Hydraulic Travel Drive Fluid Discharge for Soil Compactor Efficiency

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Solution Overview

Problem

Existing soil compactor machines face inefficiencies in their hydraulic travel drive systems, leading to suboptimal energy usage and operational performance due to inadequate fluid management based on temperature, contamination, and other parameters.

Innovation Solution

The implementation of an electro-hydraulic pressurized fluid source with a travel hydraulic pump and an exhaust valve arrangement controlled by a unit that dispenses fluid from the hydraulic circuit to a reservoir based on parameters like temperature, contamination, and operational time, ensuring efficient fluid management and energy use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If fluid is continuously discharged from the hydraulic circuit to maintain temperature, then temperature control is improved, but energy consumption increases

Engineering Contradiction:
Improvehydraulic fluid temperatureVSAvoidenergy consumption of hydraulic system
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The discharge valve is operated periodically rather than continuously, opening only when fluid temperature exceeds a threshold value. The control unit monitors temperature and triggers discrete discharge events, allowing the system to maintain temperature control while minimizing energy waste from constant fluid circulation and discharge.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system incorporates temperature sensing and control unit feedback that continuously monitors hydraulic fluid temperature and adjusts discharge valve operation accordingly. When temperature rises above the threshold, the control unit activates the discharge valve; when temperature is acceptable, the valve remains closed, creating a closed-loop control system that optimizes energy usage.

Inventive Principle:
Principle #23Feedback

2Temperature

If fluid discharge is enabled based on temperature threshold, then temperature management is improved, but fluid loss increases

Engineering Contradiction:
Improvehydraulic fluid temperatureVSAvoidhydraulic fluid loss
Core Design Contradiction:
TemperatureVSLoss of substance

Solution Approach 1:

The system discards only the portion of fluid that has exceeded the temperature threshold and is no longer useful for heat transfer, while retaining and continuing to circulate the cooler fluid that remains in the circuit. This selective discharge minimizes overall fluid loss while effectively managing temperature.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

Instead of discharging all fluid when temperature threshold is reached, the system performs partial discharge only of the overheated portion, maintaining adequate fluid volume in the circuit for continued operation while removing only the excess thermal energy.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If multiple parameters (temperature, contamination, time) are monitored for fluid discharge, then operational efficiency is improved, but system complexity increases

Engineering Contradiction:
Improvehydraulic system efficiencyVSAvoidcontrol system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The control unit is designed to perform multiple monitoring functions (temperature sensing, contamination detection, operational timing) and integrates them into a single decision-making device. This multi-functional approach allows the system to consider multiple parameters for optimized discharge decisions without requiring separate control systems for each parameter.

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

Solution Approach 2:

The patent combines temperature monitoring, contamination monitoring, and operational time tracking into a unified control system that makes discharge decisions based on the combined assessment of all parameters. This merging reduces the number of separate components and simplifies the overall control architecture while maintaining comprehensive monitoring capabilities.

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

This solution enhances the energy efficiency of the hydraulic travel drive system by optimizing fluid dispensing and replenishment, maintaining optimal operating conditions and reducing energy waste.

Implementation Method 1

an electro-hydraulic pressure fluid source with at least one electric motor and at least one drive hydraulic pump

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

a drive hydraulic circuit fed with pressure fluid by the at least one drive hydraulic pump

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 3

at least one drive hydraulic motor fed with pressure fluid from the drive hydraulic circuit

Methodology Applied
Scientific EffectHydraulic motor conversion: Hydraulic Press

Implementation Method 4

a discharge valve arrangement for discharging fluid from the drive hydraulic circuit into a fluid reservoir, a control unit for controlling the discharge valve arrangement

Methodology Applied
Scientific EffectValve flow control: Valve

Data Source

PatentEP4151889B1Ground working machine and method for operating a ground working machine
Publication Date: 2024.08.14 HAMM AG
  • EP4151889B1 patent drawingFigure 1~2

AI summary

A soil cultivation machine, in particular a soil compactor, comprises a hydraulic drive system (46), wherein the hydraulic drive system (46) comprises an electro-hydraulic pressure fluid source (48) with at least one electric motor (50) and at least one drive hydraulic pump (52), a drive hydraulic circuit (54) supplied with pressure fluid by the at least one drive hydraulic pump (52), at least one drive hydraulic motor (56, 58) supplied with pressure fluid from the drive hydraulic circuit (54), and a discharge valve arrangement (60) for discharging fluid from the drive hydraulic circuit (54) into a fluid reservoir (62).The hydraulic drive system (46) is designed to operate the discharge valve arrangement (60) to discharge fluid to the fluid reservoir (62) depending on at least one of the following parameters: a temperature of the fluid in the drive hydraulic circuit (54), an ambient temperature, a viscosity of the fluid in the drive hydraulic circuit (54), a degree of contamination of the fluid in the drive hydraulic circuit (54), a time period since the last commissioning of the hydraulic drive system (46), a time period since the last fluid discharge from the drive hydraulic circuit (54).