Spring Brake Actuator Noise Reduction via Plastic Ring
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Solution Overview
Problem
Existing electromechanical actuators for home automation and solar protection systems with spring brakes generate operating noises due to friction between the input/output members and the drum housing, caused by misalignment and direct contact, which affects the acoustic performance.
Innovation Solution
Incorporating a ring made of plastic material between the external surface of the input/output members and the internal friction surface of the drum housing to reduce noise by allowing sliding without direct contact and compensating for misalignments, thereby acting as a bearing and preventing contact that generates noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the input member and output member are made of metal (zamak) and directly contact the drum housing, then the structural strength and durability are improved, but operating noise increases due to friction between metal surfaces
Solution Approach 1:
A plastic ring is introduced as an intermediary element between the metal input/output members and the metal drum housing. This ring prevents direct metal-to-metal contact during rotation, thereby eliminating the friction-generated operating noise while still allowing the mechanical function to operate. The ring acts as a mediator that maintains the necessary mechanical connection without the harmful frictional contact.
2Object-generated harmful factors
If the input member and output member are precisely aligned with the drum axis, then direct contact and friction are reduced, but manufacturing precision requirements and cost increase
Solution Approach 1:
The invention changes the material parameter of the input/output members from solid metal to metal with an attached plastic ring. This material/composite change allows the system to tolerate misalignment without increasing friction, because the plastic ring can accommodate positional variations while maintaining low-friction contact with the drum housing, thus relaxing the manufacturing precision requirements.
3Object-generated harmful factors
If a plastic ring is added between the input/output member and drum housing, then operating noise is reduced by preventing direct metal contact, but device complexity increases
Solution Approach 1:
The plastic ring is merged with the input or output member to form a composite component. Instead of being a separate loose part, the ring is integrated onto the metal member (either by attachment or as a composite structure), reducing the number of discrete components while still providing the noise-reduction function. This merging approach maintains the beneficial effect while minimizing the increase in device complexity.
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 solution effectively reduces operating noise and compensates for misalignments, ensuring smooth operation and improved acoustic performance by eliminating direct contact between the input/output members and the drum housing.
Implementation Method 1
The friction between the external surface of the input member and/or the output member and the internal friction surface of the housing of the drum is generated by a contact of the metal constituting the input member and the member outlet
Implementation Method 2
the friction force between the coils of the coil spring and the internal friction surface of the housing of the drum is increased during the rotational driving of the coil spring in the second direction of rotation
Data Source
AI summary
An electromechanical actuator for a home automation system for closing or sun protection comprises an electric motor, a gearbox, and a spring brake (15), which includes a helical spring (22), a drum (23), an input member (24), and an output member (25). The drum (23) has a housing (26). An internal friction surface (27) of the housing (26) of the drum (23) cooperates with at least one coil of the helical spring (22). The spring brake (15) also includes at least one ring (50) disposed between an external surface (51) of the input member (24) and/or the output member (25) and the internal friction surface (27) of the housing (26) of the drum (23). The home automation system of the invention comprises such an actuator.