Yes great idea. Large Industrial equipment has this principle as standard practice from original design. The "Wearing Sleeve" as it's known is generally thicker and part of a Seal Kit, to be replaced with the seal as a set. It protects the shaft from wear and is cheap compared to replacing major and very expensive shafts and components. The principle isn't used in automotive parts that I have come across, so this Speedie Sleeve is a good thing to know. Passenger cars do a fraction of the hours that industrial equipment can do and the added cost not warranted, for most modern cars which are scraped before a seal would need replacing.
A word of warning, I work for Atlas Copco in Compressor Spare Parts and it is common for Large industrial compressors to be rebuilt and find oil still seems to be leaking from a seal, even after both the seal and wearing sleeve have been replaced. The problem is usually that the wearing sleeve has not been sealed/mounted to the shaft and the oil is actually finding its way between the shaft and the wearing sleeve giving the appearance that the seal has failed again. The "interference fit" of the sleeve is not enough to create a seal, there are various Loctite type products for mounting wearing sleeves to ensure no "leak through" of the oil/fluid the seal is designed to retain.
Cheers Stephen
A word of warning, I work for Atlas Copco in Compressor Spare Parts and it is common for Large industrial compressors to be rebuilt and find oil still seems to be leaking from a seal, even after both the seal and wearing sleeve have been replaced. The problem is usually that the wearing sleeve has not been sealed/mounted to the shaft and the oil is actually finding its way between the shaft and the wearing sleeve giving the appearance that the seal has failed again. The "interference fit" of the sleeve is not enough to create a seal, there are various Loctite type products for mounting wearing sleeves to ensure no "leak through" of the oil/fluid the seal is designed to retain.
Cheers Stephen