FAQ

Answer

1. Raceway Wear: Long-term contact between the raceway and rolling elements can cause friction, leading to wear on the raceway surface, with scratches or depressions affecting smooth operation.

Common Causes:

• Insufficient lubrication: Inadequate or improper grease can accelerate wear.
• Contamination: Dust, sand, and other foreign particles entering the raceway.

Solution:

• Lubricate regularly with high-quality grease.
• Inspect the sealing system to prevent external contamination.

2. Gear Damage: The gears of the slewing bearing can experience cracks, fractures, or wear on the tooth surfaces due to excessive load or poor lubrication, affecting transmission efficiency.

Common Causes:

• Excessive load: Overloading can cause gear deformation or breakage.
• Poor lubrication: Insufficient lubrication leads to excessive gear wear.

Solution:

• Ensure loads are within the rated capacity to avoid overloading.
• Use appropriate grease and regularly check the lubrication condition of the gears.

3. Seal Failure: Failure of the seals can lead to grease leakage or the ingress of external contaminants into the bearing, affecting its performance.

Common Causes:

• Wear and aging: Seals degrade over time, reducing their sealing ability.
• Improper installation: Incorrect installation of seals can lead to leakage.

Solution:

• Regularly inspect the condition of seals and replace aging or damaged ones.
• Ensure seals are correctly installed to prevent contaminants from entering.

4. Abnormal Vibration: Abnormal vibrations are often an early sign of issues with the slewing bearing, which may be caused by internal friction, wear, or improper assembly.

Common Causes:

• Raceway or rolling element wear: Excessive wear causes imbalance and vibration.
• Misalignment during installation: Improper bearing installation leads to uneven load distribution.

Solution:

• Regularly check vibration and use vibration analyzers to      monitor bearing condition.
• Inspect installation alignment to ensure proper bearing      centering.

5. High Temperature: Excessively high operating temperatures in a slewing bearing can be caused by poor lubrication, excessive load, or excessive friction on the raceway.

Common Causes:

• Insufficient lubrication: Grease is not applied adequately, causing overheating.
• Excessive load: Overloading causes the bearing to overheat.

Solution:

• Check and add grease to ensure proper lubrication.
• Avoid overloading and verify that the bearing load is within the rated capacity.

6. Unusual Noise: Unusual noise from a slewing bearing can be due to internal wear, foreign particles entering the bearing, or insufficient lubrication.

Common Causes:

• Contamination: Dust, sand, or other foreign particles entering the raceway.
• Raceway or rolling element wear:  Wear causes an uneven bearing surface, leading to noise.

Solution:

• Regularly clean the slewing bearing to ensure no contaminants enter.
• Inspect the raceway and rolling elements, replacing them if excessive wear is found.

7. Abnormal Bearing Clearance: Excessive or insufficient bearing clearance can affect the smooth operation of the slewing bearing. Large clearance can lead to instability, while small clearance may cause overheating or jamming.

Common Causes:

• Improper installation: Clearance not adjusted according to requirements during installation.
• Bearing wear: Wear leads to either increased or reduced clearance.

Solution:

• Adjust clearance strictly according to standards during installation.
• Regularly check bearing clearance and make adjustments as needed.

Answer

1. External Gear Slewing Bearings

• Features: External gear slewing bearings have gear teeth on the outer ring, allowing the driving mechanism to directly engage with the external teeth to rotate the bearing.
• Advantages:
1. The external gear design simplifies gear manufacturing and maintenance.
2. Larger gear diameters enhance torque transmission capability.
• Applications: Ideal for equipment requiring large diameters and external drives, such as tower cranes, excavators, wind turbines, and hoisting equipment.

2. Internal Gear Slewing Bearings

• Features: Internal gear slewing bearings have gear teeth on the inner ring, and the driving mechanism is installed inside the bearing for a more compact design.
• Advantages:
1. Internal gear design protects against external contaminants, extending service life.
2. Compact structure suitable for space-constrained equipment.
• Applications: Commonly used in space-limited or highly sealed applications, such as medical scanners, radar systems, and robotic rotation devices.

