
2. PRECAUTIONS ON USE
B–65142E/04
DESCRIPTIONS FOR THE α series
20
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.
The motor shaft oil seal diameter is as shown below.
Motor mode Oil seal diameter
α1/2
αM2/2.5
φ 15 [mm]
α3/6
αM6/9
αL6/9
αC3/6
α3/6HV
αM6/9HV
φ 24 [mm]
α12/22/30/40
αM22/30/40
αL25/50
αC12/22
α12/22/30/40HV
αM22/30/40HV
φ 35 [mm]
α65/100/150 φ 60 [mm]
α300/400 φ 70 [mm]
α1000HV φ 85 [mm]
Shaft attachment section
requirements