Before beginning the bearing installation, plan your work. Be certain that you have the correct bearing components. Also determine what tools will be required and have them on hand.

Bearings should be installed in a clean environment, free from dust, debris, moisture and other contaminants. Because of the risk of contamination from dirt, abrasives, etc., that may be present in the maintenance area, keep the outer ring assembly in its protective plastic wrap or cover it with a clean shop rag during the installation process until the bearing is ready to place in the housing.

To ensure safety during installation, while removing or installing bearings, lock or secure the rolls to avoid the risk of them rolling unexpectedly.

An induction heater can be very helpful when installing components with a tight fit. The heater can be used to warm the components, creating slight thermal growth that will ease installation.

Inspect the spacers (sleeves), shaft and the interior of the housing to ensure that there are no sharp edges, burrs, gouges or score marks. Any of these types of damage can make it difficult to install the new bearing, and may shorten its life. Do not install bearings on a damaged or worn shaft or in a damaged or worn housing.

If there are any burrs, nicks, score marks or other raised metal areas, use the appropriate tools to remove the raised metal and create a smooth surface before installing the bearing.

 

PREPARING FOR INSTALLATION

1. To provide a good mounting surface for the bearing, wipe the roll end clean of grease and dirt. Then use 180-grit emery cloth to remove small imperfections in the metal, lightly polishing the shaft where the bearing inner ring will be seated, and the interior of the housing where the outer ring will be mounted. 

2. Clean out any oil holes in the housing.

3. Check the diameter of the bearing “seat,” the area on the shaft where the bearing inner will be mounted on the shaft. Take measurements in one direction, and then rotate the micrometer 90 degrees to ensure that the shaft end is both symmetrical and the proper size. Measure the inside diameter of the housing. Take measurements in one direction, and then rotate the micrometer 90 degrees to ensure that the housing is both symmetrical and the proper size.

4. If the bearings are not going to be installed immediately, protect the mounting surface of the roll with clean plastic sheeting or cloths. Just before installing the bearing, wipe clean the shaft where the inner ring will be seated, and wipe clean the housing surface where the outer ring will be mounted.

 

INSTALLATION: END OF ROLL POSITION

1. Check the inboard roll spacers for any damage. Remove any raised metal or other physical damage with the appropriate tools.

2. Apply anti-seize lubricant or a thin layer of grease to the end of the roll/shaft where the spacer and bearing inner ring will be located.

3. Install the spacer on the end of the roll. For tight fitted spacers use an induction heater to heat the spacer to 100ºC [212ºF], or use an impact sleeve to press the spacer into position. The spacer must be firmly seated against the roll face or shaft shoulder.

4. Install the bearing inner ring on the end of the roll using the same technique and temperature used for the spacer. The inner ring must be firmly seated against the spacer.

5. Apply a thin coat of oil or grease to the inside of the housing to make the outer ring easier to insert.

6. Remove the roller assembly from the outer ring prior to assembling the outer ring in the housing. The roller-retainer assembly and outer ring are matched and the roller-retainer must be kept together during mounting process. Place the bearing outer ring (without the roller assembly) into the housing and slide it into place. The outer ring is typically a loose fit and easily mounts in the housing. If needed, use a soft-faced mallet to tap the ring into position or an induction heater to warm the housing to 100ºC [212ºF].

7. Use a feeler gauge to ensure that the contact face of the bearing outer ring is in contact with the housing shoulder or inboard cover.

8. Insert the matched roller-retainer assembly into the outer ring. Guide the rollers into the outer ring so they do not catch on the outer ring corner.

9. Lubricate the rollers using the same oil or grease used on your caster. There is no need to remove the anti-rust coating on the bearing. Rotate the roller assembly one revolution to distribute the lubricant. Center the cage and roller assembly in the outer ring.Note: At this point, the bearing components are constrained in the housing in only one direction. As you install the housing assembly on the roll end, be careful to avoid having the rollers and inner ring fall out of the front of the housing.

10. Install the housing assembly, including the bearing outer ring and roller assembly, on the bearing inner ring that’s already mounted on the roll end. Take care to align the outer assembly with the roll end. Also be careful to avoid damage to the housing seals. Rock the housing back and forth in the direction of rotation as you move it onto the roll end to ease installation and minimize the chance of damage to the rollers or inner ring.