3. Gearless Slewing Bearings

• Features: Gearless slewing bearings do not have gear teeth and rely on external friction drives or other mechanisms to rotate the bearing.
• Advantages:
1. Simple design with lower manufacturing costs.
2. Gearless design reduces gear wear and noise.
• Applications: Suitable for applications not requiring precise gear transmission, such as simple rotating devices or lightweight equipment.

Reasons for Classification

1. Adaptation to Different Mechanical Designs:
• External gear is suitable for spacious designs requiring external drive.
• Internal gear is suitable for compact structures requiring internal drive.
• Gearless type is ideal for non-gear-driven applications.
2. Meeting Different Load Requirements:
• External gear is commonly used in heavy-load applications.
• Internal gear is suitable for medium to small-sized equipment.
• Gearless type is suitable for light loads or specialized uses.
3. Environmental Adaptability:
• Internal gear offers better protection, suitable for harsh environments.
• Gearless performs well in low-pollution and low-load environments.

Answer

Thin section bearings are classified into three main types to meet different application requirements. Below is an explanation of their categories and characteristics:

1. Angular Contact Ball Bearings

• Characteristics:
• Designed to handle radial and single-direction axial loads.
• Can accommodate complex multi-directional loads by adjusting the installation angle.

• High rigidity, suitable for high-precision and high-speed applications.

• Applications:
       Commonly used in robotic joints, precision machine tools, and aerospace equipment.

2. Deep Groove Ball Bearings

• Characteristics:
• Simple design, capable of handling radial loads and moderate axial loads.
• Low friction, ideal for high-speed operations.

• Versatile and cost-effective.

• Applications:
       Frequently found in automation equipment, textile machinery, and conveyor systems.

3. Four-Point Contact Ball Bearings

• Characteristics:
• A specialized angular contact design that can simultaneously handle radial and bi-directional axial loads.
• Large contact angle increases load capacity.
• Compact structure, ideal for space-saving designs.
• Applications:
       Commonly used in rotary tables, slewing ring systems, and medical devices (e.g., CT scanners).

Why Are There Three Types?

1. Different Load Directions:
        Various applications require bearings to handle radial, axial, or combined loads.
2. Space Constraints:
        Certain equipment demands compact designs, making specific types and sizes of thin section bearings necessary.
3. Performance Optimization:
        Bearing types are designed to balance speed, precision, and rigidity.

4. Specialized Applications:
        Specific scenarios (e.g., high precision or high-speed operations) require tailored bearing solutions.

Choosing the right type of thin section bearing depends on the equipment's load conditions, space design, and operational requirements.

Answer

Roller bearings and ball bearings are commonly used bearing types, and they differ significantly in design, performance, and application scenarios.

1. Structural Differences

• Roller bearings use cylindrical, tapered, or spherical rollers as rolling elements, providing a larger contact area and higher load capacity.
• Ball bearings use spherical balls as rolling elements, which form point contact with the raceways, resulting in low friction and suitability for high-speed operation.

2. Load Capacity

• Roller bearings have a larger contact area and can withstand higher radial loads and some axial loads, making them ideal for heavy-duty applications.
• Ball bearings mainly handle radial loads but can also support limited axial loads. Their load capacity is lower compared to roller bearings.

3. Applicable Speed

• Roller bearings have higher friction and are not suitable for very high speeds but perform well in medium to low-speed applications.
• Ball bearings have low friction and are suitable for high-speed operation, making them widely used in high-speed machinery.

4. Impact Resistance

• Roller bearings have strong impact resistance, making them suitable for heavy loads and vibration conditions.
• Ball bearings have weaker impact resistance and are not suitable for high-impact load scenarios.

5. Service Life

• Due to the larger contact area, roller bearings generally have a longer service life, especially under heavy load and low-speed conditions.
• The service life of ball bearings depends on the operating speed and load, making them suitable for high-speed applications with shorter lifespan requirements.

6. Application Scenarios

• Roller bearings are suitable for high-load, low-speed, or high-impact applications such as heavy machinery, mining equipment, and wind turbines.
• Ball bearings are ideal for high-speed, low-load applications such as electric motors, household appliances, and automotive hubs.

