Page 207 - Rollingbearings

Mounting and dismounting
Measuring the clearance reduction Measuring the lock nut tightening angle
A feeler gauge is most often used to meas- This method can be used when mounting
ure the radial internal clearance in bearings with a bore diameter d ≤ 120 mm
medium-size and large spherical and CARB Recommended values for the tightening
toroidal roller bearings Recommended val- angle α are listed in the relevant product
ues for the reduction of radial internal clear- section
ance to obtain the correct interference it are Before starting the inal tightening proced-
listed in the relevant product section ure, push the bearing up onto the tapered
Before mounting, measure the clearance seat until it is irmly in position By tightening
between the outer ring and upper-most the nut through the recommended angle α
roller (ig. 37) During mounting, measure (ig. 40), the bearing is driven up over the
the clearance between the inner or outer proper distance on the tapered seat The
ring and lowest roller, depending on the bearing inner ring then has the requisite
bearing internal design (ig. 38) interference it The residual clearance
Before measuring, rotate the inner or should be checked if possible
outer ring a few times Both bearing rings
and the roller complement must be centri-
cally arranged relative to each other
For larger bearings, especially those with
a thin-walled outer ring, the measurements
are affected by the elastic deformation of the
rings, caused by the weight of the bearing or
the force to draw the feeler gauge blade
through the gap between the raceway and
an unloaded roller To establish the “true”
clearance before and after mounting, use
the following procedure (ig. 39):

1 Measure the clearance “c” at the 12 o’clock Sealing, mounting and dismounting
position for a standing bearing or at the 6
o’clock position for an unmounted bearing Fig. 39
hanging from the shaft Procedure to establish the “true” clearance before and after mounting
2 Measure the clearance “a” at the 9 o’clock
position and “b” at the 3 o’clock position a b
without moving the bearing c
3 Obtain the “true” radial internal clearance
with relatively good accuracy from
0,5 (a + b + c). B.8

c
b a

Fig. 37 Fig. 38 Fig. 40
Measuring of internal clearance before Measuring of internal clearance during Tightening angle α
mounting mounting

α

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