Self-aligning Ball Bearings Introduction

一. Core Definitions and Core Functions (Practical Orientation)

 

Spherical Ball Bearings, also known as self-aligning ball bearings, are one of the most widely used types of rolling bearings. Their core structure consists of an inner ring, outer ring, steel balls, and a cage. The outer ring raceway is spherical, which is the key to realizing the self-aligning function.

Core Functions (Practical Orientation, No Redundant Theories):

Core Load-bearing: Mainly bears radial load, and can also bear a small amount of bidirectional axial load (load capacity is lower than angular contact ball bearings, suitable for medium and light load working conditions);

 

Self-aligning Compensation: Can automatically compensate for the coaxiality deviation between the shaft and the bearing housing (the maximum self-aligning angle is usually 2°-3°), solve the misalignment problem caused by equipment installation deviation, slight shaft bending, and working condition vibration, and avoid bearing jamming and early wear;

 

Friction Reduction and Energy Saving: Replace sliding friction with steel ball rolling, greatly reduce the rotational resistance of the shaft system, reduce equipment energy consumption, reduce operating noise, and extend the overall service life of the shaft system;

 

Simplified Maintenance: Simple structure and good sealing performance (can be equipped with dust covers and seals). Daily maintenance only requires regular supplementary grease, which is suitable for various complex working conditions (such as dusty and slightly corrosive environments).

 

二. Key Points for Practical Use (Focus, Aligned with On-site Application)

 

1. Selection Points (Avoid Selection Errors and Reduce Failure Probability)

Load Matching: Select the model according to the actual radial load of the equipment to avoid overloading (for example, 12 series for light conveyors and fans, 22 series for medium water pumps, 13 series for small precision equipment, and 23 series for heavy-duty low-speed equipment); if the axial load is large, it is necessary to match with thrust bearings;

Speed Adaptation: Spherical ball bearings have a high limit speed. Conventional models (such as 1205, 2206, 1304, 2307) can meet the needs of most medium and low-speed equipment (speed ≤ 3000r/min). For high-speed working conditions, high-precision grades (P5, P4) and high-temperature grease are required;

Working Condition Adaptation: For dusty and humid environments, select models with seals (2RS); for high-temperature environments (≥120℃), select high-temperature resistant cages (copper cages) and high-temperature grease (such as lithium-based high-temperature grease); for corrosive environments, select stainless steel bearings.

 

Supplementary Model Details (2 New Models Added for Different Working Conditions)

Model 1: 1304 2RS (Self-aligning Ball Bearing) - Belongs to the 13 series, with inner diameter 20mm, outer diameter 52mm, width 15mm (complying with GB/T 281-2013 standard size), double-sided seal design, excellent dust and leakage prevention effect, self-aligning angle up to 2.5°, rated dynamic load 8.28kN, rated static load 2.85kN. It is suitable for light load and dusty working conditions such as small precision conveyors and small fans, with a limit speed (grease lubrication) of up to 8000r/min, convenient daily maintenance and high cost performance.

Model 2: 2307 CA/W33 (Self-aligning Ball Bearing) - Belongs to the 23 series, with inner diameter 35mm, outer diameter 80mm, width 21mm (complying with GB/T 281-2013 standard size), CA-type copper cage (high temperature resistant), with W33 oil channel design for convenient grease circulation and supplement, self-aligning angle up to 2°, rated dynamic load 25.5kN, rated static load 8.65kN. It is suitable for medium and heavy load, continuous operation working conditions such as medium-sized mining machinery and heavy-duty water pumps, can bear slight impact load, and operates stably in high-temperature environments (≤150℃).

 

2. Installation and Disassembly (Practical Specifications to Reduce Installation Damage)

Before Installation: Clean the journal and the inner hole of the bearing housing to remove burrs and oil stains; check the bearing appearance (no cracks, no jamming of steel balls), and apply a small amount of grease on the journal and the inner ring of the bearing for easy installation;

During Installation: Adopt the press-in method (for small bearings, such as 1204, 1304) or the hot-fitting method (for large bearings, such as 2208, 2307, heating temperature controlled at 80-100℃ to avoid high-temperature damage to the bearing). Do not directly strike the outer ring of the bearing to prevent damage to the steel balls and raceways;

During Disassembly: Use a special puller, with the force point on the inner ring (for small bearings) or outer ring (for large bearings), to avoid shaft journal strain and bearing deformation caused by forced disassembly.

