Nicotra Gebhardt AT Série Manuel D'utilisation Et De Maintenance page 32

Bearing type 1)
–
Deep groove ball bearings
Angular contact ball bearings
Self-aligning ball bearings
Cylindrical roller bearings
– non-locating bearing
– locating bearing, without external axial loads
or with light but alternating axial loads
– locating bearing, with constantly acting light axial load
– full complement 2)
Taper roller bearings
Spherical roller bearings
– when load ratio F /F < e and d
a r
series 222, 238, 239
series 213, 223, 230, 231, 232, 240, 248, 249
series 241
– when load ratio F /F < e and d
a r
series 238, 239
series 230, 231, 232, 240, 248, 249
series 241
– when load ratio F /F > e
a r
all series
CARB toroidal roller bearings
– with cage
– without cage, full complement
Thrust ball bearings
Cylindrical roller thrust bearings
Spherical roller thrust bearings
– pure axial load and rotating shaft washer
32
Per valutare la durata L
lare il rapporto C/P, il fattore di velocità
A = n x d (dove n è la velocità di rotazio-
m
ne [giri/min] e d
metro medio [mm]) e valutare il coeffi-
ciente b , che dipende dalla tipologia di
f
cuscinetto, dalla tabella seguente:
BEARING FACTORS AND RECOMMENDED LIMITS FOR SPEED FACTOR A
Bearing
factor
b
f
–
1
1
1
1,5
2
4
4
2
≤ 800 mm
m
2
2
2
> 800 mm
m
2
2
2
6
2
2) 4
2
10
4
(se il valore del fattore di velocità A supe-
ra il 70% del limite raccomandato indica-
to in tabella, si prega di consultare i ser-
vizi tecnici della Nicotra Gebhardt).
COD. 985719/05 - 01-2012
dobbiamo calco-
1
= 1/2 x (d + D) è il dia-
m
Recommended limits
for speed factor A for load ratio
C/P ≥ 15
mm/min
500 000
500 000
500 000
450 000
300 000
200 000
NA 3)
350 000
350 000
250 000
150 000
230 000
170 000
100 000
150 000
350 000
NA 3)
200 000
100 000
200 000
To evaluate the L grease life, we have to
1
calculate the load ratio C/P, the speed fac-
tor A = n x d (n is the rotational speed
m
[rpm] and d = 1/2 x (d + D) is the bearing
m
mean diameter [mm]) and the bearing fac-
tor b , which is depending on bearing
f
type, for the following table:
C/P ≈ 8 C/P = 4
400 000 300 000
400 000 300 000
400 000 300 000
300 000 150 000
200 000 100 000
120 000 60 000
NA 3) 20 000
200 000 100 000
200 000 100 000
150 000 80 000
80 000 4) 50 000
130 000 65 000
100 000 50 000
50 000 4) 30 000
50 000 4) 30 000
200 000 100 000
NA 3) 20 000
150 000 100 000
60 000 30 000
120 000 60 000
(if the speed factor A exceeds a value of
70% of the recommended limit, please
refer to the Nicotra Gebhardt Technical
department).
4)
4)
4)