Page 48 - SKF-bearing-housings

SKF bearing housings – overview, selection and application recommendations

Load carrying capacity Safe loads
The load carrying capacity of a housing In some regions, safe loads are used instead of
depends on many factors: breaking loads. These guideline values have
been established using accepted engineering
• the housing material and design and, where practices, taking safety and ultimate tensile
applicable, cap bolt strength strength of the materials into account. They
• the direction of the load reflect a safety factor of 5 against housing
• the strength of the attachment bolts and fracture, and where applicable, a minimum
support structure factor of 2 against cap bolt yield. The safe
• the condition of the support surface loads can only be fully exploited if the housing
is mounted properly and all bolts are tightened
SKF provides static housing load limits, either to the correct torque values.
in the form of breaking loads or safe loads, for
most housings. Where values are not provid- Axial load carrying capacity for bearings on
ed, the load carrying capacity is higher for the a sleeve
housing than for the bearing. When using a bearing on a sleeve on a plain
Breaking loads can be used to calculate a shaft, the axial load carrying capacity is limited
permissible load, based on a selected safety either by the bearing, sleeve or housing.
factor. Safe loads already include a safety For the axial load carrying capacity of the
factor. bearing, refer to the product information
Special attention is required for split hous- available online at skf.com/bearings. For the
ings subjected to cyclic loads or dynamic im- sleeve, the permissible axial load to safely
balance. Under these conditions, cap bolt and prevent slippage on the shaft is determined
housing cap strength (P 180° ) should be ana- by the friction between the shaft and sleeve.
lyzed carefully. For additional information, Provided the bearing is mounted correctly
contact the SKF application engineering († skf/mount.com), the permissible axial load
service. can be calculated from
Breaking loads F ap = 0,003 B d
For most SKF housings, guideline values for
the breaking loads P are provided in the rele- where
vant product chapter. To obtain the permis- F ap = maximum permissible axial load [ k N ]
sible load for a housing, the guideline value B = b earing width [mm]
should be divided by a factor based on the d = bearing bore diameter [mm]
safety requirements and operating conditions
of the application. In general engineering, a Information about the axial load carrying
safety factor of 6 is typical. The permissible capacity of the housing is provided in the
load can only be exploited if the housing is relevant product chapter.
mounted properly and all bolts are tightened
to the specified torque values. For split hous-
ings, the strength of the cap bolts should also
be considered. A minimum safety factor of 2
against cap bolt yield should be used.
The load P a is the axial breaking load of the
housing. If the incorporated bearing is mount-
ed on a sleeve, check the permissible axial load
for the sleeve († Axial load carrying capacity
for bearings on a sleeve).

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