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The maintenance of self-aligning roller bearings for elevators needs to start with seven core steps: installation, cleaning, maintenance, lubrication, environmental control, condition monitoring, and replacement. The specific methods are as follows:

1. Installation and fixation: Ensure initial accuracy

Use of special tools

During installation, hydraulic disassembly tools or induction heaters should be used to avoid direct hammering. The hydraulic disassembly tool can control the pressing force (≤ 200MPa), the temperature gradient of the induction heater does not exceed 5 ℃/min, and the maximum heating temperature does not exceed 120 ℃, to prevent bearing deformation due to uneven heating.

Control of fit tolerance

Following ISO 286 standard, the interference fit is controlled at H7/k6 level.

. If the bearing does not rotate flexibly after being pressed in, it may be due to excessive shaft size or insufficient roundness, and the tolerance or roundness needs to be adjusted.

Insulation Protection

For bearings with insulation design on the outer ring, it is necessary to ensure that the insulation is intact.

. If the insulation is damaged during installation, the shaft voltage may penetrate the oil film, causing electric spark corrosion of the rolling element surface and accelerating wear.

2. Regular cleaning: prevent foreign objects from entering

Cleaning process

Rough cleaning: In kerosene or special cleaning agents, use a brush to remove the lubricating grease and adhesive on the bearing surface to avoid foreign objects damaging the rolling surface.

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Fine cleaning: Slowly rotate the bearing in cleaning oil, carefully clean the raceway and rolling elements, and ensure that there are no residual impurities.

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Cleaning cycle

Dust environments (such as mines and cement equipment) should be cleaned every 500 hours, while ordinary environments should be cleaned every 2000 hours.

. Immediately apply rust proof oil or grease after cleaning to prevent rusting.

III. Maintenance and judgment: replace damaged parts in a timely manner

Identification of damage types

Non reusable situation: cracks, fractures, significant jamming, rust, and indentation on the inner/outer rings/rolling elements/retainers;

; Damaged sealing ring or dust cover; Creep of inner or outer diameter surface. Reusable condition: Only slight surface wear and no decrease in dimensional accuracy, confirmed to have no deep damage after inspection.

Maintenance Tools

Use iron spectrum analysis technology to detect the content of metal abrasive particles in lubricating oil (>15 μ m particles should be<1000/ml), and conduct MTF (magnetic particle inspection) testing every 2000 hours, with a focus on inspecting the stress concentration area on the roller end face.

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4. Lubrication management: Choose the appropriate lubricant

Lubricant selection

Dust environment: Use NLGI grade 3 high viscosity lithium based grease to prevent the grease from drying up and forming abrasive wear.

. High temperature environment: GCr15SiMn material or surface nitriding treatment is used, and molybdenum disulfide grease is preferred.

High humidity/corrosive environment: Spray WD-40 rust inhibitor every quarter, and inject gas-phase rust preventive oil when it is not in use for a long time.

.

Lubrication cycle and quantity

Lubrication cycle formula:

T=K × (14 × 10  

6

 )/(n ×  

d

 )

, where

K

is the environmental coefficient (0.5 for dust environment).

. The initial grease injection amount is 30% of the internal space, and an oil air lubrication system is used for high-speed operating conditions (DN value>500000).

Fifth, environmental control: adapt to different working conditions

High temperature working conditions

Install infrared temperature measuring devices to ensure that the operating temperature does not exceed 120 ℃ (ordinary steel) or 220 ℃ (high-temperature alloy).

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Install circulating water cooling channels in the bearing seat and install heat dissipation fins at the shaft end to reduce heat conduction.

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Vibration and impact environment

Pre tightening force verification: Adopting a four point contact ball bearing structure, the pre tightening amount is controlled at 20% -30% of the axial clearance.

. Buffer modification: Install polyurethane shock absorbers inside the bearing seat, and set up hydraulic buffers when the impact load exceeds 30g.

VI. Condition Monitoring: Preventing Potential Malfunctions

Basic Parameter Monitoring

Regularly measure the vibration, temperature, and noise of bearings, establish SPC control charts, and track the range of 6 σ fluctuations.

. If the vibration value exceeds 4.5mm/s RMS, it needs to be checked immediately.

Abnormal signal processing

If there is excessive noise or abnormal temperature rise in the bearing, it is necessary to closely monitor and find the cause, such as insufficient lubrication, foreign object intrusion, or installation deviation.

.

7. Replacement and Substitution: Ensure quality matching

Replacement timing

When the bearing reaches its service life or shows irreparable damage, it should be replaced in a timely manner.

. Low quality alternatives may lead to greater losses.

Alternative Selection

Choose products with the same or higher quality as the original bearings, ensuring that the materials, sealing forms, and accuracy levels match.

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