The working principle of rolling shutter doors mainly involves driving the shaft to rotate via the drive device, causing the slats to coil or uncoil, thereby achieving the lifting and closing of the door.
Core Mechanical Structure
Coiling System: The door body is composed of multiple jointed slats connected in series, fixed within the tracks, and rotates up and down around the overhead shaft. When lifting, the slats coil around the shaft; when lowering, they slide down along the inside of the guide rail.
Balance Device: A high-strength torsion spring balance mechanism ensures the door body stays balanced at any position, reducing motor load and preventing tilting. Spring roller shutters directly use the torsion spring force to control the fabric's rolling and unrolling.
Guide Rails and Support: The guide rails on both sides limit the slats' movement paths, ensuring smooth operation and a stable structure.
Drive and Control Methods
Power Drive: Mainly uses specialized motors, which drive the transmission shaft via worm gear reduction. Industrial fast doors often employ variable-frequency motors to control speed, enabling rapid lifting and smooth stopping.
Control Logic: The control system receives signals from sensors (such as radar, infrared, geomagnetic) or manual buttons to send commands to the motor. It supports remote control, mobile APP operation, and smart home integration.
Emergency Operation: Equipped with a manual clutch or chain, allowing the door to be manually lifted or lowered by hand during a power outage.
Safety and Protection Mechanisms
Limit Protection: Upper and lower limit switches are set so that the door automatically stops at the designated positions, preventing impact on the tracks.
Anti-Pinch Safety: Some models are equipped with infrared dual probes or light curtains that automatically reverse the door when encountering people or obstacles. Fast doors decelerate and cushion about 20 cm before reaching the endpoint, preventing pinching and reducing noise.
Fire Linkage: Fire shutter doors can be linked with smoke and heat alarm systems, automatically controlling the door in case of fire or via the fire control room. ...