Hydraulic Steering Unit Diagonal Orifice Neutral Position
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Solution Overview
Problem
Existing hydraulic steering units for agriculture vehicles often exhibit self-alignment of steered wheels, making it difficult to prevent and result in an uncomfortable driving experience.
Innovation Solution
A hydraulic steering unit design featuring a variable diagonal orifice connected to the main and tank flow paths, with bridge orifices closed in neutral position and the diagonal orifice open, allowing fluid flow from pressure to tank ports, and strategically opening orifices to control fluid flow and pressure for smooth steering without self-alignment, incorporating a measuring motor and auxiliary orifice for end-stop feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the orifices of the bridge arrangement are closed in neutral position to prevent self-alignment, then self-alignment is prevented, but there is no possibility for fluid flow from pressure port to working ports or back to tank port
Solution Approach 1:
The patent introduces a diagonal orifice as an intermediary element that provides an alternative fluid flow path through the main flow path and tank flow path when the bridge orifices are closed. This mediator allows continuous fluid circulation while maintaining the closed bridge configuration that prevents self-alignment, thus resolving the contradiction between stability and operational smoothness.
2Ease of operation
If the diagonal orifice is open in neutral position to allow fluid flow, then sudden pressure increase is prevented, but the bridge orifices must be closed to prevent self-alignment
Solution Approach 1:
The patent creates an asymmetric configuration where the diagonal orifice (providing feedback flow) remains open while the bridge orifices (controlling steering flow) are closed in neutral position. This asymmetric state allows the system to simultaneously achieve smooth pressure transitions through the diagonal path and prevent self-alignment by closing the bridge paths, resolving the contradiction between operational smoothness and position stability.
3Speed
If the first orifice opens faster than the second orifice, then pressure increase on steering motor is steeper, but the steering dead band increases
Solution Approach 1:
The patent employs dynamic orifice opening characteristics where the first orifice (connected to working port) opens faster than the second orifice (connected to tank flow path). This dynamic, asymmetric opening sequence creates a controlled pressure buildup that provides rapid steering response while the gradual closure sequence minimizes the dead band, resolving the contradiction between response speed and steering precision.
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 effectively prevents self-alignment, reduces the steering dead band, and provides a comfortable driving experience by allowing controlled fluid flow and pressure management, enhancing steering precision and feedback.
Implementation Method 1
a variable diagonal orifice is connect to the main flow path and to the tank flow path... allowing a flow of hydraulic fluid is still allowed through the steering unit from the pressure ports to the tank port
Implementation Method 2
a bridge arrangement of variable orifices having a first left orifice connected to the main flow path and to the left working flow path... When the orifices of the bridge arrangement are closed in neutral position... In an embodiment of the invention in a range around the neutral position the diagonal orifice and the orifices of the bridge arrangement are open
Implementation Method 3
In an embodiment of the invention a measuring motor is arranged in one of the working flow paths
Data Source
AI summary
A hydraulic steering unit includes a pressure port connected to a main flow path and a tank port connected to a tank flow path, left and right working ports connected to left and right working flow paths, respectively, a bridge arrangement of variable orifices having a first left orifice connected to the main flow path and to the left working flow path, a first right orifice connected to the main flow path and to the right working flow path, a second left orifice connected to the left working flow path and to the tank flow path, and a second right orifice connected to the right working flow path and to the tank flow path. A variable diagonal orifice is connected to the main flow path and to the tank flow path. The bridge arrangement orifices being closed in neutral position and the diagonal orifice being open in neutral position.