Geared Motor Emergency Anti-Return Device
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Solution Overview
Problem
The existing geared motors for rolling shutters suffer from jamming issues due to frictional wear between the helical torsional spring hooks and the teeth of the cylindrical cups, which impairs the emergency anti-return device's functionality, leading to unreliable and unsafe operation.
Innovation Solution
The introduction of a toothed cover with a helical compression spring and a rubber gasket between the toothed cylindrical cups addresses the jamming issue by ensuring constant engagement and preventing relative movement, thus maintaining the coupling between the reducer and the electrical motor, and reducing frictional wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the helical torsional spring hooks are engaged against the teeth of the cylindrical cups to transmit motion, then the emergency anti-return device can transmit motion from the motor to the reducer, but frictional wear between the hooks and teeth causes jamming and reduces reliability
Solution Approach 1:
A rubber gasket is introduced as an intermediary element between the helical torsional spring hooks and the teeth of the cylindrical cups. This gasket reduces direct metal-to-metal contact, thereby minimizing frictional wear and preventing jamming while still allowing effective motion transmission during normal operation and emergency anti-return functions.
2Adaptability or versatility
If the drive shaft is designed to slide axially to uncouple the motor from the reducer, then emergency uncoupling can be achieved, but constant engagement is required for normal operation
Solution Approach 1:
The drive shaft is designed with dynamic axial movement capability, allowing it to shift position along its axis. This enables the system to transition between two states: a coupled state for normal operation where the motor is engaged with the reducer, and an uncoupled state for emergencies where the drive shaft slides to disengage the motor, providing both constant engagement reliability and emergency adaptability.
3Reliability
If the helical compression spring constantly compresses the external cup against the reducer, then constant engagement is guaranteed, but the uncoupling means must overcome this antagonist force to uncouple
Solution Approach 1:
The helical compression spring is pre-loaded to constantly compress the external cup against the reducer, establishing constant engagement before any operation is needed. The uncoupling means is designed to overcome this pre-established spring force, allowing reliable engagement while providing a defined mechanism for emergency uncoupling when the spring force must be temporarily overcome.
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 enhances the reliability and safety of the geared motor by preventing jamming and ensuring smooth operation of the emergency anti-return device, allowing for reliable uncoupling and recoupling of the motor and reducer, and reducing noise during shutter operation.
Implementation Method 1
A helical torsional spring (8) is contained in the internal cup (203a) and is provided at the ends with two radial hooks (80, 81) that are faced outwards. One of said hooks is engaged against the edge of one of the teeth of the internal cup (3a), whereas the other one of said hooks is engaged against the edge of a tooth of the external cup (203b).
Implementation Method 2
The emergency anti-return device (DE) comprises a helical compression spring (205) disposed between the external cup (203b) and the electrical motor (1) in such a way that the external cup (203b) is constantly compressed by an axial thrust against the reducer (2).
Implementation Method 3
The introduction of a toothed cover with a helical compression spring and a rubber gasket between the toothed cylindrical cups addresses the jamming issue by ensuring constant engagement and preventing relative movement, thus maintaining the coupling between the reducer and the electrical motor, and reducing frictional wear.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A geared motor (100) for rolling shutters, comprises: an electrical motor (1) provided with a drive shaft (1a) that slides axially; a reducer (2) coupled to the drive shaft (1a) and to the winding shaft of a rolling shutter, uncoupling means (7) of the electrical motor (1) from the reducer (2); a non-return device (D) connected to the drive shaft (1a) to make the transmission of motion from the electrical motor (1) to the reducer irreversible, an emergency device (E) to uncouple the drive shaft (1a) from the reducer (2) when the uncoupling means (7) are operated; the emergency device (E) comprises: a toothed cover (4) slidingly integral with the drive shaft (1a) and rotationally integral with the non-return device (D) and with the reducer (2); and a helical compression spring (5) to push the toothed cover (4) in engagement with the reducer (2).