Crane for cargo duty

at maximum radius

Q = 220 kN	lmax = 23 m
A = 75 kN	amax = 11 m
O = 450 kN	o = 0.75 m
G = 900 kN	g = 3 m
W = 27 kN	r = 6.5 m

 

1) Maximum operating load including wind

F_a = Q + A + O + G
F_a = 220 + 75 + 450 + 900
F_a = 1,645 kN

M_k = Q · l_max + A · a_max + W · r - O · o - G · g
M_k = 220 · 23 + 75 · 11 + 27 · 6.5 - 450 · 0.75 - 900 · 3
M_k = 3,023.0 kNm

2) Load case incl. 25% test load without wind

F_a = Q · 1.25 + A + O + G
F_a = 275 + 75 + 450 + 900
F_a = 1,700 kN

M_k = Q · 1.25 · l _max + A · a_max - O · o - G · g
M_k = 275 · 23 + 75 · 11 - 450 · 0.75 - 900 · 3
M_k = 4,112.5 kNm

3) Maximum operating load without wind

F_a = 1,645 kN

M_k = Q · l_max + A · a_max - O · o - G · g
M_k = 220 · 23 + 75 · 11 - 450 · 0.75 - 900 · 3
M_k = 2,847.5 kNm

When selecting the bearing, load case 2) should be used for static evaluation, and load case 3) for service life.

The static load capacity of the bearing, taking into account load factor f_stat = 1.25 is checked against the "static limiting load curve", reference load:

Load case 2)

F_a' = 1,700 kN · 1.25 = 2,125 kN
M_k' = 4,112.5 kNm · 1.25 = 5,140.6 kNm

A load factor of f_L = 1.15 is used for a service life of 45,000 revolutions under full load, reference load:

Load case 3)

F_a' = 1,645 kN · 1.15 = 1,891.7 kN
M_k' = 2,847.5 kNm · 1.15 = 3,274.6 kNm

The number of bolts and strength class will be determined for the max. load without a factor:

Load case 2)

F_a = 1,700 kN
M_k = 4,112.5 kNm

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