Optimal Timing For Excavator Slew Ring Replacement

What phenomenon indicates that the excavator slewing bearing should be replaced

Appearance

Excessive clearance: stop the excavator on the flat ground, lay the bucket flat, and then carry out a rocking test on the upper platform, if the bearing swing is obvious, or there is an obvious “chuckle” when rotating the platform, then the clearance may have exceeded the standard. This is usually a sign of raceway wear.

Oil leakage: If the sealing ring of the slewing bearing is damaged, oil leakage will occur. Sealed bearing oil leakage will take away the grease, resulting in bearing dry wear, accelerated damage. If not handled in time, it will cause damage to the bearing.

Appearance deformation or crack: check whether the outer ring and inner ring of the slewing bearing have obvious deformation, bulge or crack. These are all signs of serious problems, which means that the structure has been damaged and the bearings need to be replaced immediately.

Auscultation

Abnormal sound: When the slewing drive operation, if you hear abnormal friction sound, metal impact sound, or continuous buzzing sound, this is the signal of a problem inside the bearing. Especially the kind of “click” sound, often means that the ball or roller is damaged.

Oil Analysis

Grease analysis: regularly excavator slew ring internal grease analysis. If it is found that the grease contains a large number of metal particles, especially iron filings, it means that the internal wear of the bearing is serious. This inspection can find the bearing problems earlier.

measurement

Clearance measurement: This is the most accurate method. Measure the radial and axial play of the slewing bearing with a professional tool. Each type of excavator has its standard clearance range. Once it is exceeded, it means that the bearing is seriously worn and needs to be replaced.

What factors will affect the life of the bearing

Working condition

Dust, high humidity, corrosive environment will accelerate the bearing wear and aging.

Therefore, when using the excavator, try to keep the environment clean, and the equipment can be parked in a dry and dust-free environment when we are not using it, which can greatly extend the service life of the slewing bearing and other parts.

Operating habits

Barbaric operation, frequent overload, emergency stop and turn will bring huge impact load to the slewing bearing, greatly shorten its life.

Therefore, good operating habits are very important to the operator, with reasonable load and less impact load such as emergency stop and emergency turn. And there is a sense of caring for equipment, in uneven ground operations, try to adjust the attitude, reduce the eccentric load of the slewing bearing.

Installation quality

If the flatness of the new bearing is not enough during installation and the bolt torque does not meet the requirements, problems will also occur in later use.

Maintenance

Inadequate maintenance is a common cause of early scrap of bearings.

Check regularly and lubricate on time. When adding grease each time, it is best to rotate the upper frame 1 turns to ensure that the grease is evenly distributed.

What to do to extend the life of your bearings

As mentioned above: add grease on time, select the appropriate grease, and strictly follow the requirements of the instructions; avoid long-term overload operation and try to operate within the rated load range; operate smoothly, avoid emergency stop and start as much as possible, and reduce impact; regularly check the rotation gap to find problems in advance; keep the working environment clean. Although the slewing bearing is sealed, but the external sediment, dust, more, may also enter through various ways, affecting the life of the oil seal, thereby affecting the bearing.

How to choose the right excavator slewing bearing after replacement

matching model

According to the specific model of your excavator and the manufacturer to match, be sure to ensure that its parameters, such as inner diameter, outer diameter, height, installation hole spacing, tooth shape and tooth number, etc., are completely consistent with the original. Do not match the parts will have a great security risk.

Bearing Capacity and Design Type

Single volleyball type: common in small excavators, carrying capacity is relatively small.

Double volleyball type and cross roller type: usually used for medium and large excavators, with stronger bearing capacity and greater axial force, radial force and overturning moment. When choosing, it is necessary to ensure that the bearing capacity and design type of the new bearing are consistent with the original parts, or according to the actual working conditions, choose a stronger bearing capacity.

Executive standards and certificates

Executive standards: The executive standards of the product include international standards (ISO), European standards (EN), and American standards (ANSI/ABMA). You can check the major websites according to the needs you want to buy. However, regular slewing ring bearing manufacturers produce certified products that generally meet the implementation standards and can be used with confidence.

The detailed product certificate will generally be packaged with the bearing, including the product name, model specification, production batch, manufacturer and other information. Sometimes several key information, such as model and batch number, will be engraved on the bearing body. But that’s just an overview, and the details are on the paper certificate.

At the same time, if you enter the model or batch number in the manufacturer’s official website or database, you can generally find the electronic version of the certificate and detailed technical data.

Summary

Slewing bearing as an important mechanical parts of the excavator, regular maintenance and timely inspection, timely detection of problems is a good way to extend its service life. When you need to replace the slewing bearing, you must look for a product with the right model, the right carrying capacity, the implementation of the standard and a complete certificate of conformity.