Single row cylindrical roller bearing, NU design, with snap ring
Single row cylindrical roller bearings are designed to accommodate high radial loads in combination with high speeds. Having two integral flanges on the outer ring and no flanges on the inner ring, NU design bearings can accommodate axial displacement in both directions. A snap ring, fitted in an annular groove in the outer ring, facilitates axial location of the bearings within their housings. An important feature is the separable design, which facilitates mounting and enables the bearing components to be interchanged.
High radial load carrying capacity
Low friction
Long service life
Accommodate axial displacement in both directions
Separable design
Dimensions
Bore diameter /110 mm
Outside diameter / 202 mm
Width /53 mm
Performance
Basic dynamic load rating 440 kN
Basic static load rating 520 kN
Properties
Bearing part Complete bearing
Axial displacement capability In both directions
Number of rows 1
Locating feature, bearing outer ring None
Bore type Cylindrical
Cage Machined metal
Number of flanges, outer ring 2
Number of flanges, inner ring 0
Loose flange None
Radial internal clearance C3H
Tolerance class Normal
Coating Without
Sealing Without
Lubricant None
Logistics
Product net weight 7.86 kg
Procedure
This instruction covers several designs. In most illustrations, a bearing of the NU design is used as an example.
1.Consider any additional steps required for the exact design. For example:
If the bearing is used with an angle ring, make sure that the angle ring is mounted in the correct position (refer to the assembly drawing, if needed).
If the bearing is supplied with a loose flange ring for the inner ring, make sure that the loose flange ring is mounted in the correct position (refer to the assembly drawing, if needed). The example below shows a bearing of the NUP design.
2. Coat the shaft and bearing bore surfaces with a thin layer of light oil.
3.Heat the bearing inner ring (or inner ring assembly). Use the appropriate heating process and tool (Heater selection tool).
Alternatively, an electric oven may be used. Place the bearing on supports to enable free air flow around the bearing.
Never heat bearings using an open flame.
Normally, a bearing temperature of 80 to 90 °C (145 to 160 °F) above the shaft temperature is sufficient for mounting.
Do not heat:
open bearings to a temperature above 125 °C (260 °F)
CAUTION
Do not use overpowered induction heaters, or try to heat the bearing too quickly. As the bearing inner ring heats up faster than the outer ring, there could be a risk of removing all radial clearance and creating excessive internal preload that would damage the bearing. Read the induction heater instructions before use.
4. Push the inner ring onto and along the shaft seat to its abutment and hold the ring until it grips in position.
5.Coat the housing bore and bearing outside surfaces with an anti-fretting agent.
6.Mount the bearing outer ring assembly (or outer ring) in the housing according to the application.
If the bearing has a snap ring groove in the outer ring, a snap ring can be fitted and located axially in the housing.
If the bearing has a locating slot in its outer ring, make sure that the anti-rotation pin is located correctly in the locating slot to prevent the outer ring from turning.
7.Lubricate the raceway and rollers slightly with the lubricant used in the application.
8. Assemble the shaft with the housing.
Make sure that the inner ring and outer ring are aligned and centered during assembly. Using a guiding sleeve can help.
Rotate the shaft or housing during assembly.
WARNING
During assembly, it is commonly found that the rollers are slightly skewed, or that the outer ring is not well aligned with the inner ring. If too much force is used, the ends of the rollers may create scratches, smearing and dents in the raceway. To avoid these types of damage, always oscillate (slightly rotate) the shaft or housing, enabling the rollers to roll at the same time as they move axially along the raceway. A guiding sleeve can be used to hold the rollers in position until they reach the mating ring.
9. If the bearing is to be grease lubricated, add sufficient grease. For additional information about the grease fill, refer to Additional recommendations.
10. Attach the locking device.
11. Check that the shaft or outer ring can be rotated freely.
Additional recommendations
If the bearing is factory-lubricated, disregard the following information/instructions.
For information about how to select suitable lubrication for the bearing and application, considering actual operating conditions, refer to Lubrication.
If the bearing is to be oil lubricated, make sure the lubrication system or oil bath is filled with a sufficient quantity of an appropriate oil (Selecting a suitable oil).
If the bearing is to be grease lubricated, and this has not already been done, add the relevant grease (Selecting a suitable grease).
Normally, the bearing should be filled completely with grease. However, if the bearing is to operate at high speeds, the free space in the housing should be only partially filled (30 to 50%) with grease. In non-vibrating applications, where bearings are to operate at very low speeds and good protection against contamination is required, recommends filling up 70 to 100% of the free space in the housing with grease. For more detailed information about initial grease fill, refer to Determining grease quantity for initial fill and relubrication.
