Revolving Door

Overview

A revolving door is an entrance built around a vertical axis: three glazed Door Wing leaves radiate from a central shaft and turn continuously inside a fixed cylindrical drum. Because at least one wing always bridges the opening, there is no moment when inside and outside connect directly, so the door holds a constant air seal even while people pass through. That property is the whole point of the design, it stops the stack-effect draught, heat loss and street noise that a hinged or sliding door lets in every time it opens, which is why revolving doors front lobbies, hotels and airports.

The fixed shell is the Canopy & Drum Enclosure. A domed ceiling canopy spans the top, carrying the machinery and a welded structural ring, and two curved tempered-glass quadrant walls close the sides to form the drum. The wings sweep within this drum, and brush-and-rubber seal strips ride along the wall edges so each rotating compartment stays sealed. Underfoot, the Floor Ring & Threshold anchors the bottom pivot at the axis and carries a threshold the wing sweep brushes wipe against.

How it works

The wings hang from the Center Shaft Assembly, a steel column supported by a top ball bearing in the canopy and a bottom thrust pivot in the floor. Rotation comes from the Drive Unit: a geared motor in the canopy reduces speed through a gearbox onto a sprocket that meshes a large drive ring fixed to the shaft hub, turning the whole assembly at a slow three-to-four rpm. The Control System runs the motion profile on a microcontroller board, holding the door still until someone approaches, then easing it up to speed and back down, its relay stage switches speed bands and cuts the drive on any safety trip.

People are watched by the Sensor Set. An overhead activation sensor wakes the door on approach; presence sensors on the leading wing edges and vertical post sensors at the closing gaps slow or stop rotation before anyone is touched, and an emergency-stop button halts it outright. Layered on top is the Speed Governor & Brake: a centrifugal governor caps how fast the wings can be pushed by hand, and a spring-applied brake clamps the shaft the instant power is lost or a fault trips, so the door never coasts freely.

Two further details make it usable and code-compliant. The LED Lighting Ring ring in the canopy lights each compartment as it comes around. And for egress, the wings are built to break out: under a hard push, or automatically on a fire alarm, the wing leaves fold flat against each other to clear a straight escape path, then reset afterward. All of it is tied together by the wiring, where a slip ring feeds power and signals across to the rotating assembly without twisting any cable.