Would Your Application Benefit from Using a SAF Pillow Block Bearing?

A Guide to Choosing Pillow Blocks

Pillow block bearings play a crucial role in various industrial applications, providing support and stability to rotating shafts. With their ability to handle both radial and axial loads, these bearings are widely used in machinery and equipment across different sectors. In this blog post, we will explore the benefits of SAF pillow block bearings and delve into key considerations to keep in mind when selecting the right pillow block bearings for your specific application.

Benefits of SAF Pillow Block Bearings

Pillow block bearings offer numerous advantages that make them an ideal choice for many applications.

Some key benefits include:

  1. Enhanced Load Capacity: Pillow block bearings are designed to handle both radial and axial loads, making them suitable for applications with varying load requirements.
  2. Shaft Alignment: These bearings allow for easy adjustment and alignment of the rotating shaft, ensuring smooth operation and reducing wear and tear.
  3. Simple Maintenance and Replacement: Split pillow block bearings consist of 2 pieces, a base (or saddle) and a cap.
Photo of a SAF split-housing pillow block bearing unit.

Considerations when Choosing Pillow Block Bearings for Your Application

I. Split or Solid Housing

The choice between split and solid housing depends on factors such as ease of maintenance, accessibility, and load requirements. Solid housings are made to slip onto a shaft and lock into place. This may be preferred for smaller shafts, or when you must use a certain seal style. SAF split pillow block housings are two pieces, consisting of a base (or saddle) and a cap. This is beneficial for large shafts and heavy machinery.

II. Shaft Size

Selecting the right pillow block bearing requires careful consideration of the shaft size. If you have a large shaft the SAF pillow block is likely what you need. Different manufacturers make their mounted bearings in different sizes (min and max shaft sizes for instance). But in general, mounted ball bearings accommodate shaft sizes up to about 4 inches. Mounted roller bearing units accommodate shafts up to about 7 inches. On the other hand, SAF blocks are readily available for shaft sizes up to about 12 inches (and can be specially ordered even larger).

III. Axial & Radial Load

Understanding the magnitude and direction of the loads your application will encounter is crucial. SAF pillow blocks can accommodate the heaviest of both axial (force being applied in the same direction as the shaft) and radial (force being applied perpendicular to the shaft) loads. Heavy loads require heavy machinery (like larger shafts and bearings). The largest mounted ball-bearing pillow blocks have dynamic load ratings near 30,000 lbs. Mounted spherical units top out in the 85,000 lbs. range.

IV. Speed

Different applications require varying speeds, and selecting the appropriate bearing with the right speed rating is vital to prevent premature wear and failure. SAF blocks are made for heavy loads, not super high speeds. The load capacity of the SAF pillow block will beat ball-bearing options.

This doesn’t exactly mean that SAF pillow blocks are “slow”, it just means that (in general) when compared to a ball bearing of a similar size, Its maximum speed will be lower. However, SAF have the unique ability to be set up with oil instead of grease which allows them to run faster than grease-only roller units versus solid or one-piece housings.

V. Environment

The operating environment can greatly impact the performance and longevity of pillow block bearings. SAF blocks are built to endure harsh environments! SAF bearings are often used in challenging environments because of options regarding lubrication methods and seals, paired with tough housings. With the split design, lubricants can be checked and maintained more easily than with one-piece units. This keeps the bearing protected from particulates and moisture. These features give the SAF split pillow block bearing a long service life.

VI. Lubrication

Proper lubrication is essential for minimizing friction, reducing heat, and extending the lifespan of pillow block bearings. SAF blocks have more options for lubrication! An SAF block has an oil sump which allows for the use of oil instead of grease.

Oil is good for higher speed or higher heat applications. It’s also better at carrying particle contaminants away from the bearing. But, just because this bearing can make use of an oil bath or mist system does not mean that it should. Grease has plenty of advantages as well.

Advantages of Oil and Grease

Carries heat away from the bearingsSimplifies seal design and acts as a sealant
Carries away moisture and particulate matterPermits pre-lubrication of sealed or shielded bearings
More options for flow/coolingGenerally requires less frequent lubrication

VII. Maintenance

Regular maintenance is crucial to ensure optimal performance and longevity of pillow block bearings. Installation and maintenance are easier with a SAF pillow block bearing if dealing with large shafts and heavy machinery. Because of the split housing, the caps can be removed and the shaft (with bearings still installed) can be lifted out of the base. This means that the machinery may not have to be disassembled for repair or replacement of the bearing. Additionally, the cap can be removed to view the condition of the lubricant.

VIII. Reliability

Reliability is a key consideration in any application. SAF blocks are designed to have a long service life. When selected, installed, and maintained correctly, SAF blocks are very reliable. Users can ensure that their bearing meets its designed service life by reviewing the manufacturer’s selection and maintenance recommendations. Service factors and other relevant variables or equations are typically published in manufacturer catalogs.

In Conclusion

Choosing the right pillow block bearing for your application will ensure optimal performance, efficiency, and longevity. By considering factors such as split or solid housing, shaft size, load requirements, speed, environment, lubrication, maintenance, and reliability, you can make an informed decision. Ready to take your applications to the next level?