7
—32
7.4.
Belt drive
Inspection of the belt drive
Make sure to regularly inspect the belt drive during the initial operating hours.
The drive belt will have to be inspected and retightened
– if necessary - after an operating period of between
0.5 and 4 hours under full load and thereafter in intervals of about 24 operating hours.
-
Unscrew the protective cover of the belt
-
Inspect the drive belt as shown in figure 1
If necessary, retighten the drive belt by loosening the clamping screws on the side of the motor carriage,
tightening the belt as required by adjusting the tension screws and retightening the clamping screws on the
motor carriage.
If a replacement of the belt is required, make sure to release the tension of the entire belt drive before
removing the belt! If the system is equipped with several belts, always make sure to replace the complete set!
After maintenance work, reinstall the protective cover of the belt.
Figure 1
Control of acquired belt tension force is carried out on the basis of its deflection caused by force
g
F
. To
measure the deflection position the measuring gauge with the load hook A in the center of the belt run. Zero
the trailing pointer. Apply the test force in accordance with scale C. For this, pull the measuring gauge at a 90
degrees angle away from the belt run. Read the depth of impression on scale D of the trailing pointer.
Relation of the belt tension force
p
F
, pressure
g
F
and deflection can be expressed by the following
approximate equation:
(
)
(
)
N
F
f
a
F
g
p
20
...
10
cos
/
25
,
0
−
=
.
Value of force
g
F
for belts is determined according to its cross section with keeping the deflection not smaller
than
a
f
016
,
0
(a
– axis distance), for belts specified in table 1.
Belt Cross
Section
SPZ
SPA
SPB
SPC
Y
Z
A
B
C
D
E
F
g
[N]
25...27
45...50
75
125…140
13
24
40
70
120
240
360
Table 2
Values of force
g
F
If necessary, properly set the belt pretension until the specified depth of impression
f
is reached.
If the drive belt is not properly tightened, the result will be an inadequate
transmission of power and a premature failure of the drive belt. A too high
pretension will additionally be the cause of bearing damages. When tightening the
belt, make sure that the lateral alignment of the belts does not deviate by more
than 1 degree.
•
General controls
-
bearing play too large?
-
grease leaking on bearings?
-
surface protection affected ( medium to be ventilated too aggressive!)?
-
unusual operation noise?
-
fan capacity for possibly exceeded duct system still sufficient (overloading!)?
When we have BELT DRIVE for ATEX application belt must be produced in
antistatic material and the speed of belt should be limited on 30m/s. This drive only
for use in IIB or IIIC.
