NTN - Bearing units catalog a-21000-i

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APPENDICES
Technical Data
INSTALLATION
12. Handling of the Bearing Unit
MOUNTING OF THE HOUSING
Pillow Block and Flange Types
Although an advantage of the NTN bearing unit is that it
can be fitted easily and will function efficiently on any part
of a machine, attention must be paid to the following points
in order to ensure its normal service life.
1) The surface on which the housing is mounted must be
sufficiently rigid.
2) The surface on which the housing is mounted should be
as flat as possible (The housing should set firmly in its
position). Deformation of the housing caused by
incorrect mounting will in turn cause deformation of the
bearing, leading to its premature breakdown (Fig. 12).
12.1 Mounting of the housing
12. Handling of the Bearing Unit
12.1.1 Pillow block type and flange type
Although an advantage of the NTN bearing unit is that it
3) It is desirable that the angle between the surface
can 12.1 be Mounting fitted easily of and the will housing function efficiently on any part
on which the housing is mounted and the shaft be
of a machine, attention must be paid to the following points
12.1.1 maintained Pillow block to a tolerance type and of ±2° flange (Fig. type 13 and 14).
in order to ensure its normal service life.
Although an advantage of the NTN bearing unit is that it
1) The surface on which the housing is mounted must be
can 4) Excessive be fitted easily tightening and of will the function mounting efficiently bolts may on cause any part
sufficiently rigid.
of a the machine, housing attention to deform. must Tightening be paid the to bolts the following to the proper points
2) The surface on which the housing is mounted should be
in order torque can ensure avoid its this normal issue. service Also, NTN life.
as flat as possible (Flatness:0.05 max. recommends The housing
1) The using surface a washer on with which the the bolt housing when mounting is mounted the housing must be
should set firmly in its position). Deformation of the
sufficiently
as the bolt
rigid.
housing caused alone by may incorrect cause damage mounting to the will housing.
turn cause
2) The surface on which the housing is mounted should be
deformation of the bearing, leading to its premature
as flat as possible (Flatness:0.05 max. The housing
Cartridge breakdown. Type
should set firmly in its position). Deformation of the
3) The Angle inside error diameter between of the housing mounting into which face a cartridge and shaft is
housing caused by incorrect mounting will in turn cause
type desirable unit is to inserted be within should ± be 2˚ H7 ( ± under 1˚ for general outer ring operating narrow
deformation of the bearing, leading to its premature
conditions. width type)
breakdown.
It from should relationship be so furnished with replenishment as to permit the of grease.
3) bearing For unit
Angle unit with
error to cover,
between move freely the angle
housing the error
mounting axial direction. is desirable to be as
face and shaft is
small as possible within ± 1˚ to ensure the sealing
desirable to be within ± 2˚ ( ± 1˚ for outer ring narrow
performance for the cover.
width type) from relationship with replenishment of grease.
For unit with cover, the angle error is desirable to be as
small as possible within ± 1˚ to ensure the sealing
performance for the cover.
Fig. 12
±2˚
Table 10
Recommended Torques – Hexagon Head Bolt
Units Torque
Metric N . m
Standard Lb . in.
Bolt Size Tightening Torque Bolt Size Tightening Torque
M6
5.4
392
M24
48 3472
M8
13.8
588
M27
122 5208
M10
27.5
784
M30
243 6944
M12
47.1
1078
M33
417 9548
M14
76.5
1372
M36
677 12151
M16
118
1764
M39
1042 15623
M18
162
2156
M42
1432 19095
M20
226
2744
M45
1996 24303
M22
314
2777
– –
Fig. ±2˚ 12.1
Fig. 13
Fig.
90˚±2˚
12.1
90˚±2˚
Fig. 12.2
Fig. 12.2
Fig. 14
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