11. Install the end plate on the end of the roll to secure the bearing inner ring in place. Secure the end plate using the appropriate fasteners, further secure with a locking fluid (e.g. Loctite 243). Torque the fasteners as specified by the roll manufacturer.Note: If the diameter of the end plate is large enough to cover/constrain the bearing’s roller and retainer assembly, then the housing assembly cannot fall off the end of the roll. If the end plate covers only the bearing inner ring, then the housing assembly can fall off the end of the roll, possibly causing injury. In this case, the end plate must be replaced or the snap ring version of the bearing installed. If you are interested in learning about the snap ring version, contact your Timken representative.

12. Once in place, rotate the housing back and forth to check for bearing freedom of motion. If the bearing binds or cannot move freely, remove the bearing and diagnose the problem. Before being put back into service, the bearing must rotate freely on the roll.

13. Apply sealant to the housing cover, then install the housing cover and bolt it in place according to manufacturer’s specification. If the end cover has a lubrication groove, ensure that it is in the right position.

 

INSTALLATION: CENTER OF ROLL POSITION

1. Check the inboard roll spacers for any damage. Remove any raised metal or other physical damage with the appropriate tools.

2. Apply an anti-seize lubricant or a thin layer of grease to the area on the roll where the bearing inner ring will be located.

3. If the bearing housing has removable covers on both sides, install one of the covers on the housing and bolt it in place according to manufacturer’s specification. If the end cover has a lubrication groove, ensure it is in the right position.

4. Apply a thin coat of oil or grease to the inside of the housing to make it easier to insert the bearing outer ring.

5. Remove the roller assembly from the outer ring prior to assembling the outer ring in the housing. The roller-retainer assembly and outer ring are matched and the roller-retainer must be kept together during the mounting process. Place the bearing outer ring (without the roller assembly) into the housing and press it into place. The outer ring should be a loose fit and easily mount in the housing. If it is a tight fit, you can use an induction heater to warm the housing to 100ºC [212ºF]. If needed, you can also use a soft-faced mallet to tap the ring into position.

6. Use a feeler gauge to ensure that the contact face of the bearing outer ring is in contact with the housing shoulder or inboard cover.

7. Insert the matched roller-retainer assembly into the outer ring. Guide the rollers into the outer ring so they do not catch on the outer ring corner.

8. Lubricate the rollers using the same oil or grease used on your caster. There is no need to remove the anti-rust coating on the bearing. Rotate the roller assembly one revolution to distribute the lubricant.

9. Install the bearing inner ring in the bearing. Rotate the inner ring back and forth as it is installed in order to minimize the chance of damage to the rollers or inner ring. You can use an induction heater to warm the inner ring to 100ºC [212ºF] to facilitate installation on the roll end in Step 13. Do not exceed this temperature or the inner-ring may expand to the point that it won’t fit into the bearing outer assembly.

10. Install the second cover on the housing and bolt it in place according to manufacturer’s specification. Apply sealant to the joint face, then install the housing cover and bolt it in place according to manufacturer’s specification. If the end cover has a lubrication groove, ensure it is in the right position.

11. Apply a light film of oil or grease to the outside surface of the spacers.

12. Install the spacer in the cover on one side of the housing assembly, being careful to avoid damage to the seals. If the spacers are a tight fit on the roll, you can use an induction heater to heat them to 100ºC [212ºF] to ease installation. After installing the spacer on one side, flip the housing to repeat the procedure on the other side. Be careful when flipping the housing to not dislodge the first spacer. Note: At this point, the spacers are only held in place by friction with the seals. Be careful as you handle and install the housing assembly on the roll to avoid having one or both fall out of the assembly.

13. Install the complete assembly on the roll, ensuring that the inboard spacer seats firmly against the roll body face and that the outboard spacer is not displaced from the assembly.

14. Rock the housing back and forth in the direction of rotation to check for bearing freedom of motion. If the bearing binds or cannot move freely, remove the bearing and diagnose the problem. Do not put the roll in service until you can verify that the bearing rotates freely on the roll.