Page 210 - Rollingbearings

B.8 Sealing, mounting and dismounting
Hot dismounting Dismounting bearings itted Fig. 47
Dismounting by heating is a suitable method on a tapered shaft seat Heating ring
when removing the inner rings of needle
roller bearings or cylindrical roller bearings Small bearings can be dismounted using a
of the type NU, NJ and NUP Two different mechanical or hydraulic puller that engages
tools for this purpose are common: heating the inner ring Self-centring pullers equipped
rings and adjustable induction heaters with spring-operated arms should be used
Heating rings are typically used to mount to simplify the procedure and avoid damage
and dismount the inner ring of small to to the bearing seat If it is not possible to
medium-size bearings that are all the same apply the claws of the puller to the inner
size Heating rings are made of light alloy ring, withdraw the bearing via the outer ring
They are radially slotted and equipped with or use a puller in combination with a pulling
insulated handles (ig. 47) plate (ig. 50)
If inner rings with different diameters are It is much easier and safer to dismount
dismounted frequently, SKF recommends medium-size and large bearings when the
using an adjustable induction heater These oil injection method is used This method Fig. 48
heaters (ig. 48) heat the inner ring rapidly injects oil, under high pressure, between the Adjustable induction heater
without heating the shaft two tapered mating surfaces, via a supply
Special, ixed induction heaters have been duct and a distribution groove This signii-
developed to dismount the inner rings of cantly reduces the friction between the two
large cylindrical roller bearings (ig. 49) surfaces and separates the bearing from its
Induction heaters and heating rings are seat (ig. 51)
Sealing, mounting and dismounting Fire hazard Never use an open lame a provision such as a lock nut or end Special ixed induction heater Fig. 49
available from SKF For additional inform-
ation, refer to the SKF bearing maintenance
WARNING

handbook or skf com/mapro
To avoid the risk of serious injury, attach

plate to the shaft end to limit the bear-
WARNING
ing travel when it suddenly comes loose
for hot dismounting

B.8

Fig. 50 Fig. 51
Dismounting with aid of a puller Dismounting with aid of oil injection – a
stop is provided

208