"Inside-out" seal

[Ed Landstrom]

The existing seal is 1/2" wide, so a conventional seal of the same width would fit. One problem is that the part of the shaft where the existing seal is pressed on is not smooth enough for a seal, so it would have to be polished.

The other problem is that with the bearing pressed on the shaft and the seal pressed into the bore, there is no way to assemble them. Motto says it can be done by slipping the seal onto the shaft and gradually tapping it into the bore as the mount is slid onto the shaft. That looks like an awkward operation with lots of opportunity to foul up.

I had considered turning down the shaft to make the bearing a slip fit. This way both the bearing and seal could be installed in the bore and the mount could be slid onto the shaft just like a wheel hub. If there is any reason the bearing shouldn't float on both the shaft and bore, it could be held in the bore with Loctite.

Then I thought of making an adaptor to use an 0-ring. It seems so beautifully simple there must be something wrong with it. It wouldn't involve any modification to either the shaft or the mount and making the adaptor disc is a simple enough lathe job I could even attempt it myself.