Hydraulic Turbocharger Pump for Engine Start-Stop
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Solution Overview
Problem
Hydraulic hybrid vehicles face challenges in integrating automatic start-stop technology due to the need for a significant and costly hydraulic pump-motor, which adds weight and complexity, making it impractical for passenger vehicles, especially since compression-ignition engine hydraulic brake systems lose hydraulic pressure when the engine is off.
Innovation Solution
A method that uses a hydraulic turbocharger coupled to a pump and accumulator to supply pressurized fluid to the brake system, allowing the engine to shut down while maintaining hydraulic pressure, thereby enabling automatic start-stop technology without the need for a large pump-motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a supplemental electric pump motor is added to maintain hydraulic pressure during engine-off conditions, then the brake system functionality is maintained, but the device complexity and cost increase
Solution Approach 1:
The hydraulic pump coupled to the turbocharger shaft performs multiple functions: it charges the accumulator during normal engine operation and maintains hydraulic pressure during engine-off conditions. This multi-functionality eliminates the need for a separate supplemental electric pump motor, reducing system complexity while maintaining brake system reliability.
Solution Approach 2:
The patent combines the hydraulic pump with the existing turbocharger shaft, merging two functions (turbocharging and hydraulic pressure generation) into a single integrated system. This consolidation reduces the number of separate components needed, thereby reducing device complexity and cost.
2Extent of automation
If a hydraulic pump-motor is coupled to the engine for starting and stopping both the vehicle and the engine, then automatic start-stop technology is enabled, but the weight and cost of the vehicle increase substantially
Solution Approach 1:
The system uses the existing turbocharger shaft to drive the hydraulic pump, allowing the system to generate and store hydraulic pressure using its own operational energy rather than requiring a separate motor. This self-service approach eliminates the need for additional heavy components while enabling automatic start-stop functionality.
Solution Approach 2:
The accumulator is charged with hydraulic pressure in advance during normal engine operation, preparing the system for future engine-off conditions. This preliminary action ensures that sufficient hydraulic pressure is available when the engine shuts down, enabling automatic start-stop without requiring a heavy pump-motor.
3Ease of operation
If the primary engine source supplies hydraulic pressure to the brake system, then the brake system functions normally during engine operation, but the hydraulic pressure is lost when the engine is shut off
Solution Approach 1:
The accumulator is pre-charged with hydraulic pressure during engine operation, storing energy in advance for future use. This preliminary charging ensures that hydraulic pressure is available during engine-off conditions, extending the duration of brake system availability beyond the engine's operational period.
Solution Approach 2:
The accumulator acts as an intermediary energy storage device between the engine-driven hydraulic pump and the brake system. It decouples the brake system from direct engine dependence, maintaining hydraulic pressure availability even when the engine is shut off, thereby extending the duration of action.
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 solution enables the use of automatic start-stop technology in compression-ignition engines, improving fuel economy and reducing emissions by providing a reliable hydraulic pressure source during engine-off conditions, thus avoiding the need for expensive supplemental electrical motors.
Implementation Method 1
supplying pressure to a hydraulic braking system of the vehicle from an accumulator coupled to a hydraulic pump coupled to a shaft of a turbocharger
Implementation Method 2
a hydraulic pressure accumulator coupled to a hydraulic hybrid engine may be used as a brake energy source
Data Source
AI summary
Methods and systems are provided for a vehicle engine including a turbocharger coupled to a hydraulic pump and hydraulic accumulator. In one example, a method may include, in response to the vehicle coming to a stop, supplying pressure to a hydraulic braking system of the vehicle from the accumulator coupled to a hydraulic pump coupled to a shaft of a turbocharger of an engine installed in the vehicle, and automatically shutting down the engine while the vehicle is stopped.