Maintenance Free Bearings

The goal in nearly every industrial application requiring movement through deep groove ball bearings is to reduce maintenance requirements, resulting in greater operational efficiency and decreased downtime. Downtime means a slow in productivity and overall increased operating costs. 

Maintenance-free deep groove ball bearings considerably reduce downtime and maintenance costs, as they do not require oil or grease after installation, allowing for consistently reliable use. NSK offers a comprehensive catalog of maintenance-free bearings for any industrial application. Self-lubricating bearings and bearings protected by seals and shields will protect the bearings from wear and reduce maintenance needs. 

Understanding Maintenance-Free Bearings

“Maintenance-free” typically means that the deep groove ball bearing is manufactured with the necessary lubrication needed for the life of the bearing sealed into the bearing itself, eliminating the need for any additional lubrication or maintenance. 

Conventional deep groove ball bearings are constructed of an inner and outer raceway, with ball bearings moving within this raceway. Lubrication is needed to keep the bearings moving and prevent contamination from operating environments. In maintenance-free deep groove ball bearings, a molded oil is inserted into the bearing alongside the rotating balls to provide consistent and continuous lubrication, and the bearing is sealed to keep lubrication in and contaminants out. 

Self-Lubricating Materials

NSK has a comprehensive catalog of Molded-Oil bearings as the maintenance-free deep groove ball-bearing option. These bearings are uniquely designed to prevent contamination and provide a continuous lubrication source. NSK’s patented lubricant consists of lubricating oil and polyolefin resin as a solid lubricant, which fills the space in a sealed deep groove ball bearing. 

The solid lubricant acts as a barrier, and the oil slowly seeps from the material, providing ample lubrication and allowing the bearing to move smoothly. This lubricant is clean, with twice the operating life of grease-lubricated bearings. 

Sealed Construction

In addition to their self-lubricating properties, maintenance-free bearings are also sealed to prevent contamination and damage from the operating environment. Contaminants will reduce the lifespan of the bearing and contribute to wear and tear on the overall application. With sealed bearings, there is no access for pollutants to enter the bearing and no possibility of lubrication leaking into the system and causing additional problems. 

Compared with other bearing types, including shielded bearings, sealed bearings are superior at protecting against all potential contaminants. Sealed bearings are clean, cost-efficient, and environmentally friendly, as they do not allow lubricating materials to leach into the operating environment. Sealed bearings meet the regulatory requirements in clean room applications or highly regulated industries, like pharmaceuticals or food and beverage.

Applications and Industries

Maintenance-free bearings can be used in a wide variety of applications. They can be the ideal solution for applications where bearings may be exposed to water, debris, or dust, where maintenance is complex, or where the industry's operating regulatory requirements are stringent. 

Maintenance-free deep groove ball bearings can extend their life up to two times compared to conventional bearings and are the perfect solution for remote or restricted access areas. Some of the industries and applications benefitting from maintenance-free bearings include:

• Steel mill equipment
• Pulp and paper equipment
• Semiconductor manufacturing equipment
• Food and beverage processing equipment
• Agricultural machinery
• Cleaning equipment and lines
• Conveying and packaging equipment

Considerations and Limitations

Several factors must be considered when selecting maintenance-free bearings for an industrial application. Maintenance-free bearings have a higher initial cost than traditional bearings, and some may question whether they are worth the investment. 

A maintenance-free bearing may not be necessary when the application’s needs can be met with a conventionally designed bearing. However, it is also important to note that the cost-savings in maintenance requirements and reduction in downtime can offset this initial investment and make maintenance-free bearings the more cost-effective choice. 

Another potential concern is that maintenance-free bearings should not be used in certain conditions when the operating conditions are over 250 degrees or when liquid degreasing agents, like organic solvents, are present, as both can harm the molded oil lubrication within the bearing. However, for both these applications, using extra seals can make self-lubricating bearings possible.

Most Operating Conditions

Maintenance-free bearing designs allow for deep groove ball bearings to be installed in nearly every operating condition without concern for accessibility for regular maintenance or contamination from the environment itself. 

The self-lubricating properties and advances in lubricant ensure that the bearings will continue to function even in extreme conditions. Seal construction makes sure the molded oil design of these deep groove ball bearings will stay free from contamination from the operating environment.

Increased Reliability

Maintenance-free bearings are ideal in applications where long bearing life is required without maintenance to prevent downtime or where operating conditions make regular lubrication difficult. Inaccessible bearings on all types of equipment, as well as equipment in remote areas, are excellent candidates for the use of maintenance-free bearings. 

Using maintenance-free bearings can result in substantial savings and increased reliability. Maintenance-free bearings can improve the service life of equipment, as the bearing must always move easily. As maintenance-free bearings retain their operational capacity even in extreme environments, they can operate where other bearings may fail. 

NSK has a comprehensive catalog of maintenance-free bearings for various applications that can reduce downtime and increase operational efficiency. Contact us today to learn more.