Mitsubishi Electric MELSERVO-JN Series Instruction Manual page 311

12. SERVO MOTOR
12.2.3 Permissible load for the shaft
For the permissible shaft load specific to the servo motor, refer to sections 12.5.2 (1), 12.6.4 (1) (c), 12.6.4 (2)
(c).
(1) Use a flexible coupling and make sure that the misalignment of the shaft is less than the permissible radial
load.
(2) When using a pulley, sprocket or timing belt, select a diameter that will fit into the permissible radial load.
(3) Excess of the permissible load can shorten the bearing life and damage the shaft.
(4) The load indicated in this section is static load in a single direction and does not include eccentric load.
Make eccentric load as small as possible. Not doing so may damage the servo motor.
12.2.4 Protection from oil and water
Provide adequate protection to prevent foreign matter such as oil from entering the servo motor shaft. When
installing the servo motor, consider the following in this section.
(1) Do not use the servo motor with its cable soaked in oil or water.
(2) When the servo motor is installed with the shaft upward, provide measures to prevent the servo motor
being exposed to oil or water from a machine side, gear box, etc.
POINT
Do not use a rigid coupling as it may apply excessive bending load to the
shaft, leading to shaft breakage.
<Incorrect> Capillary phenomenon
Gear
Cover
Servo
motor
Oil/water pool
Lubricating oil
Servo motor
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