Mine doesn’t spin so well any more. Something’s caught in there, apparently - when I run it under hot water for a bit whatever’s catching softens and I can use it again. I can’t see how to take it apart - it’s not a screw; it’s like a rivet. There’s no room to get anything underneath to scrape out the crud, and I don’t know if it’s oilable. Any ideas?
Try soaking it in soapy water overnight. In the morning, use it to blend some hot water.
I have taken mine apart but maybe yours doesn’t come apart. If you haven’t yet, check the bottom of the jar to see if there is a nut that holds the blade assembly in.
There might not be anything “stuck” in there, either. What passes for a “bearing” in most blenders is just a plastic sleeve in which a metal shaft rotates. Over time, that plastic sleeve can begin to break down, developing cracks or rough spots. When you soak it in hot water, it probably expands and smooths out just enough so that the metal shaft can spin freely. Trying to put oil on it would probably make it worse.
When the plastic gets bad enough, the blade will refuse to spin at all. The last one I killed produced acrid smoke and a bunch of little black plastic shavings. Nasty.
Blenders, of course, have become disposable items - you can get a perfectly serviceable blender at Target for $20.
The blade is usually removable – you just unscrew the entire bottom of the blender. If you can’t clean it by soaking (I used to use a janitorial degreaser called Jet 400), new blades are cheap. Who made your blender? Got a link?