
B-65262EN/03 SPECIFICATIONS FOR THE αiS/αi SERIES 2.HOW TO USE SERVO MOTORS
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Oil seal section requirements
The motor shaft is sealed to prevent penetration of oil into the motor
housing.
However, sealing may not be perfect under severe working
conditions.
When oil bath lubrication is provided for the gear engagement, for
example, the oil level must be below the lip of the shaft's oil seal.
Set the oil level so that oil merely splashes the lip. Thus, as the shaft
rotates, the oil seal can repel oil. If, however, pressure is applied
continuously while the shaft is stopped, oil may penetrate the lip.
When the shaft is always immersed in oil, for example, under the
condition that the motor is to be used with the shaft oriented vertically
a special design is required. For example, another oil seal could be
installed on the machine side, and a drain provided so that oil
penetrating that seal can drain off.
When grease is used for lubrication, the oil seal characteristics are
usually lost.
In either case, ensure that no pressure is applied to the oil seal lip.