Window Sash Drive With Spring Friction Self-Locking
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Solution Overview
Problem
Existing window and door drives face inefficiencies due to self-locking mechanisms that hinder motor power transmission, leading to performance losses and a need for a compact design that inhibits movement in de-energized states while maintaining efficiency.
Innovation Solution
A torque transmission arrangement using a spring coupled to a transmission element, where the spring is rotatably mounted under friction, allowing low-friction rotation in one direction and inhibiting rotation in the opposite direction by increasing friction, eliminating the need for a self-locking gearbox.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a self-locking mechanism is used in the gearbox to prevent movement when de-energized, then the drive can support the window sash weight, but the drive efficiency decreases and power loss increases
Solution Approach 1:
The self-locking function is extracted from the gearbox and implemented separately using a spring mechanism with friction elements. This allows the gearbox to operate without self-locking constraints, improving efficiency while the separate spring mechanism provides the necessary holding function when de-energized.
Solution Approach 2:
A spring mechanism acts as an intermediary between the motor and the load, providing self-locking capability through friction engagement. The spring can engage or disengage from friction elements to provide locking when needed while allowing free rotation during operation, thus resolving the contradiction between reliability and energy loss.
2Reliability
If a self-locking gearbox is used to inhibit movement in de-energized state, then the drive can hold position, but the device complexity increases
Solution Approach 1:
The drive system is segmented into separate functional components: the gearbox for torque transmission and a separate spring-based mechanism for position holding. This segmentation allows each component to be optimized independently, reducing overall system complexity while maintaining position holding capability.
Solution Approach 2:
The spring mechanism serves as an intermediary component that provides position holding without requiring the gearbox itself to be self-locking. This intermediary approach simplifies the gearbox design while still achieving the desired position holding function through the separate spring-friction engagement 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
This solution ensures self-locking during de-energized states while maintaining efficient torque transmission from the motor to the output shaft, reducing power losses and allowing for a compact design.
Implementation Method 1
a torque transmission in a first direction of rotation from the transmission element to the first drive section reduces the friction between the spring and the spring mount, so that rotation of the transmission element together with the spring is released
Implementation Method 2
a torque transmission in a second direction, in particular opposite to the first, from the transmission element to the first drive section increases the friction between the spring and the spring receptacle, thus inhibiting rotation of the transmission element together with the spring
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to a drive for a sash of a door or window, comprising a drive shaft, a motor driving the drive shaft, an output shaft for transmitting torque from the motor to the sash, and an arrangement for directionally inhibiting the torque transmission between the drive and output shafts, wherein the arrangement comprises: at least one transmission element for the torque, a spring coupled to the transmission element for common rotation, and a static spring mount by which the spring is rotatably mounted under friction, wherein the spring has at least one first drive section for interacting with the transmission element, and wherein the spring is arranged such that a torque transmission in a first direction of rotation from the transmission element to the first drive section reduces the friction between the spring and the spring mount.so that rotation of the transmission element is released together with the spring and/or that torque transmission in a second, in particular opposite to the first, direction of rotation from the transmission element to the first drive section increases the friction between the spring and the spring receptacle, so that rotation of the transmission element together with the spring is inhibited.