Electro-Hydraulic Steering With Accumulator-Assisted Pump Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electro-actuated hydraulic steering systems in work vehicles face issues with increased operator effort and slower steering in emergency conditions due to delayed hydraulic oil pumping, leading to discomfort and risk, while maintaining constant electric pump activation increases electricity consumption.
Innovation Solution
Implementing a hydraulic accumulator to provide initial hydraulic oil flow and an electric pump activation logic that deactivates the electric pump when not in use, activating it only when the steering device is active or the accumulator pressure is below a threshold, using a valve system to alternate between accumulator and load sensing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the electric pump is deactivated when the steering wheel is stationary and activated only when steering is detected, then electricity consumption is reduced, but steering response is delayed and operator comfort deteriorates
Solution Approach 1:
The hydraulic accumulator is pre-charged with hydraulic fluid before steering operations begin. When steering is detected, the accumulator immediately supplies hydraulic oil to the steering motor, eliminating the delay that would occur if the pump had to start from scratch. This preliminary storage of hydraulic energy resolves the contradiction by enabling rapid steering response without requiring the pump to be continuously running.
Solution Approach 2:
The hydraulic accumulator acts as an intermediary between the electric pump and the steering motor. It decouples the pump operation from the steering actuation, allowing the pump to be deactivated while the accumulator provides the necessary hydraulic fluid for immediate steering response. This intermediary component bridges the gap between energy conservation and steering reliability.
2Reliability
If the electric pump is kept always active to ensure immediate steering response, then steering reliability is maintained, but electricity consumption increases
Solution Approach 1:
The accumulator is pre-filled with hydraulic fluid during normal operation or when the vehicle is stationary, so that when steering is needed, the fluid is already available for immediate delivery to the steering motor. This eliminates the need for continuous pump operation while maintaining rapid steering response capability.
Solution Approach 2:
Instead of continuous pump operation, the system uses periodic or event-driven pump activation combined with accumulator recharge. The pump operates intermittently to recharge the accumulator, which then provides fluid during steering events. This periodic action pattern reduces overall energy consumption while maintaining system reliability.
3Use of energy by moving object
If the pump activation is delayed until steering detection, then electricity consumption is reduced, but steering speed decreases in emergency conditions
Solution Approach 1:
The hydraulic accumulator stores hydraulic fluid in advance, so when steering is detected, the fluid is immediately available to drive the steering motor at full speed. This preliminary preparation of hydraulic energy enables rapid steering response without requiring the pump to be continuously running, thus maintaining steering speed while reducing energy consumption.
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 deactivation of the electric pump to reduce electricity consumption and maintain smooth steering operations without operator discomfort, ensuring safe and efficient hydraulic oil supply.
Implementation Method 1
a hydraulic accumulator arranged to provide a flow of hydraulic oil in an activation phase of the hydraulic steering device
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Electro-hydraulic steering system (C) comprising an electric pump (HP) arranged to power a steering device (HSA, SA), processing means (CPU) configured to deactivate said electric pump in response to the deactivation of the steering device and in wherein the system comprises a hydraulic accumulator (HR) operatively connected with said electric pump and with said steering device and wherein said processing means are configured to activate said electric pump in response to the activation of the steering device and when a measured pressure value in said hydraulic accumulator (HR) is lower than a predetermined threshold (TH1).