Answer

To determine whether a thin-section bearing needs replacement, evaluate its performance, operating environment, and actual service life comprehensively. Below are detailed methods:

1. Evaluate the Bearing's Operating Condition

• Abnormal Noise: Persistent clicking, high-pitched, or grinding noises during operation may indicate damage to the rolling elements or raceways.
• Overheating: Abnormally high bearing surface temperature during operation may signal insufficient  lubrication, excessive internal friction, or material fatigue.
• Unusual Vibration: Sudden increases in vibration amplitude could result from deformed rolling elements or damaged inner/outer rings.

2. Assess the Physical Condition of the Bearing

• Wear on Raceways or Rolling Elements: If pitting, scratches, or flaking are observed on raceways after disassembly, the bearing is severely worn and needs immediate replacement.
• Excessive Clearance: Use measuring tools to check if the bearing clearance exceeds the manufacturer's specifications. Excessive clearance indicates bearing failure.
• Metal Debris in Lubricant: Metal debris in the grease indicates wear or breakage of internal components, necessitating bearing replacement.

3. Consider the Bearing's Service Life

• Rated Service Life: Replace the bearing if it has reached or is nearing its rated service life as specified by the manufacturer to prevent unexpected failure.
• Actual Operating Conditions: Under prolonged operation in overload, extreme temperatures, or harsh environments, the actual lifespan may be shorter than theoretical estimates, requiring regular assessment.

4. Evaluate Operational Efficiency

• Unstable Rotation: If the bearing exhibits jerky rotation or significantly increased resistance, it indicates performance degradation and necessitates replacement.
• Equipment Malfunction: If the overall efficiency of the equipment decreases, errors increase, or working precision drops, the bearing may be at fault and should be inspected and possibly replaced.

5. Perform Regular Maintenance Checks

• Regular Disassembly and Inspection: During equipment maintenance, check for signs of wear or insufficient lubrication in the bearing and replace it if necessary.
• Vibration Analysis and Temperature Monitoring: Use monitoring equipment to track vibration and temperature changes in the bearing. Persistent anomalies in the data indicate the need for replacement.

Answer
Thin-section bearings, due to their precision and thin-section structure, may encounter issues such as noise, overheating, vibration, or premature failure. Troubleshooting requires a systematic approach, from diagnosis and analysis to problem resolution. Below are detailed steps:

1. Identify the Symptoms

Common Symptoms:

• Abnormal noise (e.g., clicking, high-pitched, or low-frequency vibrations).
• Overheating (abnormally high surface temperature).
• Vibration (irregular vibrations during operation).
• Premature failure (loss of function before expected lifespan).

2. Inspect Installation Conditions

Check for correct assembly of bearings:

• Ensure that even force was applied during installation.
• Check whether the inner and outer rings are coaxially aligned.
• Verify that the interference fit is not too tight and the clearance fit is not too loose.

Tool recommendation: Use appropriate installation tools to avoid brute force impacts.

3. Check Lubrication Status

Type and quality of lubricants:

• Ensure that the lubricant used meets the manufacturer's requirements.
• Inspect the lubricant for degradation or contamination.

Appropriate amount of lubrication:

• Excess lubrication can lead to increased operating temperatures, while insufficient lubrication can exacerbate friction and wear.

4. Examine the Operating Environment

Existence of pollution sources:

• Check if the bearing is exposed to dust, moisture, or corrosive gases.

Temperature and load conditions:

• Verify that the bearing operates within its rated temperature and load range.

Vibration or shock:

• Ensure there are no abnormal vibrations or shocks affecting the bearing from external sources.

5. Analyze Bearing Wear

Checking raceways and rolling elements:

• Inspect for scratches, pitting, or flaking on raceways and rolling elements.

Check bearing clearance:

• Measure if the bearing clearance exceeds the design specifications.

Observe grease after disassembly:

• Metal debris in the grease indicates severe bearing wear.

6. Implement Corrective Actions

• If installation issues are detected, remove and reinstall the bearing properly.
• Replace with new lubricant and re-lubricate as per the specified amount.
• Replace the bearing promptly if it is severely worn or has failed.
• Provide sealed protection for the bearing, isolate contaminants, or adjust environmental parameters.