Hydrostatic Steering Unit With Switchable Dual Dosing Modes

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Solution Overview

Problem

Existing steering apparatuses for vehicles, particularly agricultural and heavy-duty vehicles, struggle to provide both responsive and non-responsive driving modes efficiently, leading to slow and tiring maneuvers in confined spaces and instability on rough terrain.

Innovation Solution

A steering apparatus with a hydraulic steering actuator, a hydrostatic steering unit, and dual dosing devices, controlled by solenoid valves, allows for adjustable hydraulic fluid supply based on steering shaft rotation, enabling both reactive and non-reactive driving modes, enhancing maneuverability and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single dosing device is used with small displacement to ensure stability on road, then steering response is moderate, but maneuvering in confined spaces becomes slow and tiring

Engineering Contradiction:
Improvesteering stabilityVSAvoidmaneuvering speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system dynamically switches between different dosing devices based on operating conditions. A first dosing device with small displacement is used for stable road driving, while a second dosing device with large displacement is engaged for rapid maneuvering in confined spaces. The switching is controlled by a control unit that detects operational context and activates the appropriate dosing device accordingly.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The dosing unit is segmented into multiple independent dosing devices (first dosing device with small displacement, second dosing device with large displacement). Each dosing device can be selectively activated based on the specific operational requirement, allowing the system to optimize performance for different scenarios without compromise.

Inventive Principle:
Principle #1Segmentation

2Productivity

If a single dosing device with large displacement is used for fast maneuvering, then productivity in confined spaces improves, but steering becomes unstable and insecure on road

Engineering Contradiction:
Improvemaneuvering speedVSAvoidsteering stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system dynamically adapts the dosing device configuration based on operating conditions. When maneuvering in confined spaces, the control unit activates the second dosing device with large displacement for rapid response. When driving on road, the system switches to the first dosing device with small displacement to maintain stability and prevent excessive steering corrections.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The dosing unit is divided into multiple dosing devices with different displacement characteristics. The control unit selectively engages the appropriate dosing device based on the operational context, ensuring optimal performance for both rapid maneuvering and stable road driving without relying on a single compromised design.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the hydraulic jack remains connected to the dosing unit in neutral configuration, then responsive mode is achieved for automotive driving, but wheel movements due to external stresses cause unwanted steering shaft rotation

Engineering Contradiction:
Improvedriving intuitivenessVSAvoidsteering shaft stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The system dynamically switches between reactive and non-reactive modes based on operating conditions. In reactive mode (for road driving), the hydraulic jack remains connected to the dosing unit, allowing wheel movements to automatically reposition the steering shaft. In non-reactive mode (for rough terrain or self-driving), the connection is disconnected, preventing unwanted steering shaft rotation from external stresses.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the hydraulic connection state parameter between the hydraulic jack and dosing unit based on operational requirements. The control unit activates or deactivates the hydraulic connection in neutral configuration, switching the system between reactive and non-reactive modes to match the current driving conditions.

Inventive Principle:
Principle #35Parameter changes

4Stability of the object's composition

If the hydraulic jack is isolated from the dosing unit in neutral configuration, then steering shaft stability is maintained, but responsive mode is lost and driving becomes less intuitive

Engineering Contradiction:
Improvesteering shaft stabilityVSAvoiddriving intuitiveness
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The system dynamically adjusts the hydraulic connection between the hydraulic jack and dosing unit based on operating conditions. When stability is prioritized (rough terrain, self-driving), the connection is disconnected. When responsiveness is needed (road driving), the connection is re-established, allowing the steering system to automatically adapt to wheel movements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the hydraulic connectivity parameter by activating or deactivating the connection between the hydraulic jack and dosing unit in neutral configuration. This parameter change enables the system to switch between stable and responsive modes, matching the driver's needs based on the current operational context.

Inventive Principle:
Principle #35Parameter changes

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 solution provides faster and more direct steering in tight spaces while maintaining stability at higher speeds, significantly improving the operating capabilities of the steering system.

Implementation Method 1

controlled by solenoid valves, allows for adjustable hydraulic fluid supply

Methodology Applied
Scientific EffectSolenoid valve actuation: Solenoid

Implementation Method 2

a hydraulic steering actuator, a hydrostatic steering unit, and dual dosing devices, controlled by solenoid valves, allows for adjustable hydraulic fluid supply

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 3

a dosing unit, wherein the distributor comprises: an inlet port for a hydraulic fluid, an outlet port for the hydraulic fluid

Methodology Applied
Scientific EffectHydraulic dosing: Pump

Data Source

PatentEP4667323A1Steering apparatus
Publication Date: 2025.12.24 OGNIBENE POWER
  • EP4667323A1 patent drawingFigure 1
  • EP4667323A1 patent drawingFigure 2~5
  • EP4667323A1 patent drawingFigure 3~4

AI summary

A steering apparatus (100) for vehicles is described, comprising at least: a hydraulic steering actuator (105) and a hydrostatic steering unit (155); wherein the hydrostatic steering unit (155) comprises: a distributor (160) and a dosing unit (165); wherein the distributor (160) comprises: an inlet port (185), an outlet port (190), a first and a second connection port (195, 200), a first and a second service port (205, 210), and a movable intercept member (295), actuatable by a steering shaft (175), which is adapted to assume a neutral configuration, wherein it connects each of said first and second service ports (205, 210) with one of said first and second connection ports (195, 200); wherein the steering apparatus (100) further comprises: first valve means (235), for example a first solenoid valve, actuatable between a first operating configuration, wherein they separate said first and second connection ports (195, 200) from said hydraulic steering actuator (105), and a second operating configuration, wherein they connect said first and second connection ports (195, 200) with said hydraulic steering actuator (105); and wherein the dosing unit (165) comprises at least two dosing devices (300, 305), both actuatable by the steering shaft (175), of which: a first dosing device (300) connected between the first and second service ports (205, 210), and a second dosing device (305) associated with second valve means (330) actuatable, preferably by means of a second solenoid valve (375), between a first operating configuration, wherein they separate said second dosing device (305) from the service ports (205, 210), and a second operating configuration, wherein they connect said second dosing device (305) in parallel with the first dosing device (300).