Crossed tapered roller bearings are high-performance bearings that are mainly used in high-speed machine tool applications, equipment with high rotational accuracy requirements, and other fields. Crossed tapered roller bearings install two sets of bearing raceways and rollers together at right angles, with adjacent rollers facing in opposite directions, with spacers installed between the rollers, and support pads installed on the rollers.
This structure allows the two half-rows of rollers to fit into the same space, effectively improving the bearing's load capacity and rotational accuracy. At the same time, the bearing's angle and tapered geometry make the effective span of the bearing several times larger than the actual width of the bearing itself. Therefore, installation is a relatively complex but critical process that requires careful operation and following certain steps.
Check the shaft and housing:
Carefully check the machining quality of the matching surfaces of the shaft and housing, the end faces of the bosses, the grooves and the connection surfaces to ensure that there are no defects.
Remove burrs and residues from all matching connection surfaces, especially the sand on the unmachined surface of the casting.
Cleaning and lubrication:
Use gasoline or kerosene to thoroughly clean the bearings and related parts, and then dry them to ensure cleanliness.
Provide good lubrication for the bearings, generally using grease or oil lubrication. Choose grease that is free of impurities, anti-oxidation, anti-rust and has excellent extreme pressure properties, and control the filling amount to between 30%-60% of the volume of the bearing and the bearing box.
Choose a suitable installation method:
Cross-tapered roller bearings can be installed face to face or back to back, depending on the application requirements.
Install the outer ring of the bearing:
Press the surface marked "A" of the outer ring of the bearing downward into the gear ring, and use a thickness regularization ring to check whether the gap between the contact surfaces is balanced.
Use a flange to lock the outer ring of the bearing on the gear ring, and tighten it step by step by diagonally locking the screws.
Install the inner ring of the bearing:
Press the "A" side of the lower inner ring of the bearing downward into the journal, and use the thickness adjustment ring to check whether the distance between the contact surfaces is even.
Step by step, cross the rollers into the track, making sure that the large end of the rollers faces the outer ring of the bearing, and then insert the spacer.
Combination installation:
Slip the combination of the outer ring of the bearing and the gear ring concentrically onto the journal where the lower inner ring of the bearing has been placed.
Place thick blocks of equal height so that the lower track of the outer ring of the bearing is slightly higher than the track surface of the lower inner ring of the bearing to facilitate the placement of the rollers and the spacer.
Remove the thick blocks and slowly turn the gear ring to properly position all rolling elements.
Install the inner ring of the bearing:
Install the inner ring of the bearing with the "C" face upward onto the journal.
Slowly turn the gear ring to put the rollers and the spacer in place.
Adjust the axial clearance:
Use the adjusting nut on the journal, the adjusting gasket and the thread in the bearing seat hole, or use preload springs and other methods to adjust the axial clearance.
The size of the axial clearance depends on the bearing arrangement, bearing spacing, and the materials of the shaft and bearing seat, and needs to be determined according to the working conditions.
For bearings with high load and high speed, the effect of temperature rise on the axial clearance needs to be considered, and the clearance should be increased appropriately.
For bearings with low speed and vibration, clearance-free or preload installation should be adopted.
Check the installation quality:
Use tools such as micrometers to check the size of the axial clearance to ensure that it meets the design requirements.
Carry out a trial run to check the operation and temperature rise of the bearing to ensure that there are no abnormalities.
Protective gloves must be worn throughout the installation process to ensure safety.
The installation of the bearing can only be carried out horizontally, using a vertical rotating shaft.
Before installation, the relevant parameters of the bearing support surface should be measured and recorded, such as the inner diameter of the gear ring, the outer diameter and depth of the journal ring, etc.
The bearing is tightly assembled, and it may be necessary to preheat the inner ring of the bearing and the bearing seat to an appropriate temperature (such as 80 degrees Celsius) during installation to simplify the installation process.
The above steps and precautions can ensure the correct installation and good operation of the cross tapered roller bearing.
