Immersed Motor-Pump Hydraulic Unit for Cooling and Vibration Damping

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Solution Overview

Problem

Existing hydraulic power units for self-propelled vehicles suffer from bulkiness due to complex cooling systems, vibrations, and noise caused by the combined operation of electric motors and hydraulic pumps, which are unpleasant for users.

Innovation Solution

A compact hydraulic power unit design where the motor-pump unit is partially or fully immersed in hydraulic fluid, equipped with temperature sensors and probes to regulate fluid and motor temperatures, reducing the need for a dedicated cooling system and minimizing vibrations through elastic mounting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a dedicated cooling system with radiator is added to cool the electric motor, then the motor temperature is controlled, but the device becomes bulkier and more complex

Engineering Contradiction:
Improvemotor temperatureVSAvoidcooling system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the cooling function with the hydraulic system by immersing the motor-pump unit in the hydraulic fluid reservoir. The hydraulic fluid serves dual purposes: hydraulic medium and cooling medium, eliminating the need for separate cooling components like radiators and cooling fans.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hydraulic fluid performs multiple functions simultaneously: it transmits hydraulic power through the pump and cools the motor-pump unit through thermal conduction. This multi-functionality reduces system complexity by combining what would traditionally require separate systems.

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

2Power

If the motor and hydraulic pump operate together, then hydraulic power is generated, but high-frequency vibrations and noise are produced

Engineering Contradiction:
Improvehydraulic power outputVSAvoidvibrations and noise
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The hydraulic fluid acts as an intermediary damping medium between the motor-pump unit and the vehicle chassis. The fluid absorbs and dissipates high-frequency vibrations through viscous damping, reducing the transmission of vibrations and noise to the vehicle structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs elastic mounting elements that provide flexible coupling between the motor-pump unit and the vehicle chassis. These elastic elements absorb vibrations and isolate noise, reducing the transmission of harmful vibrations while maintaining mechanical support.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If the reservoir is made larger to provide sufficient suction for the hydraulic pump, then the pump can operate reliably, but the overall size of the hydraulic power unit increases

Engineering Contradiction:
Improvepump suction reliabilityVSAvoidreservoir volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent combines the cooling function with the hydraulic reservoir by immersing the motor-pump unit in the hydraulic fluid. This integration allows the reservoir to serve dual purposes: providing hydraulic fluid for pump operation and serving as a cooling medium, thereby reducing the need for additional cooling components that would increase overall system volume.

Inventive Principle:
Principle #5Merging (Combining)

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 design achieves reduced vibrations, noise, and compactness while effectively cooling the components, enhancing operational efficiency and reliability.

Implementation Method 1

the hydraulic pump can be easily cooled by the hydraulic fluid present in the reservoir

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The hydraulic fluid can also serve to reduce the vibrations and noise generated by the motor-pump unit

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP4239195B1Hydraulic control unit
Publication Date: 2025.11.19 MATHIEU YNO
  • EP4239195B1 patent drawingFigure 1
  • EP4239195B1 patent drawingFigure 2
  • EP4239195B1 patent drawingFigure 3

AI summary

The invention relates to a hydraulic power unit comprising a hydraulic circuit equipped with a reservoir containing a hydraulic fluid and at least one pump unit (20) comprising a first part (22), a second part (24), a motor (26), and a hydraulic pump (30) driven by the motor (26). The pump unit (20) is positioned in the reservoir such that the first part (22) of the pump unit (20) is immersed in the hydraulic fluid.