Window Drive Pressure Equalization via Gas Volume
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Solution Overview
Problem
Existing window and door drive systems face challenges in reliable pressure equalization due to complex sealing issues and potential leaks in elastic enveloping bodies used for thermal expansion compensation, which can lead to operational failures like 'wing dropping'.
Innovation Solution
A drive system design that includes a housing filled with hydraulic fluid and a gas volume in the spring chamber, where the gas can only transfer to the damping chamber through a sleeve or piston rod with an inlet opening positioned to remain surrounded by fluid at all temperatures, preventing gas entry into the damping space and ensuring reliable pressure equalization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gas volume enclosed by an elastic enveloping body is provided for pressure equalization, then thermal expansion compensation is achieved, but the sealing becomes complex and may become leaky due to aging
Solution Approach 1:
The patent extracts the gas volume from the elastic enveloping body and places it directly in the spring chamber, eliminating the need for complex sealing of the enveloping body. The gas volume is now bounded by the rigid housing and piston surfaces rather than an elastic membrane, removing the sealing complexity while maintaining pressure equalization function
Solution Approach 2:
The patent eliminates the elastic enveloping body (flexible shell) entirely and replaces it with a rigid chamber design where the gas volume is contained by the housing and piston surfaces. This removes the sealing issues associated with elastic membranes while achieving the same pressure compensation function
2Reliability
If foam is used for pressure equalization, then thermal expansion compensation is achieved, but damage from pressure peaks in continuous operation may occur
Solution Approach 1:
The patent changes the physical state and properties of the pressure equalization medium from foam (compressible solid) to gas volume (compressible gas). The gas can accommodate pressure peaks more effectively through compression and expansion, maintaining reliability under continuous operation with pressure variations
3Reliability
If the inlet opening is not completely surrounded by hydraulic fluid, then gas may enter the damping chamber causing wing dropping, but positioning the inlet opening centrally limits the gas volume
Solution Approach 1:
The patent positions the inlet opening in the central region of the spring chamber, using the vertical dimension and gravitational separation to keep the gas volume above the inlet opening while maintaining sufficient gas volume for pressure equalization. This spatial arrangement prevents gas entry into the damping chamber while preserving the quantity of gas needed
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 configuration provides a simpler, cost-effective, and more reliable pressure equalization, preventing unwanted 'wing dropping' and ensuring consistent operation across varying temperatures and positions, including during storage and transport.
Implementation Method 1
compensate for the change in volume of the hydraulic fluid as a result of thermal expansion
Implementation Method 2
hydraulic fluid can only be transferred from the spring chamber into the damping chamber through a sleeve that is connected to the piston and extends into the spring chamber
Implementation Method 3
a piston which is arranged in the housing, interacts with an output shaft to open and close the sash and is acted upon in the closing direction by a spring unit
Implementation Method 4
a damping chamber in which a damping force acting in the opening direction on the piston can be generated
Data Source
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AI summary
An actuator for a window, door, or similar sash comprises a housing and a piston arranged within the housing. The piston, which interacts with an output shaft to open and close the sash, is acted upon in the closing direction by a spring unit. The housing is divided into a spring chamber containing the spring unit and a damping chamber. The housing is filled with hydraulic fluid such that a gas volume serving for pressure equalization is retained in the spring chamber. Hydraulic fluid can only be transferred from the spring chamber into the damping chamber through a sleeve connected to the piston and extending into the spring chamber, or through a piston rod having at least one outflow channel. The cavity of the sleeve or outflow channel is connected to the spring chamber via at least one inlet opening.The piston rod is arranged in the spring chamber and each inlet opening is positioned so that each inlet opening of the sleeve or piston rod is completely surrounded by the hydraulic fluid even at the lowest operating temperature of the drive.