2022 December the First Week GQZ Technical Knowledge: Large sealed bearings create a new pattern in heavy industry
Hot tags: spherical roller bearing(9)
Setting seals in large spherical roller bearings for heavy industrial applications can greatly improve overall performance and reduce total cost of ownership.
Bearings rarely operate under ideal conditions. In heavy industry fields such as mining and mineral processing, large spherical roller bearings are the core components of various rotating equipment. However, in these industries, the operating conditions of bearings are often very bad, which may lead to a significant reduction in the life of bearings, especially for open bearings.
SKF actively responded to the needs of heavy industry customers, not only expanding the product range of sealed spherical roller bearings to large size bearings (outer diameter from 800 mm to 2500 mm), but also bringing sealed spherical roller bearings into the standard configuration range of several commonly used bearing series in these industries. With the most complete sealed spherical roller bearings in the market, SKF can provide sealing solutions with multiple advantages, helping customers reduce total cost of ownership, extend maintenance intervals, and reduce grease consumption.
Many enterprises are eager to extend the service life of bearings, reduce the total cost of ownership by reducing the consumption of lubricating grease and the disposal cost of waste lubricating grease, and also hope to improve the utilization rate of equipment. This can be achieved by extending the service life and reducing unplanned downtime caused by bearing failure. The solution required by these enterprises is to avoid unnecessary and often dangerous daily maintenance work of supplementing grease, so as to provide a safe, clean and beautiful workplace.
SKF sealed spherical roller bearing products can meet these needs.
With SKF's calculation tool, you can intuitively understand the potential savings of the solution from open bearing to sealed bearing. In most cases, it is easy to switch to sealed bearings, and you only need to directly select the replacement products from the standard products provided by SKF.
Daniel Ortega, Product Line Manager of SKF Sealed Spherical Roller Bearings, said, "The use of sealed bearings is the best way to extend the MTBF."
Easy replacement from open bearing to sealed bearing
In order to set seals on large bearings, SKF has modified the bearing outer ring design to suit seal installation and adopted the same width dimension as the ISO standard for open bearings most commonly used in heavy industry. Since the two bearings have the same width and load capacity, customers can successfully change from open bearing to sealed bearing.
The sealing materials selected by SKF (hydrogenated nitrile rubber and G-Ecopur cast polyurethane) can cope with different bearing operating environments. In SKF factory, the handling and installation of seals during assembly also meet strict standards. Bearings with an inner diameter of less than 1000 mm are sealed with hydrogenated nitrile rubber fixed by a snap ring. Bearings with an inner diameter greater than 1000 mm are sealed with G-Ecopur, which is bolted to the bearing cup.
The design adopts wear-resistant seal, and can keep the sealing surface fit during operation. The bearing is pre filled with lubricating grease of special formula and sealed with high-performance contact type. SKF also provides on-site installation services and special tools for easy installation. The improper installation of bearings on shafts is one of the reasons for the failure of large bearings.
Figure 1: Large sealed spherical roller bearings.
Greatly reduce grease consumption
In mineral processing applications, four large spherical roller bearings are commonly used in high-pressure grinding rolls. For open bearing structures with a maintenance interval of three months, up to 540 kg of grease is normally used for certain sizes of bearings. However, with SKF Explorer sealed spherical roller bearings, the same maintenance interval only requires 7 kg of grease, which greatly reduces the cost and environmental impact.
In addition, the sealed bearing can prevent the entry of pollutants and the loss of lubricating grease, so it can be regarded as a long-term investment to improve the utilization rate of equipment. The equipment maintenance depends on the wear condition of the roller press itself, rather than the preventive maintenance of the bearing after shutdown.
With this sealed solution, production efficiency and equipment utilization can be improved while reducing the total cost of ownership.
Extend the service life of the bearing
Sealed spherical roller bearings have more components, so the initial investment will be slightly higher than open bearings. However, as the service life of the bearing is extended, the consumption of lubricating grease is reduced, and the replenishment interval is extended, the operating cost savings are obvious. This results in increased equipment utilization and safer workplaces, which can help customers save specific costs.
Although the operating conditions of each equipment are different, practical experience shows that the service life of bearings can be extended to more than 2 to 3 times at least, and can be extended to more than 9 times in some applications.
Grease savings can be as high as 99%, depending on the specific operating conditions and pollution of the equipment.
In the environment with solid pollutants, since sealed spherical roller bearings reduce the consumption of lubricating grease, they can reduce carbon dioxide emissions. In addition, they can also reduce the transportation demand of lubricating grease? Dispose of grease accordingly? Less, so it is also beneficial to protect the environment. In addition, SKF also provides another triple protection solution for extremely harsh environments, with an average life of three times that of open bearings. With this triple protection solution, the frequency of grease replenishment may be reduced from once a week to twice a year, saving 90% of time and lubrication costs, while improving the safety of maintenance personnel.
Figure 2: The upgraded SKF triple protection solution.
The sealed solution for large bearings is an important step forward to deal with the challenging industrial environment and provides a comprehensive and sustainable solution for equipment operation.
Figure 3: Friction is halved and speed is doubled.
SKF sealed spherical roller bearing of the largest size available
The 241/900 bearing is one of the largest sealed spherical roller bearings manufactured by SKF. The three ton bearing is designed for the most common roller press on the market and has been put into use in a large copper mine in Peru. It is the same size as the standard SKF open bearing, with an inner diameter of 900 mm, an outer diameter of 1420 mm and a width of 515 mm. The seal is made of rubber coated steel skeleton with the same contour, and its characteristics are the same as those used in other existing SKF sealed spherical roller bearings.
This sealed spherical roller bearing is installed on the horizontal shaft. As the copper mine is located in the desert, and the grinding process will produce very fine stone chips, so that the bearing is in the operating condition of very much dust, there is a serious risk of pollution. The roller press is a heavy load application equipment, and the bearing needs to withstand frequent impact loads. The radial load is the main load, and the highly polluted site environment makes the bearing have a major risk of premature failure. SKF's custom seals are designed to more than double the bearing life by significantly reducing the risk of contamination in this application.
More about GQZ Spherical Roller Bearing：
GQZ precious-quality spherical roller bearing with reasonable price for customers all over the world and first-class service and unrivaled products.
Dealing with very heavy radial and axial loads in applications prone to misalignment or shaft deflections? Meet the challenge with GQZ spherical roller bearings, whose high load carrying capacity and ability to accommodate misalignment help you obtain low maintenance costs and long bearing service life. GQZ invented this bearing type and our range is the widest in the industry today – both open and sealed. Our assortment includes spherical roller bearings designed for many applications, including wind turbine main shafts, continuous casters, vibratory applications and high-speed applications, as well as bearings with Solid Oil, split bearings.