REXNORD - MARBETT - MCC
B78
L
h
L
10h
Fc
17
28,5
20
33,5
25
38,5
30
46
35
53,5
40
60
45
65
50
70
100.000
10.000
50.000
1.000
5.000
100
500
40
45
50
35
GPF=1
65
70
75
80
85
90
95
100
105
110
60
700.000
600.000
500.000
400.000
300.000
200.000
nxdm=100.000
< 20.000
55
55
dm
d
d
dm
dia.
d
mm
dia.
dm
mm
Grease life in bearings lubricated for life
Formula to calculate
grease life in bearings
lubricated for life
(dry use recommended)
This procedure allows to calculate the grease life as a function of its quality and
bearing type, dimension, rotating speed, applied loads and working temperature.
Diagram 1
- Grease nominal life
L
10h
This diagram allows to determine the nominal grease life
L
10h
(hours), as a function of
rotating speed
n
(rpm), mean diameter
dm
(mm), bearing working temperature (°C).
Greases are classiIed by a factor GPF (Grease Performance Factor), related to their
temperature performance. ±n this table we consider a grease with GPF = 1, which is
the grease used in all Marbett ²ife²ube bearings.
= Grease life (hours).
= Grease nominal life (hours). See Diagram 1.
= Correction factor. See Diagram 2.
L
h
= L
10
x F
c
Grease life (hours)
= At room temperature, with normal working conditions, the grease works at a temperature lower than 55°C.
n = rotational speed (rpm)
dm = mean diameter (mm)
dm (mm)
= mean
diameter.
Type
A
Type
D
Operating temperature (°C)
Grease nominal life L
10h
(hours)