Daikin ZH5LMGU [26/58] Installation of bearings

Si50-402 Overhaul Instructions

Semi-Hermetic Single Screw Compressor Version IV 25

4.3.2 Installation of Bearings

Before installing the bearings, clean the bearing holder and suction end cover.

Caution It can be presumed that condensate is produced around the bearing after it is cooled down to

-50°C or less with dry ice or the like. Therefore, after inserting the bearing in the housing, heat it

up with a drier to remove the moisture.

1. Main Shaft Bearing

(1) Suction end cover (outer ring of cylindrical roller bearing)

Cool the outer ring of the cylindrical roller bearing down to -50°C or less with dry ice or the

like. Be sure to insert the bearing to the contact surface. After the bearing is inserted, fix it

with a C-type retainer ring.

(2) Screw shaft (inner ring of cylindrical roller bearing)

Heat the inner ring of the bearing (120°C max.), and insert the tip of the screw shaft.

After the shaft is inserted, place a plate and hammer the shaft all the way. Then, mount the

C-type retainer ring.

(3) Main bearing holder (angular-contact ball bearing, deep groove ball bearing)

Insert the bearings into the main bearing holder. Since fitting is tight, cool the bearings to a

temperature of -50°C or lower using dry ice. After inserting the bearings, mount the beveled

C-type retainer ring.

Be sure to install the bearings in the correct direction.

The beveled C-type retainer is tapered. After installation, hammer it into the groove.

Fig. 4-26 Direction of bearings