Matched tapered roller bearings
The SKF assortment of matched single row tapered roller bearings (fig. 1) is based on popular sizes of single row tapered roller bearings. Depending on the application requirements, matched tapered roller bearings are available in different designs and variants:
- matched bearings arranged face-to-face
- matched bearings arranged back-to-back
- matched bearings arranged in tandem
- basic design and SKF Explorer bearings
High load carrying capacity
Depending on the design, matched bearings are suitable for heavy radial and axial loads. The axial load carrying capacity of tapered roller bearings increases with increasing contact angle α. The size of the contact angle, which is usually between 10° and 30°, is related to the calculation factor e (→ product tables): the larger the value of e, the larger the contact angle.
Axial loads in both directions
Depending on the design, matched bearings locate the shaft axially in both directions with a specific axial clearance or preload.
Depending on the design, matched bearings provide a relatively stiff bearing arrangement.
Delivered as a set
The bearings and ring spacer(s) are matched in production, are delivered as a set and are ready-to-mount.
The projection lines of the raceways of each single bearing meet at a common point on the bearing axis (apex point A, fig. 2) to provide a true rolling action and therefore low frictional moments during operation.
The optimized roller end design and surface finish on the flange (fig. 3) of each single bearing promote lubricant film formation, resulting in lower friction. This also reduces frictional heat and flange wear. In addition, the bearings can better maintain preload and run at reduced noise levels.
Long service life
The crowned raceway profiles of basic design bearings and the logarithmic raceway profiles of SKF Explorer bearings optimize the load distribution along the contact surfaces, reduce stress peaks at the roller ends (fig. 4), and reduce the sensitivity to misalignment and shaft deflection compared with conventional straight raceway profiles (fig. 5).
Enhanced operational reliability
Optimized surface finish on the contact surfaces of the rollers and raceways supports the formation of a hydrodynamic lubricant film.
Consistency of roller profiles and sizes
The rollers incorporated in SKF tapered roller bearings are manufactured to such close dimensional and geometrical tolerances that they are practically identical. This provides optimal load distribution between rollers within one and evenly between both matched bearings as well, reduces noise and vibration, and enables preload to be set more accurately.
Running-in period with reduced temperature peaks
Tapered roller bearings typically have a running-in period, during which a conventional design tapered roller bearing experiences a significant amount of friction, resulting in wear. This effect is noticed as a temperature spike (diagram 1). With SKF tapered roller bearing designs, friction, wear and frictional heat are significantly reduced, provided the bearings are mounted and lubricated correctly.