Swing Energy Recovery System with Variable Relief Valve
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Solution Overview
Problem
Existing swing-type excavation machines, such as hydraulic excavators, face inefficiencies due to wasted energy in high-pressure fluid exiting the swing motor during deceleration and limitations in pressure relief settings, which can lead to heating and increased cooling demands.
Innovation Solution
A swing energy recovery system that includes a pump, motor, energy recovery arrangement, pressure relief valve, and controller to selectively recover and reuse pressurized fluid energy, adjust pressure relief settings based on operating conditions, and optimize energy use during different segments of the excavation work cycle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high-pressure fluid is restricted to slow and stop the work tool at the end of each swing, then the work tool can be decelerated and stopped, but energy is wasted and fluid heating occurs requiring increased cooling capacity
Solution Approach 1:
The patent converts the harmful high-pressure fluid that would normally be wasted during swing deceleration into a beneficial resource by directing it to an accumulator. The accumulator stores this pressurized fluid, which is then reused during swing acceleration, transforming energy waste into energy recovery and reducing the need for cooling.
2Device complexity
If a single relief pressure setting is used in the hydraulic system, then the system is simpler to design, but it cannot adapt to different operating conditions and may cause problems during accumulator malfunction
Solution Approach 1:
The patent implements a variable relief valve with multiple adjustable pressure settings instead of a fixed single-setting relief valve. This dynamic adjustment capability allows the system to adapt to different operating conditions, such as normal operation, accumulator charging, and accumulator malfunction scenarios, thereby improving system versatility without excessive complexity.
3Speed
If pressurized fluid is continuously supplied to accelerate the swing motor, then swing acceleration is maintained, but energy consumption increases
Solution Approach 1:
The patent uses the accumulator to store pressurized fluid in advance during swing deceleration phases. This pre-stored energy is then released during subsequent acceleration phases, eliminating the need for continuous high-energy pump operation and reducing overall energy consumption while maintaining swing acceleration performance.
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
The system enhances machine efficiency by recovering and reusing energy, reducing waste and cooling requirements, and providing adaptive pressure relief to protect components during abnormal conditions.
Implementation Method 1
an accumulator configured to store pressurized fluid discharged from the swing motor during swing deceleration and release the pressurized fluid back to the swing motor during swing acceleration
Implementation Method 2
a pressure relief valve configured to reduce fluid pressure when it exceeds a threshold level
Data Source
AI summary
A swing energy recovery system for a machine is disclosed. The swing energy recovery system may have a pump configured to pressurize fluid, a motor driven by a flow of pressurized fluid from the pump, and an energy recovery arrangement configured to receive pressurized fluid discharged from the motor and selectively supply pressurized fluid to the motor. The swing energy recovery system may also have a pressure relief valve associated with the motor, and a controller in communication with the energy recovery arrangement and the pressure relief valve. The controller may be configured to selectively adjust a setting of the pressure relief valve based on an operating condition of the energy recovery arrangement.