Mitsubishi Electric PUHY-P250YNW-A Service Handbook page 279

[8-15 Maintenance/Inspection Schedule ]
5. Grease replenishing method
(1) Grease type, Replenishment amount and frequency
Product name
Alvania Grease S No.3
(2) Grease replenishing method
Replenish grease using a grease gun (Photo 1) from the grease fitting mounted on thehousing.
Be careful to prevent dust or other foreign materials from getting into the grease to be replenished.
If thegrease fitting is contaminated, wipe it off before replenishing.
Photo 1:Grease gun
Grease is injected into the inside of the bearing from the grease hole of the outer ring through
the grease groove provided on the circumference of the spherical bearing seat from the grease
fitting replenishing port.
Injected grease is stirred by the rotation of the bearing and mixed with previously-injected
grease in the bearing and excess grease is discharged from the section between the slinger
and outer ring through the rubber seal lip part. (Photo 3, Fig. 1)
Photo 3:Normal grease discharging conditions
from inside the bearing
Re-lubrication should be performed during operation to cause the grease to be spread into every
corner of the inside of the bearing.
However, if it is difficult to replenish grease during operation because replenishment during
operation at high speed may cause dangerous accidents, after replenishing the grease while operation is
stopped, continue to replenish while performing intermittent operation to cause the grease to be mixed by
manual operation or regular operation.
Replenishing with a large amount of grease at one time while operation is stopped may cause the rubber seal
to be peeled by internal pressure acting on the rubber seals on both sides from the grease and the seals may
come in contact with the slinger.
In this case, the rotation torque will increase, which may cause abnormal heating conditions to
be generated if the insert bearing unit is operated without correcting the situation.
*This document is an excerpt from the instruction manual which was made by bearing maker(ASAHI SEIKO)
80
- chapter 8
Manufacture name Soap-based grease
Showa Shell Sekiyu
Photo 2:Example of filling with a grease gun
Replenishment amount
Li 10.5 g
Fig 1:Grease circulation route
Replenishment Frequency
once a year
BS_08_C