Page 54 - SKF-bearing-housings

SKF bearing housings – overview, selection and application recommendations

Mounting Attachment bolt tightening
Applying the specified torque to a bolt during
Mounting instructions are supplied with most installation is extremely important. Improper
SKF bearing housings, or with the correspond- torque values can lead to machinery move-
ing seal kit. For additional information about ment during operation. This can cause mis-
mounting, refer to the SKF bearing mainten- alignment between machine parts, which will
ance handbook or the information available eventually lead to premature damage to bear-
online at skf.com/mount. ings and other components.
Recommended tightening torque values are
provided in the product chapters and are based
Preparations prior to mounting on bolt manufacturers’ recommendations.
Mounting housings (and bearings) requires All bolts should be tightened with an accur-
care, accuracy and the appropriate tools. Prior ate torque wrench (in at least two stages) or
to mounting, do the following: a hydraulic bolt tensioner. SKF recommends
using a HYDROCAM hydraulic bolt tensioner in
• Make sure that the work area is clean. applications where the attachment bolt has an
• Study any drawings or instructions to deter- end protruding above the tightening nut.
mine the correct order in which to assemble These tensioners reduce the risk of over tight-
the various components. ening and enable bolts to be installed accu-
• Make sure that all the necessary compon- rately without the need of a torque wrench.
ents and tools are at hand. The tensioners also provide uniform assembly
• Clean the support surface. preload or uniform bolt elongation.
• Check that the support surface meets the
requirements for flatness († Specifications
for shafts and housing support surfaces, Using shims
page 45). Shims can be used to raise the centre height
• Check that the shaft seats and seal counter- of a housing. SKF recommends using shims
faces meet the requirements for dimensional made of stainless sheet steel with sufficient
and form accuracy, roughness and hardness strength and the ability to withstand corrosion
(† Specifications for shafts and housing from several media. Shims made from soft
support surfaces, page 45). metals like copper or brass typically compress
• Chamfer or round any shaft edges over over time, causing looseness, which can even-
which a seal lip will pass. tually lead to misalignment. Whenever pos-
sible, use only one shim and never stack more
than three shims.
SKF tools and products
The SKF assortment of mounting tools and CAUTION: Make sure that the shim covers
products includes mechanical tools, hydraulic the complete contact surface between the
tools, heating equipment and gloves. For add- housing base and the support surface
itional information, refer to the product infor- († fig. 23). If shims are placed under the
mation available online at mapro.skf.com. housing feet only, the bearing seat can distort.

Lifting housings Using locating (stabilizing) rings
Many SKF bearing housings are supplied with A bearing in the locating position must be se-
eye bolts for safe and easy handling. The eye cured axially in the housing. If the bearing seat
bolts are designed to support the weight of the in the housing and the bearing width do not
housing only, and not the incorporated bearing match, locating (stabilizing) rings († fig. 24)
or shaft. are required. Typically, two locating rings are
When lifting, make sure that the eye bolts required per housing. One ring should be
are only subjected to load in the direction of placed on each side of the bearing. If only one
the shank axis. The load should be evenly dis- locating ring is required, it should be installed
tributed across the number of eye bolts. on the same side as the lock nut. When placing

50