Multitech 1777.8/7-10 G3 operating instructions Multitec, Fixed bearing

If there is no suitable torque wrench available for tightening the shaft nuts, proceed as follows, depending on the pump version:

Self-locking nut on drive end (or non-drive end on versions C und D)

GTighten the shaft nut firmly

GLoosen the shaft nut again

GApply thread-locking agent to the thread (e.g. LOCTITE)

GModerately tighten the shaft nut

Nut with lockwasher on drive end (or non-drive end on versions C und D)

GTighten the shaft nut firmly

GLoosen the shaft nut again

GModerately tighten the shaft nut

GBend over lockwasher

Nut with locknut on drive end (or non-drive end on versions C und D)

GTighten the first shaft nut firmly

GLoosen the first shaft nut again

GModerately tighten the first shaft nut

GBlock the first shaft nut with a suitable tool and tighten the locknut firmly against the first shaft nut

Nut with locknut on non-drive end (all versions except C and D)

GModerately tighten the first shaft nut

GBlock the first shaft nut with a suitable tool and tighten the locknut firmly against the first shaft nut

Fixed bearing

The fixed bearing is the coupling-side bearing at the coupling end. Pump size 32 is equipped with deep-groove ball bearings. The other pump sizes are fitted with angular contact ball bearings in X arrangement (see sectional drawing).

The spacer discs 551.1 serve to position the rotor in axial direction.

Axial adjustment of the rotor is not required. The correct axial position of the rotor is achieved by inserting spacer discs 551.1 to a total thickness of 1.6 mm (1 x 1 mm + 3 x 0.2 mm) in bearing housing 350.1 on the side of the bearing (or angular contact ball bearings).

Caution	On the old versions, the rotor is axially positioned
	by inserting spacer discs 551.1 on both sides of

the bearing (or angular contact ball bearings) to a total thickness of 1.6 mm each.

Cover bolts 901.1 (or 901.8 for oil-lubricated bearings) must be tightened in diagonally opposite sequence to the following torques:

MTC 32/50/65 :	30 Nm
MTC 100/125/150 :	40 Nm

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Multitec

After installation of the bearings, the following checks shall be made:

-Grease-lubricated bearings: Check the clearance between cover 360.1 and bearing housing 350.1 after having tightened bolts 901.1. There should be a clearance between 0.2 mm and 0.8 mm. Cover 360.1 must not rest on the bearing housing 350.1.

-Oil lubricated bearings: Check the clearance between cover 360.2 and bearing housing 350.1 by verifying the dimensions prior to re-assembly (if bearings or cover have to be replaced).

Rolling element bearing sizes

Grease-lubricated bearings

0.2 ...0.8 mm

Fig. 40

Pump size	Fixed bearing 320.1	Radial bearing 320.2
32	6309 ZZ C3-HT	6309 ZZ C3-HT
50	2 x 7309 BUA	6309 ZZ C3-HT
65	2 x 7309 BUA	6309 ZZ C3-HT
100	2 x 7312 BUA	6312 C3
125	2 x 7312 BUA	6312 C3
150	2 x 7315 BUA	6315 C3

Oil lubricated bearings 0.2... 0.8 mm

Fig. 41

The same rolling element bearings are installed for oil lubrication as for grease lubrication.

Exception: Instead of bearing type 6309 ZZ C3-HT, rolling element bearing type 6309C3 is used for oil lubrication.