problem

Existing pump units for motor vehicle drive trains, such as clutch and gearbox actuators, face challenges in protecting solenoid valves from environmental influences and corrosion, while also achieving efficient heat transfer and low dynamic pressure loss.

Innovation Solution

The solenoid valve is positioned within the storage container mounted on the pump housing, surrounded by hydraulic fluid, allowing for protection against corrosion and efficient cooling, with a compact design and short paths for improved reaction times and reduced dynamic pressure loss. Additionally, the solenoid valve has a coil surrounded by hydraulic fluid, and a return outlet to prevent 'dead volume', and an armature with a bearing gap filled with hydraulic fluid for enhanced damping properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the solenoid valve is positioned within the storage container surrounded by hydraulic fluid, then protection against corrosion and environmental influences is improved, but the device complexity increases

Engineering Contradiction:
Improveprotection against corrosionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The solenoid valve is integrated within the storage container housing, merging the valve housing with the storage container structure. This integration protects the solenoid valve from corrosion and environmental influences while avoiding the need for separate protective housings, thus not increasing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Hydraulic fluid serves as an intermediary medium that surrounds and protects the solenoid valve components (coil, armature, bearing gap) from direct exposure to environmental influences and corrosion, while also providing cooling and lubrication functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If the solenoid valve is attached directly to the pump housing, then compactness is improved, but manufacturing precision requirements increase

Engineering Contradiction:
ImprovecompactnessVSAvoidmanufacturing precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The solenoid valve is directly mounted on the pump housing, merging multiple components into a compact integrated unit. This eliminates the need for separate mounting brackets or intermediate structures, achieving compactness while using standard mounting techniques.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The solenoid valve housing is designed as a separate component that can be manufactured independently and then mounted on the pump housing, allowing for specialized manufacturing of the valve housing while keeping the overall assembly compact.

Inventive Principle:
Principle #1Segmentation

3Object-generated harmful factors

If the bearing gap is filled with hydraulic fluid, then damping properties are improved, but fluid consumption increases

Engineering Contradiction:
Improvedamping propertiesVSAvoidfluid consumption
Core Design Contradiction:
Object-generated harmful factorsVSQuantity of substance

Solution Approach 1:

The hydraulic fluid in the bearing gap serves multiple functions: providing damping properties for the armature, lubricating the bearing surfaces, and contributing to the overall cooling of the solenoid valve. This multi-functionality justifies the fluid consumption as it delivers multiple benefits simultaneously.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The hydraulic fluid system is designed to continuously circulate through the bearing gap and return to the storage container, creating a self-sustaining lubrication and damping system that doesn't require additional fluid consumption beyond the normal system operation.

Inventive Principle:
Principle #25Self-service

4Temperature

If the coil is surrounded by hydraulic fluid, then heat transfer is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveheat transferVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The coil is integrated within the solenoid valve housing that is itself positioned within the storage container, creating a nested structure where hydraulic fluid naturally surrounds the coil. This merging of components achieves excellent heat transfer without requiring separate cooling channels or complex thermal management structures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Hydraulic fluid acts as an intermediary heat transfer medium between the coil and the storage container environment, efficiently carrying away heat generated by the coil during solenoid operation while allowing for simple manufacturing of the surrounding structures.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively protects the solenoid valve from corrosion, enhances heat transfer, and provides precise control over hydraulic pressure with reduced dynamic pressure loss and improved reaction times, resulting in a compact and efficient pump unit.

Implementation Method 1

the solenoid valve can be cooled by the hydraulic fluid

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

a preferably annular free space which is filled with hydraulic fluid is provided between the coil and the housing. This results in an even better transfer of heat between the solenoid valve and the hydraulic fluid

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

the bearing gap is filled with hydraulic fluid. By the armature also being washed around by hydraulic fluid, foreseeable damping properties arise at all times

Methodology Applied
Scientific EffectDamping: Damping

Implementation Method 4

the bearing gap is filled with hydraulic fluid. By the armature also being washed around by hydraulic fluid, foreseeable damping properties arise at all times

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Implementation Method 5

In the event of a cold start, the solenoid valve can be used to heat the hydraulic fluid

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3623620B1Pump unit for providing a hydraulic pressure for actuating an actuator in the drive train of a motor vehicle
Publication Date: 2021.08.18 FTE AUTOMOTIVE GMBH & CO KG
  • EP3623620B1 patent drawingFigure 1
  • EP3623620B1 patent drawingFigure 2
  • EP3623620B1 patent drawingFigure 3~4

AI summary

Pump unit for providing a hydraulic pressure for actuating an actuator in the drive train of a motor vehicle, in particular a clutch actuator or gearbox actuator, with a pump (2), a storage container (6) for hydraulic fluid and at least one solenoid valve (4). The solenoid valve (4) is arranged within the storage container (6) such that it is surrounded by hydraulic fluid.