Siemens CGGV Manual De Usuario
- 21 -
Maintenance
To Replace Bearings
1. Remove bolts holding bearing housing to yoke.
2. Remove bolts holding end caps to housings.
3. Remove end housings. Observe location of
2. Remove bolts holding end caps to housings.
3. Remove end housings. Observe location of
bearing shims, and remove shims if necessary.
4. Remove snap ring or locknut in front of bearing.
5. Use bearing puller and exert force only on inner
5. Use bearing puller and exert force only on inner
race to remove bearing from shaft.
6. Check shaft and housing diameter for proper size
with micrometer. Clean or replace inner bearing
cap, and slide cap onto shaft.
cap, and slide cap onto shaft.
7. Heat the new bearing in an oven (200
°F). While
hot, slide the bearing onto shaft (high thrust units
using angular contact bearings having a slip-fit on
shaft and need not be heated). Make certain the
inner race makes a firm even contact with shaft
shoulder.
using angular contact bearings having a slip-fit on
shaft and need not be heated). Make certain the
inner race makes a firm even contact with shaft
shoulder.
8. Let bearing cool - if grease lubricated bearing,
pack caps per Grease Repacking Table with
proper grade of grease. Pack all open bearings
full between balls or rollers, but remove excess
grease from the outside of the retainers. Packing
of a cap or bearing housing cavity should be done
with a grease gun.
proper grade of grease. Pack all open bearings
full between balls or rollers, but remove excess
grease from the outside of the retainers. Packing
of a cap or bearing housing cavity should be done
with a grease gun.
9. Before reassembling the top end cap after
installing new bearings, check the top edges of the
inner and outer races with a dial indicator for
squareness of mounting. To assure quiet
operation and good bearing life, total indicator
reading in each case must be within 0.001 in.
inner and outer races with a dial indicator for
squareness of mounting. To assure quiet
operation and good bearing life, total indicator
reading in each case must be within 0.001 in.
10. Indicate the outer race, attach the indicator body
to the shaft, allow the button to bear on the outer
race, and then rotate the shaft slowly by hand.
race, and then rotate the shaft slowly by hand.
11. Indicate the inner race, attach the indicator body
to the bearing bracket, allow the button to bear on
the top edge of the inner race, and then rotate the
shaft slowly by hand.
the top edge of the inner race, and then rotate the
shaft slowly by hand.
12. Reinstall bearing shims; if used; reassemble end
caps and end housings.
CAUTION
Striking outer race exposes the race to brinelling
Do not subject bearing to impact.
Protect the shaft end with a cap. If bearing is reusable,
make certain the puller applies pressure against the
bearing inner race only. If puller will not hook the bearing
inner race, fabricate a split bushing and install it between
inner race, fabricate a split bushing and install it between
the bearing and the puller hooks.
Figure 6. Removing Bearing with a Puller
Grease Repacking Table
Grease Quantity
Type
Bearing
Operating
Position
(Shaft)
Top End
Cap
Bottom End
Cap
Outer
Inner
Outer
Inner
Open
Deep
Deep
Groove
Vertical
2/3
Full
1/3
Full
1/3
Full
2/3
Full
Angular
Contact
Contact
Vertical
2/3
Full
1/3
Full
1/3
Full
2/3
Full
Single
Shielded
Vertical
Full
1/3
Full
1/3
Full
Full
Roller
Vertical
2/3
Full
1/3
Full
1/3
Full
2/3
Full
End Play
Machines designed for applications involving primarily
continuous heavy downthrust but having momentary
upthrust are equipped with angular contact or
spherical roller bearings. Spherical roller bearings
may be preloaded with springs (See Figure 8). The
end play is most often 0.005 to 0.008 in. but see the
motor outline for the exact value for your motor. The
bottom bearing takes the momentary upthrust and
prevents reverse loading of the top bearings. End
play is limited by shims when the thrust block is
shrunk on the shaft or by tightening the locknut on the
shaft above the bearing mounting sleeve. The thrust
bearings on 2 pole motors are mounted directly on the
shaft and do not require an adjustment by the shims or
locknut.
continuous heavy downthrust but having momentary
upthrust are equipped with angular contact or
spherical roller bearings. Spherical roller bearings
may be preloaded with springs (See Figure 8). The
end play is most often 0.005 to 0.008 in. but see the
motor outline for the exact value for your motor. The
bottom bearing takes the momentary upthrust and
prevents reverse loading of the top bearings. End
play is limited by shims when the thrust block is
shrunk on the shaft or by tightening the locknut on the
shaft above the bearing mounting sleeve. The thrust
bearings on 2 pole motors are mounted directly on the
shaft and do not require an adjustment by the shims or
locknut.