Automatic Curved Sliding Door VS. 3/4 Wing Revolving Door

Automatic curved doors and automatic revolving doors are much popular for modern buildings like hotels, shopping malls, office buildings etc.. Both curved sliding door & 3/4 wing revolving door are automatic type in this article, and the curved sliding door is the full-circle type here .

I. Core Differences in Basic Definition & Movement Mode

1. Full-Curved Automatic Sliding Door. Essentially a curved linear automatic door. Two curved glass door leaves slide reciprocally along a top circular curved track in an arc trajectory. When fully open, both leaves retract toward both sides along the curve and close afterward, it has no central vertical spindle.

2. 3/4 Wing Automatic Revolving Door . A central spindle rotary door. Three or four door wings are rigidly fixed to a vertical central main shaft and rotate circumferentially as a whole around the spindle continuously. Individual door leaves cannot slide separately, and the entire assembly moves in a circular path at all times.

II. In-Depth Comparison of Drive Systems (Key Section)

▪ Drive Structure of Full-Curved Sliding Door

1. Complete Drive Assembly

Integrated top drive beam, brushless DC servo motor, circular timing belt transmission system, sets of curved hanging rollers, multiple tension/idler pulleys, controller, top curved aluminum alloy track, buffer limit devices.

2. Transmission Principle

One motor drives a timing pulley, an S8M circular timing belt wraps around the full-circle track, with both belt ends fixed to the left and right door leaves respectively. Forward/reverse rotation of the motor pulls the belt, and hanging rollers drive the door leaves to slide synchronously left and right along the curved track.

Transmission form: Belt + hanging roller sliding transmission, rotary motion converted to curved linear sliding motion .

Force bearing point: All door weight is borne by top hanging rollers, vertical load is carried by the track .

Reduction mechanism: Built-in worm & worm gear reducer for low noise operation .

Guide accessories: Multiple inner track idler pulleys fitted for curved routing to prevent belt derailment .

3. Drive Characteristics

No central vertical column or bottom load-bearing spindle, all drive components are concentrated on the top header .

Two independent synchronously sliding leaves, supports single-side half-open mode, full-open mode and locking mode .

Low manual pushing resistance for easy manual operation during power failure .

▪ Drive Structure of 3/4-Wing Revolving Door

1. Complete Drive Assembly

Vertical central main spindle, top drive housing, high-power helical gear reduction motor, planetary gear reducer, electromagnetic brake, heavy-duty upper & lower thrust bearings, rigid connection flanges for door wings, dedicated PLC revolving door controller, full perimeter safety light curtains, bottom load-bearing bearing base.

2. Transmission Principle

Multi-stage helical gear reducer amplifies torque, output shaft directly connects to the central main spindle, which drives all 3/4 door wings to rotate circumferentially as a rigid unit. No belts adopted, purely rigid gear-spindle transmission.

Transmission form: Central spindle gear rotary transmission, rotary motion directly drives the full set of door wings for circular rotation .

Force bearing point: Upper and lower central spindle bearings carry total door wing weight plus wind load, axial gravity is borne by the bottom bearing .

Reduction mechanism: 2~3 stage hard-tooth helical gear reducer, output torque 400~600 N·m .

Balance structure: Cross tie rods installed between door wings to offset eccentric rotary load and avoid spindle deformation .

3. Drive Characteristics

Mandatory solid central column running from floor to top drive box .

All door wings rigidly interlocked to rotate as one unit, single-leaf independent opening is unavailable .

Electromagnetic brake locks spindle under power failure, requiring substantial force for manual pushing .

Dual upper/lower load-bearing bearings required, strict installation tolerance for floor levelness and spindle verticality (tolerance ≤2mm over 3m height) .

III. Mechanical Structure Comparison

IV. Differences in Control System & Sensor Logic

1. Control Logic of Full-Curved Sliding Door

Sensors: Microwave radar at entrance, motor activates upon human approach, door leaves slide open along the curve to both sides, auto-close after delay when pedestrian leaves .

Operation Modes: Auto full open, half-open (single side only), permanent hold open, locked .

Safety Protection: Belt rebound anti-pinch triggered by obstacle detection during closing, anti-collision protection only on leaf edge .

Control Logic: Recurrent start-stop cycle, door rests stationary after completing one open-close cycle until next trigger signal .

2. Control Logic of 3/4 Wing Revolving Door

Sensors: Entrance radar + inner door wing safety light curtains, automatic speed increase when pedestrian enters, low-speed standby when vacant .

Operation Modes: Continuous circulating rotation, stop & lock, fire forced stop .

Safety Protection: Full perimeter anti-pinch light curtains, bottom door wing anti-collision strips, spindle overload torque protection, reverse rotation anti-collision function .

Control Logic: Uninterrupted circular circulation, never fully stationary, always maintaining separated passage compartments .

V. Comparison of Passage Capacity, Space Occupancy, Energy Consumption , Maintenance

1. Pedestrian Throughput

Full-curved sliding door: Wide unobstructed passage after full opening, simultaneous access for pedestrians, wheelchairs and trolleys, capacity 60–80 persons per minute .

3/4-wing revolving door: Only 1–2 occupants per compartment, trolley passage restricted, capacity 30–50 persons per minute, prone to congestion during peak hours .

2. Space Requirement

Full-curved sliding door: Minimum inner diameter 2.4–3.6m, no central column occupying internal passage space .

Revolving door: Minimum inner diameter ≥3.0m, central column blocks passage, narrower effective clear width at identical diameter .

3. Air Tightness & Energy Saving

Revolving door performs best: Constant partition between indoor & outdoor air flow, reducing air conditioning energy consumption by ~30%, ideal for extreme hot/cold climates .

Full-curved sliding door: Good sealing when closed, yet direct air convection occurs when fully open, energy saving efficiency improved by only 15%~20% .

Annual Maintenance

Curved sliding door: Work scope includes curved track cleaning, timing belt replacement, hanging roller lubrication.

Revolving door: Regular spindle bearing grease refilling, door wing balance calibration, gear wear inspection required.

Failure Rate: Curved sliding door features simple structure with easily replaceable belts, revolving doors face complex repairs and expensive spare parts once gears or spindle bearings wear out .