Lenze DSD - Manual (Page 113)

Lenze · Drive Solution Designer · Manual · DMS 4.2 EN · 12/2013 · TD23
113
7 Applications
7.8 Hoist drive without counterweight
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7.8 Hoist drive without counterweight
In the case of winches, power is transmitted from the drive on the load via a cable drum and a rope.
The load can be arranged with or without a vertical guide (rolls, slide rails). The rope can be deflected
once or several times or have reevings (pulley block principle). By means of ropes or belts only one
direction of force can be transmitted. Therefore it is only used for applications with a low accelera-
tion clearly below the acceleration due to gravity of 1 g (1 g = 9.81 m/s²). Typical winch applications
are load cranes of all types, scenery winches in theatres, storage and retrieval units, and manually
operated hoists. A winch installation controlled by the winch speed is connected to the winch me-
chanically or electrically via an individual installation drive and carries out the correct installation of
the cable in one or several layers. One-layer systems partly have grooves in the cable drum, into
which the cable is installed.
• Cranes that are designed as overhead cranes, gantry cranes and construction cranes or as simple
hoists lift loads by means of cable winches and operate with different types of reeving. The drive
units, just like the wheel drives, are often mounted to constructional elements that travel along.
• In order to move sceneries in theatres vertically, often several cables are required next to each
other for each scenery, which act on the sceneries via cross members. The cables of the stage
and scenery lifters are wound synchronously on mechanically coupled winches that are axially
arranged next to each other. The winches are actuated by a central hoist drive. Tangential pres-
sure rollers provide for a safe cable guide in the grooves of the cable drum. The cables can have
lengths of up to 50 m.
• When the application is calculated in the DSD, changes of the cable drum radius during winding
and additional losses can be taken into consideration.