Hydraulic Steering Dynamic Orifice Flow Utilization

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Solution Overview

Problem

Existing hydraulic steering arrangements lack the capability for dynamic steering with a simple construction, as they waste the flow from the load sensing port and require complex orifice management for efficient steering.

Innovation Solution

Incorporating a dynamic main orifice connected between the load sensing port and the main flow path downstream the main orifice, and a dynamic drain orifice between the load sensing port and the return flow path, allowing the dynamic flow to be utilized for steering, with the dynamic main and amplification orifices opening before the traditional orifices, and a safety valve to regulate the flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the flow from the load sensing port is directed to the tank port in existing hydraulic steering arrangements, then the system maintains a simple construction, but the dynamic flow is wasted and cannot be used for steering

Engineering Contradiction:
Improvewaste of dynamic flowVSAvoidsteering capability at small angles
Core Design Contradiction:
Loss of energyVSEase of operation

Solution Approach 1:

The patent converts the previously wasted dynamic flow from the load sensing port into a useful steering flow by introducing a dynamic main orifice that directs this flow to the main flow path, enabling steering at small angles where the traditional main orifice remains closed

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces dynamic orifices (dynamic main orifice and dynamic drain orifice) that automatically adjust their opening degrees based on operating conditions, allowing the system to utilize dynamic flow for steering while maintaining simple construction without complex manual controls

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If the main orifice and amplification orifice are closed in neutral position, then the system maintains stable neutral position, but steering cannot start until these orifices open

Engineering Contradiction:
Improveneutral position stabilityVSAvoidsteering response speed
Core Design Contradiction:
Stability of the object's compositionVSSpeed

Solution Approach 1:

The dynamic main orifice opens before the main orifice and amplification orifice, preliminarily establishing a flow path that enables steering to start earlier at small angles, while the main orifices remain closed to maintain neutral stability

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the dynamic main orifice is connected to the main flow path between the main orifice and measuring motor orifice, then the measuring motor can control the dynamic flow, but the construction becomes more complex

Engineering Contradiction:
Improvesteering control precisionVSAvoidorifice connection complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The measuring motor is given a dual function: it not only measures the steering angle but also controls the dynamic flow through the measuring motor orifice, eliminating the need for separate control mechanisms and simplifying the overall construction despite the additional connection

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

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

Enables efficient use of the dynamic flow for steering at small angles, allows the measuring motor to control the dynamic flow, and maintains a constant amplification factor across the working range, while simplifying the construction and improving steering precision.

Implementation Method 1

Hydraulic fluid from the load sensing port of the pressure source is directed to the tank port. As the flow from the load sensing port of the pressure source flows always to a tank port, steering will start as soon as the main orifice and the amplification orifice open.

Methodology Applied
Scientific EffectHydraulic flow:

Implementation Method 2

a dynamic main orifice connected between the load sensing port and the main flow path downstream the main orifice and a dynamic drain orifice connected between the load sensing port and the return flow path

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 3

a measuring motor, an amplification flow path having an amplification orifice and being arranged between the pressure port and the working port arrangement

Methodology Applied
Scientific EffectHydraulic actuation: Hydraulic Press

Data Source

PatentEP4311741B1Hydraulic steering arrangement
Publication Date: 2024.09.25 DANFOSS POWER SOLUTIONS APS
  • EP4311741B1 patent drawingFigure 1
  • EP4311741B1 patent drawingFigure 2~4

AI summary

A hydraulic steering arrangement (1) is described, the hydraulic steering arrangement (1) comprising a supply port arrangement (P, T) having a pressure port (P) and a tank port (T), a working port arrangement having two working ports (L, R), a main flow path (2) having a main orifice (A1) and at least one further orifice (A2, A3, A4) downstream the main orifice (A1), the main flow path (2) being arranged between the pressure port (P) and the working port arrangement (L, R), a return flow path (4) arranged between the working port arrangement (L, R) and the tank port (T), a measuring motor (3), an amplification flow path (6) having an amplification orifice (Au) and being arranged between the pressure port (P) and the working port arrangement (L, R), and an adjustable pressure source (9) connected to the pressure port (P) and having a load sensing port (18), wherein a main drain orifice (Adrain) is connected between the main flow path (2) downstream the main orifice (A1) and the return flow path (4). Such a steering arrangement should have the possibility of dynamic steering with a simple construction. To this end a dynamic main orifice (A1-dyn) is connected between the load sensing port (18) and the main flow path (2) downstream the main orifice (A1), and a dynamic drain orifice (Adrain-dyn) is connected between the load sensing port (18) and the return flow path (4), which dynamic drain orifice (Adrain-dyn) is open when the dynamic main orifice (A1-dyn) is closed.