9
Malfunctions
Possible malfunctions/remedy
Assembly and Operating Instructions – M1..N Series Single-Stage Helical Gear Units
96
Fault
Possible cause
Measure
Oil leaking
•
From cover plate
•
From inspection
cover
•
From bearing cover
•
From mounting
flange
•
Seal not tight at:
– Cover plate
– Inspection cover
– Bearing cover
– Mounting flange
•
Tighten the bolts on the respective
cover. Observe the gear unit. Contact
SEW‑EURODRIVE if oil is still leaking
Oil leaking
1)
•
From oil seal
•
Too much oil
•
Check oil level; correct if necessary
•
Sealing lip of the oil seal turned
up
•
Vent the gear unit, observe the gear
unit. Contact SEW‑EURODRIVE if oil is
still leaking.
•
Oil seal damaged/worn
•
Check oil seals; replace if necessary
Oil leaking
•
At the gear unit
breather
•
Too much oil
•
Check oil level, correct if necessary
•
Drive not installed in proper
mounting position
•
Install gear unit breather correctly and
adjust the oil level
•
Frequent cold starts (oil foaming)
and/or high oil level
•
Install oil expansion tank
Oil leaking
•
From the screw plug
•
From the oil drain
valve
•
Seal not tight
•
Retighten the screw
•
Fittings loosened
•
Retighten the fitting and screw
No oil pump suction
•
Air in the suction line of the oil
pump
•
Fill oil into the suction line and the oil
pump, vent the pump at the pressure
side
•
Oil pump defective
•
Consult SEW‑EURODRIVE
Pressure switch does
not switch
•
Air in the suction line of the oil
pump
•
Fill the suction line and oil pump with oil
•
Vent the pump at the pressure side
•
Pressure switch connected incor-
rectly
•
Check the connection
•
Pressure switch defective
•
Replace pressure switch
•
Oil pump defective
•
Consult SEW‑EURODRIVE
Malfunction in the oil-
water or oil-air cooling
system
•
Malfunction of the oil-water or oil-
air cooling system
•
Observe the separate operating instruc-
tions for the oil-water or oil-air cooling
system.
Gear unit does not
reach cold start temper-
ature
•
Thermostat set incorrectly
•
Check the setting of the thermostat
•
Oil heating defective or connect-
ed incorrectly
•
Check the oil heater for proper connec-
tion and function; replace if necessary
•
Heat dissipation too great due to
unfavorable climatic conditions
•
Protect the gear unit from cooling off
during the warm-up phase
1) During the run-in phase (24-hour runtime), it is normal for (small amounts of) oil/grease to leak from the oil seal (see also DIN 3761).
29203856/EN – 03/2020
