British Pound
Click flag to change Currency
My Account You are not logged in
Login
 

Categories

Site Search

Information


Back to Index

Split Cylindrical Roller Bearings

Split cylindrical roller bearings are intended primarily for bearing arrangements which are difficult to access or for cranked shafts. It is advantageous to use them in all cases where the maintenance or replacement of non-split bearings would require considerable extra time-consuming effort and would cause long and expensive or even inadmissible machine downtime. The main applications for split cylindrical roller bearings are cold tube rolling mill (Pilger mill) crankshafts, bucket wheel excavators, rolling mill drive spindles as well as large ventilation installations.

SKF produces single row (fig) or double row (fig) split cylindrical roller bearings to order. The design of the bearing is tailored to the particular installation. Before finalising the design of a bearing arrangement incorporating split cylindrical roller bearings it is advisable to contact the SKF application engineering service.

Split single row cylindrical roller bearings

The single row bearings are suitable for most of the applications outlined above and are therefore available in a correspondingly large number of designs. All bearings are divided in the middle. The division of the rings is at an angle to the bearing axis to prevent interruption of the over-rolling process (fig).

BCS.1 design Outer ring with two integral flanges. Inner ring with two integral flanges. Loose split clamping rings with split sealing rings. Split machined brass cage. Can be relubricated via the inner and outer rings (fig).

BCS.2 design Flangeless outer ring. Inner ring with two integral flanges. Loose split clamping rings with split sealing rings. Split machined brass cage. Can be relubricated via the inner and outer rings (fig).

BCS.3 design Outer ring with two integral flanges. Inner ring with two integral flanges. Loose split clamping rings. Split machined brass cage (fig).

BCS.4 design Flangeless outer ring. Inner ring with two integral flanges. Loose split clamping rings. Split machined brass cage (fig).

BCS.5 design Outer ring with two integral flanges. Inner ring with two integral flanges. Loose split clamping rings with split sealing rings. Split machined brass cage. Can be relubricated via the inner and outer rings. Split flange rings and seals. Some bearings are fitted with seals of nitrile rubber (NBR) or fluoro rubber (fig).

With reference to fluoro rubber seals please see warning text under Note.

BCS.6 design Outer ring with two integral flanges. Inner ring with two integral flanges. Loose split clamping rings with split sealing rings. Split machined brass cage. Can be relubricated via the inner and outer rings. Split stepped flange rings and seals. Some bearings are fitted with seals of nitrile rubber (NBR) or fluoro rubber (fig).

With reference to fluoro rubber seals please see warning text under Note.

BCS.7 design Outer ring with two integral flanges. Inner ring with two integral flanges. Loose split clamping rings. Split machined brass cage. Split flange rings and labyrinth rings (fig).

BCS.8 design Outer ring with two integral flanges. Inner ring with two integral flanges. Inner ring screwed together. Split machined brass cage (fig).

BCS.9 design Flangeless outer ring. Inner ring with two integral flanges. Inner ring screwed together. Split machined brass cage (fig).

BCS.10 design Outer ring with one integral flange. Inner ring with one integral flange, screwed at one side. One loose split clamping ring. Split machined brass cage or split pin-type machined steel cage (fig).

Note At temperatures above 300 C, fluoro rubber seals will give off toxic fumes and vapours. Should overheating occur, the material will still be dangerous to handle even in the cold state.

Split double row cylindrical roller bearings

Split double row cylindrical roller bearings (fig) were developed for the bearing arrangements of the drive spindles of rolling mills and are supplied in a design appropriate to this application.

The split outer rings are held together after mounting by the housing and, to order, they may be supplied with keys to prevent turning. The inner rings are split at an angle to the bearing axis and are held in position on their seat by clamping rings. The axial internal clearance in the bearing is such that thermal changes in the universal joint spindle length can be accommodated within the bearing.

DimensionsThe dimensions (single row / double row) of split cylindrical roller bearings have not been standardized.

TolerancesSplit cylindrical roller bearings are produced to Normal tolerances, except for the inner and outer ring widths. The Normal tolerances are in accordance with ISO 492:2002.

Internal clearanceSKF split cylindrical roller bearings are produced as standard with Normal radial internal clearance. The values correspond to ISO 5753:1991 and are given in the product tables.

The axial internal clearance of the double row bearings is at least 0,5 mm.

MisalignmentSKF split single and double row cylindrical roller bearings have a "logarithmic" contact profile in the roller raceway contact which ensures a favourable stress distribution and enables minor angular misalignments of up to 2 minutes of arc to be tolerated in the double row bearings.

Shaft and housing tolerancesFor split cylindrical roller bearings which are subjected to alternating directions of load and rotation and also relatively heavy loads (P > 0,12 C) it is recommended that the shaft be machined to tolerance h6. For bearings under constant direction loads which are lighter (P < 0,12 C) shaft seats machined to h7 are also acceptable. For light loads and low speeds it is possible to use tolerance h9/IT7, normally recommended for adapter sleeve mounting of bearings.

The tolerance recommended for the housing bore seat is H7.

Split bearings are frequently used as replacements for the original equipment non-split bearings as this is often the only possible way of replacing the bearings in situ. In such cases the shaft should be machined to a tolerance m6 to r7. This gives the desired interference fit for the non-split inner rings. The split inner rings have a correspondingly larger bore to prevent a gap occurring in the join after mounting.

SpeedsBecause of the split design vibrations are produced in operation which limit the speed capability of split bearings to approximately 50% of that of non-split bearings. Since general guideline values cannot be given it is advisable to contact the SKF application engineering service if the bearings are to operate at relatively high speeds.

Load carrying capacitySplit cylindrical roller bearings have less capacity to carry load than non-split bearings as comparatively fewer rollers can be incorporated because of the split design of the cage.

The over-rolling of the joins in the raceways by the rollers is taken into account when calculating the equivalent dynamic load bearing by a factor, the value of which depends on the mode of operation, see under "Equivalent dynamic bearing load".

Dynamic axial load carrying capacityBearings with integral flanges on both inner and outer rings can support axial loads in addition to radial loads. The axial load carrying capacity is determined by the ability of the sliding surfaces of the roller end/flange contact to support loads. It is also influenced by the division of the rings and the type of lubrication. Operating temperature and heat transfer from the bearing also play a part.

Guideline values for the permissible axial load which can be applied to single row cylindrical roller bearings can be obtained from

Fap = C0/(40b)

where

Fap = maximum permissible axial load [kN]

C0 = basic static load rating (see product data) [kN]

b = factor for mode of machine operation (see table 1)

The values of the permissible axial load Fap obtained from the equation are valid for continuously acting constant axial loads and grease lubrication. Higher values can be allowed if oil lubrication is used. In case of doubt, please contact the SKF application engineering service.

Equivalent dynamic bearing load

For split cylindrical roller bearings operating under purely radial load

P = b Fr

Values of factor b, which takes into consideration the mode of operation of the machine and the requirements regarding smooth running, will be found in table 1.

Equivalent static bearing load

P0 = Fr


Cylindrical roller bearings | Single row cylindrical roller bearings | Double row cylindrical roller bearings | Multi-row cylindrical roller bearings | Single row full complement cylindrical roller bearings | Double row full complement cylindrical roller bearings | Multi-row full complement cylindrical roller bearings | Split cylindrical roller bearings

Back to Index

This page is still under construction. All bearing information remains the property and copyright of SKF Group.