Fan turns on but blades won’t spin

My Vornado fan turns on but the blades won’t spin unless I spray lubricant on the shaft underneath the blades. I’ve had to do this once a week for a few months now but recently I’m having to do this every other day now. It’s an expensive fan and I’m a novice at electrical repairs, is this something that I can fix with a part replacement and simple troubleshooting or is my fan completely done functioning?