Page 205 - Rollingbearings

Mounting and dismounting
Hot mounting Mounting adjusted bearing both directions to be sure that there is
It is generally not possible to mount larger arrangements proper contact of the roller ends with the
bearings without heating either the bearing guide lange on the inner ring Without
or the housing, as the force required to The following recommendations refer only to proper contact, the measured result will not
mount a bearing increases considerably with the adjustment of the mounted clearance for be correct
increasing bearing size bearing arrangements with single row
The requisite difference in temperature angular contact ball bearings or tapered
between the bearing ring and shaft or hous- roller bearings Mounting bearings with a
ing depends on the degree of interference The mounted clearance of single row tapered bore
and the diameter of the bearing seat Gener- angular contact ball bearings and single row
ally, open bearings must not be heated to tapered roller bearings is only established For bearings with a tapered bore, inner rings
more than 120 °C (250 °F) SKF does not when the bearing is adjusted against a sec- are always mounted with an interference it
recommend heating bearings capped with ond bearing Usually, they are arranged The degree of interference is determined by
seals or shields above 80 °C (175 °F) How- back-to-back or face-to-face, and one bear- how far the bearing is driven up onto a
ever, if higher temperatures are necessary, ing ring is axially displaced until a given tapered shaft seat or an adapter or with-
make sure that the temperature does not clearance or preload is obtained For infor- drawal sleeve As the bearing is driven up the
exceed the permissible temperature of either mation about bearing preload, refer to tapered seat, its radial internal clearance is
the seal or grease, whichever is lowest Selecting preload, page 186 reduced This reduction in clearance, or the
When heating bearings, local overheating The appropriate value for the clearance to axial drive-up distance, can be measured to
must be avoided To heat bearings evenly be obtained when mounting depends on the determine the degree of interference and
and reliably, SKF recommends using SKF bearing size and arrangement, and operat- the proper it Recommended values of
electric induction heaters (ig. 30) If hot- ing conditions such as load and temperature clearance reduction and axial drive-up are
plates are used, the bearing must be turned Since there is a deinite relationship between listed in the relevant product section
over a number of times The seals on sealed the radial and axial clearance of angular The SKF Drive-up Method is a reliable and
bearings should never contact the heating contact ball bearings and tapered roller well-proven method for mounting SKF
plate directly Place a ring between the plate bearings, it is suficient to specify one value, bearings on tapered seats For additional
and bearing Read and follow the safety pre- generally the axial clearance for the information, refer to the SKF Drive-up
cautions on page 197 arrangement This speciied value is then Method Program (skf com/drive-up)
For additional information about these obtained by measuring the clearance during Sealing, mounting and dismounting
mounting methods, refer to the SKF bearing adjustment and by loosening or tightening a Small and medium-size bearings
maintenance handbook nut on the shaft or a threaded ring in the
housing bore or by inserting calibrated Bearings with bore diameters up to 80 mm
washers or shims between one of the bear- (d ≤ 80 mm), can be driven up onto a
ing rings and its abutment The actual tapered seat using either a bearing itting
method used to adjust and measure the tool or, preferably, a lock nut For adapter
clearance depends on whether this is an sleeves, use the sleeve nut that can be tight-
occasional or repetitive process ened with a hook or impact spanner With-
One way to check the axial clearance in a drawal sleeves can be driven into the bearing B.8
bearing arrangement is to use a dial indica- bore using a bearing itting tool or a nut
tor attached to the hub (ig. 31) When Starting from a 50 mm thread, SKF hydraul-
adjusting tapered roller bearings and meas- ic nuts can also be used.
uring clearance, the shaft or housing should
be turned through several revolutions in Medium-size and large bearings

Larger bearings, with bore diameters
Fig. 30 Fig. 31 greater than 80 mm (d > 80 mm), require
SKF electric induction heater Checking of axial clearance using a dial considerably more force to mount There-
indicator fore, SKF hydraulic nuts should be used
Where applicable, SKF also recommends
using shafts and sleeves with grooves and
ducts for the oil injection method When
combining the two methods, bearing
mounting and dismounting becomes much
faster, easier and safer For additional infor-
mation about the oil injection equipment
required for both the hydraulic nut and the
oil injection method, refer to skf com/mapro
and skf com/mount

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