Page 57 - NSK_CAT_E1102m_A7-141

BEARING HANDLING

14.2.2 Mounting of Bearings with Tapered Bores become too tight and the true residual clearance may Table 14.1 Mounting of Spherical Roller Bearings with Tapered Bores
become too small. In this case, as shown in Fig. 14.9. Units : mm
Bearings with tapered bores are mounted on tapered
shafts directly or on cylindrical shafts with adapters one half of the total clearance at points and b (which Bearing Bore Reduction in Radial Push-in amount in axial direction Minimum Permissible
or withdrawal sleeves (Figs. 14.4 and 14.5). Large Diameter Clearance Residual Clearance
spherical roller bearings are often mounted using are on a horizontal line passing through the
hydraulic pressure. Fig. 14.6 shows a bearing d min. max. Taper 1 : 12 Taper 1 : 30 CN C3
mounting utilizing a sleeve and hydraulic nut. Fig. 14.7 bearing center) and c (which is at the lowest position min. max.
shows another mounting method. Holes are drilled in over incl. 0.025 0.030 min. max. 0.010 0.025
the sleeve which are used to feed oil under pressure to of the bearing) may be used as the residual clearance. 0.030 0.035 0.40 0.45 0.015 0.030
the bearing seat. As the bearing expands radially, the When a self-aligning ball bearing is mounted on a shaft 30 40 0.030 0.035 0.45 0.55 −− 0.025 0.035
sleeve is inserted axially with adjusting bolts. with an adapter, be sure that the residual clearance 40 50 0.040 0.045 0.45 0.55 −− 0.030 0.040
Spherical roller bearings should be mounted while does not become too small. Sufficient clearance for 50 65 0.60 0.70 −−
checking their radial-clearance reduction and referring easy alignment of the outer ring must be allowed. 65 80 −−
to the push-in amounts listed in Table 14.1. The radial
clearance must be measured using clearance gauges. 14.3 Operation Inspection 80 100 0.045 0.055 0.70 0.85 1.75 2.15 0.035 0.050
In this measurement, as shown in Fig. 14.8, the
clearance for both rows of rollers must be measured After the mounting has been completed, a running 100 120 0.050 0.060 0.75 0.90 1.9 2.25 0.045 0.065
simultaneously, and these two values should be kept test should be conducted to determine if the bearing
roughly the same by adjusting the relative position of has been mounted correctly. Small machines may be 120 140 0.060 0.070 0.90 1.1 2.25 2.75 0.055 0.080
the outer and inner rings. manually operated to assure that they rotate smoothly.
When a large bearing is mounted on a shaft, the outer Items to be checked include sticking due to foreign 140 160 0.065 0.080 1.0 1.3 2.5 3.25 0.060 0.100
ring may be deformed into an oval shape by its own matter or visible flaws, uneven torque caused by 2.75 3.5 0.070 0.110
weight. If the clearance is measured at the lowest part improper mounting or an improper mounting surface, 160 180 0.070 0.090 1.1 1.4 3.25 4.0 0.070 0.110
of the deformed bearing, the measured value may be and excessive torque caused by an inadequate
bigger than the true value. If an incorrect radial internal clearance, mounting error, or seal friction. If there are 180 200 0.080 0.100 1.3 1.6
clearance is obtained in this manner and the values in no abnormalities, powered operation may be started.
Table 14.1 are used, then the interference fit may 200 225 0.090 0.110 1.4 1.7 3.5 4.25 0.080 0.130
4.0 4.75 0.090 0.140
225 250 0.100 0.120 1.6 1.9 4.25 5.5 0.100 0.150

250 280 0.110 0.140 1.7 2.2

280 315 0.120 0.150 1.9 2.4 4.75 6.0 0.110 0.160
5.5 6.75 0.120 0.180
315 355 0.140 0.170 2.2 2.7 6.0 7.5 0.130 0.200

355 400 0.150 0.190 2.4 3.0

400 450 0.170 0.210 2.7 3.3 6.75 8.25 0.140 0.220
7.5 9.25 0.160 0.240
450 500 0.190 0.240 3.0 3.7 8.5 11.0 0.170 0.270

500 560 0.210 0.270 3.4 4.3

560 630 0.230 0.300 3.7 4.8 9.25 12.0 0.200 0.310

630 710 0.260 0.330 4.2 5.3 10.5 13.0 0.220 0.330

710 800 0.280 0.370 4.5 5.9 11.5 15.0 0.240 0.390

800 900 0.310 0.410 5.0 6.6 12.5 16.5 0.280 0.430

900 1 000 0.340 0.460 5.5 7.4 14.0 18.5 0.310 0.470

1 000 1 120 0.370 0.500 5.9 8.0 15.0 20.0 0.360 0.530

Remarks The values for reduction in radial internal clearance are for bearings with CN clearance.
For bearing with C3 Clearance,the maximum values listed should be used for the reduction
in radial internal clearance.

Fig. 14.4 Mounting with Adapter Fig. 14.5 Mounting with Withdrawal Sleeve
Oil
Large machines, which cannot be turned by hand,
CC a b c c can be started after examination with no load, and the
c power immediately cutoff and the machine allowed to
Fig. 14.8 Clearance Measurement coast to a stop. Confirm that there is no abnormality
Fig. 14.6 Mounting with Fig. 14.7 Mounting with Special Sleeve Fig. 14.8 of Spherical Roller Bearing Fig. 14.9 Measuring Clearance in Large Spherical Roller such as vibration, noise, contact of rotating parts, etc.
Fig. 14.6 Hydraulic Nut Fig. 14.7 and Hydraulic Pressure Fig. 14.9 Bearing Powered operation should be started slowly without
load and the operation should be observed carefully
A 118 until it is determined that no abnormalities exist, then
gradually increase the speed, load, etc. to their normal
levels. Items to be checked during the test operation
include the existence of abnormal noise, excessive rise
of bearing temperature, leakage and contamination of
lubricants, etc. If any abnormality is found during the
test operation, it must be stopped immediately and the
machine should be inspected. If necessary, the bearing
should be dismounted for examination.

A 119