
Cylindrical roller bearings
Cylindrical roller bearings are roller bearings with cylindrical rolling elements. They are separable, i.e. at least one of the rings is devoid of one raceway, which allows assembly and slight displacements relative to the fixture during operation. They are used to carry much heavier loads than ball bearings of the same size.
This bearings have a detachable construction. We can separate their individual parts without using much force. It means that the bearing, actually the ring, is without a raceway. This allows the bearing to lean out from the housing in one or the other direction. This greatly simplifies the bearing montage and allows to transfer of larger loads.
The cylindrical roller bearing consists of:
– outer ring
– inner ring
– cage
– rollers
There are several different types marked with symbols NU, NJ, NUP, N, NF for single row bearings as well as NNU, NN for double row bearings depending on the design or lack of rim side.
There are many divisions of cylindrical roller bearings (among others in terms of axial forces transferability). However, we can distinguish primarily single-row, double-row and multi-row bearings. Single row bearings are ideal for very high speeds at exposure to misalignment. Double-row bearings also take over tipping moments in addition to very large radial loads and axial loads in both directions. Multi-row ones give the possibility of transferring large radial loads while keeping high rotational speed and load capacity.
Using
This bearings are primarily used in bearings where the bearing capacity of the thrust ball bearings is insufficient. This type of bearings, because of its construction, can carry much higher radial loads than conical and ball bearings. The low friction resistance, and the high load capacity of cylindrical roller bearings, is an irreplaceable complement to the transmission mechanisms. With appropriate use, the bearings can operate for up to 30 years (for example in rolling mill gears).