To seal efficiently, radial shaft seals must run against a smooth, round counterface. If the counterface becomes worn, the seals will no longer be able to fulfill their function, which is to retain lubricant and exclude contaminants.
Typically, the counterface becomes scored when a contaminant particle is caught under the sealing lip and abrades a track as the shaft rotates. As this continues, the seal will enable more particles to pass or get stuck, and seal efficiency deteriorates, eventually leading to malfunction of the component that the seal is meant to protect. To rectify the situation, it is necessary to repair the shaft surface since a seal replacement will not be sufficient. To repair the shaft, it is usually necessary to disassemble the machine in order to either replace the shaft or grind down the counterface until it is again within specification.
SKF Speedi-Sleeve (fig 1) is a well-proven solution to overcome problems with worn shafts without having to disassemble the shaft or changing the seal dimensions, while offering an excellent sealing surface. Now, SKF has developed a new generation SKF Speedi-Sleeve with features providing an even further enhanced sealing system performance. Using SKF Speedi-Sleeve, combined with an SKF radial shaft seal, customers will benefit from a more consistent and increased durability of the sealing system. This will enable a more stable maintenance planning with improved predictability of the system service life. SKF Speedi-Sleeve is available for shaft diameters up to approximately 203 mm (8 in.). For larger shaft diameters, SKF offers wear sleeves for heavy industrial applications (fig 2).
If the shaft cannot be ground and hardened as a seal counterface or if a replaceable seal counterface is required, needle roller bearing inner rings with non-directionally ground raceway (designation IR .. EGS) can be used (fig 3).