Vehicle Transmission Hydraulics With Switched Pump Circuit Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vehicle transmissions face inefficiencies in hydraulic systems due to differing hydraulic requirements between clutch control and lubrication circuits, leading to high energy losses and increased complexity with dual pumps.
Innovation Solution
A hydraulic arrangement featuring a single pump with a control valve that switches between system and lubrication circuits based on pressure thresholds, utilizing a storage unit to maintain pressure and reduce switching frequency, and a holding valve unit for stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single pump is used to supply both system circuit and lubrication circuit, then device complexity and cost are reduced, but hydraulic efficiency and pressure stability deteriorate due to conflicting flow rate requirements
Solution Approach 1:
The control valve dynamically switches between connecting the pump to the system circuit and the lubrication circuit based on real-time pressure sensor feedback. This dynamic switching allows a single pump to adaptively meet the different flow rate requirements of two circuits with conflicting hydraulic demands, maintaining system efficiency while reducing device complexity
Solution Approach 2:
Pressure sensors in both circuits provide feedback signals to the control unit, which monitors pressure levels and triggers valve switching when threshold values are reached. This feedback mechanism ensures stable pressure control in both circuits despite using a single pump, preventing energy loss while maintaining simplicity
2Ease of manufacture
If a single pump is used to supply both circuits, then cost is reduced, but pressure stability in each circuit deteriorates
Solution Approach 1:
Pressure sensors continuously monitor both circuits and provide feedback to the control unit. When pressure in either circuit reaches a threshold value, the control unit activates the control valve to switch connections, thereby stabilizing pressure in both circuits while using a single pump, reducing manufacturing cost without sacrificing pressure stability
Solution Approach 2:
The control valve acts as an intermediary component that dynamically redirects hydraulic flow between the two circuits based on pressure conditions. This intermediary mechanism enables a single pump to maintain stable pressure in both circuits by preventing over-pressurization, achieving cost-effective manufacture while preserving pressure stability
3Stress or pressure
If pump continuously supplies system circuit to maintain high pressure, then system circuit pressure stability is improved, but lubrication circuit receives insufficient flow rate
Solution Approach 1:
The control valve performs periodic switching between connecting the pump to the system circuit and the lubrication circuit based on pressure threshold feedback. During system circuit pressurization phases, the valve directs flow to maintain high pressure; when threshold is reached, it switches to supply the lubrication circuit, ensuring both circuits receive adequate hydraulic medium quantity while maintaining system pressure
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 cost-effective and energy-efficient operation of vehicle transmissions with a single pump, achieving hydraulic circuit efficiency comparable to dual pump systems while maintaining stable pressure and reducing energy losses.
Implementation Method 1
a hydraulic pump (12) for generating a system pressure for a hydraulic system circuit (14) and a lubrication pressure for a hydraulic lubrication circuit (16)
Implementation Method 2
a control valve (28) which is switchable between different switching positions and which, depending on its switching position, acts as a hydraulic connection between the pump (12) and the system circuit (14) or between the pump (12) and the lubrication circuit (16)
Implementation Method 3
a storage unit (30), in particular a diaphragm accumulator or an accumulator, which is connected to the system circuit (14), wherein a working pressure above a minimum working pressure can be maintained for a relatively long time for the system circuit (14), without the pump (12) being required for this purpose
Data Source
AI summary
A hydraulic arrangement for a vehicle transmission includes a hydraulic pump for providing a system pressure for a first hydraulic system circuit and a lubrication pressure for a second hydraulic lubrication circuit. The arrangement also includes a control valve connected between a pump outlet of the pump and the two hydraulic circuits and has two different switching positions. The control valve, depending on its switching position, acts as a hydraulic connection between the pump and the system circuit or between the pump and the lubrication circuit.