Electro-Hydraulic Steering in Soil Compactors for Demand-Based Pump Control
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Solution Overview
Problem
Existing soil cultivation machines, such as compactors, face challenges in operating their hydraulic steering and drive systems with high energy consumption and inefficiency, particularly due to the inability to adapt to changing operational demands.
Innovation Solution
The implementation of an electro-hydraulic steering system with an electric motor powered by a battery, which adjusts its speed based on steering information and operating state to optimize energy use, combined with an independent hydraulic drive system using a separate electric motor to operate each system efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a diesel engine drives hydraulic pumps for both steering and drive systems, then sufficient power is available, but energy consumption is high and the system cannot adapt to changing operational demands
Solution Approach 1:
The patent divides the hydraulic power supply into two independent systems: a steering hydraulic system with its own electric motor and pump, and a drive hydraulic system with separate electric motors and pumps. This segmentation allows each system to be optimized and controlled independently, enabling adaptability to changing operational demands while reducing overall energy consumption compared to a single diesel engine driving all pumps.
Solution Approach 2:
The patent replaces the mechanical coupling of a diesel engine to hydraulic pumps with electrically driven pumps. Each hydraulic system (steering and drive) has its own electric motor that can be independently controlled based on actual operational needs, allowing the system to adapt to changing demands and consume only the necessary amount of energy rather than continuously running at high power.
2Reliability
If hydraulic pumps are operated at constant high speed to ensure sufficient pressure fluid supply, then steering responsiveness is maintained, but energy consumption increases
Solution Approach 1:
The patent implements dynamic speed control of electric motors driving hydraulic pumps based on actual operational requirements. The control unit adjusts the rotational speed of each electric motor according to the current steering angle, steering angle change rate, and driving state, ensuring sufficient pressure fluid supply for responsive steering while minimizing energy consumption during low-demand periods.
Solution Approach 2:
The system uses feedback from steering sensors that detect steering angle and steering angle change rate, combined with feedback about the driving state, to dynamically adjust the speed of electric motors driving hydraulic pumps. This closed-loop control ensures steering responsiveness is maintained when needed while reducing energy consumption during normal operation.
3Device complexity
If a single hydraulic system is used for both steering and drive functions, then device complexity is reduced, but the ability to operate each system efficiently independently is lost
Solution Approach 1:
The patent segments the hydraulic system into independent steering and drive subsystems, each with its own electric motor and pump. This segmentation enables independent optimization and control of each system based on its specific operational requirements, improving overall efficiency and adaptability despite the increased structural complexity.
Solution Approach 2:
While segmented into independent systems, the patent maintains universality through a common control unit that manages both steering and drive hydraulic systems. The control unit receives inputs from various sensors and coordinates the operation of multiple electric motors and pumps, enabling efficient independent operation of each subsystem while maintaining system-wide coordination.
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
This approach reduces energy consumption and maintains emergency steering capabilities while providing mechanical feedback, ensuring efficient operation by adapting to changing demands without the need for structural modifications to the hydraulic pumps.
Implementation Method 1
an electro-hydraulic pressure fluid source with at least one steering hydraulic pump (40) driven by at least one electric motor (38)
Implementation Method 2
The electric motor (38) of the hydraulic steering system (30) is controlled by a control unit (42) and is supplied with power from a voltage source, for example, a battery (44)
Implementation Method 3
at least one steering hydraulic pump (40) driven by at least one electric motor (38) for feeding pressure fluid into a steering hydraulic circuit (34)
Data Source
Figure 1~2
Figure 3
AI summary
A soil cultivation machine, in particular a soil compactor, comprises a hydraulic steering system (30) with at least one steering element (26) actuated with pressure fluid and an electro-hydraulic pressure fluid source (36) with at least one steering pressure fluid pump (40) driven by at least one electric motor (38) for feeding pressure fluid into a steering pressure fluid circuit (34).