Hydraulic Pump Speed Protection via Fluidic Decoupling

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Solution Overview

Problem

Hydraulic systems in commercial vehicles face damage and high repair costs due to impermissible overspeed of fixed displacement pumps, leading to particle contamination and damage to connected functional devices, such as hydrostatic auxiliary drives.

Innovation Solution

A protection configuration that detects excessive pump speed, pressure, or flow rates and automatically decouples the functional devices from the pump using a detection unit and electronic control system, preventing damage by blocking or fluidically isolating them when safety criteria are met.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed displacement pump is used to convert mechanical energy into hydraulic energy, then the pump can operate at constant speed coupled to the rear axle, but the pump may impermissibly overspeed due to various malfunctions causing mechanical overload and particle contamination

Engineering Contradiction:
Improvepump speed control reliabilityVSAvoidparticle contamination to functional devices
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A protection configuration is introduced as an intermediary system between the pump and functional devices. This configuration includes detection means for monitoring pump speed and a control mechanism that activates when a safety criterion (such as limit speed) is exceeded, thereby protecting functional devices from particle contamination without requiring changes to the pump itself

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The protection configuration performs preliminary detection and protection actions before damage occurs. By continuously monitoring pump speed and activating protective measures when approaching dangerous operating conditions, the system prevents particle generation and subsequent contamination of functional devices

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the pump operates at high speed to maintain hydraulic function, then the hydraulic system can function properly, but damage to the pump can occur leading to high repair costs and system failure

Engineering Contradiction:
Improvehydraulic energy conversion rateVSAvoidpump mechanical integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The protection configuration implements a feedback mechanism where detection means continuously monitor pump operating parameters (such as speed, pressure, or flow rate) and provide information to a control system. When parameters indicate dangerous operating conditions, the control system activates protective measures, creating a closed-loop control that maintains productivity while preventing mechanical damage

Inventive Principle:
Principle #23Feedback

3Device complexity

If no protection system is installed, then the hydraulic system structure remains simple, but functional devices are vulnerable to damage from pump failures and particle contamination

Engineering Contradiction:
Improvehydraulic system structureVSAvoidfunctional device protection
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

A protection configuration is introduced as an intermediary system between the pump and functional devices. This configuration includes detection means for monitoring pump speed and a control mechanism that activates when a safety criterion (such as limit speed) is exceeded, thereby protecting functional devices from particle contamination without requiring changes to the pump itself

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The protection configuration is designed as a separate, modular system that can be added to existing hydraulic systems without fundamentally redesigning the entire system. The detection means and control mechanisms are segmented into distinct functional components that can be independently installed and maintained

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2832573B1Hydraulic system with pump speed safety system
Publication Date: 2019.09.11 MAN TRUCK & BUS SE
  • EP2832573B1 patent drawingFigure 1
  • EP2832573B1 patent drawingFigure 2

AI summary

The invention relates to a hydraulic system (H) for a motor vehicle, in particular a commercial vehicle. The hydraulic system (H) comprises a pump (6) and at least one functional device (1, 3, 4, 5, 7, 8, 9, 10, 11) which is fluidically connected to the pump (6). The hydraulic system (H) is characterized in particular by a protective configuration (S) which serves to protect the functional device (1, 3, 4, 5, 7, 8, 9, 10, 11) from the effects of damage to and/or in the pump (6).