Spherical Roller Bearing Mounting and Dismounting: Step-by-Step Guide

Why Mounting Procedure Matters

The most perfectly manufactured spherical roller bearing will fail prematurely if it is mounted incorrectly. Studies indicate that 16% of premature bearing failures are directly attributable to incorrect mounting — improper fit, excessive force, contamination during installation, or incorrect clearance adjustment.

This guide covers the standard mounting and dismounting procedures for spherical roller bearings with both cylindrical and tapered bores.

Before You Begin

Cleanliness

Contamination during mounting is one of the most common causes of early bearing failure:

• Work in a clean, dry area — not on the production floor if possible
• Clean the shaft seat and housing bore thoroughly
• Remove all burrs, nicks, and corrosion from the shaft
• Verify that the shaft and housing dimensions are within tolerance
• Keep the bearing in its original packaging until the moment of installation
• Wear clean gloves — skin oils can cause corrosion

Verify Components

Before starting:

• Check that the bearing designation matches the specification
• Verify that the clearance marking (C3, C4, etc.) is correct
• Inspect the bearing visually for any damage from shipping or handling
• Confirm that the shaft seat and housing bore diameters are correct using a micrometer or bore gauge

Mounting Cylindrical Bore Bearings

Cold Mounting (Small to Medium Bearings, < 100mm Bore)

1. Apply a thin film of light oil to the shaft seat
2. Place the bearing squarely on the shaft
3. Use a mounting sleeve (tube) that contacts ONLY the inner ring face — never apply force through the outer ring or cage
4. Press or tap the bearing into position using even, controlled force
5. Do not use a hammer directly on the bearing — always use a mounting sleeve

Hot Mounting (Medium to Large Bearings, > 100mm Bore)

For larger bearings, heating the bearing expands the inner ring, allowing it to slide onto the shaft with minimal force:

1. Induction heater: The preferred method. Fast, clean, and controllable.
2. Oil bath: Heat the bearing in clean oil to 80–90°C. Use a support to prevent the bearing from contacting the bottom of the tank.
3. Oven: Heat gradually to 80–90°C. Do not exceed 120°C — higher temperatures can alter the bearing’s metallurgical properties.

Critical rule: The temperature differential between the inner and outer rings must not exceed 60°C during heating — otherwise the bearing’s internal clearance may be permanently affected.

After heating:

1. Wipe the shaft seat with a clean cloth
2. Slide the hot bearing onto the shaft quickly but carefully
3. Press the inner ring firmly against the shaft shoulder
4. Hold the bearing in position until it cools and grips the shaft
5. After cooling, verify that the bearing rotates freely

Mounting Tapered Bore Bearings

Tapered bore bearings (designation suffix K) are mounted using an adapter sleeve or withdrawal sleeve. The mounting procedure involves driving the bearing up the tapered sleeve to achieve the correct reduction in radial internal clearance.

Adapter Sleeve Method

1. Slide the adapter sleeve onto the shaft
2. Slide the bearing onto the adapter sleeve
3. Install the lock nut and lock washer
4. Tighten the lock nut using a hook spanner — this drives the bearing up the taper
5. Measure the clearance reduction during tightening:
   • Insert feeler gauges between the outer ring and an unloaded roller
   • The initial (unmounted) clearance minus the reduced clearance equals the amount of interference fit achieved
   • For most industrial applications, a clearance reduction of 0.040–0.070mm is typical for a 100mm bore bearing
6. When the correct clearance reduction is achieved, lock the nut in place with the lock washer tang

Hydraulic Nut Method (Large Bearings)

For large bearings (> 200mm bore), a hydraulic nut replaces the mechanical lock nut:

1. Mount the bearing on the adapter sleeve
2. Thread the hydraulic nut onto the sleeve
3. Connect the hydraulic pump
4. Apply pressure gradually while measuring clearance reduction
5. When target clearance is achieved, lock the mechanical nut and release hydraulic pressure

Dismounting

Cylindrical Bore Bearings

1. Use a bearing puller with jaws that grip the inner ring only — never the outer ring
2. Apply pulling force evenly and gradually
3. For tight fits, apply penetrating oil to the shaft-bore interface and allow time to work
4. If the bearing was hot-mounted, reheat the inner ring with an induction heater to expand it

Tapered Bore Bearings

1. Remove the lock nut and lock washer
2. Use a hydraulic nut to push the bearing off the taper
3. For adapter sleeve mounts, tap the sleeve inward to release the bearing
4. For large bearings, hydraulic-assisted withdrawal sleeves provide oil injection ports

Post-Mounting Verification

After mounting, verify:

• The bearing rotates freely and smoothly by hand
• There is no unusual noise or roughness
• The lock nut or retaining mechanism is secure
• Grease has been applied to the bearing (unless factory-sealed)
• External seals are correctly positioned
• The housing is correctly torqued to specification