Self-Charging Air Spring Precharge Assembly for Pressure Loss
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Solution Overview
Problem
Air springs used in applications like pneumatic shock absorbers and nail guns face performance degradation due to gas leakage, requiring frequent recharging and wasting energy to maintain initial high pressures, with no effective method to automatically maintain optimal air pressure within the precharge chamber.
Innovation Solution
A modified air spring assembly with a sleeve and piston rod system that includes a one-way valve and a stiff compression spring to automatically replenish air pressure in the precharge chamber by drawing in fresh air when pressure falls below the design point, ensuring consistent operation without external recharging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sliding seal is used between the floating piston and cylinder wall to retain compressed gas, then gas leakage is minimized, but pressure loss over time still occurs and the system requires external recharging
Solution Approach 1:
The piston rod is modified to include an integrated air charging mechanism that automatically replenishes compressed air in the precharge chamber when pressure drops below the design point, eliminating the need for external recharging systems and enabling the system to maintain its own operational pressure
Solution Approach 2:
A one-way valve is installed in the piston rod that allows compressed air to be charged into the precharge chamber during manufacturing or initial operation, and a stiff compression spring is added to automatically draw in fresh air when pressure falls, performing the recharging action before complete pressure loss occurs
2Duration of action of moving object
If initial precharge pressure is set above the gas pressure requirement to account for leakage, then operational time is extended, but energy is wasted to overcome excessive pressure during compression
Solution Approach 1:
The stiff compression spring acts as a pressure-sensitive feedback mechanism that automatically activates the air charging function only when the precharge chamber pressure drops below the design point, thereby maintaining optimal pressure without excessive over-pressurization and reducing the energy required for compression during normal operation
Solution Approach 2:
The system dynamically adjusts the precharge chamber pressure by introducing fresh air only when needed (when pressure falls below design point), rather than maintaining a constantly high pressure, thus optimizing the balance between operational duration and compression energy requirements
3Reliability
If a separate air compressor is used to maintain air pressure in the precharge chamber, then pressure is maintained, but device complexity increases
Solution Approach 1:
The air charging function is merged with the existing piston rod structure by installing a one-way valve and air passage directly in the piston rod, eliminating the need for a separate air compressor or external recharging system while maintaining reliable pressure in the precharge chamber
Solution Approach 2:
The piston rod is given multiple functions: it transmits mechanical force during normal air spring operation and simultaneously serves as an integrated air charging mechanism when pressure drops, eliminating the need for separate dedicated recharging components
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 modified air spring assembly effectively maintains optimal air pressure within the precharge chamber, reducing the need for frequent recharging and minimizing energy waste, while maintaining the primary function of storing and releasing energy efficiently.
Implementation Method 1
A one-way valve is provided which allows compressed air to be inserted into this chamber
Implementation Method 2
A modified air spring assembly with a sleeve and piston rod system that includes a one-way valve and a stiff compression spring to automatically replenish air pressure in the precharge chamber
Implementation Method 3
A force exerted on the piston rod toward the floating piston and the subsequent travel of the floating piston against the compressed air charge in the precharge chamber require the input of energy
Data Source
AI summary
The present embodiment generally relates to a mechanical assembly which modifies and enhances the performance of a critical portion of the parts which comprise an air spring assembly. A key element common with an air spring assembly is the precharge chamber. This chamber is filled at the factory with compressed gas and along with a floating piston and a piston rod, creates the basic air spring assembly. Although this is a sealed chamber, the potential for air leakage is well documented. The inability to maintain the design gas pressure in the precharge chamber requires the chamber to initially be overcharged to remain functional even with the slow loss of air charge. The present invention demonstrates how the precharge assembly found in all such air springs can be modified and, with the addition of a few parts, be capable of maintaining the precharge pressure at an optimum level.