Elevator Roping Ratio (Reeving Ratio)
Simplified explanation:
Distance traveled by wire ropes on traction sheave : Distance traveled by car
1:1 Roping Ratio
Rope travels 1 m → Car travels 1 m
Structure: Wire ropes are fixed directly to the car and counterweight; no deflection sheave on car top.
Application: High-speed passenger elevators (≥2.0 m/s), high-end machine-room elevators, and modernization of old elevators.
2:1 Roping Ratio (Most widely used in the industry)
Rope travels 2 m → Car travels 1 m
Structure: Deflection sheaves (moving pulleys) are installed on top of the car and counterweight.
Application: Residential passenger elevators with speed 1.0～1.75 m/s, most machine-room-less elevators, residential traction elevators.
4:1 Roping Ratio
Rope travels 4 m → Car travels 1 m
Structure: Two sets of deflection sheaves on the car top; multi-stage moving pulley system.
Application: Heavy-duty freight elevators (3t, 5t, 8t). Rarely adopted for passenger elevators.
