CAVEX® - MOTOR-GEAR as

Worm Gear Units
Service Factors for
Crane Installations
CAVEX
When using gear units with alternating loads – as they usually exist in crane installations – a classification according to FEM is recommended. For
this purpose, the factor for driven machine f 1 and the peak torque factor f 3 can be derived from table 2 on page 14 in accordance with the group
of mechanism standard values M 1...M 8 in table 1 below – depending on the load (state of loading of mechanism L 1...L 4) and the duty (classes of
utilization of mechanism T 0...T 9).
To take into account the load distribution in case of alternating loads within a representative period of time t, the cubic mean factor K is calculated
by:
3
P1 P
Here, P 1...P n is the operating cycle within the time cycle t 1...t n.
Load
T1 P1 1.0
T2 P2 0.4
T3 P3 0.1
t1 t2 t3 0 10 50
Duration of use
100
1.0
3 t1 t
K = • + ... •
0.733
0.467
0.2
t1 t2 t3 t4 0 16.7 33.3 50 100
12 K88 DE/EN/FR
Pn P
1.0
t 1
Service classification
3 tn t
L 1 L 2 L 3 L 4
Table 1 Group classification of mechanisms
0.4
t 2
0 50 100
1.0
0.8
t1 t2 0 90 100
See FEM 1001 Section I
3rd Edition, Table T.2.1.3.5
Type Ty e of aappliance liance
Particulars concerning
Type of mechanism
Designation
nature of use (*)
Hoisting Luffing Traverse Travel
Assembling cranes M2 - M3 M1 - M2 M1 - M2 M2 - M3
Stocking and reclaiming transporters Hook duty M5 - M6 - M4 - M5 M5 - M6
Stocking and reclaiming transporters Grab or magnet M7 - M8 - M6 - M7 M7 - M8
Workshop cranes M6 - M4 M5
Overhead travelling cranes, pig-breaking cranes,
scrapyard cranes
Grab or magnet M8 - M6 - M7 M7 - M8
Bridge cranes for unloading, bridge cranes for
containers, other bridge cranes (with crab and/
or slewing jib crane)
Bridge cranes for unloading, bridge cranes
(with crab and/or slewing jib crane
Drydock cranes, shipyard jib cranes, jib cranes for
dismantling
Dockside cranes (slewing, on gantry, ...)
floating cranes and pontoon derriks
Dockside cranes (slewing, on gantry, ...)
floating cranes and pontoon derriks
Floating cranes and pontoon derricks for very
heavy loads (usually greater than 100 t)
a) Hook or spreader duty
b) Hook duty
M6 - M7
M4 - M5
M3 - M4
-
M6 - M7
M4 - M5
M4 - M5
M4 - M5
Grab or magnet M8 M3 - M4 M7 - M8 M4 - M5
Hook duty M5 - M6 M4 - M5 M4 - M5 M5 - M6
Hook duty M6 - M7 M5 - M6 - M3 - M4
Grab or magnet M7 - M8 M6 - M7 - M4 - M5
M3 - M4 M3 - M4 - -
Deck cranes Hook duty M4 M3 - M4 M2 M3
Deck cranes Grab or magnet M5 - M6 M3 - M4 M4 - M5 M3 - M4
Tower cranes for building M4 M4 M3 M3
Derricks M2 - M3 M1 - M2 - -
Railway cranes allowed to run in trains M3 - M4 M3 - M3 - -
Automotive cranes Hook duty M3 - M4 M2 - M3 - -
*) Only a few typical cases of use are shown, by way of guidance, in this column.
If the system is driven via an electric or hydraulic motor, a factor for prime mover f 2 = 1 may be provided.
The factors shown on page 14 are empirical values. Prerequisite for their application is that the machinery and equipment mentioned correspond
to generally accepted design- and load specifications. In case of deviations from standard conditions, please refer to us.
For driven machines which are not listed in this table, please refer to us.