Machine-Roomless Lifts
This revolutionary lift system is based on the first major breakthrough in lifting technology in nearly 100 years. Designed for buildings between about 2 and 30 stories, this system employs a smaller sheave than conventional geared and gearless lifts. The reduced sheave size, together with a redesigned machine, allows the machine to be mounted within the hoistway itself—eliminating the need for a bulky machine room on the roof. Just as unique are the flat polyurethane-coated steel belts, an Otis invention for the Gen2® lift system, that replace the heavy, woven steel cables that have been the industry standard since the 1800s. The belts make the smaller sheave possible. They are only 3 mm thick, yet they are as strong as woven steel cables and far more durable, flexible and space-saving.

Gearless Traction Lifts
In 1903, Otis introduced the design that would become the standard in the lift industry—the gearless traction lift. These lifts typically operate at speeds greater than 2.5 metres per second. In a gearless traction machine, woven steel cables called hoisting ropes are attached to the top of the lift car and wrapped around the drive sheave in special grooves. The other ends of the cables are attached to a counterweight that moves up and down in the hoistway on its own guide rails. The combined weight of the lift car and the counterweight presses the cables into the drive sheave grooves, providing the necessary traction as the sheave turns. Gearless technology makes the tallest buildings in the world possible, such as Malaysia’s Petronas Towers.

Geared Traction Lifts
As the name implies, the electric motor in this design drives a gear-type reduction unit, which turns the hoisting sheave. While slower than a typical gearless lift, the gear reduction offers the advantage of requiring a less powerful motor to turn the sheave. These lifts typically operate at speeds from 1.75 to 2.5 metres per second and carry loads of up to 2000 kg. An electrically controlled brake between the motor and the reduction unit stops the lift, holding the car at the desired floor level.