Hydraulic Pump Swivel Angle Control for Work Vehicle Speed
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Solution Overview
Problem
Existing speed control systems for work vehicles, such as excavators, experience power loss due to thermal energy released during throttling down the supply pressure to achieve desired load pressures, leading to inefficiencies, especially during operations requiring different pressure and flow rates for multiple functions.
Innovation Solution
A device and method that control the driving speed of work vehicles by directly regulating the drive motor's speed and adjusting the swivel angle of the hydraulic drive motor or pump, eliminating the need for throttling and minimizing power loss by generating a supply pressure close to the required load pressure, especially during pure driving operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If supply pressure is throttled down to load pressure via throttle device, then desired load pressure is achieved, but power loss occurs in the form of thermal energy
Solution Approach 1:
The invention changes the operating parameters of the hydraulic pump by adjusting the swivel angle to match the supply pressure to the required load pressure, eliminating the need for throttling. This parameter adjustment allows the pump to deliver pressure closer to the actual demand, thereby reducing the pressure excess that causes power loss during throttling operations.
Solution Approach 2:
The invention implements dynamic control of the hydraulic pump's swivel angle based on real-time operational requirements. By dynamically adjusting the pump displacement rather than using static throttling, the system adapts supply pressure to match varying load demands, eliminating continuous power loss associated with fixed pressure throttling.
2Speed
If control slide is used to regulate driving speed, then speed control is achieved, but pressure excess and power loss occur
Solution Approach 1:
The invention changes the control approach from regulating flow through throttling to regulating pump displacement via swivel angle adjustment. This parameter change allows speed control to be achieved at the source (pump output) rather than through pressure reduction, eliminating the power loss associated with maintaining pressure excess.
Solution Approach 2:
The invention extracts the pressure regulation function from the control slide/throttle device and relocates it to the hydraulic pump itself. By taking out the pressure control function from the throttling path and implementing it at the pump, the system eliminates the need for pressure excess and the associated power losses.
3Stress or pressure
If supply pressure is generated with pressure excess, then highest load pressure requirement is met, but thermal energy is released during throttling
Solution Approach 1:
The invention changes the supply pressure parameter from a fixed high value with pressure excess to a dynamically adjusted value that matches load requirements. By adjusting the pump swivel angle, the supply pressure is optimized to meet the actual load pressure need, eliminating the pressure differential that causes thermal energy release during throttling.
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 power loss and enhances efficiency by eliminating the need for throttling, allowing for precise control of driving speed while maintaining optimal pressure and flow rates, even during parallel operations.
Implementation Method 1
a drive motor (1) drives a hydraulic pump (2) in order to pressurize a pressure medium
Implementation Method 2
The pressure medium drives a hydraulic drive motor (5) to move
Implementation Method 3
control/regulating elements, such as spool valves, for setting the different consumers, via which the different load pressures and flow rates can be set
Data Source
Figure 1
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Figure 3
AI summary
The apparatus has a drive motor (1), a hydraulic pump (2), a control slide (4), a hydraulic traction motor (5), a hydraulic drive as well as a controller (7). The running speed of the hydraulic traction motor is controlled/regulated through the speed of the drive motor, while the hydraulic drive does not produce any drive power. The hydraulic pump is fully outwardly pivoted. The direction of rotation of the hydraulic travel motor is controlled/regulated through the control slide. An independent claim is included for method for controlling/regulating running speed of work vehicle.