Page 208 - Rollingbearings

B.8 Sealing, mounting and dismounting
Measuring the axial drive-up
Test running Fig. 41
Bearings with a tapered bore can be Equipment for the SKF Drive-up Method
mounted by measuring the axial drive-up of Once assembly is complete, an application
the inner ring on its seat Recommended should undergo a test run to determine that
values for the required axial drive-up are all components are operating properly Dur-
listed in the relevant product section ing a test run, the application should run 2
However, the SKF Drive-up Method is under partial load and, where there is a wide
recommended for medium-size and large speed range, at low or moderate speeds
bearings This method provides a reliable IMPORTANT: A rolling bearing should 1
and easy way to determine the degree of never be started up unloaded and then rap-
interference The correct it is achieved by idly accelerated to high speed, as there is a
controlling the axial displacement of the signiicant risk that the rolling elements will
bearing from a pre-determined position The slide and damage the raceways A minimum
equipment for the SKF Drive-up Method is bearing load needs to be applied (refer to
4
shown in ig. 41 It includes an SKF hydraulic Minimum load in the relevant product
nut (1) itted with a dial indicator (2), and a section) 3
hydraulic pump (3) itted with a pressure Any noise or vibration can be checked
gauge (4) using SKF condition monitoring equipment
The SKF Drive-up Method is based on a Normally, bearings produce an even “purr-
two-step mounting procedure (ig. 42): ing” noise Whistling or screeching indicates
inadequate lubrication An uneven rumbling Fig. 42
• Step 1 or hammering is, in most cases, caused by Two-step mounting procedure for the SKF
Sealing, mounting and dismounting • Step 2 immediately after start-up is normal In the s s Start position
the presence of contaminants in the bearing
Drive-up Method
Push the bearing to its starting position by
applying the prescribed pressure to the
or to bearing damage caused during
hydraulic nut
mounting
“Zero” position
An increase in bearing temperature
Increase the pressure on the hydraulic nut
Final position
case of grease lubrication, the temperature
so the bearing inner ring is pushed further
does not drop until the grease has been
on its tapered seat to its inal position The
evenly distributed in the bearing arrange-
prescribed displacement is measured by
ment, after which an equilibrium tempera-
the dial indicator
ture is reached Unusually high or constantly
peaking temperatures indicate too much
Recommended values for the requisite oil
preload or that the bearing is radially or axi-
axial displacement to reach the inal position
for individual bearings are available from the
ally distorted Other causes could be that
SKF Drive-up Method Program
B.8 pressure to reach the start position and the lubricant in the arrangement, too heavy
associated components have not been made
or mounted correctly, or that the seals are
(skf com/drive-up)
generating too much heat
Measuring the inner ring expansion
Measuring the inner ring expansion is a Fig. 43
quick and accurate method for determining Mounting with SKF SensorMount
the correct position of large spherical and
CARB toroidal roller bearings on their seats
(d ≥ 340 mm, depending on the series) To
apply this method, use common hydraulic
mounting tools and a SensorMount, which
consists of a bearing with a sensor embed-
0.450
ded in the inner ring and a dedicated hand-
held indicator (ig. 43) Aspects such as
ON CLR MAX
0FF
bearing size, shaft material and design (solid TMEM 1500
or hollow), and surface inish do not need
any special consideration

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