4
screws, mounted in the bearing hous-
ings, are loosened so that bearing and
conical cover can be withdrawn from the
shaft. Now the bearings can be removed
from the conical covers. Both bearing
and bearing housing are replaced.
Figure 8. CNA 630-1000/R
CNB 500-1000/R & CNB-M 500-1000/R
(See fig. 9)
The bearing assembly consists of bearing
tube, a ball bearing, a roller bearing and
shaft which is mounted between two
conical covers in the back plate of the fan
casing and is provided with a grease nip-
ple. The bearing assembly must be re-
greased for approx. every 2000 hours of
operation with a high-quality lithium
grease, penetration class 2 (e. g. SKF Al-
falub LGMT-2).
If the sealing ring at the farthest end of
the bearing tube (behind belt pulley) is
pushed away from the bearing during
greasing, push it in place towards the
bearing and remove surplus grease.
When replacing the bearings first re-
move belt guard, V-belts and fan belt
pulley. Then remove the conical covers
with bearing assembly and impeller, the
impeller is withdrawn from the shaft
and the covers are screwed off the bear-
ing casing. At last pull shaft and bearings
out of the bearing tube from the end
where the ball bearing is and remove the
bearings.
Figure 9. CNB 500-1000/R
6.8 Dismounting of motor for
CNA & CNA-M and
CNB/D & CNB/D-M
When changing the motor to a motor
with another number of poles it must be
checked that the speed of the motor does
not exceed the max. permissible speed
which is stated on the nameplate of the
fan. Also check that the motor rating is
sufficient for the changed power con-
sumption. In case of motor with frequen-
cy converter check also speed and power
consumption as when changing the mo-
tor. When mounting the motor the im-
peller must be carefully centred in rela-
tion to the inlet cone.
CNA & CNA-M, 250-400/D and
CNB & CNB-M, 400/D
(See fig. 10)
The motor is mounted on a conical cover
which is mounted direct in the back plate
of the fan casing. The motor must be a
standard motor with B-14 flange with
threaded holes). If so, the fan casing is in-
tended for universal mounting which is
the positions 0, 90, 180, and 270.
Dismount the motor by removing the
conical cover with motor. After that
withdraw the impeller from the motor
shaft and remove the motor from the
conical cover.
Type / Size
Bearing
assembly
Bearing
house,
Item no.
Bearings
Shaft
Re-greasing
Bearing
type-1
Bearing
type-2
Drawing no.
Bearing
diameter
[mm]
Amount of
grease
[g]
CNA 250
Flg.double bearing
388812-0
6305-RS1
6305-RS1
489663-0
25
11
CNA 315
Flg.double bearing
388812-0
6305-RS1
6305-RS1
489663-0
25
11
CNA 400
Flg.double bearing
388812-0
6305-RS1
6305-RS1
489663-0
25
11
CNA 500
Flg.double bearing
388811-0
6306-RS1
6306-RS1
388810-0
30
14
CNA 630
FY 35 TF
FY 507 M
YAR 207 2F
<-----
451390-0
35
-
CNA 710
FY 35 TF
FY 507 M
YAR 207 2F
<-----
423164-0
35
-
CNA 800
FY 40 TF
FY 508 M
YAR 208 2F
<-----
423165-0
40
-
CNA 900
FY 40 TF
FY 508 M
YAR 208 2F
<-----
423166-0
40
-
CNA 1000
FY 55 TF
FY 511 M
YAR 211 2F
<-----
423167-0
55
-
CNB 400
Flg.double bearing
388811-0
6306-RS1
6306-RS1
388810-0
30
14
CNB 500
Flange bearing
326872-0
6308-RS1
NU-308
326878-0
40
20
CNB 630
Flange bearing
326871-0
6310-RS1
NU-310
326877-0
50
30
CNB 710
Flange bearing
341042-0
6311-RS1
NU-311
326876-0
55
35
CNB 800
Flange bearing
341044-0
6311-RS1
NU-311
326875-0
55
35
CNB 900
Flange bearing
341046-0
6312-RS1
NU-312
326874-0
60
40
CNB 1000
Flange bearing
341048-0
6312-RS1
NU-312
326873-0
60
40
Table 4. Bearing types and grease amount