 

3. Daily Maintenance Points (Reduce Failure Rate and Extend Service Life)

Lubrication Management: Regularly supplement grease (usually every 3-6 months, shortened to 1-2 months under harsh working conditions). The amount of each supplement is 1/3-1/2 of the internal space of the bearing to avoid overheating caused by excessive grease and dry friction caused by insufficient grease; Model 1304 2RS is recommended to use lithium-based grease, and Model 2307 CA/W33 is suitable for high-temperature lithium-based grease to meet its high-temperature working condition requirements;

Condition Inspection: Observe the bearing temperature during daily inspection (normal operating temperature ≤70℃, shut down for inspection if it exceeds 80℃, check for lubrication, load or installation problems), noise (no abnormal noise), and shut down for maintenance in time if leakage or jamming is found;

Replacement Standard: The bearing must be replaced when the following conditions occur - steel ball wear, scratches or pitting on the raceway, bearing clearance exceeding the standard value (such as the standard clearance of 1205 bearing is 0.008-0.028mm, 1304 bearing is 0.010-0.030mm, 2307 bearing is 0.012-0.035mm), and grease leakage caused by seal damage.

 

三. Actual Application Cases (Realistic and Referenceable, Supporting

 

Case 1: Idler of Mine Belt Conveyor

Application Scenario: Idler shaft system of mine belt conveyor. Working Condition Characteristics: Medium and light load, continuous operation, slight misalignment during installation (it is difficult to achieve complete coaxiality when installing idlers), and much dust.

Selected Model: 1204 2RS (with double-sided seals, dust and leakage prevention). Core Functions: Use the self-aligning function to compensate for idler installation deviation and slight shaft bending, reduce idler jamming and wear; the seal design prevents mine dust from entering the bearing, reducing maintenance frequency; the radial load capacity is suitable for the idler operating load (single idler load ≤500kg).

Application Effect: The service life of the bearing can reach 12-18 months, which is 60% longer than that of ordinary deep groove ball bearings (without self-aligning function), the maintenance cost is reduced by 40%, and the conveyor shutdown caused by idler bearing failure is effectively avoided.

 

Case 2: Main Shaft of Industrial Centrifugal Fan

Application Scenario: Main shaft of industrial workshop centrifugal fan. Working Condition Characteristics: Medium speed operation (speed 1500-2800r/min), slight shaft deflection (the fan main shaft is long and prone to slight bending during operation), and low noise operation is required.

Selected Model: 2208 CA/W33 (self-aligning ball bearing, CA-type cage, with W33 oil channel for easy lubrication). Core Functions: Compensate for main shaft deflection through the self-aligning function to avoid local wear of the bearing raceway; low friction characteristics reduce fan operating noise (noise ≤75dB); W33 oil channel design facilitates regular supplementary grease, adapting to the continuous operation needs of the fan.

Application Effect: The fan operates continuously without failure, the bearing operating temperature is stable at 55-65℃, and the service life can reach more than 24 months, meeting the continuous production needs of the industrial workshop and reducing production interruption caused by bearing failure.

 

四. Common Problems and Solutions (Practical Focus)

 

Fault 1: Bearing Overheating (Temperature ≥80℃) - Cause: Excessive/insufficient grease, over-tight installation, excessive load; Solution: Adjust the amount of grease, loosen the bearing installation clearance, check whether the equipment load exceeds the standard; for Model 2307 CA/W33, additionally check whether the grease is suitable for high-temperature working conditions to avoid lubrication failure at high temperature.

 

 

Fault 2: Bearing Abnormal Noise (Jamming, Abnormal Noise) - Cause: Steel ball/raceway wear, foreign objects entering the bearing, insufficient lubrication; Solution: Replace the bearing, clean foreign objects inside the bearing, supplement grease; for Model 1304 2RS, focus on checking whether the seal is damaged to prevent foreign objects from entering.

 

 

Fault 3: Bearing Grease Leakage - Cause: Seal damage, seal deformation during installation; Solution: Replace the seal, reinstall and ensure the seal fits tightly; for models with 2RS suffix (1204 2RS, 1304 2RS), select a special seal matching the model.