29
ROSSI
GEARMOTORS
UT.D 123 rev. 3
8 - Maintenance
Do all checks and verifications according to
table 15
.
8.1 - Generals
Before starting any maintenance operations (disassembling, oil chan-
ge, seal ring change, etc.):
– disconnect the motor (including the auxiliary equipments) from the
electrical supply, and the gear reducer from load;
– be sure that all safety systems have been activated against the
accidental starting and if necessary, utilize mechanical locking
devices (to be removed before commissioning);
– ensure there is
no potential explosive atmosphere
all around.
Maintenance procedure:
– LOTO (Lockout/tagout): the machine must be disconnected (electri-
cally and mechanically segregated from the installation).
– HOT Works: hot fitting of components (ex. to the shaft end) can
absolutely only be made in certified safe areas.
Do not weld anything to the reducer/gearmotor as this can damage
gear pairs, bearings, oil seals.
Do not use the casing to ground welding equipment.
Maintenance technicians must wear appropriate work apparel (anti-
static clothing, gloves, etc.).
Stop the machine
and isolate the power supply to ensure there will be
no accidental starts in the following circumstances:
a) when maintaining labyrinth seals and greaser;
b) when maintaining bearings with separate lubrication of the back-
stop device;
c) when doing following checks:
– cleaning of external surfaces and air passages of gear reducer
or gearmotor;
– oil level;
– visible checks for oil deterioration (metal parts, water, sludge,
etc.);
– correct tightening of the fastening bolts, the shrink disc, if any,
and bonding connection;
– cleanliness of filter and functionality of valve of filler plug;
d) lubricant leak.
e) exceeding the critical limits of safety devices, if any.
For gear reducers with level plug or equivalent system (plug for flowing
over level, plug with dipstick) verify that oil level has not lowered.
For
gear reducers without level plug, check for oil leaks
(dripping,
oil spots, etc.)
with the machine running and at rest
.
In case of lubricant leak, before commissioning again the gear redu-
cer or gearmotor:
– collect the a.m. lubricant and dispose of it according to the law
in force;
– identify the cause of leak (if necessary, consult ROSSI MOTO-
RIDUTTORI).
– reset the level and the quantity requested.
Accumulation of dust to a depth of over
0.2
mm impedes
efficient heat dispersal from the gear reducer or gearmo-
tor casing and
must be removed.
Be sure that the safety and control devices are effective.
Attention!
After a running period, even if thermal range is
not achieved, gear reducer is subject to a light internal
overpressure which may cause burning liquid discharge.
Therefore, before loosening whichever plug wait until gear
reducer has become cold; if not possible, take the necessary protec-
tion measures against burning due to warm oil contact. ln any case,
always proceed with great care.
Maximum oil temperatures indicated in lubrication table
(see ch 6.2) do not represent a hindrance to the gear
reducer regular running.
Oil change
:
– for lubrication interval see table 6.2;
– during the oil change, after having unscrewed also the filler plug
in order to improve the discharge, it is recommended to clean
internally the gear reducer casing using the same oil type suitable
for the running. Check that all oil has been expelled by inclining
the gear reducer or by removing the remaining oil quantity, if, any,
through a suction pump. For the next filling use a 25
m oil filter.
When dismounting the cap (whenever gear reducers are provided
with),
reset the sealing with adhesive on cleaned and degreased
mating surfaces
.
All bolts which may be damaged during assembling and disassem-
bling operations are to be replaced with new ones having equivalent
specifications and resistance class.
Occasional maintenance such as replacement of gear pairs, bea-
rings, etc. must only be done by qualified ROSSI MOTORIDUTTORI
technicians.
We recommend to purchase spare parts and accessories from
ROSSI MOTORIDUTTORI.
ROSSI MOTORIDUTTORI undertakes and grants no responsibilty
or guarantee for any damages and/or malfunctions arising from the
use of non-original ROSSI MOTORIDUTTORI spare parts and/or
accessories.
If not running for long periods, the gear reducer is to be put into
short service every three weeks; If not running for more than 6
months the gear reducer is to be stored properly: consult ROSSI
MOTORIDUTTORI.
8.2 - Cooling coil
In case of long non-running periods at ambient temperatures lower
than or equal to 0 °C, the coil should be emptied out using compres-
sed air to blast out all the coolant, so as to avoid freezing-up which
would cause the coil to break.
Verify that there are no deposits inside the coil which may obstruct
water circulation or affect cooling. If any, wash the coil with suitable
chemical cleaning products or consult ROSSI MOTORIDUTTORI.
8.3 - Seal rings
Duration depends on several factors such as dragging speed, tem-
perature, ambient conditions, etc.; as a rough guide it can vary from
1 600 to 12 500 hrs. At any rate, replace seal rings every 5 years.
It is always recommended that the seal rings are replaced with
new ones when they are removed or during periodic checks of gear
reducer; in this case, the new ring should be generously greased and
positioned so that the seal line does not work on the same point of
sliding contact as the previous ring.
Oil seals must be protected against heat radiation, also during the
shrink fitting of parts, if applicable.
When replaced, the new seal rings must be made in fluoro-
rubber (VITON
®
).
8.4 - Bearings
Since there are many different types of bearings in a gear reducer
(roller, tapered roller, straight roller, etc.) and each bearing working
with different loads and speeds depending on the input speed, the
nature of the load of the driven machine, the transmission ratio, etc.,
and with different lubricants (oil bath, oil splash, grease, oil circula-
tion, etc.) it is not possible to define any periodical maintenance and
replacement of bearings in advance.
It is therefore
necessary to undertake periodical checks (accor-
ding to table 15) to verify noise level and vibrations with the
help of appropriate diagnostic equipment and instruments.
If
the measured values worsen even slightly it is necessary to stop
gear reducer or gearmotor and after having inspected inside, if need
be, consult ROSSI MOTORIDUTTORI.
If the failure of a bearing and the stopping of the machinery
constitute a danger to people, execute a continuous monito-
ring of vibrations and noise level.
8.5 - Metal filler plug with filter and valve
When the plug is to be cleaned (see ch. 6.1) unscrew it from the gear
reducer (preventing any debris or other foreign items from entering
the reducer), disassemble the cover, wash it with solvent, dry with
compressed air and reassemble it. This operation is to be made at
least every six months; if the surrounding operating evironment
requires so, reduce the maintenance interval.
