WP6-Brochure-E4 brochure - ELA European Lift Association.

Figure 3‐26. Helical gear
Planetary gears are also used by some of the equipment manufacturers to replace the low
efficiency worm gears. They have the additional advantage, over helical gears, of occupying
less space.
A variety of roping systems can be employed dependant on the particular conditions of each
installation (e.g. machine positioning, rated load and speed, available space, etc.). Examples of
commonly used roping systems are shown in Figure 3‐27.
(a) (b) (c) (d) (e)
Figure 3‐27. Commonly used roping systems (source: Mitsubishi)
a 1:1 Single wrap Mid‐, low‐speed lifts
b 1:1 Double wrap High‐speed lifts
c 2:1 Double wrap High‐speed lifts
d 2:1 Single wrap Freight lifts, Machine‐roomless
lifts
e 2:1 Single wrap Machine‐room‐less lifts
In lifts that use 1:1 roping schemes, the car travels a distance equivalent to the perimeter of
the sheave, for each revolution. In Europe, however, most of the lifts are roped 2:1, which
means that the sheave must turn twice as much for the car to travel the same distance as in
1:1 roped lift. With the 2:1 roping scheme, however, the motor is only required to produce half
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