Full complement cylindrical roller bearings

Full complement cylindrical roller bearings are suitable for the following situations.
The bearing arrangement is to be subjected to particularly high radial loads 
the bearing arrangement has to be subjected not only to very high radial forces but also to high axial loads from one direction (semi-locating bearing function) 
bearing arrangements operating under the above conditions must have very high stiffness
the axial displacement of the shaft with respect to the bearing housing must be compensated for in the bearing without restriction
very high radial loads occur at low speeds, i.e. the bearings do not need to reach speeds as high as those of ➤section and ➤linked cylindrical roller bearings with cages
particularly space-saving designs are required despite high loads
the bearings should be separable (not self-retaining) for easy mounting 

Construction

Full complement cylindrical roller bearings have three main parts - the flanged inner ring, the cylindrical rollers and the outer ring. Depending on the arrangement, snap rings, angle rings or seals are added.
The following constructions are the most common

NCF

These are the most common full complement cylindrical roller bearings. The inner ring has two retaining edges, the outer ring has a retaining edge on one side and a snap ring on the other side to hold the bearing assembly. ncf bearings are capable of carrying axial loads from one side and they can accommodate some of the smaller axial displacements of the shaft. The
permissible values of displacement are shown in the dimension table.

Double row bearings

Double row full complement cylindrical roller bearings have perforated lubrication grooves in the outer ring to adequately lubricate the rolling space into each row of cylindrical rollers. the inner rings of the NNC, NNCL and NNCF designs have three guide flanges to ensure the guiding accuracy of the cylindrical rollers. They are distinguished by the number of guide flanges and snap rings in the outer ring. These components prevent the rolling element from falling out.

NNC

The outer ring is fitted with a guide flange on one side and a retaining ring on the other to keep the cylindrical rollers in place. These bearings can withstand axial loads in both directions.

NNCL

NNCL bearings have a non-retentive outer ring and can therefore withstand a certain amount of displacement of the axial bearing rings from each other.

NNCF

The outer ring has a flange and a snap ring. These components accommodate axial load transmission in one direction as well as certain axial displacements of the housing.

NNF

NNF bearings with a guiding flange in a two-piece inner ring held together by a retaining ring. The outer ring has a guide flange. These bearings can also carry axial loads in both directions and the greater the distance between each row of cylindrical rollers, the more they can transmit tilting moments.
NNF bearings have an outer ring that is 1mm narrower than the inner ring and have two stop ring grooves. These bearings are supplied as standard with seals on both sides and an internal space filled with grease, enabling the bearings to operate under standard operating conditions of up to 110°C.

Tolerance

The standard tolerance class for full complement cylindrical roller bearings is P0. Production of bearings with higher tolerances should be discussed in advance. The dimensional tolerances are in accordance with international standards and are specified in the ISO 492 standard.
The NNC design is an exception to the above because it is available in various outer ring widths. They can vary by up to twice the tolerance.

radial clearance

Full complement cylindrical roller bearings are manufactured and supplied with standard radial clearances or C3 clearances. Radial clearance C2 (less than the standard clearance) or C4, C5 (greater than the standard and C3 clearance). The radial clearance values are in accordance with ISO 5753. These values apply to manufactured and unassembled bearings.

Stable operation at higher temperatures

Special stabilised bearings for operating temperatures above 120°C with individually heat-treated components to ensure dimensional and form stability over the temperature range of 150°C to 400°C (S0, S1, S2, S3 and S4) are provided for long-term exposure. Delivery of stabilised bearings should be discussed in advance.

Misalignment

he internal construction of the rolling contact area allows cylindrical bearings to be operated with a certain misalignment of the two rings.
The standard values are
3´ - bearing series 18
2´ - bearing series 22, 23, 29 and 30

Equivalent dynamic bearing loads

If a radial load is applied to a cylindrical bearing without axial forces, the dynamic load is calculated as follows
P r = F r
If the cylindrical bearing is subjected to both radial and axial loads, the dynamic load is calculated as follows
P r = F r for F a /F r ≤ e
P r = 0,92.F r + YF a for F a /F r > e
where
e = calculation factor
e = 0,15 for double row bearings
e = 0,2 for bearing series 18
e = 0,3 for other bearings

Y = Axial load factor
Y = 0,6 for bearing series 18
Y = 0,4 for other bearings
The trouble-free operation of cylindrical bearings subjected to axial loads requires the simultaneous application of radial loads, where the F a /F r ratio should not exceed the value 0.5.

Key features

Single row full complement cylindrical roller bearings are part of radial roller bearings. These bearings consist of a solid outer ring, an inner ring and a full complement set of rolling elements. Due to the absence of a cage, the bearing can accommodate as many rolling elements as possible. The ends of the rollers are profiled, which means that they have a slight lateral bend towards the ends. This modified linear contact between the raceway and the rolling elements prevents damaging edge stresses.

Design properties

Designed to meet the interchangeable boundary dimensions specified by ISO/DIN (where available).
Sold as a fully assembled component.
Available in single and double rows in the same size range.
Complete construction, cage not included.
High capacity, but running speed may be an issue requiring close application review.
Assembled outer ring design provides significant internal axial float capability.

Applications

Gearing
Crop shears
Rolling mills
General industry

Features and Benefits

High load carrying capacity
Bearings without cage contain the maximum number of rollers. Therefore, due to their second row of rollers, double row full complement cylindrical roller bearings are suitable for very heavy radial loads.
High stiffness
The increased number of rollers increases the radial stiffness.
Long service life.