The Complete Guide to Pillow Block Bearings


Pillow block bushing by Monroe

Pillow block bearings are used in a wide variety of machines. Also known as plummer block bearings, they are designed to support a rotating shaft. The shaft is inserted into the center of a pillow block bearing, at which point it will be secured in place. If you’re thinking about using a pillow block bearing, though, there are a few things you should know.

What Are Pillow Block Bearings?

Pillow block bearings are pedestal-like units consisting of a mounting frame and an enclosed bearing. The mounting frame supports fasteners, whereas the bearing supports a rotating shaft.

How Do Pillow Block Bearings Work?

You might be wondering how pillow block bearings work exactly. While available in different styles, they all feature an enclosed bearing in the center. As previously mentioned, the bearing is designed to accommodate a rotating shaft.

The bearing in the center of a pillow block bearing typically has a smaller diameter than that of the rotating shaft with which it’s used. It’s not a substantial difference in size. Rather, the bearing diameter might be just 0.025 millimeters smaller. Because it’s smaller, though, the bearing allows for a tight fit. The rotating shaft will fit snugly in the bearing.

The Benefits of Pillow Block Bearings

Pillow block bearings are commonly used in machinery applications, specifically those that involve a rotating shaft. They allow for a limited degree of misalignment. Even if the rotating shaft isn’t perfectly aligned, the pillow block bearing will hold it in place.

Like with other bearings, pillow block bearings can reduce vibrations. The inner walls of the bearing are made of bronze, which is separated from the rest of the pillow block bearing by a layer of neoprene. The neoprene wall acts as an oil-resistant flexing medium. It will flex while absorbing any vibrations to which it’s exposed.

Pillow block bearings are low maintenance. The only real maintenance they require is the occasional oiling. Placing a few drops of oil around the bearing will ensure smooth operation. It will reduce friction while allowing the shaft to rotate more smoothly once inside of the bearing.

In Conclusion

Pillow block bearings are essential components used in a wide range of industrial applications. They provide stability, support and smooth rotation for shafts within machinery. You can find them in different styles, but all pillow block bearings consist of a housing frame and an enclosed bearing, the latter of which supports a rotating shaft.

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