Sealed, Single-row Angular Contact Ball Bearings From SKF: Maintenance-free Because Really "cool"

Sealed variants have long been established in deep groove ball bearings. The same applies to spherical roller bearings, of which SKF - based on the available range - can provide tailor-made solutions for practically every relevant application. The company has now transferred its sealing know-how gained in these product areas to angular contact ball bearings. As a result, in addition to the classic open bearings, single-row angular contact ball bearings with integrated seals and grease filling are now available ex works.

The advantages

Since external sealing is no longer required and fewer components are required, time and costs can be saved even during assembly. This is all the more true since the installation also eliminates the error-prone greasing step: The bearings are delivered ex works with the optimal amount of grease (for most applications). In addition, the bearings are effectively protected against contamination right from the start. At the same time, the sealed bearings allow for more compact designs due to their smaller space requirements, a requirement that is increasingly being made. Last but not least, the angular contact ball bearings lubricated for life drastically reduce the consumption of lubricant, which protects the wallet of the user as well as the environment and the maintenance effort to a minimum.

The technology

The double-row version of the SKF single-row angular contact ball bearings (suffix: 2RZ) has seals made of acrylonitrile butadiene rubber (NBR). This material is suitable for a very wide temperature range: from -40 ° C to 100 ° C. NBR can even tolerate 120 ° C for a short time. In addition, the developers at SKF reinforced the seals with sheet steel reinforcement in order to increase their mechanical stability.

Picture gallery

Picture gallery with 8 pictures

A plastic cage made of glass fiber reinforced polyamide (suffix P) is used as standard inside the bearings. The cage is particularly low-friction and light. This allows high speeds, for example. It also has good emergency running properties.

The SKF bearings are lubricated with a high-quality polyurea grease (abbreviation GXN), which is suitable for most applications. Since sealed bearings are usually not relubricated, the grease service life largely determines the bearing service life. Ergo, it is important to minimize those factors that damage fat. The temperature plays an important role here, because high storage temperatures cause the fat to “age” quickly. Conversely, this means: the cooler the better. According to the rule of thumb, the grease service life doubles when the operating temperature drops by 15 ° C (although in practice the grease service life is of course also influenced by factors such as loads, speed parameters or misalignments).

Based on this knowledge, SKF has optimized its sealed single-row angular contact ball bearings in such a way that the bearing generates as little frictional heat as possible - and paid special attention to the seals: These are designed without contact. As a result, the sealed single-row angular contact ball bearings from SKF work much "cooler" than many competitive products. For example, comparative tests have shown that the mean operating temperature of the SKF solution is up to 20% lower than that of comparable bearings. The peak temperatures are even up to 30% lower. Thanks to the much lower heat development, these SKF bearings can achieve longer service lives or - at the same temperature level - higher speeds.

Content of the article:

• Page 1: Sealed, single-row angular contact ball bearings from SKF: Maintenance-free because really "cool"
• Page 2: The sealing effect

> Next page