Paired Single Row Taper Roller Bearings are ready to mount bearing units. Paired taper roller bearings are used in applications where either the load capacity of single bearings does not meet the requirements, or a defined axial play has to overcome the time - consuming adjustment of taper roller bearing assemblies under the conditions of a multiple mounting. Paired taper roller bearings consist of two single row taper roller bearings that have been matched using spacers for a specific axial clearance or, if required, a preload. Depending on the particular requirements, such pairs may be supplied arranged either in tandem arrangement, (suffix "DT"), in face to face arrangement, (suffix "DF") or in back to back arrangement, (suffix "DB") as shown in the sketch below. Several types of paired NKE taper roller bearings are produced as units arranged Face to Face (suffix DF) as standard. Other arrangements are produced upon order request.

NKE produce single row taper roller bearingsas units in the following arrangements:Tandem Arrangement, (suffix DT) Taper roller bearings in tandem arrangements are used where the actual thrust force exceeds the load capacity of a single taper roller bearing. Tandem arrangement thrust forces are accommodated in one direction only and distributed to both bearings equally. Taper roller bearings in tandem arrangement must always be adjusted against another bearing arranged in parallel which guides the shaft in the opposite direction. When in tandem arrangement taper roller bearing require two spacers for matching as a unit, the desired total width of the bearing arrangement must be defined when ordering. Face to face arrangement, (suffix DF) Thrust forces are accommodated in both directions by each of the taper roller bearings. Due to their relatively small support width bearing pairs arranged face to face do not provide a very accurate alignment of the bearing positions. But, these arrangements are less suitable to support tilting moments due to their lower stiffness. For bearing pairs arranged face to face the heating of the shaft will cause either a reduction of axial internal clearance or an increase in preloading forces. Back to back arrangement, (suffix DB) Axial forces are, similar to bearings arranged face to face, accommodated in both directions by each of the bearings. Taper roller bearings arranged back to back provide very rigid bearing arrangements due to their enlarged support width. They also effectively support tilting moments. Bearing pairs arranged back to back are unsuitable to compensate for any misalignments. Taper roller bearing pairs arranged back to back require two spacers for matching as a unit, the desired total width of bearing arrangement must be defined at ordering.Generally, single row taper roller bearings arranged in pairs should not be exposed to misalignments as they may generate considerable additional and cause high running noise levels. Such additional forces due to misalignment will shorten the service life of taper roller bearings significantly. Paired NKE Taper Roller Bearings are produced in normal tolerance class (PN) as standard. These bearings may also be produced with closer tolerance classes(e.g. P6X) on request. The total width tolerance of NKE - taper roller bearing units arranged face to face consist of the internal axial play of the bearing pair and twice the width deviation of the each single bearing.

All information courtesy NKE Bearings Austria www.nke.at