Split cylindrical roller bearings

Product Description

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. 

Bearings for rolling mills

The work rolls of large four-high rolling stands are driven via universal joint drive shafts (Figure 1). After every rolling cycle the height of the rolls is adjusted. The drive shafts must follow the adjusting movement. Therefore they have universal joints. Due to the height adjustment, the shaft length varies as well, which has to be compensated in a coupling sleeve.

The universal joint shafts are generally very long to ensure that the deflection angles do not become too large. Because of the high torques which have to be transmitted they are strong and heavy.

In larger rolling mills, the weight of universal joint shafts is supported in split single or double row cylindrical roller bearings in order to relieve the joints and couplings from the weight. Changes in the position of the universal joint shafts are compensated in the housing suspensions.

The split bearing design is necessary as the flanges forged to the universal joint shaft are considerably larger than the shaft diameter at the bearing seats.

In the past few years, several rolling mills were already successfully converted from sliding bearings to rolling bearings. This has reduced the maintenance expenditure and, in particular, grease consumption significantly.

bearing design

The split cylindrical roller bearings for the locating and floating bearing positions have one or two roller rows (Figure 2).

The bearing outer rings, inner rings and rollers are made of casehardening steel. This makes the bearings more insensitive to vibration and axial shock loads occurring in operation.

Inner rings, outer rings and cages are split. The split inner rings are located on the shaft by locking rings. 

Load limit

Load limit

The load ratings of the split cylindrical roller bearings are listed in the bearing tables.

The load accommodated by split bearings must be limited. A load limit of P/Cr 0,2 should be observed. Axial loads are supported by the cylindrical roller bearings' lips.

Experience shows that the axial load Fa amounts to 10...20 % of the radial load Fr. These axial loads are supported reliably. If higher axial loads are expected to occur, please send us an enquiry – indicating the load and speed – to have the lips’ load carrying capacity checked.

Fits

Shaft diameter and bearing bore should fit as closely as possible. If a shaft diameter is too large, it will not fit well (Figure 3). We recommend to machine the shaft to tolerance g6 or h6 to obtain a probable fit clearance of a few microns.

After tightening the screws of the locking rings, a gap of 0,3 to 0,4 mm (Figure 3) will be obtained at the joints. This produces a tight fit of the bearing inner ring on the shaft. The housing bore should be machined to H6 or H7.  

Application

Application:

  ●  Belt conveyor

  ●  Fans

  ●  Screw conveyor

  ●  Bucket elevator

  ●  Stacker Reclaimers

  ●  Ball mills

  ●  Water turbine

  ●  Wind energy test rig

  ●  Marine propulsion

  ●  Pilger mills

  ●  Link spindles