Maintenance tips for split-type cross-roller bearings to extend their service life.

Split-type crossed roller bearings, with their high rigidity, high precision, and ease of installation, are widely used in industrial robots, CNC rotary tables, precision measurement equipment, and other applications. However, many users experience premature bearing failure due to inadequate maintenance. Proper maintenance goes beyond simply greasing; it requires systematic operating procedures. Drawing on years of field service experience, Jiuliang Bearings has developed a practical set of maintenance guidelines that can extend bearing life by more than 30%. The following discussion covers four key areas—lubrication, installation, cleaning, and routine inspections—and highlights common operational pitfalls.

Lubrication Management: A Core Maintenance Component of Split-Type Crossed-Roller Bearings

Both insufficient and excessive lubrication can accelerate bearing wear. In split-type crossed roller bearings, the contact stresses between the rolling elements and raceways are high, placing stringent demands on the grease’s adhesion and extrusion resistance. It is recommended to use a lithium-based grease containing extreme-pressure additives, with a consistency grade of NLGI 2–3. Jiu Li bearings are pre‑filled with an appropriate amount of grease at the factory, so no additional lubrication is required after initial installation; however, once in service, a greasing schedule should be established based on operating conditions.

Refueling Cycle and Quantity Control

• General operating conditions (speed < 500 rpm, temperature -20 to 70°C): Top up every 250 hours or quarterly.
• High-load or high-speed operating conditions: Inspect every 100 hours, or adjust based on vibration monitoring data.
• The recommended fill level is 30% to 40% of the bearing’s internal volume; overfilling increases stirring resistance and can lead to temperature rise.

When lubricating, use a dedicated grease gun and inject the grease slowly through the bearing’s side grease fitting while rotating the bearing to ensure even coverage of the rollers. Do not mix greases from different brands or with different base oils; Jiu Liang Bearings recommends using products from the same brand to maintain chemical stability.

Installation and Removal Guidelines: Preventing Hidden Damage

The outer and inner rings of split-type cross-roller bearings typically feature a separable design; improper installation can easily result in uneven loading of the rollers or scoring of the raceways. Prior to installation, it is essential to verify that the roundness and coaxiality of the shaft and housing bore meet the specifications outlined in the drawings, and that the surface roughness of the mating surfaces does not exceed Ra ≤ 1.6 μm.

Key steps

1. Clean the mating surfaces. : Remove burrs, rust, and oil stains by wiping with a lint-free cloth dampened with alcohol.
2. Apply force evenly : Use a press-fit tool or a copper rod; do not strike the bearing end face directly. The striking points should be symmetrically distributed around the circumference, and each tap should be light.
3. Preload adjustment : Split-type crossed roller bearings typically require axial preload to eliminate clearance. Tighten the mounting bolts according to the preload torque values provided by Jiuliang Bearings; a torque wrench is recommended, and bolts should be tightened in a cross‑pattern, in stages.
4. Rotational detection After installation, manually rotate the output shaft; it should turn smoothly without any binding or jamming. If unusual noises or resistance are detected, disassemble the unit to check whether the rollers are misaligned.

When disassembling, avoid any forceful hammering; it is recommended to use a dedicated puller or pressure plate to apply even pressure across the separation surface. Jiuliang Bearings provides detailed drawings of matching disassembly and assembly tools, which can be obtained from Technical Support.

Cleaning and Sealing Protection: Prevents Particles from Entering the Raceway

Split-type cross-roller bearings are extremely sensitive to contaminants. Even micron‑scale hard particles that enter the raceway can cause indentations on the rolling elements, which may progressively develop into spalling. Consequently, cleanliness and sealing are critical aspects of maintenance that must not be overlooked.

Key Points for Daily Cleaning

• After the equipment is shut down, use a soft-bristle brush or vacuum cleaner to remove metal chips and residual cutting fluid from around the bearing housing.
• Avoid using compressed air to directly blow clean bearing seals, as high‑pressure air streams may force contaminants into the interior.
• If the bearing is exposed and lacks a protective shield, it is recommended to install a labyrinth seal or a rubber lip seal. Jiuliang Bearings can supply matching sealing components.

In addition, prior to replacing the grease, completely drain the old grease and clean the grease reservoir. Rinse with a dedicated cleaning agent—such as kerosene or a low-viscosity mineral oil—and be sure to blow dry any residual cleaner before applying new grease.

Regular Inspections and Fault Alerts

Regular inspections can detect abnormalities early, preventing unexpected shutdowns. Inspection items include temperature, vibration, and noise. Under normal operating conditions, the temperature difference between the outer ring of a split-type crossed roller bearing and the ambient temperature typically does not exceed 30°C. If the temperature continues to rise, the machine should be stopped to check the lubrication condition or whether it is overloaded.

Vibration monitoring is performed using acceleration sensors; the presence of sidebands at the rolling-element passage frequency in the spectrum indicates possible early-stage fatigue. Stethoscopes or electronic stethoscopes can also aid in diagnosis: a crisp metallic knocking sound suggests damage to the rollers or cage, while a dull, grinding noise points to inadequate lubrication. Jiu Liang Bearings recommends recording vibration data quarterly and maintaining a trend‑analysis log.

Common Maintenance Misconceptions

• Misconception 1: The belief that the more grease you apply, the better.   Excessive lubrication can cause churning and heat generation, which in turn accelerates the oxidation and hardening of the grease.
• Misconception #2: Using gasoline or diesel to clean bearings.   Such solvents can dissolve residual grease and may corrode cage materials; therefore, a dedicated cleaning agent should be used.
• Misconception #3: Neglecting levelness during installation.   Even though split bearings can compensate for slight misalignments, long-term tilted installation will lead to severe wear on the rollers on one side.

Professional Support and After-Sales Service

If you encounter issues that are difficult to assess during maintenance, or if your equipment operates continuously under extreme conditions—such as high vacuum or highly corrosive environments—we recommend contacting the Jiu Liang Bearing Technical Department to develop a tailored solution. In addition to offering high‑quality split-type cross roller bearings, Jiu Liang Bearing provides installation training, on‑site guidance, and remanufacturing and repair services, helping customers reduce total lifecycle costs.

Properly maintained split-type crossed roller bearings can achieve a service life exceeding 1.5 times their design life. By following the aforementioned maintenance tips and scheduling regular professional servicing, your equipment will continue to operate with high precision over the long term. For more detailed maintenance manuals or selection charts, please visit the Jiuliang Bearing official website or contact our customer service hotline.