Pneumatic Door Closer Eliminates Oil Leakage and Viscosity Issues
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Solution Overview
Problem
Prior art door closers, such as mechanical spring and hydraulic door closers, suffer from issues like oil leakage, variable closing speeds due to viscosity changes with temperature, and reduced service life due to dust contamination, leading to impact forces and noise.
Innovation Solution
A pneumatic door closer utilizing a rotary energy-storing mechanism with high pressure gas chambers and a sliding piston assembly, where gas flows between chambers to control door closure, avoiding oil-based issues and using a throttle ring to regulate closing speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If full hydraulic door closer or oil-air hybrid driven door closer is used to control door closing speed, then door closure can be adjusted according to user requirements and door body and frame are protected, but oil leakage occurs frequently causing door cannot close fully
Solution Approach 1:
The patent extracts and removes the hydraulic oil system from the door closer mechanism, replacing it with a pneumatic system that uses compressed air instead of oil. This eliminates the oil leakage problem entirely while maintaining the door closing control function through the pneumatic chamber and piston assembly.
Solution Approach 2:
The patent replaces the hydraulic mechanical system with a pneumatic system. The hydraulic oil-based mechanism is substituted with compressed air-driven pneumatic chambers and pistons, fundamentally changing the fluid medium from liquid to gas to eliminate leakage issues associated with hydraulic systems.
2Speed
If hydraulic oil is used to control door closing speed, then door closing speed can be adjusted, but viscosity of oil varies with air temperature changes influencing flowing rate and closing speed
Solution Approach 1:
The patent substitutes the temperature-sensitive hydraulic oil system with a pneumatic system using compressed air. Gas viscosity is less sensitive to temperature changes compared to hydraulic oil, providing more consistent door closing speed across different temperature conditions while maintaining adjustable speed control through the pneumatic valve mechanism.
Solution Approach 2:
The patent changes the physical parameter of the control fluid from liquid (hydraulic oil with high temperature-dependent viscosity) to gas (compressed air with lower temperature-dependent viscosity). This parameter change results in more stable door closing speed performance across varying temperatures while retaining speed adjustability through the pneumatic control valve.
3Speed
If control valve is provided in air communication with atmosphere in oil-air hybrid door closer, then door closing can be controlled, but dusts mixed in air enter oil cavity causing larger oil viscosity and affecting closing speed
Solution Approach 1:
The patent extracts and eliminates the hydraulic oil cavity from the system, replacing it with a pneumatic chamber. By removing the oil-based component entirely, the system eliminates the problem of dust contamination entering the fluid cavity and causing increased viscosity, as the pneumatic system uses compressed air that does not suffer from the same contamination issues.
Solution Approach 2:
The patent substitutes the oil-based hydraulic mechanism with a pneumatic system. The control valve now controls compressed air flow rather than oil flow, and the pneumatic chamber replaces the oil cavity. This substitution eliminates dust contamination problems because compressed air does not accumulate dust particles in the same way hydraulic oil does, maintaining consistent door closing speed.
4Duration of action of stationary object
If mechanical spring door closer is used to close door automatically, then door returns to original position accurately and timely, but large impact force is generated when closing door causing people to be bumped and impact noise
Solution Approach 1:
The patent uses a pneumatic system with compressed air chambers and pistons to replace the mechanical spring mechanism. The pneumatic system provides controlled, gradual door closing through regulated air pressure and flow, eliminating the sudden impact force of spring-based systems while maintaining timely door return through the elastic properties of compressed air.
Solution Approach 2:
The patent changes the energy storage and release mechanism from elastic mechanical springs to compressed pneumatic gas. This parameter change transforms the force delivery from sudden high-impact spring release to controlled gradual pneumatic expansion, reducing impact force and noise while maintaining door return timing through the compressibility and elastic recovery of the pneumatic system.
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 pneumatic door closer provides consistent and controlled door closure without oil leaks or temperature-dependent speed variations, reducing impact forces and noise, while being cost-effective and environmentally friendly.
Implementation Method 1
gas flows within the chamber to opposite sides of the piston as the door opens and closes
Implementation Method 2
a first piston assembly, and a second piston assembly... The second piston assembly drives the closed space into a first air chamber and a second air chamber
Data Source
AI summary
A pneumatic door closer includes a rotary energy-storing mechanism including a housing and a driving mechanism. The driving mechanism includes a cylinder, a second piston assembly and a sealing element, the sealing element is in an air tight connection with the cylinder and the second piston assembly, to form a closed space filled with high pressure gas in the cylinder. The second piston assembly drives the closed space into a first air chamber and a second air chamber in communication with each other. The driving mechanism also includes a first piston assembly connected to the second piston assembly. The pneumatic door closer also includes a transmission mechanism having one end received in the housing and another end connected to the door frame.